Page 307           Environment and Ecology             Ecology is the study of the relationship between organisms and the environments in which they live, including all living and nonliving components. The chief environmental factors governing the distribution of plants and animals are temperature, humidity, soil, light intensity, day length, food supply, and interaction with other organisms. The term was coined by the German biologist Ernst Haeckel in 1866. Ecology may be concerned with individual organisms (for example, behavioral ecology or feeding strategies), with populations (for example, population dynamics), or with entire communities (for example, competition between species for access to resources in an ecosystem, or predator—prey relationships). Applied ecology is concerned with the management and conservation of habitats and the consequences and control of pollution.             Elements of an Ecosystem             The narrow zone that supports life on our planet, the biosphere, is limited to the waters of earth, a fraction of its crust, and the lower regions of the atmosphere. The biosphere is made up of all of earth's ecosystems. It is affected by external forces such as the sun's rays, which provide energy, the gravitational effects of the sun and moon, and cosmic radiations.             ecosystems             An ecosystem is an integrated unit consisting of a community of living organisms—bacteria, animals, and plants—and the physical environment—air, soil, water, and climate—that they inhabit. Individual organisms interact with each other and with their environment, or habitat, in a series of relationships that depends on the flow of energy and nutrients through the system. These relationships are usually complex and finely balanced, and in theory natural ecosystems are selfsustaining. However, major changes to an ecosystem, such as climate change, overpopulation, or the removal of a species, may threaten the system's sustainability and result in its eventual destruction. For instance, the removal of a major carnivore predator can result in the destruction of an ecosystem through overgrazing by herbivores.             system diversity Ecosystems can be identified at different scales or levels, ranging from macrosystems to microsystems. The global ecosystem (the ecosphere), for instance, consists of all the earth's physical features—its land, oceans, and enveloping atmosphere (the geosphere)—together with all the biological organisms living on earth; on a smaller scale, a freshwater-pond ecosystem includes the plants and animals living in the pond, the pond water and all the substances dissolved or suspended in that water, together with the rocks, mud, and decaying matter at the bottom of the pond. Thus, ecosystems can contain smaller systems and be contained within larger ones.             equilibrium and succession The term ''ecosystem" was first coined in 1935 by a British ecologist, Arthur Tansley (1871–1955), to refer to a community of interdependent organisms with dynamic relationships between consumer levels, that can respond to change without altering the basic characteristics of the system. For example, cyclical changes in populations can sometimes result in large fluctuations in the numbers of a species, and are a fundamental part of most ecosystems, but because of the interdependence of all the components, any change in one part of its nature will result in a reaction in other parts of the community. In most cases, these reactions work to restore the equilibrium or balance of nature, but on occasions the overall change or disruption will be so great as to alter the system's balance irreversibly and result in the replacement of one type of ecosystem with another. Where this occurs as a natural process, as in the colonization of barren rock by living organisms, or the conversion of forest to grassland as a result of fires

 

 

Page 308         succession The succession of plant types along a lake. As the lake gradually fills in, a mature climax community of trees forms inland from the shore. Extending out from the shore, a series of plant communities can be discerned with small, rapidly growing species closest to the shore.             started by lightning, it is known as ecosystem development or ecological succession.             carrying capacity The maximum number of organisms that can be supported by a particular environment is called its carrying capacity. If the carrying capacity of an ecosystem is exceeded by overpopulation, there will be insufficient resources and one or more species will decline until an equilibrium, or balance of nature, is restored. Similarly, if the number of species in an environment is less than the carrying capacity, the population will tend to increase until it balances the available resources. Human interference frequently causes disruption to the carrying capacity of an area, for instance by the establishment of too many grazing animals on grassland, the over-culling of a species, or the introduction of a non-indigenous species into an area.             food chains             One of the main features of an ecosystem is its biodiversity. Members are usually classified either as producers (those that can synthesize the organic materials they need from inorganic compounds in the environment) or consumers (those that are unable to manufacture their own food directly from these sources and depend upon producers to meet their needs). Thus plants, as producers, capture energy originating from the sun through the process of photosynthesis and absorb nutrients from the soil and water; these stores of energy and nutrients then become available to the consumers—for example, they are passed via the herbivores that eat the plants, to the carnivores that feed on the herbivores. The sequence in which energy and nutrients pass through the system is known as a food chain, and the energy levels within a food chain are termed trophic levels. At each stage of assimilation, energy is lost by consumer functioning, and so there are always far fewer consumers at the end of the chain. This can be represented diagrammatically by a pyramid with the primary producers at the base; it is termed a pyramid of numbers. At each level of the chain, nutrients are returned to the soil through the decomposition of excrement and dead organisms, thus becoming available once again to plants, and completing a cycle crucial to the stability and survival of the ecosystem.             natural cycles             The biosphere is an interactive layer incorporating elements of the atmosphere, hydrosphere, and lithosphere, and involving natural cycles such as carbon, nitrogen, and water cycles. Human interference in the earth's natural systems, which began with the transition of human society from nomadic hunter-gatherer tribes into settled agriculture-based communities, gathered pace in the 18th and 19th centuries with the coming of the agricultural revolution and the Industrial Revolution. The technological revolution of the 20th century, with its programs of industrialization and urbanization and intensive farming practices, has become a major threat, damaging the planet's ecosystems at all levels.             carbon cycle The carbon cycle is the circulation of carbon through the natural world. The movements of carbon from one reservoir to another (carbon fluxes) controls the amount of carbon dioxide in the atmosphere. Carbon dioxide is released into the atmosphere by volcanism, metamorphism, decay of organic matter, burning of fossil fuels, and respiration by living organisms. It is drawn out of the atmosphere by chemical weathering of silicate rock, reactions between the atmosphere and the oceans (eventually forming carbonate rocks like limestone), burial of organic matter, and plant photosynthesis. The oceans absorb 25–40% of all carbon dioxide released into the atmosphere.             Today, the carbon cycle is in danger of being disrupted by the increased burning of fossil fuels and the burning of large tracts of tropical forests, both of

 

 

Page 309         carbon cycle The carbon cycle is necessary for the continuation of life. Since there is only a limited amount of carbon in the earth and its atmosphere, carbon must be continuously recycled if life is to continue. Other chemicals necessary for life—nitrogen, sulfur, and phosphorus, for example—also circulate in natural cycles.     earthworms         earthworms produce nitrous oxide as a by-product from digesting soil nitrates and nitrites. Soil with earthworms contains five times as much nitrous oxide as soil without.               which can release large amounts of carbon into the atmosphere, contributing to the greenhouse effect (described in Chapter 7).             nitrogen cycle The nitrogen cycle is the process of nitrogen passing through the ecosystem. Nitrogen, in the form of inorganic compounds (such as nitrates) in the soil, is absorbed by plants and turned into organic compounds (such as proteins) in plant tissue. A proportion of this nitrogen is eaten by herbivores, with some of this in turn being passed on to the carnivores, which feed on the herbivores. The nitrogen is ultimately returned to the soil both as excrement and when organisms die and are converted back to inorganic form by decomposers.             Although about 78% of the atmosphere is nitrogen, this cannot be used directly by most organisms. However, certain bacteria and cyanobacteria (bluegreen algae) are capable of nitrogen fixation. Some nitrogen-fixing bacteria live mutually with leguminous plants (peas and beans) or other plants (for example, alder), where they form characteristic nodules on the roots. The presence of such plants increases the nitrate content, and hence the fertility, of the soil.             water or hydrological cycle The water cycle, or hydrological cycle, is the natural circulation of water through the biosphere. It is a complex system involving a number of physical and chemical processes (such as evaporation, precipitation, and infiltration) and stores (such as rivers, oceans, and soil).             soil             Soil, an environmental feature of many ecosystems, is the loose covering of broken rocky material and decaying organic matter overlying the bedrock of the earth's surface. It is comprised of minerals, organic matter (called humus) derived from decomposed plants and organisms, living organisms, air, and water. Soils differ according to climate, parent material, rainfall, relief of the bedrock, and the proportion of organic material. The study of soils is pedology.             A soil can be described in terms of its soil profile, that is, a vertical cross-section from ground-level to the bedrock on which the soils sits. The profile is     soil         To remember the chief constituents of soil:             All hairy men will buy razors.             (air, humus, mineral salts, water, bacteria, rock particles)

 

 

Page 310 soil         A handful of soil contains up to 5,000 species of bacteria.               divided into layers called horizons. The A horizon, or topsoil, is the uppermost layer, consisting primarily of humus and living organisms and some mineral material. Most soluble material has been leached from this layer or washed down to the B horizon. The B horizon, or subsoil, is the layer where most of the nutrients accumulate and is enriched in clay minerals. The C horizon is the layer of weathered parent material at the base of the soil.             Two common soils are the podzol and the chernozem soil. The podzol is common in coniferous forest regions where precipitation exceeds evaporation. The A horizon consists of a very thin litter of organic material producing a poor humus. The needles of coniferous trees take a long time to decompose. The relatively heavy precipitation causes leaching of minerals, as nutrients are washed downward.             Chernozem soils are found in grassland regions, where evaporation exceeds precipitation. The A horizon is rich in humus due to decomposition of a thick litter of dead grass at the surface. Minerals and moisture migrate upward due to evaporation, leaving the B and A horizons enriched.             The organic content of soil is widely variable, ranging from zero in some desert soils to almost 100% in peats.             Soils influence the type of agriculture employed in a particular region—light well-drained soils favor arable farming, whereas heavy clay soils give rise to lush pasture land.             soil erosion Soil erosion, the wearing away and redistribution of the earth's soil layer, is caused by the action of water, wind, and ice, and also by improper methods of agriculture. If unchecked, soil erosion results in the formation of deserts (desertification). It has been estimated that 20% of the world's cultivated topsoil was lost between 1950 and 1990.             If the rate of erosion exceeds the rate of soil formation (from rock and decomposing organic matter), then the land will become infertile. The removal of forests (deforestation) or other vegetation often leads to serious soil erosion, because plant roots bind soil, and without them the soil is free to wash or blow away, as in the American dust bowl. The effect is worse on hillsides, and there has been devastating loss of soil where forests have been cleared from mountainsides, as in Madagascar.             Improved agricultural practices such as contour plowing are needed to combat soil erosion. Windbreaks, such as trees or strips planted with coarse grass, are valuable, and organic farming can reduce soil erosion by as much as 75%.             climate             Climate is another environmental factor in an ecosystem. A climate is the combination of weather conditions at a particular place over a period of time—usually a minimum of 30 years. A classification of climate encompasses the averages, extremes, and frequencies of all meteorological elements such as temperature, atmospheric pressure, precipitation, wind, humidity, and sunshine, together with the factors that influence them. The primary factors involved are: the earth's rotation and latitudinal effects; ocean currents; large-scale movements of wind belts and air masses over the earth's surface; temperature differences between land and sea surfaces; and topography. Climatology, the scientific study of climate, includes the construction of computer-generated models, and considers not only present-day climates, their effects and their classification, but also long-term climate changes, covering both past climates (paleoclimates) and future predictions. Climatologists are especially concerned with the influence of human activity on climate change.             climate classification The word "climate" comes from the Greek klima, meaning an inclination or slope (referring to the angle of the sun's rays, and thus latitude) and the earliest known classification of climate was that of the ancient Greeks, who based their system on latitudes. In recent times, many different systems of classifying climate have been devised, most of which follow that formulated by the German climatologist Wladimir Köppen (1846–1940) in 1900. These systems use vegetation-based classifications such as desert, tundra, and rainforest. Classification by air mass is used in conjunction with this method. This idea was first introduced in 1928 by the Norwegian meteorologist Tor Bergeron, and links the climate of an area with the movement of the air masses it experiences.             In the 18th century, the British scientist George Hadley developed a model of the general circulation of atmosphere based on convection. He proposed a simple pattern of cells of warm air rising at the Equator and descending at the poles. In fact, due to the rotation of the earth, there are three such cells (now called Hadley cells) in each hemisphere. The first two of these consist of air that rises at the Equator and sinks at latitudes north and south of the tropics; the second two exist at the mid-latitudes where the rising air from the sub-tropics flows toward the cold air masses of the third pair of cells circulating from the

 

 

Page 311         two polar regions. Thus, in this model, there are six main circulating cells of air above ground producing seven terrestrial zones—three rainy regions (at the Equator and the temperate latitudes) resulting from the moisture-laden rising air, interspersed and bounded by four dry or desert regions (at the poles and subtropics) resulting from the dry descending air.             prevailing winds Regions are also affected by different wind systems, which result from the rotation of the earth and the uneven heating of surface air. As air is heated by radiation from the sun, it expands and rises, and cooler air flows in to take its place. This movement of air produces belts of prevailing winds. Because of the rotation of the earth, these are deflected to the right in the northern hemisphere and to the left in the southern hemisphere. This effect, which is greater in the higher latitudes, is known as the Coriolis effect. Because winds transport heat and moisture, they affect the temperature, humidity, precipitation, and cloudiness of an area. As a result, regions with different prevailing wind directions may have different climates.             temperature variations The amount of heat received by the earth from the sun varies with latitude and season. In equatorial regions, there is no large seasonal variation in the mean daily temperature of the air near the ground, while in the polar regions, temperatures in the long winters, when there is little incoming solar radiation, fall far below summer temperatures. The temperature of the sea, and of the air above it, varies little in the course of day or night, whereas the surface of the land is rapidly cooled by lack of solar radiation. Similarly, the annual change of temperature is relatively small over the sea but much greater over the land. Thus, continental areas are colder than maritime regions in winter, but warmer in summer. This results in winds blowing from the sea which, relative to the land, are warm in winter and cool in summer, while winds originating from the central parts of continents are hot in summer and cold in winter. On average, air temperature drops with increasing land height at a rate of 1°C/1.8°F per 90 m/300 ft—so that even in equatorial regions, the tops of mountains can be snow-covered throughout the year.             climate changes Changes in climate can occur naturally or as a result of human activity. Natural variations can be caused by fluctuations in the amount of solar radiation reaching the earth—for example, sunspot activity is thought to produce changes in the earth's climate. Variations in the earth's orbit around the sun, known as the Milankovitch hypothesis, is also thought to bring about climatic changes. Natural events on the surface of the earth, such as volcanic eruptions and the effects of El Niño (the warm ocean surge of the Peru Current, occurring in the eastern Pacific, off South America), can result in temporary climate changes on a worldwide scale, sometimes extending over several months or even years. Human influences on the climate range from localized effects such as cloud seeding to produce rain, to the global effects of acid rain from industrial emissions; pollution; and the destruction of the rainforests. The study of past climates, paleoclimatogy, involves the investigation of climate changes from the ice ages to the beginning of instrumental recording in the 19th century.             Biomes             A biome is a broad natural assemblage of plants and animals shaped by common patterns of vegetation and climate. The varied distribution of land and sea areas produce the complexity of the general circulation of the atmosphere; this, in turn, directly affects the distribution of climate. Centered on the Equator is a belt of tropical rainforest, which may be either constantly wet or monsoonal (having wet and dry seasons in each year). On either side of this is a belt of savanna, with lighter seasonal rainfall and less dense vegetation, largely in the form of grasses. Then there is usually a transition through steppe (semi-arid) to desert (arid), with a further transition through steppe to what is termed Mediterranean climate with dry summers. Beyond this is the moist, temperate climate of middle latitudes, and then a zone of cold climate with moist winters. Where the desert extends into middle latitudes, however, the zones of Mediterranean and moist temperate climates are missing, and the transition is from desert to a cold climate with moist winters. In the extreme east of Asia a cold climate with dry winters extends from about 70° N to 35° N. The polar caps have tundra and glacial climates, with little or no precipitation.             rain forest Rain forests are areas of dense forest usually found on or near the Equator where the climate is hot and wet. Moist air brought by the converging tradewinds rises because of the heat, producing heavy rainfall. Over half the tropical rain forests are in Central and South America, primarily the lower Amazon and the coasts of Ecuador and Columbia. The rest are in Southeast Asia (Malaysia, Indonesia, and New Guinea) and in West Africa and the Congo.             Tropical rain forests once covered 14% of the earth's land surface, but are now being destroyed at an increasing rate as their valuable timber is harvested and the land cleared for agriculture, causing problems

 

 

Page 312 Countries Losing Greatest Areas of Forest       Source: Food and Agriculture Organization (FAO) of the United Nations     1990–95       Rank     Country Area of lost forest (hectares)       1     Brazil 2,554,000       2     Indonesia 1,084,000       3     Congo, Democratic Republic of 740,000       4     Bolivia 581,000       5     Mexico 508,000       6     Venezuela 503,000       7     Malaysia 400,000       8     Myanmar 387,000       9     Sudan 353,000       10     Thailand 329,000       11     Paraguay 327,000       12     Tanzania 323,000       13     Zambia 264,000       14=     Colombia 262,000   Philippines 262,000       16     Angola 237,000       17     Peru 217,000       18     Ecuador 189,000       19     Cambodia 164,000       20     Nicaragua 151,000       21     Laos 148,000       22     Vietnam 135,000       23     Papua New Guinea 133,000       24     Madagascar 130,000       25     Cameroon 129,000       26     Central African Republic 128,000       27     Nigeria 121,000       28     Afghanistan 118,000       29     Ghana 117,000       30     Mozambique 116,000       31     Guinea-Bissau 114,000       32     Honduras 102,000       33     Chad 94,000       34     Gabon 91,000       35     Argentina 89,000       36     Hong Kong, China 87,000       37     Guatemala 82,000       38     Guinea 75,000       39     Botswana 71,000       40     Panama 64,000           of deforestation. Although by 1991 over 50% of the world's rain forests had been removed, they still comprise about 50% of all growing wood on the planet, and harbor at least 40% of the earth's species (plants and animals).             The vegetation in tropical rain forests typically includes an area of dense forest called selva. A canopy formed by high branches of tall trees provides shade for lower layers. Underneath there is an intermediate layer of shorter trees and tree roots, and lianas. The ground cover consists mainly of mosses and ferns. The lack of seasonal rhythm causes adjacent plants to flower and shed leaves simultaneously. Chemical weathering and leaching take place in the iron-rich soil due to the high temperatures and humidity.             Rain forests comprise some of the most complex and diverse ecosystems on the planet, deriving their energy from the sun and photosynthesis. The trees are the main producers. Herbivores such as insects, caterpillars, and monkeys feed on the plants and trees and in turn are eaten by the carnivores, such as ocelots and puma. Fungi and bacteria, the primary decomposers, break down the dead material from the plants, herbivores, and carnivores with the help of heat and humidity. This decomposed material provides the nutrients for the plants and trees.             The rain forest ecosystem helps to regulate global weather patterns—especially by taking up carbon dioxide (CO2) from the atmosphere—and stabilizes the soil. Rain forests provide the bulk of the oxygen needed for plant and animal respiration. When deforestation occurs, the microclimate of the mature forest disappears; soil erosion and flooding become major problems since rain forests protect the shallow tropical soils. Once an area is cleared it is very difficult for shrubs and bushes to reestablish because the soils are poor in nutrients. This causes problems for plans to convert rain forests into agricultural land—after two or three years the crops fail and the land is left bare. Clearing of the rain forests may lead to a global warming of the atmosphere, and contribute to the greenhouse effect.             Tropical rain forests are characterized by a great diversity of species, usually of tall broad-leaved evergreen trees, with many climbing vines and ferns, some of which are a main source of raw materials for medicines. A tropical forest, if properly preserved, can yield medicinal plants, oils (from cedar, juniper, cinnamon, sandalwood), spices, gums, resins (used in inks, lacquers, linoleum), tanning and dyeing materials, forage for animals, beverages, poisons, green manure, rubber, and animal products (feathers, hides, honey). Other types of rain forest include montane, upper montane or cloud, mangrove, and subtropical.             Traditional ways of life in tropical rain forests are disappearing. The practice of shifting cultivation, in which small plots of forest are cultivated and

 

 

Page 313         desert slopes, Argentina Eroded desert slopes near Tres Cruces in the Quebrada da Humahuaca in Jujuy province, Argentina. K. G. PrestonMafham/Premaphotos Wildlife             abandoned after two or three harvests, is being replaced by slash-and-burn cultivation on such a large scale that the rain forests cannot regenerate. As a result, hunting and gathering as a way of life also is becoming less viable. In the last 30 years Central America has lost almost two-thirds of its rain forests to cattle ranching.             savanna             Savannas, or savannahs, are extensive open tropical grasslands with scattered trees and shrubs. They cover large areas of Africa, North and South America, and northern Australia. The soil is acidic and sandy and generally considered suitable only as pasture for lowdensity grazing. The name was originally given by Spaniards to the treeless plains of the tropical South American prairies. Most of North America's savannas have been built over.             A new strain of rice suitable for savanna conditions was developed in 1992. It not only grew successfully under test conditions in Colombia but also improved pasture quality so grazing numbers could be increased twentyfold.             steppe             Steppe is the temperate grasslands of Europe and Asia. Sometimes the term refers to other temperate grasslands and semi-arid desert edges.             desert             Deserts are arid areas with sparse vegetation (or, in rare cases, almost no vegetation). Soils are poor, and many deserts include areas of shifting sands. Deserts can be either hot or cold. Almost 33% of the earth's land surface is desert, and this proportion is increasing.             The tropical desert belts of latitudes from 5° to 30° are caused by the descent of air that is heated over the warm land and therefore has lost its moisture. Other natural desert types are the continental deserts, such as the Gobi, which are too far from the sea to receive any moisture; rain-shadow deserts, such as California's Death Valley, which lie in the lee of mountain ranges, where the ascending air drops its rain only on the windward slopes; and coastal deserts, such as the Namib, where cold ocean currents cause local dry air masses to descend. Desert surfaces are usually rocky or gravelly, with only a small proportion being covered with sand. Deserts can be created by changes in climate, or by the human-aided process of desertification.             Characteristics common to all deserts include irregular rainfall of less than 250 mm/19.75 in per year, very high evaporation rates often 20 times the annual precipitation, and low relative humidity and cloud cover. Temperatures are more variable; tropical deserts have a big diurnal temperature range and very high daytime temperatures (58°C/136.4°F has been recorded at Azizia in Libya), whereas mid-latitude deserts have a wide annual range and much lower winter temperatures (in the Mongolian desert the mean temperature is below freezing point for half the year).             Desert soils are infertile, lacking in humus and generally gray or red in color. The few plants capable of surviving such conditions are widely spaced, scrubby, and often thorny. Long-rooted plants (phreatophytes) such as the date palm and musquite commonly grow along dry stream channels. Salt-loving plants

 

 

Page 314 Largest Deserts in the World Desert Location Area1           sq km           sq mi     Sahara northern Africa       9,065,000           3,500,000     Gobi Mongolia/northeastern China       1,295,000           500,000     Patagonian Argentina       673,000           260,000     Rub al-Khali southern Arabian peninsula       647,500           250,000     Chihuahuan Mexico/southwestern U.S.A.       362,600           140,000     Taklimakan northern China       362,600           140,000     Great Sandy northwestern Australia       338,500           130,000     Great Victoria southwestern Australia       338,500           130,000     Kalahari southwestern Africa       260,000           100,000     Kyzyl Kum Uzbekistan       259,000           100,000     Thar India/Pakistan       259,000           100,000     Sonoran Mexico/southwestern U.S.A.       181,300           70,000     Simpson Australia       103,600           40,000     Mohave southwestern U.S.A.       51,800           20,000           1desert areas are very approximate because clear physical boundaries may not occur               (halophytes) such as saltbushes grow in areas of highly saline soils and near the edges of playas (dry saline lakes). Others, such as the xerophytes, are drought-resistant and survive by remaining leafless during the dry season or by reducing water losses with small waxy leaves. They frequently have shallow and widely branching root systems and store water during the wet season (for example, succulents and cacti with pulpy stems).             woodland             Woodlands are areas in which trees grow more or less thickly; they are generally smaller than forests. Temperate climates, with four distinct seasons a year, tend to support a mixed woodland habitat, with some conifers but mostly broad-leaved and deciduous trees, shedding their leaves in autumn and regrowing them in spring. In the Mediterranean region and parts of the southern hemisphere, the trees are mostly evergreen.             Temperate woodlands grow in the zone between the cold coniferous forests and the tropical forests of the hotter climates near the Equator. They develop in areas where the closeness of the sea keeps the climate mild and moist.             Old woodland can rival tropical rain forest in the             evergreen forest Evergreen forest with Indian elephants in the foreground, in Periyar national park, Kerala, India. Its canopy is multistory, with older trees rising above younger ones, indicating that it is an old established forest and a rich habitat containing many species of plants and animals. K. G. Preston Mafham/Premaphotos Wildlife

 

 

Page 315         number of species it supports, but most of the species are hidden in the soil. A study in Oregon, United States, in 1991 found that the soil in a single woodland location contained 8,000 arthropod species (such as insects, mites, centipedes, and millipedes), compared with only 143 species of reptile, bird, and mammal in the woodland above.             The trees determine the character of the wood. Sometimes a single species dominates, as in a pine or beech wood, but there is often a mixture of two or more co-dominants, as in a mixed oak and ash wood. Beneath the tree canopy there is frequently a layer of shrubs and beneath these the herbaceous plants. Woodland herbs grow in shady conditions and are adapted in various ways to make the best possible use of the available sunlight. The woodland floor provides moist conditions in which mosses and liverworts thrive and many fungi grow in the soil or on rotting wood. The trees themselves provide habitats for climbing plants, mosses, liverworts, lichens, fungi, and microscopic algae.             wetland             A permanently wet land area or habitat is called a wetland. Wetlands include areas of marsh, fen, bog, flood plain, and shallow coastal areas. Wetlands are extremely fertile. They provide warm, sheltered waters for fisheries, lush vegetation for grazing livestock, and an abundance of wildlife. Estuaries and seaweed beds are more than 16 times as productive as the open ocean.             The term is often more specifically applied to a naturally flooding area that is managed for agriculture or wildlife. A water meadow, where a river is expected to flood grazing land at least once a year thereby replenishing the soil, is a traditional example.             The largest area of tidal wetlands in Japan, a 3,550-hectare/8,800-acre area in Isahaya Bay, near Nagasaki, is threatened by a 7-km/4.3-mi-long barrier erected across the bay in 1997 as part of a flood control project. The wetlands, cut off from the tidal waters, are drying out rapidly and the ecosystem is likely to die if the barrier is not removed. The mudflats are home to 282 species of birds, crustaceans, and fish, including 21 endangered species.             taiga             Taiga is the Russian name for the forest zone south of the tundra, found across the northern hemisphere. Here, dense forests of conifers (spruces and hemlocks), birches, and poplars occupy glaciated regions punctuated with cold lakes, streams, bogs, and marshes. Winters are prolonged and very cold, but the summer is warm enough to promote dense growth.             The varied fauna and flora are in delicate balance because the conditions of life are so precarious. This ecology is threatened by mining, forestry, and pipeline construction.             tundra             Tundra is a region of high latitude almost devoid of trees, resulting from the presence of permafrost. The vegetation consists mostly of grasses, sedges, heather, mosses, and lichens. Tundra stretches in a continuous belt across northern North America and Eurasia. Tundra is also used to describe similar conditions at high altitudes. The term was originally applied to the topography of part of northern Russia, but is now used for all such regions.             Environmental Issues             Environmental issues are matters relating to the detrimental effects of human activity on the biosphere, their causes, and the search for possible solutions. Since the Industrial Revolution, the demands made by both the industrialized and developing nations are increasingly affecting the balance of the earth's natural resources. Over a period of time, some of these resources are renewable—trees can be replanted, soil nutrients can be replenished—but many resources, such as fossil fuels and minerals, are nonrenewable and in danger of eventual exhaustion. In addition, humans are creating many other problems which may endanger not only their own survival, but also that of other species. For instance, deforestation and air pollution are not only damaging and radically altering many natural environments, they are also affecting the earth's climate by adding to the greenhouse effect and global warming, while water pollution is seriously affecting aquatic life, including fish populations, as well as human health.             public awareness Concern for the environment is not just a late-20th-century issue. In England, the first smoke-abatement law dates from 1273, while in 1306 the burning of coal was prohibited in London because of fears of air pollution. However, the inspiration for the creation of the modern environmental movements came about from the publication in 1962 of the U.S. biologist Rachel Carson's book Silent Spring, in which she attacked the indiscriminate use of pesticides. This, combined with the increasing affluence of Western nations, which allowed people to look beyond their everyday needs, triggered an awareness of environmental issues on a global scale and resulted in the formation of the Green movement. In the mid-1960s, the detection of chlorofluorocarbons (CFCs) in the atmosphere by the British scientist James Lovelock led to a realization of the damaging effects of ozone

 

 

Page 316         depletion and added to public concern for the environment, as did his development of the Gaia hypothesis, which views the earth as a single integrated and self-sustaining organism.             Gaia hypothesis The concept of the earth as a single organism, or ecosystem, was formulated in the mid-1960s by the British scientist James Lovelock, while researching the possibility of life on Mars for NASA's space program. The Gaia hypothesis, named for an ancient Greek earth goddess, views the planet as a self-regulating system in which all the individual elements coexist in a symbiotic relationship. In developing this hypothesis, Lovelock realized that the damage effected by humans on many of the earth's ecosystems was posing a threat to the viability of the planet itself. The effects of this disruption are now becoming apparent in the changing landscapes and climates of almost every region or biome of the planet. They can be seen in the desertification of the Sahel, the shrinking of the Aral Sea in Central Asia, the destruction of tropical rain forests, and the creation of the holes in the ozone layer over the Arctic and Antarctic because of the pollution of the atmosphere with greenhouse gases. These gases include carbon and sulfur-dioxide emissions from the combustion of fossil fuels, and the CFCs widely used as propellants and refrigerants. The thinning of the protective ozone layer surrounding the planet, with its consequent threat of global warming, affects the basic functioning of energy flow within every ecosystem of the planet, from microorganisms to the ecosphere itself.       Friends of the Earth Home Page http://www.foe.co.uk/         The Friends of the Earth Home Page appeals for raised awareness of environmental issues with masses of information and tips for action from Friends of the earth. The site hosts lengthy accounts of several campaigns undertaken by FoE on climate, industry, transportation, and sustainable development. It also maintains an archive of press releases from FoE on some of the most controversial environmental problems encountered in the course of last year around the world.           international measures In 1972 the United Nations Environment Programme (UNEP) was formed to coordinate international measures for monitoring and protecting the environment, and in 1985 the Vienna Convention for the Protection of the Ozone Layer, which promised international cooperation in research, monitoring, and the exchange of information on the problem of ozone depletion, was signed by 22 nations. Discussions arising out of this convention led to the signing in 1987 of the Montréal Protocol. In 1992, representatives of 178 nations met in Rio de Janeiro for the United Nations Conference on Environment and Development. Known as the "Earth Summit," this was one of the most important conferences ever held on environmental issues. UN members signed agreements on the prevention of global warming and the preservation of forests and endangered species, along with many other environmental issues.     Carbon Dioxide Emissions for OECD Countries Source: Organization for Economic Cooperation and Development (OECD) The data are from energy use only; waste in international marine bunkers is excluded. (Data as of January 1997.) Rank Country Carbon dioxide per capita (metric tons) 1 Luxembourg 27 2 U.S.A. 20 3= Australia 16   Canada 16 5= Belgium 12   Denmark 12   Finland 12   Czech Republic 12 9= Netherlands 11   Germany 11 11= U.K. 10   Ireland, Republic of 10 13= Iceland 9   Japan 9   Poland 9 16= New Zealand 8   Norway 8 18= Austria 7   Italy 7   South Korea 7   Greece 7 22= Sweden 6   Spain 6   Switzerland 6   France 6   Hungary 6 27 Portugal 5 28 Mexico 4 29 Turkey 2           global warming             Average global temperature has increased approximately 1°F/0.5°C over the past century. Global

 

 

Page 317         temperature has been highly variable in earth history and many fluctuations in global temperature have occurred in historical times, but this most recent episode of warming coincides with the spread of industralization, prompting the hypothesis that it is the result of an accelerated greenhouse effect caused by atmospheric pollutants, especially carbon dioxide gas. Recent melting and collapse of the Larsen Ice Shelf, Antarctica, is a consequence of global warming. Melting of ice is expected to raise sea level in the coming decades.             In addition to a rise in average global temperature, global warming has caused seasonal variations to be more pronounced in recent decades. Examples are the most severe winter on record in the eastern United States in 1976–77 and the record heat waves in the Netherlands and Denmark the following year.       Global Warming http://pooh.chem.wm.edu/chemWWW/courses/chem105/projects/group1/page1.html         Interesting step-by-step explanation of the chemistry behind global warming. There is information on the causes of global warming, the environmental effects, and the social and economic consequences. The views of those who challenge the assertion that the world is warming up are also presented.           Natural, perhaps chaotic, climatic variations have not been ruled out as the cause of the current global rise in temperature, but scientists are still assessing the likely influence of anthropogenic (human-made) pollutants. Assessing the impact of humankind on global climate is complicated by the natural variability of global temperature on both geological and human time scales. The present episode of global warming has thus far still left England approximately 1°C cooler than during the peak of the so-called Medieval Warm Period (1000 to 1400 A.D.). The latter was part of a purely natural climatic fluctuation on a global scale. With respect to historical times, the interval between the Medieval Warm Period and the rise in temperatures we see today was unusually cold throughout the world.             deforestation             Deforestation is the destruction of forest for timber, fuel, charcoal burning, and clearing for agriculture and extractive industries, such as mining, without planting new trees to replace those lost (reforestation) or working on a cycle that allows the natural forest to regenerate. Deforestation causes fertile soil to be blown away or washed into rivers, leading to soil erosion, drought, flooding, and loss of wildlife. It may also increase the carbon dioxide content of the atmosphere and intensify the greenhouse effect, because there are fewer trees absorbing carbon dioxide from the air for photosynthesis.             Many people are concerned about the rate of deforestation as great damage is being done to the habitats of plants and animals. Deforestation ultimately leads to famine, and is thought to be partially responsible for the flooding of lowland areas—for example, in Bangladesh—because trees help to slow down water movement.             Soil degradation and erosion are becoming as serious as the loss of the rain forest. It is estimated that more than 10% of the world's soil lost a large amount of its natural fertility during the latter half of the 20th century. Some of the worst losses are in Europe, where 17% of the soil is damaged by human activity such as mechanized farming and fallout from acid rain. Mexico and Central America have 24% of soil highly degraded, mostly as a result of deforestation.     Deforestation of Tropical and Temperature Forest Worldwide Source: Food and Agriculture Organization (FAO) of the United Nations (In hectares.) Region       Forest area     Total change Annual change Annual change       (%)               1990–95           1990           1995       Africa       538,978,000           520,237,000           –18,741,000           –3,748,000           –0.7     Asia       490,812,000           474,172,000           –16,640,000           –3,328,000           –0.7     Europel       144,044,000           145,988,000           1,944,000           389,000           0.3     Former USSR1       813,381,000           816,167,000           2,786,000           557,000           0.1     North and Central           America       537,898,000           536,529,000           –1,369,000           –274,000           –0.1     Oceania       91,149,000           90,695,000           –454,000           –91,000           –0.1     South America       894,466,000           870,594,000           –23,872,000           –4,774,000           –0.5           1 No tropical forests exist in these regions, thus totals represent only temperate forests.

 

 

Page 318         The first deforestation occurred more than 2,000 years ago in areas surrounding the Mediterranean as wood was increasingly used for fuel, building materials, and the construction of ships. Throughout the next two millennia most of the woodland in Europe was destroyed as demands increased. The current wave of deforestation in the tropics dates back only 30 years, but even so has reduced the amount of intact forest ecosystem from 34% of total land in the affected areas to 12%. Deforestation in the tropics is especially serious because such forests do not regenerate easily and because they are such a rich source of biodiversity. The Food and Agriculture Organization (FAO) of the United Nations estimated that the deforestation rate for the tropics between 1990 and 1995 was 130,000 sq km/50,200 sq mi a year.             desertification             The destruction of fertile topsoil, and consequent soil erosion, as a result of human activity is becoming a worldwide problem. About 25% of the planet's land surface is now thought to be at risk due to increased demand from expanding populations. This damage and destruction results not only from increased demand for food, but also as a result of changes in agricultural practices. Desertification of vast areas, such as in the Sahel in northern Africa, have resulted from the replacement of traditional farming methods in these marginal lands for the present-day cultivation of cash crops such as groundnuts and cotton. The consequence has been that the soil has lost its fertility and the land has become arid. Similarly, changes in agricultural practices produced the dust bowl in the United States in the 1930s and, more recently, the move from mixed farming to arable and the removal of hedges in order to enlarge fields for the use of modern agricultural machinery has resulted in the loss of topsoil in the large areas of the English Fenlands.             Sahel The Sahel (Arabic sahil ''coast") is the marginal area to the south of the Sahara, Africa, from Senegal to Somalia, which experiences desert-like conditions during periods of low rainfall. The desertification is partly due to climatic fluctuations but has also been caused by the pressures of a rapidly expanding population, which has led to overgrazing and the destruction of trees and scrub for fuelwood. In recent years many famines have taken place in the area.             The average rainfall in the Sahel ranges from 100 mm/4 in to 500 mm/20 in per year, but the rainfall over the past 30 years has been significantly below average. The resulting famine and disease are further aggravated by civil wars. The areas most affected are Ethiopia and the Sudan.             pollution             The term pollution refers to the harmful effect on the environment of by-products of human activity, principally industrial and agricultural processes—for example, noise; smoke; car emissions; chemical and radioactive effluents in air, seas, and rivers; pesticides; radiation; sewage; and household waste. Pollution contributes to the greenhouse effect.             Environmental pollution can have natural sources, for example volcanic activity, which can cause major air pollution or water pollution and destroy flora and fauna. In terms of environmental issues, however, environmental pollution relates to human actions. The extraction, transportation, utilization, and waste products of nonrenewable resources for fuel all give rise to pollutants of one form or another. The effects of these pollutants can have consequences not only for the local environment, but also at a global level.             Pollution control involves higher production costs for the industries concerned, but failure to implement adequate controls may result in irreversible environmental damage and an increase in the incidence of diseases such as cancer. Radioactive pollution results from inadequate nuclear safety.             Many people think of air, water, and soil pollution as distinctly separate forms of pollution. However, each part of the global ecosystem—air, water, and soil—depends upon the others, and upon the plants and animals living within the environment. Thus, pollution that might appear to affect only one part of the environment is also likely to affect other parts.             air pollution Air pollution is any contamination of the atmosphere caused by the discharge, accidental or deliberate, of a wide range of toxic airborne substances. Often the amount of the released substance is relatively high in a certain locality, so the harmful effects become more noticeable. The cost of preventing any discharge of pollutants into the air is prohibitive, so attempts are more usually made to reduce the amount of discharge gradually and to disperse it as quickly as possible by using a very tall chimney, or by intermittent release.     hydrocarbons         In summer, in a city the size of Melbourne, Australia, the mowing of lawns increases atmospheric hydrocarbons by 10%.               The emission of vehicle exhausts or acidic gases from a power plant might appear to harm only the surrounding atmosphere. But once released into the air they are carried by the prevailing winds, often for several hundred kilometers, before being deposited as acid rain.

 

 

Page 319 Sulfur Oxides, Nitrogen Oxides, and Carbon Dioxide Emissions for OECD Countries Source: Organization for Economic Cooperation and Development (OECD) (Data as of January 1997. N/A = not available.) Country Emissions per capita   Sulfur oxides (kg) Nitrogen oxides (kg) Carbon dioxide (metric tons) Australia N/A N/A 16 Austria 9 23 7 Belgium 25 35 12 Canada 91 68 16 Czech Republic 125 36 12 Denmark 30 53 12 Finland 22 54 12 France 17 26 6 Germany 37 27 11 Greece 50 33 7 Hungary 72 18 6 Iceland 29 81 9 Ireland, Republic of 53 37 10 Italy 25 37 7 Japan 7 12 9 South Korea 34 26 7 Luxembourg 26 N/A 27 Mexico N/A N/A 4 Netherlands 9 35 11 New Zealand N/A 43 8 Norway 8 51 8 Poland 68 29 9 Portugal 27 26 9 Spain 53 31 6 Sweden 11 45 6 Switzerland 5 19 6 Turkey 29 9 2 U.K. 47 38 10 United States 63 74 20           smog Smog is a natural fog containing impurities, mainly nitrogen oxides and volatile organic compounds (VOCs) from domestic fires, industrial furnaces, certain power stations, and internal-combustion engines (gasoline or diesel). It can cause substantial illness and loss of life, particularly among chronic bronchitics, and damage to wildlife.             acid rain Acid rain is acidic precipitation thought to be caused principally by the release into the atmosphere of sulfur dioxide (SO2) and oxides of nitrogen, which dissolve in pure rainwater making it acidic. Sulfur dioxide is formed by the burning of fossil fuels, such as coal, that contain high quantities of sulfur; nitrogen oxides are contributed from various industrial activities and from car exhaust fumes.             Acidity is measured on the pH scale, where the value of 0 represents liquids and solids that are completely acidic and 14 represents those that are highly alkaline. Distilled water is neutral and has a pH of 7. Normal rain has a value of 5.6. It is slightly acidic due to the presence of carbonic acid formed by the mixture of carbon dioxide (CO2) and rainwater. Acid rain has values of 5.6 or less on the pH scale.             Acid deposition occurs not only as wet precipitation (mist, snow, or rain), but also comes out of the atmosphere as dry particles (dry deposition) or is absorbed directly by lakes, plants, and masonry as gases. Acidic gases can travel over 500 km/310 mi a day so acid rain can be considered an example of transboundary pollution.             Acid rain is linked with damage to and the death of forests and lake organisms in Scandinavia, Europe, and eastern North America. It also results in damage to buildings and statues. U.S. and European power stations that burn fossil fuels release about 8 g/ 0.3 oz of sulfur dioxide and 3 g/0.1 oz of nitrogen oxides per kilowatt-hour. According to the U.K. Department of the Environment figures, emissions of sulfur dioxide from power stations would have to be decreased by 81% in order to arrest damage.             The main effect of acid rain is to damage the chemical balance of soil, causing leaching of important minerals including magnesium and aluminum. Plants living in such soils, particularly conifers, suffer from mineral loss and become more prone to infection. The minerals from the soil pass into lakes and rivers, disturbing aquatic life, for instance, by damaging the gills of young fish and killing plant life. Lakes affected by acid rain are virtually clear due to the absence of green plankton. Lakes and rivers suffer more direct damage as well because they become

 

 

Page 320         acidified by rainfall draining directly from their catchment.             Owing to reductions in sulfur emissions, the amount of sulfur deposited per hectare of farm land has fallen from around 50 kg/110 lb in 1979 to 10 kg/22 lb in 1995. According to German research in 1995, although acid rain is harmful to crops, it also provides essential sulfur. There has been an increased incidence of sulfur-deficiency diseases in plants in the period 1990–95.             catalytic converter A catalytic converter is a device fitted to the exhaust system of a motor vehicle in order to reduce toxic emissions from the engine. It converts harmful exhaust products to relatively harmless ones by passing the exhaust gases over a mixture of catalysts coated on a metal or ceramic honeycomb (a structure that increases the surface area and therefore the amount of active catalyst with which the exhaust gases will come into contact). Oxidation catalysts (small amounts of precious palladium and platinum metals) convert hydrocarbons (unburned fuel) and carbon monoxide into carbon dioxide and water, but do not affect nitrogen oxide emissions. Three-way catalysts (platinum and rhodium metals) convert nitrogen oxide gases into nitrogen and oxygen.             Over the lifetime of a vehicle, a catalytic converter can reduce hydrocarbon emissions by 87%, carbon monoxide emissions by 85%, and nitrogen oxide emissions by 62%, but will cause a slight increase in the amount of carbon dioxide emitted. Catalytic converters are standard in the United States, where a 90% reduction in pollution from cars was achieved without loss of engine performance or fuel economy. Only 10% of cars in Britain had catalytic converters in 1993.             Catalytic converters are destroyed by emissions from leaded gasoline and work best at a temperature of 300°C. The benefits of catalytic converters are offset by any increase in the number of cars in use.             Unfortunately, catalytic converters emit nitrous oxide, which is itself a potent greenhouse gas. Vehicle emissions of nitrous oxide increased in the United States by 49% in the period 1990–96 reflecting an increase in the number of vehicles fitted with catalytic converters (vehicles with catalytic converters emit five times the amount of nitrous oxide of those without).             pesticides             Chemicals used in farming, gardening, or indoors to combat pests cause a number of pollution problems through spray drift onto surrounding areas, pollution of the groundwater, direct contamination of users or the public, and as residues on food. Pesticides are of three main types: insecticides (to kill insects), fungicides (to kill fungal diseases), and herbicides (to kill plants, mainly those considered weeds). The safest pesticides include those made from plants, such as the insecticides pyrethrum and derris.             Pyrethrins are safe and insects do not develop resistance to them. Their impact on the environment is very small as the ingredients break down harmlessly.             More potent are synthetic products, such as chlorinated hydrocarbons. These products, including DDT and dieldrin, are highly toxic to wildlife and often to human beings, so their use is now restricted by law in some areas and is declining. Safer pesticides such as malathion are based on organic phosphorus compounds, but they still present hazards to health. The aid organization Oxfam estimates that pesticides cause about 10,000 deaths worldwide every year.             Pesticides were used to deforest southeast Asia during the Vietnam War, causing death and destruction to the area's ecology and lasting health and agricultural problems.             Many pesticides remain in the soil, since they are not biodegradable, and are then passed on to foods. More than half of all potatoes sampled in 1995 contained residues of a storage pesticide; seven different             marine pollution Rubbish deposited in the sea by waste disposal from land or ships. Chris McTernan

 

 

Page 321         pesticides were found in carrots, with concentrations up to 25 times the permitted level; and 40% of bread contained pesticide residues.             water pollution             This consists of any addition to fresh or sea water that disrupts biological processes or causes a health hazard. Common pollutants include nitrates, pesticides, and sewage, although a huge range of industrial contaminants, such as chemical by-products and residues created in the manufacture of various goods, also enter water—legally, accidentally, and through illegal dumping.             oil spills The leakage of oil from an ocean-going tanker, a pipeline, or other source can kill all shore life, clogging up the feathers of birds and suffocating other creatures. At sea, toxic chemicals leach from the oil into the water below, poisoning sea life. Mixed with dust, the oil forms globules that sink to the seabed, poisoning sea life there as well. Oil spills are broken up by the use of detergents but such chemicals can themselves damage wildlife. The annual spillage of oil is 8 million barrels a year. At any given time tankers are carrying 500 million barrels.             groundwater pollution             In 1980 the UN launched the "Drinking Water Decade," aiming for cleaner water for all by 1990. However, in 1994 it was estimated that approximately half of all people in the developing world did not have safe drinking water. A 1995 World Bank report estimated that some 10 million deaths in developing countries were caused annually by contaminated water.     Major Oilspills Throughout the World (Date as of January 1997). Date Location Description Amount       metric tons millions of gallons March 1967 off Cornwall, England grounding of Torrey Canyon 118,000       35.4     June 1968 off South Africa Hull failure of World Glory 37,000       11.0     December 1972 Gulf of Oman collision of Sea Star with another ship 103,500       31.0     May 1976 La Caruña, Spain grounding of the Urquioia 60–70,000       18.0–21.0     December 1976 Nantucket, Massachusetts, U.S.A. grounding of Argo Merchant 25,000       7.5     February 1977 mid-Pacific Haiwaüan Patriot develops leak and catches fire 100,000       30.0     April 1977 North Sea blowout of well in Ekofisk oil field 270,000       81.0     March 1978 Portsall, Brittany, France grounding of the Amoco Cadiz 226,000       68.0     June 1979 Gulf of Mexico blowout of well in Ixtoc 1 oil field 600,000       180.0     July 1979 off Tobago, Caribbean collision of the Atlantic Empress and Aegean Captain 370,000       111.0     February 1983 Persian Gulf blowout of well in Nowruz oil field 600,000       180.0     August 1983 off Cape Town, South Africa fire on board the Castillo de Beliver 250,000       75.0     September 1985 Delaware River, Delaware, U.S.A. grounding of Grand Eagle 1,500       0.5     January 1988 Floreffe, Pennsylvania, U.S.A. collapsing of Ashland oil storage tank 2,400–2,500       0.7–0.8     March 1989 Prince William Sound, off Alaskan Coast, U.S.A. grounding of Exxon Valdez 37,000       11.0     June 1989 Canary Islands fire on board the Kharg 5 65,000       19.5     January 1991 Sea Island Terminal of Persian Gulf deliberate release of oil by Iraqi troops at end of Persian Gulf War 799,120       240.0     January 1993 Shetland Islands, Scotland grounding of Braer 130,000       39.0     August 1993 Tampa Bay, Florida, U.S.A. collision of two barges and a Philippine freighter 984       0.3     January 1996 Pembrokeshire coastline of Wales, British Isles grounding of Sea Empress >100,000       19.0     January 1996 south shore of Rhode Island, U.S.A. grounding of the tugboat Scandia and North Cape tanker it was towing 1,000       0.3

 

 

Page 322         ozone depletion             Ozone (O3), a highly reactive pale-blue gas, is formed when the molecule of the stable form of oxygen (O2) is split by ultraviolet radiation or electrical discharge. It forms the ozone layer in the upper atmosphere, which protects life on earth from ultraviolet rays, a cause of skin cancer.             Chemicals that destroy the ozone in the stratosphere are called ozone depleters. Most ozone depleters are chemically stable compounds containing chlorine or bromine, which remain unchanged for long enough to drift up to the upper atmosphere. The best known are chlorofluorocarbons (CFCs), but many other ozone depleters are known, including halons, used in some fire extinguishers; methyl chloroform and carbon tetrachloride, both solvents; some CFC substitutes; and the pesticide methyl bromide.             chlorofluorocarbons             Chlorofluorocarbons (CFCs) are a class of synthetic chemicals that are odourless, nontoxic, nonflammable, and chemically inert. The first CFC was synthesized in 1892, but no use was found for it until the 1920s. Since then their stability and apparently harmless properties have made CFCs popular as propellants in aerosol cans, as refrigerants in refrigerators and air conditioners, as degreasing agents, and in the manufacture of foam packaging. They are partly responsible for the destruction of the ozone layer. In June 1990 representatives of 93 nations, including the United States and the U.K., agreed to phase out production of CFCs and various other ozone-depleting chemicals by the end of the 20th century.       The Chemistry of the Ozone Layer http://pooh.chem.wm.edu/chemWWW/courses/chem105/projects/group2/page1.html         Interesting step-by-step introduction to the ozone layer for those wishing to understand the chemistry of ozone depletion, the role of chlorofluorocarbons, the consequences of increased radiation for life on earth, and actions to tackle the problem.           When CFCs are released into the atmosphere, they drift up slowly into the stratosphere, where, under the influence of ultraviolet radiation from the sun, they react with ozone (O3) to form free chlorine (Cl) atoms and molecular oxygen (O2), thereby destroying the ozone layer that protects earth's surface from the sun's harmful ultraviolet rays. The chlorine liberated during ozone breakdown can react with still more ozone, making the CFCs particularly dangerous to the environment. CFCs can remain in the atmosphere for more than 100 years.             Replacements for CFCs are being developed, and research into safe methods for destroying existing CFCs is being carried out. In 1996 it was reported that chemists at Yale University, United States, had developed a process for breaking down freons and other gases containing CFCs into nonhazardous compounds.             Resources             A resource is a commodity that can be used to satisfy human needs. Resources can be categorized into human resources, such as labor, supplies, and skills, and natural resources, such as climate, fossil fuels, and water. Natural resources may be further divided into nonrenewable resources and renewable resources.             A nonrenewable resource is a natural resource, such as coal or oil, that takes thousands or millions of years to form naturally and can therefore not be replaced once it is consumed. The main energy sources used by humans are nonrenewable. Renewable natural resources are replaced by natural processes in a reasonable amount of time. Soil, water, forests, plants, and animals are all renewable resources as long as they are properly conserved. Solar, wind, wave, and geothermal energies are based on renewable resources.             water supply             The water supply is the distribution of water for domestic, municipal, or industrial consumption. Water supply in sparsely populated regions usually comes from underground water rising to the surface in natural springs, supplemented by pumps and wells. Urban sources are deep artesian wells, rivers, and reservoirs, usually formed from enlarged lakes or dammed and flooded valleys, from which water is conveyed by pipes, conduits, and aqueducts to filter beds. As water seeps through layers of shingle, gravel, and sand, harmful organisms are removed and the water is then distributed by pumping or gravitation through mains and pipes.             water treatment Often other substances are added to the water, such as chlorine and fluoride; aluminum sulfate, a clarifying agent, is the most widely used chemical in water treatment. In towns, domestic and municipal (road washing, sewage) needs account for about 135 1/30 gal per head each day. In coastal desert areas, such as the Arabian peninsula, desalination plants remove salt from sea water. The earth's waters, both fresh and saline, have been polluted by industrial and domestic chemicals, some of which are toxic and others radioactive.             drought A period of prolonged dry weather can disrupt water supply and lead to drought. The area of the world subject to serious droughts, such as the Sahara, is increasing because of destruction of forests,

 

 

Page 323         lake A lake near Morondava in Madagascar. The water lilies are Nymphaea stellata and the trees in the distance, growing on dry land, are baobabs Adansonia grandidieri. Most lakes are the focal point of an ecosystem, drawing together a broad range of animal and plant life. Premaphotos Wildlife             overgrazing, and poor agricultural practices. A World Bank report in 1995 warned that a global crisis was imminent: chronic water shortages were experienced by 40% of the world's population, notably in the Middle East, northern and sub-Saharan Africa, and central Asia. In 1997, 1.4 billion people (25% of the     The Largest Reservoirs by Volume in the World Source: Institute of Civil Engineers, London Reservoir Location Year completed Volume       cubic m (millions) cubic yd (millions) Owen Falls1 Uganda 1954       204,800           266,240     Bratsk Russia 1964       169,000           219,700     High Aswan Egypt 1970       162,000           210,600     Kariba Zimbabwe/Zambia 1959       160,368           208,478     Akosombo Ghana 1965       147,960           192,348     Daniel Johnson Canada 1968       141,851           184,406     Guri Venezuela 1986       135,000           175,500     Krasnoyarsk Russia 1967       73,300           95,290     W. A. C. Bennett Canada 1967       70,309           91,402     Zeya Russia 1978       68,400           88,920     Cabora Bassa Mozambique 1974       63,000           81,900     La Grande 2 Barrage Canada 1978       61,715           80,230     La Grande 3 Barrage Canada 1981       60,020           78,026     Ust-llim Russia 1977       59,300           77,090     Boguchany Russia2         58,200           75,660     Kuibyshev Russia 1955       58,000           75,400     Serra de Mesa Brazil _2       54,400           70,720     Caniapiscau Barrage         K. A. 3 Canada 1980       53,790           69,927     Bukhtarma Kazakhstan 1960       49,800           64,740     Atatürk Turkey 1992       48,700           63,310           1 This volume is not fully obtainable by the dam: the major part of it is the natural capacity of the lake. Owen Falls is not the largest artificial lake. 2 Under construction.

 

 

Page 324 Water Scarcity Water-scarce countries, 1992, with projections for 20101 per capita renewable water supplies region/country       1992     2010 change (%)   (cubic meters/cubic feet per person)   Africa       Algeria       730/25,779     500/17,657 –32 Botswana       710/25,072     420/14,832 –41 Burundi       620/21,894     360/12,713 –42 Cape Verde       500/17,657     290/10,241 –42 Djibouti       750/26,485     430/15,185 –43 Egypt       30/1,059     20/706 –33 Kenya       560/19,775     330/11,653 –41 Libya       160/5,650     100/3,531 –38 Mauritania       190/6,709     110/3,884 –42 Rwanda       820/28,957     440/15,538 –46 Tunisia       450/15,891     330/11,653 –27 Middle East       Israel       330/11,653     250/8,828 –24 Jordan       190/6,709     110/3,884 –42 Qatar       40/1,412     30/1,059 –25 Saudi Arabia       140/4,944     70/2,472 –50 Syria       550/19,422     300/10,594 –45 United Arab Emirates       120/4,238     60/2,119 –50 Yemen       240/8,475     130/4,591 –46 Other       Barbados       170/6,003     170/6,003 0 Belgium       840/29,663     870/30,723 +4 Hungary       580/20,482     570/20,129 –2 Malta       80/2,825     80/2,825 0 Netherlands       660/23,307     600/21,188 –9 Singapore       210/7,416     190/6,709 –10 Additional countries by 2010       Malawi       1,030/36,373     600/21,188 –42 Sudan       1,130/39,904     710/25,072 –37 Morocco       1,150/40,610     830/29,310 –28 South Africa       1,200/42,376     760/26,838 –37 Oman       1,250/44,142     670/23,660 –46 Somalia       1,390/49,086     830/29,310 –40 Lebanon       1,410/49,792     980/34,607 –30 Niger       1,690/59,680     930/32,841 –45 1 Countries with per capita renewable water supplies of less than 1,000 cubic meters per year; does not include water flowing in from neighboring countries.           population) had no access to safe drinking water.             In 1992, the town of Cgungungo in the Atacama Desert, South America, began using a system to convert water from fog as a public water supply. The system supplies 11,000 1/2,400 gal of water per day.             waste             Materials that are no longer needed and are discarded are termed waste. Examples are household waste, industrial waste (which often contains toxic chemicals), medical waste (which may contain organisms

 

 

Page 325 Waste Generated in OECD Countries Source: Organization for Economic Corporation and Development (OECD) (Data as of January 1997. N = nil or negligible. N/A = not available.) Country Industrial waste per unit of GDP1(metric tons per $ millions) Municipal waste (kg per capita) Nuclear waste per unit of energy2 (metric tons per Mtoe3) Australia       125     N/A       N     Austria       53     430       N     Belgium       76     470       2.0     Canada       N/A     630       7.4     Czech Republic       232     230       1.1     Denmark       24     520       N     Finland       201     410       2.2     France       100     560       5.1     Germany       60     360       1.4     Greece       44     310       N     Hungary       104     420       N/A     Iceland       2     660       N     Ireland, Republic of       N/A     N/A       N     Italy       22     470       N     Japan       61     410       1.9     South Korea       67     390       1.8     Luxembourg       164     530       N     Mexico       70     320       0.1     Netherlands       30     540       0.2     New Zealand       N/A     N/A       N     Norway       39     620       N     Poland       117     290       N/A     Portugal       N/A     350       N     Spain       28     370       1.6     Sweden       95     440       4.8     Switzerland       5     380       3.0     Turkey       86     390       N     U.K.       59     350       5.2     United States       142     730       1.2     1 GDP = gross domestic product. 2 Wastes from spent fuel in nuclear power plants, in metric tons of heavy metal per million metric tons of oil equivalent (primary energy supply). 3 Mtoe = million metric tons.           that cause disease), and nuclear waste (which is radioactive). By recycling, some materials in waste can be reclaimed for further use. In 1990 the industrialized nations generated 2 billion metric tons of waste. In the United States, 40 metric tons of solid waste are generated annually per person, roughly twice as much as in Europe or Japan.             There has been a tendency to increase the amount of waste generated per person in industrialized countries, particularly through the growth in packaging and disposable products, creating a "throwaway society."             recycling Some industrial and household waste (such as paper, glass, and some metals and plastics) can be reprocessed so that the materials can be reused. This saves expenditure on scarce raw materials, slows down the depletion of nonrenewable resources, and helps to reduce pollution. Aluminum is frequently recycled because of its value and special properties that allow it to be melted down and re-pressed without loss of quality, unlike paper and glass, which deteriorate when recycled.             The United States recycles only around 25% of its waste (1998), compared to around 33% in Japan.

 

 

Page 326 Municipal Waste Generation for OECD Countries: Top 20 Source: Organization for Economic Cooperation and Development (OECD) (Data as of January 1997.) Rank Country Municipal waste per capita (kg) 1 United States 730 2 Iceland 660 3 Canada 630 4 Norway 620 5 France 560 6 Netherlands 540 7 Luxembourg 530 8 Denmark 520 9= Italy 470   Belgium 470 11 Sweden 440 12 Austria 430 13 Hungary 420 14= Finland 410   Japan 410 16= Turkey 390   South Korea 390 18 Switzerland 380 19 Spain 370 20 Germany 360           However, all U.S. states encourage or require local recycling programs to be set up. It was estimated in 1992 that 4,000 cities collected waste from 71 million people for recycling. Most of these programs were set up between 1989 and 1992. Around 33% of newspapers, 22% of office paper, 64% of aluminum cans, 3% of plastic containers, and 20% of all glass bottles and jars were recycled.             In 1998, the United States was recycling only 25% of its domestic waste, compared with 6% for Britain and up to 70% in parts of Canada. Britain recycles only 27% of its glass compared with 80% for the Netherlands; and 16% of steel packaging compared with 67% for Germany.       Recycle City http://www.epa.gov/recyclecity/         Recycle City is a child-friendly site of the U.S. Environmental Protection Agency designed to help people to live more ecologically. The site includes a host of fun games and activities to encourage children to think about waste disposal issues.           energy             Fossil fuels, such as coal, oil, and natural gas, formed from the fossilized remains of plants that lived hundreds of millions of years ago, are nonrenewable resources and will eventually run out. Extraction of coal and oil causes considerable environmental pollution, and burning coal contributes to problems of acid rain and the greenhouse effect. Alternative energy, or renewable energy, is energy from sources that are renewable and ecologically safe, as opposed to sources that are nonrenewable with toxic byproducts, such as fossil fuels and uranium (for nuclear power). The most important alternative energy source is flowing water, harnessed as hydroelectric power (described in Chapter 15, together with other alternative, renewable, energy technologies). Other sources include the oceans' tides and waves (harnessed by tidal power stations, floating booms, and other technologies; see Chapter 15), wind power (harnessed by windmills and wind turbines), the sun (solar energy), and the heat trapped in the earth's crust (geothermal energy).       Bioenergy Information Network http://www.esd.ornl.gov/bfdp/         U.S. government site about the possibilities and research into producing energy from rapidly replaced trees and grasses. There are sections on "biopower basics," "the biopower industry," and a library of photos and video stills.           geothermal energy Geothermal energy is extracted for heating and electricity generation from natural steam, hot water, or hot dry rocks in the earth's crust. It is an important source of energy in volcanically active areas such as Iceland and New Zealand. (See Chapter 15 for more details.)       Geothermal Technologies Program http://www.eren.doe.gov/geothermal/         Interesting geothermal home page of the U.S. Department of Energy. There is a description of various geothermal energy sources and technologies being developed to exploit them. There is information about a number of energy authorities across the world tapping geothermal energy.

 

 

Page 327         solar energy Solar energy is derived from the sun's radiation. The amount of energy falling on just 1 sq km/0.4 sq mi is about 4,000 megawatts, enough to heat and light a small town. In one second the sun gives off 13 million times more energy than all the electricity used in the United States in one year. Solar heaters have industrial or domestic uses. They usually consist of a black (heat-absorbing) panel containing pipes through which air or water, heated by the sun, is circulated, either by thermal convection or by a pump.             Solar energy may also be harnessed indirectly using solar cells (photovoltaic cells) made of panels of semiconductor material (usually silicon), which generate electricity when illuminated by sunlight. Although it is difficult to generate a high output from solar energy compared to sources such as nuclear or fossil fuels, it is a major nonpolluting and renewable energy source used as far north as Scandinavia as well as in the southwestern United States and in Mediterranean countries.             A solar furnace, such as that built in 1970 at Odeillo in the French Pyrenees, has thousands of mirrors to focus the sun's rays; it produces uncontaminated intensive heat (up to 3,000°C/5,4000°F) for industrial and scientific or experimental purposes. The world's first solar power station connected to a national grid opened in 1991 at Adrano in Sicily. Scores of giant mirrors move to follow the sun throughout the day, focusing the rays into a boiler. Steam from the boiler drives a conventional turbine. The plant generates up to 1 megawatt.             In March 1996 the first solar power plant capable of storing heat was switched on in California's Mohave Desert. Solar 2, part of a three-year government-sponsored project, consists of 2,000 motorized mirrors that will focus the sun's rays on to a 91-m/300 ft metal tower containing molten nitrate salt. When the salt reaches 565°C/1049°F it boils water to drive a 10-megawatt steam turbine. The molten salt retains its heat for up to 12 hours.             Despite their low running costs, their high installation cost and low power output have meant that solar cells have found few applications outside space probes and artificial satellites. Solar heating is, however, widely used for domestic purposes in many parts of the world, and is an important renewable source of energy.             wind power Wind energy can be harnessed to produce power (see Chapter 15 for more details).             Conservation             Conservation is the action taken to protect and preserve the natural world, usually from pollution, overexploitation, and other harmful features of human activity. The late 1980s saw a great increase in public concern for the environment, with membership in conservation groups, such as Friends of the earth, Greenpeace, and the U.S. Sierra Club, rising sharply. Globally the most important issues include the depletion of atmospheric ozone by the action of chlorofluorocarbons (CFCs), the build-up of carbon dioxide in the atmosphere (thought to contribute to an intensification of the greenhouse effect), and deforestation.     wind turbine         The wind turbine is the modern counterpart of the windmill. The rotor blades are huge-up to 100 m/330 ft across-in order to extract as much energy as possible from the wind. Inside the turbine head, gears are used to increase the speed of the turning shaft so that the electricity generation is as efficient as possible.               Action by governments has been prompted and supplemented by private agencies, such as the World Wide Fund for Nature (formerly the World Wildlife Fund). In attempts to save particular species or habitats, a distinction is often made between preservation—that is, maintaining the pristine state of nature exactly as it was or might have been—and conservation, the management of natural resources in such a way as to integrate the requirements of the local human population with those of the animals, plants, or the habitat being conserved.             biodiversity             Biodiverstiy is the measure of the variety of the earth's animal, plant, and microbial species; of genetic differences within species; and of the ecosystems that support those species. Its maintenance is important for ecological stability and as a resource for research into, for example, new drugs and crops. In the 20th century the destruction of habitats is believed to have resulted in the most severe and rapid loss of biodiversity in the history of the planet.             Estimates of the number of species vary widely because many species-rich ecosystems, such as tropical forests, contain unexplored and unstudied habitats. Especially among small organisms, many are unknown; for instance, it is thought that only 1–10% of the world's bacterial species have been identified.             threats to biodiversity The most significant threat to biodiversity comes from the destruction of rain

 

 

Page 328 Protected Areas of the World       Source: Fish and Wildlife Service           The International Union for the Conservation of Nature and Natural Resources (IUCN) identifies a protected area as an area of land and/or sea dedicated to the protection and maintenance of biological diversity and natural and associated cultural resources that are managed through legal or other effective means. The main purposes of management of a region or area as a protected area are: for scientific research; wilderness protection; preservation of species and genetic diversity; maintenance of environmental services; protection of specific natural and cultural features; tourism and recreation; education; sustainable use of resources from natural ecosystems; and maintenance of cultural and traditional attributes. The table only includes those areas greater than 10 sq km/4 sq mi in extent, or completely protected islands of more than 1 sq km/0.4 sq mi, classified in any of the IUCN management categories. (N = nil or negligible.)     1996                   Country     Area Number of protected Area protected Land area protected         sq km           sq mi           areas           sq km           sq mi     (%)1       Afghanistan           652,090           251,707           6           2,184           843     0.33       Albania           28,748           11,097           11           340           131     1.18       Algeria           2,381,741           919,352           19           119,192           46,020     5.00       Angola           1,246,700           481,226           6           26,412           10,198     2.12       Antarctica           14,266,827           5,508,422           19           2,425           936     0.02       Antigua and Barbuda           441           170           2           61           24     13.86       Argentina           2,780,092           1,073,116           86           43,731           16,885     1.57       Armenia           29,800           11,500           4           2,139           826     7.18       Australia           7,682,300           2,966,136           892           935,455           361,180     12.18       Austria           83,500           32,374           170           20,058           7,744     23.92       Azerbaijan           86,600           33,400           12           1,909           737     2.20       Bahamas           13,864           5,352           10           1,244           480     8.97       Bangladesh           144,000           55,585           8           968           374     0.67       Belarus           207,600           80,100           10           2,425           936     1.17       Belgium           30,510           11,784           3           771           298     2.53       Belize           22,963           8,864           14           3,231           1,247     14.07       Benin           112,622           43,472           2           7,775           3,002     6.90       Bhutan           46,500           17,954           9           9,661           3,730     20.72       Bolivia           1,098,581           424,052           25           92,330           35,649     8.40       Bosnia-Herzegovina           51,129           19,745           5           251           97     0.49       Botswana           582,000           225,000           9           106,633           41,171     18.54       Brazil           8,511,965           3,285,618           273           321,898           124,285     3.78       Brunei           5,765           2,225           10           1,151           444     19.97       Bulgaria           110,912           42,812           46           3,699           1,428     3.34       Burkina Faso           274,122           105,811           12           26,619           10,278     9.71       Burundi           27,834           10,744           3           889           343     3.19       Cambodia           181,035           69,898           20           29,978           11,575     16.56       Cameroon           475,440           183,638           14           20,504           7,917     4.31       Canada           9,970,610           3,849,674           640           825,455           318,708     8.32       Central African Republic           622,436           240,260           13           61,060           23,575     9.77       Chad           1,284,000           495,624           9           114,940           44,378     8.95       Chile           756,950           292,257           66           137,251           52,992     18.26       China           9,596,960           3,599,975           463           580,666           224,195     6.05       Colombia           1,141,748           440,715           79           93,580           36,131     8.22       Congo, Democratic           2,344,900           905,366           8           99,166           38,288     4.23       Republic of                       Congo, Republic of the           342,000           132,012           10           11,774           4,546     3.44       Costa Rica           51,100           19,735           29           6,386           2,466     12.55           (table continued on next page)

 

 

Page 329         (table continued from previous page)           Country     Area       Number of protected     Area protected Land area protected         sq km           sq mi           areas           sq km           sq mi     (%)1 Côte d'lvoire       322,463           124,471           12           19,929           7,695     6.18 Croatia       56,538           21,824           29           3,853           1,488     6.82 Cuba       110,860           42,820           53           8,928           3,447     7.80 Cyprus       9,251           3,571           4           753           290     8.14 Czech Republic       78,864           30,461           34           10,668           4,119     13.53 Denmark       43,075           16,627           113           13,888           5,362     32.24 Djibouti       23,200           8,955           1           100           39     0.43 Dominica       751           290           1           69           27     9.15 Dominican Republic       48,442           18,700           17           10,483           4,047     21.64 Ecuador       461,475           178,176           15           111,139           42,910     24.08 Egypt       1,001,450           386,990           12           7,932           3,063     0.79 El Salvador       21,393           8,258           2           52           20     0.24 Estonia       45,000           17,000           39           4,402           1,700     9.76 Ethiopia       1,096,900           423,403           23           60,226           23,253     5.45 Fiji       18,333           7,078           5           189           73     1.03 Finland       338,145           130,608           82           27,286           10,535     8.10 France       543,965           209,970           110           56,015           21,627     10.30 Gabon       267,667           103,319           6           10,450           4,035     3.90 Gambia       10,402           4,018           5           229           88     2.15 Georgia       69,700           26,911           15           1,869           722     2.68 Germany       357,041           137,853           504           91,957           35,505     25.77 Ghana       238,305           91,986           9           11,036           4,261     4.63 Greece       131,957           50,935           24           2,231           861     1.69 Greenland       2,186,000           844,014           2           982,500           379,344     44.95 Guatemala       108,889           42,031           17           8,330           3,216     7.65 Guinea       245,857           94,901           3           1,635           631     0.67 Guyana       214,969           82,978           1           586           226     0.27 Haiti       27,750           10,712           3           97           37     0.35 Honduras       112,100           43,282           44           8,628           3,331     7.70 Hungary       93.032           35,910           53           5,740           2,216     6.17 Iceland       103,000           39,758           22           9,159           3,536     8.91 India       3,166,829           1,222,396           374           143,507           55,408     4.53 Indonesia       1,191,443           740,905           175           185,653           71,680     9.67 Iran       1,648,000           636,128           68           82,996           32,045     5.04 Ireland, Republic of       70,282           27,146           12           468           181     0.68 Israel       20,800           8,029           15           3,078           1,188     14.82 Italy       301,300           116,332           172           22,748           8,783     7.55 Jamaica       10,957           4,230           1           15           6     0.13 Japan       377,535           145,822           80           27,582           10,649     7.46 Jordan       89,206           34,434           10           2,903           1,121     3.02 Kazakhstan       2,717,300           1,049,150           9           8,915           3,442     0.33 Kenya       582,600           224,884           36           35,038           13,528     6.01 Kiribati       717           277           3           266           103     38.93 Korea, North       120,538           46,528           2           579           224     0.47 Korea, South       98,799           38,161           28           6,938           2,679     7.05 Kuwait       17,819           6,878           2           270           104     1.11 Kyrgyzstan       198,500           76,641           5           2,841           1,097     1.43 Laos       236,790           91,400           17           24,400           9,421     10.30 Latvia       63,700           24,595           45           7,747           2,991     12.16 Lebanon       10,452           4,034           1           35           14     0.34 Lesotho       30,355           11,717           1           68           26     0.22 Liberia       111,370           42,989           1           1,292           499     1.16 Libya       1,759,540           679,182           6           1,730           668     0.10           (table continued on next page)

 

 

Page 330         (table continued from previous page)           Country     Area Number of protected Area protected Land area protected         sq km           sq mi           areas           sq km           sq mi     (%)1 Liechtenstein       160           62           1           60           23     37.50 Lithuania       65,200           25,174           76           6,347           2,451     9.73 Luxembourg       2,586           998           1           360           139     13.93 Macedonia, Former       25,700           9,920           16           2,165           836     8.42 Yugoslav Republic of Madagascar       587,041           226,598           37           11,153           4,306     1.88 Malawi       118,000           45,560           9           10,585           4,087     11.25 Malaysia       329,759           127,287           54           14,848           5,733     4.46 Mali       1,240,142           478,695           11           40,120           15,490     3.24 Mauritania       1,030,700           397,850           4           17,460           6,741     1.69 Mauritius       1,865           720           3           40           15     2.16 Mexico       1,958,201           756,198           65           97,287           37,563     4.93 Moldova       33,700           13,012           2           62           24     0.18 Mongolia       1,565,000           604,480           15           61,678           23,814     3.94 Morocco       458,730           177,070           10           3,621           1,398     0.79 Mozambique       799,380           308,561           1           20           8     N Myanmar       676,577           261,228           2           1,733           669     0.26 Namibia       824,300           318,262           12           102,178           39,451     12.40 Nepal       147,181           56,850           12           11,085           4,280     7.84 Netherlands       41,863           16,169           79           3,885           1,500     9.44 New Zealand       268,680           103,777           206           61,478           23,737     23.19 Nicaragua       127,849           49,363           59           9,035           3,488     6.10 Niger       1,186,408           457,953           5           84,162           32,495     7.09 Nigeria       923,773           356,576           19           29,713           11,472     3.22 Northern Marianas       477           184           4           15           6     3.23 Norway       387,000           149,421           114           55,365           21,376     17.09 Oman       272,000           105,000           29           37,363           14,426     13.74 Pakistan       796,100           307,295           55           37,209           14,366     4.63 Palau       508           196           1           12           5     2.44 Panama       77,100           29,768           15           13,263           5,121     16.89 Papua New Guinea       462,840           178,656           5           820           317     0.18 Paraguay       406,752           157,006           19           14,830           5,726     3.65 Peru       1,285,200           496,216           22           41,762           16,124     3.25 Philippines       300,000           115,800           27           6,059           2,339     2.02 Poland       312,683           120,628           111           30,636           11,829     9.80 Portugal       92,000           35,521           25           5,826           2,249     6.31 Qatar       11,400           4,402           1           16           6     0.14 Romania       237,500           91,699           39           10,849           4,189     4.57 Russia       17,075,500           6,591,100           199           655,368           253,038     3.84 Rwanda       26,338           10,173           2           3,270           1,263     12.42 St. Kitts and Nevis       269           104           1           26           10     10.00 St. Lucia       617           238           1           15           6     2.41 St. Vincent and the Grenadines       388           150           2           83           32     21.30 Samoa       2,840           1,097           3           101           39     3.55 Saudi Arabia       2,200,518           849,400           10           62,014           23,944     2.58 Senegal       196,200           75,753           10           21,807           8,420     11.09 Seychelles       453           175           3           379           146     93.79 Sierra Leone       71,740           27,710           2           820           317     1.13 Singapore       622           240           1           28           11     4.54 Slovak Republic       49,035           18,940           40           10,155           3,921     72.36 Slovenia       20,251           7,817           10           1,081           417     5.34 Somalia       637,700           246,220           1           1,800           695     0.29 South Africa       1,222,081           471,723           237           69,283           26,750     5.85           (table continued on next page)

 

 

Page 331         (table continued from previous page)           Country     Area Number of protected Area protected Land area protected         sq km           sq mi           areas           sq km           sq mi     (%)1 Spain       504,750           194,960           215           42,456           16,392     8.41 Sri Lanka       65,600           25,328           56           7,960           3,073     12.13 Sudan       2,505,815           967,489           16           93,825           36,226     3.74 Suriname       163,820           63,243           13           7,360           2,842     4.49 Swaziland       17,400           6,716           4           459           177     2.64 Sweden       450,000           173,745           214           29,890           11,541     6.78 Switzerland       41,300           15,946           109           7,307           2,821     17.70 Taiwan       36,179           13,965           14           4,266           1,647     11.54 Tajikistan       143,100           55,251           3           857           331     0.60 Tanzania       945,000           364,865           30           138,900           53,629     14.78 Thailand       513,115           198,108           111           70,203           27,105     13.66 Togo       56,800           21,930           11           6,469           2,498     11.39 Trinidad and Tobago       5,130           1,981           6           157           61     3.07 Tunisia       164,150           63,378           7           449           173     0.27 Turkey       779,500           300,965           44           8,194           3,164     1.05 Turkmenistan       488,100           188,406           8           11,116           4,292     2.28 Uganda       236,600           91,351           31           10,987           4,242     8.07 Ukraine       603,700           233,089           20           5,224           2,017     0.87 United Kingdom       244,100           94,247           191           51,280           19,799     20.94 United States       9,368,900           3,618,770           1,494           1,042,380           402,463     11.12 Uruguay       176,200           68,031           8           3,209           1,239     0.17 Uzbekistan       447,400           172,741           10           2,442           943     0.55 Venezuela       912,100           352,162           100           263,223           101,631     28.86 Vietnam       329,600           127,259           59           13,298           5,134     4.03 Yugoslavia       58,300           22,503           21           3,470           1,340     3.40 Zambia       752,600           290,579           21           63,636           24,570     8.46 Zimbabwe       390,300           150,695           25           30,678           11,845     7.86 1 The figures in the percentage of land area protected column may be inflated due to the inclusion of protected marine areas in the calculation.           forests and other habitats in the southern hemisphere. It is estimated that 7% of the earth's surface hosts 50–75% of the world's biological diversity. Costa Rica, for example, has an area less than 10% of the size of France but possesses three times as many vertebrate species.             In 1992 an international convention for the preservation of biodiversity was signed by over 100 world leaders. The convention called on industrialized countries to give financial and technological help to developing countries to allow them to protect and manage their natural resources, and profit from growing commercial demand for genes and chemicals from wild species. However, the convention was weakened by the United States' refusal to sign because of fears it would undermine the patents and licenses of biotechnology companies.       Welcome to Coral Forest http://www.blacktop.com/coralforest/         Welcome to Coral Forest is a site dedicated to explaining the importance of coral reefs for the survival of the planet. It is an impassioned plea on behalf of the world's endangered coral reefs and includes a full description of their biodiversity, maps of where coral reefs are to be found (no less than 109 countries), and many photos.           A report issued in 1995, after almost a decade of research sponsored by the World Bank and international organization groups, designated 1,306 sites worldwide as marine protection areas (MPAs); of these, 155 were singled out for further protection, including the Bering Strait and Kachemak Bay, both in Alaska. The MPAs were selected on the basis of genetic diversity, biological productivity, and the extent to which they provided habitats for endangered species.             wildlife trade The international trade in live plants and animals, and in wildlife products such as skins, horns, shells, and feathers, has made some species virtually extinct, and threatens whole ecosystems (for

 

 

Page 332         example, coral reefs). Wildlife trade is to some extent regulated by CITES (Convention on International Trade in Endangered Species).             Species almost eradicated by trade in their products include many of the largest whales, crocodiles, marine turtles, and some wild cats. Until recently, some 2 million snakeskins were exported from India every year. Populations of black rhino and African elephant have collapsed because of hunting for their horns and tusks (ivory), and poaching remains a problem in cases where trade is prohibited.             whaling             Whales have been killed by humans since at least the Middle Ages. There were hundreds of thousands of whales at the beginning of the 20th century, but the invention of the harpoon gun in 1870 and improvements in ships and mechanization have led to the near-extinction of several species of whale. Commercial whaling was largely discontinued in 1986, although Norway and Japan have continued commercial whaling. Traditional whaling areas include the coasts of Greenland and Newfoundland, but the Antarctic, in the summer months, supplies the bulk of the catch.             Whales are killed for whale oil (made from the thick layer of fat under the skin called ''blubber"), which is used as a lubricant, or for making soap, candles, and margarine; for the large reserve of oil in the head of the sperm whale, used in the leather industry; and for ambergris, a waxlike substance from the intestines of the sperm whale, used in making perfumes. Whales have also been killed for use in petfood manufacture in the United States and Europe, and as a food in Japan. The flesh and ground bones are used as soil fertilizers.             The International Whaling Commission (IWC) was established in 1946 to enforce quotas on whale killing. It was largely unsuccessful until the 1970s, when world concern about the possible extinction of the whale mounted. By the end of the 1980s, 90% of blue, fin, humpback, and sperm whales had been wiped out, and their low reproduction rates mean that populations are slow to recover.             After 1986 only Iceland, Japan, Norway, and the USSR continued with limited whaling for "scientific purposes," and proposals made by Japan, Norway, and the USSR for further scientific whaling were rejected by the IWC in 1990, when a breakaway whaling club was formed by Norway, Greenland, the Faeroes, and Iceland. In 1991 Japan, which has been repeatedly implicated in commercial whaling, held a "final" whale feast before conforming to the regulations of the IWC. In 1992 the IWC established the Revised Management Procedure (RMP), to provide a new basis for regulating the exploitation of whales.             In 1994 it was revealed that Soviet whaling fleets had been systematically killing protected whales for over 40 years and exceeding their permitted quotas by more than 90%, leading to a revision of estimates of the remaining number of whales. The IWC's decision in May 1994 to create a vast Southern Ocean whale sanctuary was supported by 23 member states; Japan voted against it, and Norway abstained.

 

 

Page 333         Environment and Ecology Chronology     Environment and Ecology Chronology c. 3100 B.C. The Egyptian king Menes has a large (15 m/49 ft high) masonry dam built on the Nile south of Memphis (Cairo) to provide water for irrigation and for the city. It is the first large-scale dam. c. 900 B.C. Natural gas begins to be used in China. c. 800 B.C. Long underground aqueducts called "qanats" are driven horizontally into hillsides in Persia to tap groundwater. They are still a major source of water in Iran. c. 400 B.C. The Chinese begin to use bitumen for cooking food and burning in lamps—the first use of oil as a source of energy. c. 325 B.C. Greek scholar Theophrastus writes about the relationship between organism, and between organisms and their environment—the first ecological study. c. 200 B.C. Coal is first used in China as fuel. 100 The Romans begin the mining of coal in Britain. 536 Dust from volcanic eruptions in Southeast Asia is flung high in the atmosphere, blocking out sunlight and cooling the climate, causing a server winter as far away as Europe, where the Mediterranean is covered by a "dry fog." c. 600 Climate change in Peru accelerates the decline of the South American Moche civilization, silting up the canals that irrigate their principal city. 644 The earliest references to the Arab use of windpower dates to Persia at this time. Persian windmills have towers with horizontal sails inside. The wind enters and exits through carefully-positioned inlets. 1040 Water power is employed in hemp mills at Graisivaudan, France. c. 1125 Tidal mills are built near the mouth of the River Adour, France, to take advantage of the flow of water constantly changing with the tides. 1180 A windmill with vertical sails (not a horizontal post mill) is recorded for the first time in western Europe, at Saint-Sauveur-le-Vicomte, Normandy. 1190 Coal is mined for use in iron forges at Liège, Flanders, apparently the first application for which the mineral was used. Coal mining also begins in France at around this time. 1233 Coal is mined at the English town of Newcastle for the first time and rapidly becomes popular as a fuel, although some complain about the pollution. 1233 The first piped water supply in England takes water from Paddington to Westminster, London. 1273 Complaints in London, England, about pollution produced from the burning of "seacoal" mined at Newcastle lead to an eventual prohibition on coal burning throughout England. 1594–97 A sharp climatic downturn leads to harvest failures and high grain prices throughout Europe. The shortage causes crises of subsistence, dearth, and famine; unrest, vagabondage, and revolt increase. 1614–42 The Dutch captain Jan May claims Jan Mayen island in the Arctic Ocean as a whaling base; it is deserted after 28 years, when the local whales have been exterminated. 1615 In an effort to conserve the dwindling forests in England, particularly the large (usually) oak trees required for naval ships, timber (large wood) is forbidden as fuel for glass furnaces, which are expanding rapidly as windows are more commonly glazed. 1766 English chemist Henry Cavendish produces nitrogen dioxide by passing electricity through a nitrogen-oxygen mixture; it stimulates experiments on ways to enrich the soil. 1800 Scottish chemist William Cruickshank purifies water by adding chlorine. 1807 British inventor William Cubitt develops "patent sails." Used on windmills, they automatically adjust the sails to the speed and direction of the wind. 1818 French scientist Francois de Larderel exploits the energy of geothermal emissions of steam at Larderello, Italy. 1821 The world's first natural gas well is sunk at Fredonia, New York. Lead pipes distribute the gas to consumers for lighting and cooking. 1827 French engineer Benoît Fourneyron builds the world's first water turbine. It generates 6 horsepower. 1840 German chemist Christian Schönbein discovers ozone. 1853 The Forest of Fontainebleau in France becomes the first designated nature reserve. 1856 The world's first oil refinery opens at Ploiesti, Romania. 1859 U.S. engineer Edwin Drake drills the world's first oil well, at Titusville, Pennsylvania. Drilled to a depth of 21 m/69 ft it produces 1,818 l/400 gal per day. His success, coinciding with a growing demand for oil products, especially kerosene, leads to further drilling. 1864 Norwegian engineer Sven Foyn invents the gun-launched harpoon with an explosive head. It permits hunting the faster and more

 

 

Page 334   plentiful fin, sei, and blue whales and ushers in the era of modern whaling. 1864 Yosemite National Park, California, is established. It is the first state park and becomes a national park in 1894. 1869 German embryologist Ernst Haeckel coins the word "ecology." 1872 Yellowstone National Park is created in Wyoming and Montana. The world's first national park, it is also the United States' largest at 898,000 ha/2.2 million ac. 1885 Banff National Park is established in Canada, the country's first national park. 1892 U.S. naturalist John Muir founds the Sierra Club to preserve scenic resources in the United States Aug 26, 1895 The first large hydroelectric power station begins operating at Niagara Falls, U.S.A. Fourneyron water turbines are used to turn three 5,000-horsepower Westinghouse electric generators, providing 3,750 kW of alternating current to Buffalo, New York. 1895 The National Trust is founded in Britain to preserve country houses, parks, gardens, and areas of natural beauty. 1896 Swedish chemist Svante August Arrhenius discovers a link between the amount of carbon dioxide in the atmosphere and global temperature. 1898 The 19,500 sq km/7,500 sq mi Kruger National Park is established (in part) in South Africa. 1903 The U.S. president Theodore Roosevelt establishes the first U.S. national wildlife refuge on Pelican Island, off the east coast of Florida. 1905 Roosevelt creates the U.S. Forest Service and establishes millions of acres of additional forest reserves. 1906 The U.S. National Forests Commission is established. 1907 Etosha National Park, one of the world's largest game reserves, covering 22,270 sq km/8,600 sq mi, and Namib Desert National Park (23,400 s q km/9,035 sq mi), containing the only desert in southern Africa, are established in South West Africa (Namibia). June 1908 Roosevelt appoints a 57-member National Commission for the Conservation of Natural Resources. The Commission will be directed by Gifford Pinchot, who first applied the term "conservation" to the environment. 1908 Kaziranga National Park, Assam, India is established; it serves as a refuge for the Indian rhinoceros. 1913 French physicist Charles Fabry discovers the ozone layer in the upper atmosphere. 1917 Mount McKinley National Park (now Denali National Park) in Alaska is established; it encompasses Mount McKinley, the highest mountain in North America. Covering 24,419 sq km/9,428 sq mi, it is the largest national park in the United States. 1919 Grand Canyon National Park, Arizona, is established. Covering 4,931 sq km/1,904 sq mi, it preserves 160 km/100 mi of the Grand Canyon. 1921 Ujong-kulon Nature Reserve is established in Java, Indonesia; it contains the last natural forest in Java and is a refuge for the Javanese tiger and Javanese rhinoceros. 1922 Wood Buffalo National Park, Alberta, Canada, is established. The largest national park in tht world, covering 44,800 sq km/17,300 sq mi, it contains the only remaining free-ranging buffalo herds. c. 1925 U.S. chemist Thomas Midgley discovers Freon-12 (dichlorodifluoromethane), a chloroflurocarbon (CFC) used in refrigeration. 1930 Hundreds of people fall ill and 60 die during a four-day fog in the industrialized Meuse Valley in Belgium. It is the first recorded air pollution disaster. 1930–36 The Boulder Dam (renamed Hoover Dam in 1947) on the Colorado River (on the border of Arizona and Nevada) is constructed to provide hydroelectricity. The dam is 221 m/726 ft high and 379 m/1,244 ft wide, and the lake behind the dam, Lake Mead, is 185 km/115 mi long making it the largest artificial lake in the United States. 1931 The U.S. corporation Du Pont introduces Freon, a chlorofluorocarbon (CFC), as an aerosol propellant and refrigerant; it begins to replace ammonia in refrigerators. 1932 The largest hydroelectric power station in Europe is built at Zaporozhye on the River Dnieper, USSR; it produces 560 megawatts of electricity. Nov 11–13, 1933 A dust storm blows topsoil form South Dakota as far east as New York State; the U.S. Department of Agriculture sets up a Soil Erosion Service to teach farmers tilling methods that minimize erosion. 1933 British biochemist Ernest Kennaway discovers that hydrocarbons produced from incomplete combustion, and found in cigarette smoke, car exhausts, and air pollution, can cause cancer in test animals. These are the first chemical carcinogens to be isolated. 1934 Ecuador makes part of the Galápagos Islands a wildlife sanctuary to protect its unique flora and fauna. It is extended in 1959 and in 1968 becomes the Parque Nacional Galápagos.

 

 

Page 335 1935 A "Green Belt" scheme is put in to operation around London, England, to prevent excessive development. 1940 The U.K. government creates Serengeti National Park in Tanganyika (modern Tanzania); it covers an area of 14,763 sq km/5,700 sq mi and provides a refuge for the rare black rhinoceros. 1945 The chemical herbicides 2,4-D, 2,4,5,-T and IPC are introduced; they herald a new era in chemical weed control as their high toxicity permits them to be used in dosages as low as one or two pounds per acre. 1947 Everglades National park is established in Florida. 1948 The Fresh Kills landfill site on Staten Island, New York, opens. By the 1990s its volume will exceed that of the Great Wall of China, making it the largest artificial structure on the earth. 1948 Tsavo National Park is created in Kenya; it offers a refuge for the black rhinoceros. Oct 25, 1952 A hydroelectric power station and dam are opened at Donzère-Mondragon in the Rhône Valley of France. The project is part of a larger scheme to produce 25% of France's electricity in the Rhône Valley. Dec 1952 Smog hits London, England: weather conditions and industrial and domestic pollution combine to produce a haze of toxic pollutants, which limit visibility to a few feet. It lasts for three weeks, and over 4,000 people, mostly elderly, die from respiratory problems caused by poor air quality. The disaster leads to antipollution legislation. 1956 The Clean Air Act is passed by the U.K. Parliament. It prohibits the burning of untreated coal in London and successfully reduces the emission of sulfur-oxide pollution. Sept 9, 1961 An international conference is held in Tanganyika (now Tanzania) for preserving African wildlife. 1961 Chobe National Park, which contains a fossilized lake bed, and Gemsbok National Park, the largest national park in Africa, covering 24,305 sq km/9,384 sq mi, are established in Bechuanaland (now Botswana). 1961 The World Wildlife Fund (now Worldwide Fund for Nature) is established to promote conservation. 1965 The Gir Lion National Park is established in India. It is the last remaining natural habitat of the Asiatic lion. 1966 The U.S. Department of the Interior issues the first rare and endangered species list; 78 species are included. Congress passes the Rare and Endangered Species Act to protect them. 1967 The International Whaling Commission prohibits hunting blue, right, gray, and humpback whales. 1967 U.S. scientists Syukuvo Manabe and R. T. Wetherald warn that the increase in carbon dioxide in the atmosphere, produced by human activities, is causing a "greenhouse effect," which will raise atmospheric temperatures and cause a rise in sea levels. June 1969 Pesticides spilled into the Rhine by a chemical company in Frankfurt am Main kill millions of fish and contaminate the drinking water of the Netherlands. Jan 15, 1971 The Aswan High Dam in Egypt is officially opened. Its reservoir, Lake Nasser, is 300 km/186 mi long and necessitated the relocation of the Abu Simbel temple complex. The dam allows Egypt to control the annual flooding of the Nile but increases incidence of the disease schistosomiasis. 1971 Greenpeace, the environmental campaign organization, is founded to protest against U.S. nuclear testing at Amchitka Island, Alaska. 1971 The United States bans the importation of all whale products. June 1972 The United Nations Conference on the Human Environment is held in Stockholm, Sweden; the first international conference on the state of the environment, its aim is to improve the world's environment through monitoring, resource management, and education. 1972 Dennis Meadow's The Limits to Growth is published by the Massachusetts Institute of Technology. Based on a Club of Rome report and computer simulation, it predicts environmental catastrophe if the depletion of the earth's resources, overpopulation, and pollution are not acted upon immediately. 1972 The first section of the Transamazonia Highway is completed in Brazil; designed to assist settlement and exploitation of the underpopulated Amazon River Basin, when completed it will run 15,100 km/3,400 mi from Recife on the Atlantic coast to Cruzeiro do Sul near the Peruvian border. 1972 The U.K. and several other European countries sign an agreement prohibiting aircraft and ships from dumping toxic and plastic waste into the Atlantic; it is the first major international agreement governing pollution of the sea. 1972 The United Nations Environment Program (UNEP) is established; its aim is to advise and coordinate environmental activities within the United Nations. 1972 The United States restricts the use of DDT because it is discovered that it thins the eggshells of predatory birds, lowering their reproductive rates. Aug 30, 1973 Kenya bans hunting elephants and trading in ivory.

 

 

Page 336 Sept 24, 1973 An accident at the Windscale power station in Cumberland (now Cumbria), northwest England, releases radiation into the surrounding area and raises concern about the safety of nuclear power; the station subsequently changes its name to Sellafield. 1973 An international conference on the environment held in Lebanon warns that the Mediterranean is being turned into a "dead sea" by the sewage and industrial waste being dumped into it. 1973 Fearing the extinction of kangaroos, Australia bans the sale and export of live animals and hides. 1973 Representatives from 80 nations sign the Convention on International Trade in Endangered Species (CITES) that prohibits trade in 375 endangered species of plants and animals and the products derived from them, such as ivory; the United States does not sign. 1973 The U.S. Fish and Wildlife Bureau issues the first Endangered and Threatened Species List. 1974 Mexican chemist Mario Molina and U.S. chemist F. Sherwood Rowland warn that the chlorofluorocarbons (CFCs) used in refrigerators and as aerosol propellants may be damaging the atmosphere's ozone layer that filters out much of the sun's ultraviolet radiation. 1974 The Brazilian government begins a $5-billion scheme to replace gasoline for cars with an alcohol and gasoline mixture; by 1980, 750,000 cars run on "gasohol." 1974 The Parque Nacional da Amazonia is established in Brazil; with an area of 10,000 sq km/4,000 sq mi, it preserves a large area of tropical rain forest. 1975 The Ecology Party is founded in Britain (known since 1985 as the green Party). 1975 The Worldwatch Institute is founded in the United States to research the interdependence of the world economy and the environment. Dec 17, 1976 More than 180,000 barrels of crude oil are spilled into the Atlantic off Nantucket Island when the Liberian tanker Argo Merchant breaks in two after running aground the previous day. 1976 The American Panel on Atmospheric Chemistry warns that the earth's ozone layer may be being destroyed by chlorofluorocarbons (CFCs) from spray cans and refrigeration systems. April 20, 1977 U.S. president Jimmy Carter proposes a radical energy conservation plan to reduce U.S. dependency on imported oil; it involves tax on imported oil, and incentives for purchasing fuel-efficient cars and the discovery of new resources. Congress greatly modifies the program. April 1977 A Norwegian oil well in the North Sea blows out of control for eight days spilling about 8.2 million gallons of crude oil into the sea and creating an oil slick 32 km/20 mi long. Aug 4, 1977 Carter signs legislation establishing the U.S. Department of Energy, aiming to develop a plan for energy conservation and development after the "oil shock." Energy becomes the twelfth cabinet department and the first instituted since 1966. 1977 California enforces strict antipollution legislation compelling car manufacturers to install catalytic converters that reduce exhaust emissions by 90%. 1977 The United States signs the Convention on International Trade in Endangered Species (CITES). Jan 23, 1978 Sweden bans aerosol sprays because of their damaging effect on the environment. It is the first country to do so. March 16, 1978 The U.S. oil tanker Amoco Cadiz runs aground off Brittany, France, spilling 1.62 million barrels of oil into the sea and contaminating 177 km/110 mi of coastline. Aug 1978 Toxic chemical (PCBs, dioxins, and pesticides) leak into the basements of houses in the Love Canal neighborhood of Niagara Falls, New York. The site, an abandoned canal, was used as a chemical waste dump by the Hooker Chemicals and Plastic Corporation 1947–53. Residents are evacuated but their long-term exposure results in high rates of chromosomal damage and birth defects. It is the worst environmental disaster involving chemical waste in U.S. history. Nov 5, 1978 A referendum in Austria stops the Zwentersdorf nuclear power station from being switched on. 1978 The United States bans the use of chlorofluorocarbons (CFCs) as spray propellants in order to reduce damage to the ozone layer. July 11, 1979 The International Whaling Commission bans the hunting of sperm whales. 1979 The first International Agreement dealing with transnational air pollution is signed by European members of the United Nations. 1980 A ten-year World Climate Research Program is launched to study and predict climate changes and human influence on climate change. 1981 The U.S. Committee on the Atmosphere and Biosphere reports evidence linking acid rain to sulfur emissions from power plants. 1981 The U.S. government-commissioned Global 2000 Report to the President is published; it

 

 

Page 337   predicts global environmental catastrophe if pollution, industrial expansion, and population are not brought under control. 1981 The world's largest solar power generating station, Solar One, is completed in California; it has a capacity of 10 megawatts. 1981 U.S. pilot Stephen Ptacek crosses the English Channel from Paris, France, to Manston, Kent, England (a journey of 368 km /180 mi) in 5.5 hrs in Solar Challenger, the first solar-powered aircraft; it uses 16,000 solar cells. 1981 U.S. scientists Adam Heller and Ferdinand Thiel develop a liquid junction cell that converts 11.5% of solar energy into electricity. April 30, 1982 Agreement is reached at the United Nations' Law of the Sea Conference on an international convention governing the use and exploitation of the sea and seabed; the United States and U.K. do not sign. 1982 The Convention on Conservation of Antarctic Marine Living Organisms comes into effect, establishing a protective oceanic zone around the continent. 1984 The Itaipu power plant on the Paraná River o the border between Brazil and Paraguay starts operating; the largest generating station in the world, it produces 13,200 megawatts of electricity. 1984 The pesticide DDT is banned in Britain. March 1985 The British Antarctic Survey detects a hole in the ozone layer which opens each year in the spring over Antarctica. 1985 Catalytic converters that require lead-free fuel are made mandatory in Switzerland for private cars. Switzerland is the first country to pass such a law. 1985 The International Whaling commission bans commercial whaling, in order to prevent the extinction of whales. April 26, 1986 A major accident at the Chernobyl nuclear power station near Kiev, USSR, is announced after abnormally high levels of radiation are reported in Sweden, Denmark, and Finland. Shortly after the accident more than 30 firefighters and plant workers die from radiation exposure and over the next few years an estimated 6,500 to 45,000 people die from cancer. High rates of genetic defects are also reported, and a vast area of land will be uninhabitable for thousands of years. Nov 1, 1986 Water supplies along the Rhine are contaminated and millions of fish are killed when a fire at the Sandoz pharmaceutical company near Basel, Switzerland, results in 1,000 metric tons of toxic chemicals being discharged into the river. 1986 Two wells 4 km/2.5 mi deep and connected at the bottom are used to generate 4 megawatts of geothermal power at the Los Alamos National Laboratory in New Mexico, U.S.A. Water introduced in one well emerges from the other at a temperature of 190°C/375°F. July 15–Oct 2, 1987 Tax incentives in Brazil encouraging conversion of jungle into ranch land result in an average of over 25,920 sq km/10,000 sq mi of Amazon rain forest being burned each day during a 79-day period. 1987 At a conference in Montreal, Canada, an international agreement, the Montreal Protocol, is reached to limit the use of ozone-depleting chlorofluorocarbons (CFCs) by 50% by the end of the century; the agreement is later condemned by environmentalists as "too little, too late." 1987 The world's most powerful wind-powered generator begins operating in the Orkney Islands, Scotland; it produces 3 megawatts of electricity. March 27, 1989 As the oil spill from the tanker Exxon Valdez, aground in Prince William Sound, Alaska, spreads over 100 sq mil/260 sq km, a state of emergency is declared in the area affected. Oct 16, 1989 The Convention on International Trade in Endangered Species (CITES) agrees to a total ban on trading in ivory. 1989 Brazil suspends tax incentives favouring burning in the Amazon jungle in response to worldwide environmentalist opinion; land clearance continues, however. 1990 The British company Imperial Chemical Industries (ICI) develops the first practical biodegradable plastic, Biopal. Nov 15, 1990 A Clean Air Act in the United States raises standards for emissions made by utilities and industrial concerns. Feb 22-Nov 3, 1991 Hundreds of Kuwaiti oil wells are set alight by Iraqi soldiers during the Gulf War; the last fire is extinguished on November 3. 1991 "Biosphere 2," an experiment that attempts to reproduce the world's biosphere in miniature within a sealed glasshouse, is launched in Arizona, United States. Eight people remain sealed inside for two years. 1991 The Antarctic Treaty is signed by the 39 nations. It imposes a 50-year ban on mineral exploitation in Antarctica. 1991 The European Space Agency's first remote-sensing satellite (ERS-1) is launched into polar orbit to monitor the earth's temperature from space. 1991 The world's first solar-power station connected to a national grid goes on line at Adrano, Sicily. Giant mirrors follow the sun throughout the day, focusing the rays onto a steam boiler that drives a conventional turbine. The plant generates up to one megawatt. Feb 11, 1992 U.S. president George Bush announces that the United States will phase out CFCs

 

 

Page 338   (chlorofluorocarbons) by 1995; British secretary of state for the environment Michael Heseltine makes a similar announcement for the U.K. three days later. June 3–14, 1992 The United Nations Conference on Environment and Development is held in Rio de Janeiro, Brazil. It is attended by delegates from 178 countries, most of whom sign binding conventions to combat global warming and to preserve biodiversity (the latter is not signed by the United States). 1993 An ice core drilled in Greenland, providing evidence of climate change over 250,000 years, suggests that sudden fluctuations have been common and that the recent stable climate is unusual. 1993 German shops are obliged to take back the packaging of many of the products they sell for recycling and it becomes illegal to throw away packaging from most large electronic items. 1993 The world's largest array of photovoltaic cells, at Davis, California, is plugged into the local electricity system, producing 479 kilowatts, enough for 125 homes. June 14, 1994 Representatives of 25 European countries and Canada sign a United Nations protocol in Oslo, Norway, to reduce sulfur emissions, a cause of acid rain. 1994 The International Whaling Commission establishes a whale sanctuary in Antarctica. 1994 The United Nations Basel Convention bans the transport of hazardous waste, from the 25 industrialized nations that make up the Organization for Economic Cooperation and Development (OECD), across international boundaries. April 1995 The European Space Agency's earth-sensing satellite ERS-2 is launched successfully. It will work in tandem with ERS-1, launched in 1991, to take measurements of global ozone. June 10–20, 1995 The Shell oil company begins towing its disused North Sea oil platform Brent Spa to a dumping site in the Atlantic; on 16 June, Greenpeace activists occupy the platform and on June 20, following a boycott of Shell gasoline stations in Germany and the Netherlands, the company cancels the dumping. Aug 1995 The world's first commercial wave-powered electricity generator begins operating on the River Clyde, Scotland. Known as "Osprey," it generates 2 megawatts of electricity. 1995 The Prince Gustav Ice Shelf and the northern Larsen Ice Shelf in Antarctica begin to disintegrate—a result of global warming. Feb 15, 1996 The Liberian-registered Sea Empress supertanker runs aground at the entrance to Milford Haven Harbour, south Wales, U.K. Salvage attempts fail and 128,000 tonnes of light crude oil are spilled into the sea. March 1996 The first solar power plant capable of storing heat, "Solar 2," becomes operational. Located in California's Mohave Desert, it consists of 2,000 motorized mirrors that focus the sun's rays on to a tower containing molten nitrate salt, which retains its heat for up to 12 hours. The molten salt is used to boil water to drive a 10-megawatt steam turbine. Oct 4, 1996 The World Conservation Union (IUCN) publishes the latest Red List of endangered species. Over 1,000 mammals are listed, far more than on previous lists. The

 

 

Page 339   organization believes it has underestimated the risks of habitats from pollution and that the number of endangered species is greater than previously thought. June 9–29, 1997 At the tenth, Convention on International Trade in Endangered Species (CITES) convention in Harare, Zimbabwe, the elephant is downlisted to CITES Appendix II (vulnerable) and the ban on ivory exportation in Botswana, Namibia, and Zimbabwe is lifted. June 26, 1997 The second earth Summit takes place in New York, New York. Delegates report on progress since the 1992 Rio summit and note that progress on the Rio biodiversity convention has been slower than on the convention on climate. The delegates fail to agree on a deal to address the world's escalating environmental crisis. Dramatic falls in aid to the so-called Third World countries, which the 1992 summit promised to increase, are at the heart of the breakdown. June–Nov 1997 Plantation owners in Indonesia, burning forests to clear land, cause the worst forest fires in Southeast Asian history. World record levels of atmosphere pollution reach life-threatening levels; up to 20 million people in Indonesia are affected with throat and respiratory inflammations and diarrhea. By September the fires have consumed between 300,000–600,000 hectares/740,300–1,480,000 acres. July 25, 1997 The U.S. Senate votes unanimously to pass a resolution that urges President Clinton not to agree to an international treaty that limits emissions of greenhouse gases by industrialized countries, warning that such a pact could pose a threat to the U.S. economy. Sept 7, 1997 Australian researcher William de la Mare, using old whaling records which record data on every whale caught since the 1930s, including the ship's latitude, announces the discovery that Antarctic sea-ice could have decreased by up to a quarter between the mid-1950s and the 1970s. The finding has major implications, both the global climate conditions as well as for whaling. Oct 22, 1997 U.S. president Bill Clinton announces a proposal to fight global warming by introducing $5 billion in tax breaks to companies who agree to reduce their greenhouse emissions. Nov 25, 1997 The Federal Energy Regulatory Commission orders the U.S. company Edwards Manufacturing to demolish the 160-year-old Edwards Dam on the Kennebec River, Maine, to give sturgeon and salmon a chance to reach their spawning grounds. It is the first time a working hydroelectric dam has been ordered to be removed. Jan 22, 1998 The Australian government bans Japanese fishing boats from its waters after Japan refuse to limit its fishing of bluefin tuna, a probable endangered species. Jan 1998 The German Red Cross estimates that 10,000 children a month are dying from malnutrition in North Korea and that two million died in 1997. The famine has been caused by poor agricultural practices that have brought environmental catastrophe. April 8, 1998 The International Union for the Conservation of Nature (IUCN), based in Switzerland, publishes a survey which reports that one in every eight known plant species in the world is in danger of becoming extinct. April 17, 1998 An iceberg 40 km/25 mi long and 4.8 km/3 mi wide breaks off from the Larson B ice shelf in Antarctica. Global warming is thought to be the cause.

 

 

Page 340         Biographies             Carson, Rachel Louise (1907–1964) U.S. biologist, writer, and conservationist. Her book Silent Spring (1962), attacking the indiscriminate use of pesticides, especially DDT, inspired the creation of the modern environmental movement. Other publications include The Sea Around Us (1951) and The Edge of the Sea (1955), an ecological exploration of the seashore. While writing about broad scientific issues of pollution and ecological exploitation, she also raised important issues about the reckless squandering of natural resources by an industrial world.             Elton, Charles Sutherland (1900–1991) British ecologist, a pioneer of the study of animal and plant forms in their natural environments, and of animal behavior as part of the complex pattern of life. He defined the concept of food chains and originated the concept of the "pyramid of numbers" as a method of representing the structure of an ecosystem in terms of feeding relationships. He was instrumental in establishing the Nature Conservancy Council in 1949, and was much concerned with the impact of introduced species on natural systems. His books include Animal Ecology and Evolution (1930) and The Pattern of Animal Communities (1966).             Kelly, Petra (1947–1992) German politician and activist who was a vigorous campaigner against nuclear power and other environmental issues and founded the German Green Party in 1972. Deeply concerned with radioactivity in the environment, she carried out pioneering ecological work in her position with the European Economic Community. She emerged as the German Green Party's most prominent early spokesperson, and the leader of its pragmatic ("realo") wing as the party split into its increasingly bitter divisions. She was Green member of the German parliament 1983–90, and was one of the first Green MPs in the world.             Lovelock, James (1919– ) British scientist who began the study of CFCs in the atmosphere in the 1960s (though he did not predict the damage they cause to the ozone layer) and who later elaborated the Gaia hypothesis.             MacArthur, Robert Helmer (1930–1972) Canadian-born U.S. ecologist who did much to change ecology from a descriptive discipline to a quantitative, predictive science. For example, his index of vegetational complexity (foliage height diversity) in 1961 made it possible to compare habitats and predict the diversity of their species in a definite equation. Investigating population biology, he examined how the diversity and relative abundance of species fluctuate over time and how species evolve. In particular, he managed to quantify some of the factors involved in the ecological relationships between species.             Mellanby, Kenneth (1908– ) British ecologist and entomologist who in the 1960s drew attention to the environmental effects of pollution, particularly by pesticides. He advocated the use of biological control methods, such as introducing animals that feed on pests.             Muir, John (1838–1914) Scottish-born U.S. conservationist. From 1880 he headed a campaign that led to the establishment of Yosemite National Park, United States, in 1890. He was named adviser to the National Forestry Commission in 1896 and continued to campaign for the preservation of wilderness areas for the rest of his life.             Porritt, Jonathon (1950– ) British environmental campaigner, director of Friends of the earth 1984–90. He has stood in both British and European elections as a Green (formerly Ecology) Party candidate.             Rotblat, Joseph (1908– ) Polish physicist. He began working on the atomic bomb as part of the Manhattan Project but withdrew in 1944 when he received intelligence that the Germans were not working on a bomb. He was instrumental in the formation of Pugwash, a group of scientists working towards nuclear disarmament. He was awarded the Nobel Peace Prize in 1995 (shared with Pugwash).             Schumacher, Fritz (Ernst Friedrich) (1911–1977) German economist. He believed that the increasing size of institutions, coupled with unchecked economic growth, creates a range of social and environmental problems. He argued his case in books like Small is Beautiful (1973), and established the Intermediate Technology Development Group.             Scott, Peter Markham (1909–1989) British naturalist, artist, and explorer, founder of the Wildfowl Trust at Slimbridge, Gloucestershire, England, in 1946, and a founder of the World Wildlife Fund (now World Wide Fund for Nature). The son of Antarctic explorer Robert Falcon Scott, he led ornithological expeditions and published many books on birds, including Key to the Wild Fowl of the World (1949) and Wild Geese and Eskimos (1951). He was the first president of the World Wildlife Fund 1961–67.             Glossary             A             abiotic factor nonorganic variable within the ecosystem, affecting the life of organisms. Examples include temperature, light, and soil structure. Abiotic factors can be harmful to the environment, as when sulfur dioxide emissions from power stations produce acid rain.             aerogenerator wind-powered electricity generator. These range from large models used in arrays on wind farms (wind turbines) to battery chargers used on yachts.             aerosol particles of liquid or solid suspended in a gas. Fog is a common natural example. Aerosol cans contain a substance such as scent or cleaner packed under pressure with a device for releasing it as a fine spray. Most aerosols used chlorofluorocarbons (CFCs) as propellants until these were found to cause destruction of the ozone layer in the stratosphere.             agrochemical artificially produced chemical used in modern, intensive agricultural systems. Agrochemicals include nitrate

 

 

Page 341         and phosphate fertilizers, pesticides, some animal-feed additives, and pharmaceuticals. Many are responsible for pollution and almost all are avoided by organic farmers.             alkylphenolethoxylate (APEO) chemical used mainly in detergents, but also in herbicides, cleaners, packaging, and paints. Nonylphenol, a breakdown product of APEOs is a significant river pollutant; 60% of APEOs end up in the water. Nonylphenol, and other APEO breakdown products, have a feminizing effect on fish: male fish start to produce yolk protein and the growth of testes is slowed.             animal rights extension of the concept of human rights to animals on the grounds that animals may not be able to reason but can suffer and are easily exploited by humans. The animal-rights movement is a general description for a wide range of organizations, both national and local, that take a more radical approach than the traditional welfare societies. More radical still is the concept of animal liberation, that animals should not be used or exploited in any way at all.             B             balance of nature in ecology, the idea that there is an inherent equilibrium in most ecosystems, with plants and animals interacting so as to produce a stable and continuing system of life on earth. The activities of human beings can, and frequently do, disrupt the balance of nature.             beach nourishment the adding of extra sand to the foreshore of a beach to act as a buffer against the sea and reduce erosion.             biodegradable capable of being broken down by living organisms, principally bacteria and fungi. In biodegradable substances, such as food and sewage, the natural processes of decay lead to compaction and liquefaction, and to the release of nutrients that are then recycled by the ecosystem.             biofeedback modification or control of a biological system by its results or effects. For example, a change in the position or trophic level of one species affects all levels above it.             biofouling buildup of barnacles, mussels, seaweed, and other organisms on underwater surfaces, such as ships' hulls. Marine industries worldwide spend at least £1.4 billion controlling biofouling by scraping affected surfaces and painting with antifouling paint.             biomass the total mass of living organisms present in a given area. It may be specified for a particular species (such as earthworm biomass) or for a general category (such as herbivore biomass). Estimates also exist for the entire global plant biomass. Measurements of biomass can be used to study interactions between organisms, the stability of those interactions, and variations in population numbers. Where dry biomass is measured, the material is dried to remove all water before weighing.             bioreactor sealed vessel in which microbial reactions can take place. The simplest bioreactors involve the slow decay of vegetable or animal waste, with the emission of methane that can be used as fuel. Laboratory bioreactors control pH, acidity, and oxygen content and are used in advanced biotechnological operations, such as the production of antibiotics by genetically-engineered bacteria.             BioSphere 2 (BS2) ecological test project, a "planet in a bottle," in Arizona, United States. Under a sealed glass and metal dome, different habitats are recreated, with representatives of nearly 4,000 species, to test the effects that various environmental factors have on ecosystems. Simulated ecosystems, or "mesocosms," include savanna, desert, rain forest, marsh and Caribbean reef. The response of such systems to elevated atmospheric concentrations of carbon dioxide gas (CO2) are among the priorities of Biosphere 2 researchers.             biotic factor organic variable affecting an ecosystem—for example, the changing population of elephants and its effect on the African savanna.             Blueprint for Survival environmental manifesto published in 1972 in the U.K. by the editors of the Ecologist magazine. The statement of support it attracted from a wide range of scientists helped draw attention to the magnitude of environmental problems.             brownfield site site that has previously been developed; for example, a derelict area in the inner city. Before brownfield sites can be redeveloped, site clearance is often necessary, adding to the development cost. The surrounding area may be of poor environmental quality but there is often a surprising level of biodiversity on brownfield sites—for example at one site in London, England, 300 species of flowering plant were found—and there is often a high proportion of invertebrate species.             Brundtland Report findings of the World Commission on Environment and Development, published in 1987 as Our Common Future. It stressed the necessity of environmental protection and popularized the phrase "sustainable development." The commission was chaired by the Norwegian prime minister Gro Harlem Brundtland.             bycatch, or bykill, in commercial fishing, that part of the catch that is unwanted. Bycatch constitutes approximately 25% of global catch, and consists of a variety of marine life, including fish too small to sell or otherwise without commercial value, seals, dolphins, sharks, turtles, and even seabirds.             C             carbon sequestration disposal of carbon dioxide waste in solid or liquid form. From 1993 energy conglomerates such as Shell, Exxon, and British Coal have been researching ways to reduce their carbon dioxide emissions by developing efficient technologies to trap the gas and store it securely—for example, by burying it or dumping it in the oceans.             carrying capacity in ecology, the maximum number of animals of a given species that a particular area can support. When the carrying capacity is exceeded, there is insufficient food (or other resources) for the members of the population. The population may then be reduced by emigration, reproductive failure, or death through starvation.             chemical oxygen demand (COD) measure of water and effluent quality, expressed as the amount of oxygen (in parts per million) required to oxidize the reducing substances present.             Chipko Movement Indian grass-roots villagers' movement campaigning against the destruction of their forests. Its broad principles are nonviolent direct action, a commitment to the links between village life and an unplundered environment, and a respect for all living things.

 

 

Page 342         CITES (abbreviation for Convention on International Trade in Endangered Species) international agreement under the auspices of the International Union for the Conservation of Nature (IUCN) with the aim of regulating trade in endangered species of animals and plants. The agreement came into force in 1975 and by 1997 had been signed by 138 states. It prohibits any trade in a category of 8,000 highly endangered species and controls trade in a further 30,000 species. Animals and plants listed in Appendix 1 of CITES are classified endangered; those listed in Appendix 2 are classified vulnerable.             climax community assemblage of plants and animals that is relatively stable in its environment. It is brought about by ecological succession, and represents the point at which succession ceases to occur.             climax vegetation the plants in a climax community.             Club of Rome informal international organization that aims to promote greater understanding of the interdependence of global economic, political, natural, and social systems. Members include industrialists, economists, and research scientists. Membership is limited to 100 people. It was established in 1968.             colonization spread of species into a new habitat, such as a freshly cleared field, a new highway shoulder, or a recently flooded valley. The first species to move in are called pioneers, and may establish conditions that allow other animals and plants to move in (for example, by improving the condition of the soil or by providing shade). Over time a range of species arrives and the habitat matures; early colonizers will probably be replaced, so that the variety of animal and plant life present changes. This is known as succession.             community assemblage of plants, animals, and other organisms living within a circumscribed area. Communities are usually named by reference to a dominant feature such as characteristic plant species (for example, a beech-wood community), or a prominent physical feature (for example, a freshwater-pond community).             competition interaction between two or more organisms, or groups of organisms (for example, species), that use a common resource which is in short supply. Competition invariably results in a reduction in the numbers of one or both competitors, and in evolution contributes both to the decline of certain species and to the evolution of adaptations.             compost organic material decomposed by bacteria under controlled conditions to make a nutrient-rich natural fertilizer for use in gardening or farming. A well-made compost heap reaches a high temperature during the composting process, killing most weed seeds that might be present.             container habitat small self-contained ecosystem, such as a water pool accumulating in a hole in a tree. Some ecologists believe that much can be learned about larger ecosystems through studying the dynamics of container habitats, which can contain numerous leaf-litter feeders and their predators.             contaminated land land that is considered to pose a health risk to humans because of pollution; usually land that has been the site of industrial activity.             corridor, wildlife route linking areas of similar habitat, or between sanctuaries. For example there is a corridor linking the Masai Mara reserve in Kenya and the Serengeti in Tanzania. On a smaller scale, disused railroads provide corridors into urban areas for foxes.             D             daminozide (trade name Alar) chemical formerly used by fruit growers to make apples redder and crisper. In 1989 a report published in the United States found the consumption of daminozide to be linked with cancer, and the U.S. Environmental Protection Agency (EPA) called for an end to its use. The makers have now withdrawn it worldwide.             debt-for-nature swap agreement under which a proportion of a country's debts are written off in exchange for a commitment by the debtor country to undertake projects for environmental protection. Debt-for-nature swaps were set up by environment groups in the 1980s in an attempt to reduce the debt problem of poor countries, while simultaneously promoting conservation.             dioxin any of a family of over 200 organic chemicals, all of which are heterocyclic hydrocarbons. The term is commonly applied, however, to only one member of the family, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), a highly toxic chemical that occurs, for example, as an impurity in the defoliant Agent Orange, used in the Vietnam War (1954–75), and sometimes in the weedkiller 2,4,5-T. It has been associated with a disfiguring skin complaint (chloracne), birth defects, miscarriages, and cancer.             drift net long straight net suspended from the water surface and used by commercial fishermen. Drift nets are controversial as they are indiscriminate in what they catch. Dolphins, sharks, turtles, and other marine animals can drown as a consequence of becoming entangled.             E             Earth Summit (officially United Nations Conference on Environment and Development) international name given to meetings aiming at drawing measures toward environmental protection of the world. The first summit took place in Rio de Janeiro, Brazil, in June 1992. Treaties were made to combat global warming and protect biodiversity (the latter was not signed by the United States). The second earth Summit was held in New York in June 1997 to review progress on the environment. The meeting agreed to work towards a global forest convention in the year 2000 with the aim of halting the destruction of tropical and old-growth forests.             ecotourism growing trend in tourism to visit sites that are of ecological interest, for example the Galápagos Islands. Ecotourism generates employment and income for local people, providing an incentive for conservation, but if carried out unscrupulously it can lead to damage of environmentally sensitive sites.             effluent liquid discharge of waste from an industrial process, usually into rivers or the sea. Effluent is often toxic but is difficult to control and hard to trace.             electromagnetic pollution electric and magnetic fields set up by high tension power cables, local electric sub-stations, and domestic items such as electric blankets. There have been claims that these electromagnetic fields are linked to

 

 

Page 343         increased levels of cancer, especially leukemia, and to headaches, nausea, dizziness, and depression.             endangered species plant or animal species whose numbers are so few that it is at risk of becoming extinct. Officially designated endangered species are listed by the International Union for the Conservation of Nature.             energy conservation methods of reducing energy use through insulation, increasing energy efficiency, and changes in patterns of use. Profligate energy use by industrialized countries contributes greatly to air pollution and the greenhouse effect when it draws on nonrenewable energy sources.             environmental audit another name for green audit.             eutrophication excessive enrichment of rivers, lakes, and shallow sea areas, primarily by nitrate fertilizers washed from the soil by rain, by phosphates from fertilizers, and from nutrients in municipal sewage, and by sewage itself. These encourage the growth of algae and bacteria which use up the oxygen in the water, thereby making it uninhabitable for fishes and other animal life.             evolutionary toxicology study of the effects of pollution on evolution. A polluted habitat may cause organisms to select for certain traits, as in industrial melanism for example, where some insects, such as the peppered moth, are darker in polluted areas, and therefore better camouflaged against predation.             extinction complete disappearance of a species or higher taxon. Extinctions occur when an animal becomes unfit for survival in its natural habitat usually to be replaced by another, better-suited animal. An organism becomes illsuited for survival because its environment is changed or because its relationship to other organisms is altered. For example, a predator's fitness for survival depends upon the availability of its prey.             F             field studies study of ecology, geography, geology, history, archeology, and allied subjects, in the natural environment as opposed to the laboratory.             firewood principal fuel for some 2 billion people, mainly in the Third World. In principle a renewable energy source, firewood is being cut far faster than the trees can regenerate in many areas of Africa and Asia, leading to deforestation.             flue-gas desulfurization process of removing harmful sulfur pollution from gases emerging from a boiler. Sulfur compounds such as sulfur dioxide are commonly produced by burning fossil fuels, especially coal in power stations, and are the main cause of acid rain.             food chain sequence showing the feeding relationships between organisms in a particular ecosystem. Each organism depends on the next lowest member of the chain for its food. A pyramid of numbers can be used to show the reduction in food energy at each step up the food chain.             forest area where trees have grown naturally for centuries, instead of being logged at maturity (about 150–200 years). A natural, or old-growth, forest has a multistory canopy and includes young and very old trees (this gives the canopy its range of heights). There are also fallen trees contributing to the very complex ecosystem, which may support more than 150 species of mammals and many thousands of species of insects. Globally forest is estimated to have covered around 68 million sq km/26 million sq mi during prehistoric times. By the late 1990s this is believed to have been reduced by half.             forestation or afforestation planting of trees in areas that have not previously held forests. (Reforestation is the planting of trees in deforested areas.) Trees may be planted (1) to provide timber and wood pulp; (2) to provide firewood in countries where this is an energy source; (3) to bind soil together and prevent soil erosion; and (4) to act as windbreaks.             fur hair of certain animals. Fur is an excellent insulating material and so has been used as clothing. This is, however, vociferously criticized by many groups, as the methods of breeding or trapping animals are often cruel. Mink, chinchilla, and sable are among the most valuable, the wild furs being finer than the farmed.             G             green accounting inclusion of economic losses caused by environmental degradation in traditional profit and loss accounting systems.             green audit inspection of a company to assess the total environmental impact of its activities or of a particular product or process.             green consumerism marketing term used especially during the 1980s when consumers became increasingly concerned about the environment. Labels such as ''eco-friendly" became a common marketing tool as companies attempted to show that their goods had no negative effect on the environment.             greenhouse effect phenomenon of the earth's atmosphere by which solar radiation, trapped by the earth and re-emitted from the surface as infrared radiation, is prevented from escaping by various gases in the air.             green movement collective term for the individuals and organizations involved in efforts to protect the environment. The movement encompasses political parties such as the Green Party and organizations like Friends of the Earth and Greenpeace.             Greenpeace international environmental pressure group, founded in 1971, with a policy of nonviolent direct action backed by scientific research. In 1997 Greenpeace had a membership in 43 "chapters" worldwide.             green tax proposed tax to be levied against companies and individuals causing pollution. For example, a company emitting polluting gases would be obliged to pay a correspondingly significant tax; a company that cleans its emissions, reduces its effluent and uses energy-efficient distribution systems, would be taxed much less.             H             habitat localized environment in which an organism lives, and which provides for all (or almost all) of its needs. The diversity of habitats found within the earth's ecosystem is enormous, and they are changing all the time. Many can be considered inorganic or physical; for example, the Arctic ice

 

 

Page 344         cap, a cave, or a cliff face. Others are more complex; for instance, a woodland or a forest floor. Some habitats are so precise that they are called microhabitats, such as the area under a stone where a particular type of insect lives. Most habitats provide a home for many species.             Hidrovia Project controversial plan to turn the 3,400 km/2,100 mi Paraguay-Paraná river system into a shipping lane. To create a navigable canal up to 50 km/32 mi wide and 4 km/2.5 mi deep the river system will need to be dredged, dammed, and diverted at various stages. In June 1995, the United Nations Environmental Program called on the governments of the La Plata Basin to halt work on the project until studies on environmental impact had been completed.             hum, environmental disturbing sound of frequency about 40 Hz, heard by individuals sensitive to this range, but inaudible to the rest of the population. It may be caused by industrial noise pollution or have a more exotic origin, such as the jet stream, a fast-flowing high-altitude (about 15,000 m/50,000 ft) mass of air.             I             indicator species plant or animal whose presence or absence in an area indicates certain environmental conditions, such as soil type, high levels of pollution, or, in rivers, low levels of dissolved oxygen. Many plants show a preference for either alkaline or acid soil conditions, while certain trees require aluminum, and are found only in soils where it is present. Some lichens are sensitive to sulfur dioxide in the air, and absence of these species indicates atmospheric pollution.             integrated pest management (IPM) use of a coordinated array of methods to control pests, including biological control, chemical pesticides, crop rotation, and avoiding monoculture. By cutting back on the level of chemicals used the system can be both economical and beneficial to health and the environment.             International Union for the Conservation of Nature (IUCN) organization established by the United Nations to promote the conservation of wildlife and habitats as part of the national policies of member states.             irrigation artificial water supply for dry agricultural areas by means of dams and channels. Drawbacks are that it tends to concentrate salts at the surface, ultimately causing soil infertility, and that rich river silt is retained at dams, to the impoverishment of the land and fisheries below them.             IUCN abbreviation for International Union for the Conservation of Nature.             ivory hard white substance of which the teeth and tusks of certain mammals are made. Among the most valuable are elephants' tusks, which are of unusual hardness and density. Ivory is used in carving and other decorative work, and is so valuable that poachers continue to illegally destroy the remaining wild elephant herds in Africa to obtain it.             L             landfill site large holes in the ground used for dumping household and commercial waste. Landfill disposal has been the preferred option in the United States and the U.K. for many years, with up to 85% of household waste being dumped in this fashion. However, the sites can be dangerous, releasing toxins and other leachates (see leaching) into the soil and the policy is itself wasteful both in terms of the materials dumped and land usage.             leaching process by which substances are washed through or out of the soil. Fertilizers leached out of the soil drain into rivers, lakes, and ponds and cause water pollution. In tropical areas, leaching of the soil after the destruction of forests removes scarce nutrients and can lead to a dramatic loss of soil fertility. The leaching of soluble minerals in soils can lead to the formation of distinct soil horizons as different minerals are deposited at successively lower levels.             life-cycle analysis assessment of the environmental impact of a product, taking into account all aspects of production (including resources used), packaging, distribution and ultimate end.             M             methyl bromide pesticide gas used to fumigate soil. It is a major ozone depleter. The European Union proposed a total ban on usage by 2001 at a meeting in July 1998, and the United States intends to ban use by 2001.             Montréal Protocol international agreement, signed in 1987, to stop the production of chemicals that are ozone depleters by the year 2000.             N             national park land set aside and conserved for public enjoyment. The first was Yellowstone National Park, United States established in 1872. National parks include not only the most scenic places, but also places distinguished for their historic, prehistoric, or scientific interest, or for their superior recreational assets. They range from areas the size of small countries to pockets of just a few hectares.             nature reserve area set aside to protect a habitat and the wildlife that lives within it, with only restricted admission for the public. A nature reserve often provides a sanctuary for rare species.             niche "place" occupied by a species in its habitat, including all chemical, physical, and biological components, such as what it eats, the time of day at which the species feeds, temperature, moisture, the parts of the habitat that it uses (for example, trees or open grassland), the way it reproduces, and how it behaves.             nitrate pollution contamination of water by nitrates. Increased use of artificial fertilizers and land cultivation means that higher levels of nitrates are being washed from the soil into rivers, lakes, and aquifers. There they cause an excessive enrichment of the water (eutrophication), leading to a rapid growth of algae, which in turn darkens the water and reduces its oxygen content. The water is expensive to purify and many plants and animals die. High levels are now found in drinking water in arable areas. These may be harmful to newborn babies, and it is possible that they contribute to stomach cancer, although the evidence for this is unproven.             noise unwanted sound. Permanent, incurable loss of hearing can be caused by prolonged exposure to high noise levels (above 85 decibels). Over 55 decibels on a daily outdoor basis is regarded as an unacceptable level.             nuclear safety the use of nuclear energy has given rise to concern over safety. Anxiety has been heightened by accidents such as those at Windscale (renamed Sellafield), U.K., in

 

 

Page 345         1973; Three Mile Island, United States, in 1979; and Chernobyl, Ukraine, in 1986. There has also been mounting concern about the production and disposal of nuclear waste, the radioactive and toxic by-products of the nuclear energy industry. Burial on land or at sea raises problems of safety, environmental pollution, and security. Nuclear waste has an active half-life of thousands of years and no guarantees exist for the safety of the various methods of disposal.             Nuclear safety is still a controversial subject since governments will not recognize the hazards of radiation and radiation sickness. In 1990 a scientific study revealed an increased risk of leukaemia in children whose fathers had worked at Sellafield between 1950 and 1985. Sellafield is the world's greatest discharger of radioactive waste, followed by Hanford, Washington, United States.             O             organic farming farming without the use of synthetic fertilizers (such as nitrates and phosphates) or pesticides (herbicides, insecticides, and fungicides) or other agrochemicals (such as hormones, growth stimulants, or fruit regulators). Food produced by genetic engineering cannot be described as organic.             organophosphosphate insecticide insecticidal compounds that cause the irreversible inhibition of the cholinesterase enzymes that break down acetylcholine. As this mechanism of action is very toxic to humans, they should be used with great care. Malathion and permethrin may be used to control lice in humans and have many applications in veterinary medicine and in agriculture.             overfishing fishing at rates that exceed the sustained-yield cropping of fish species, resulting in a net population decline. For example, in the North Atlantic, herring has been fished to the verge of extinction and the cod and haddock populations are severely depleted. In the developing world, use of huge factory ships, often by fisheries from industrialized countries, has depleted stocks for local people who cannot obtain protein in any other way.             oxyfuel fuel enriched with oxygen to decrease carbon monoxide (CO) emissions. Oxygen is added in the form of chemicals such as methyl tertiary butyl ether (MTBE) and ethanol. The use of oxyfuels in winter is compulsory in 35 U.S. cities. There are fears, however, that MTBE can cause health problems, including nausea, headaches, and skin rashes.             ozone layer thin layer of the gas ozone in the upper atmosphere that shields the earth from harmful ultraviolet rays.             P             packaging material, usually of metal, paper, plastic, or glass, used to protect products, make them easier to display, and as a form of advertising. Environmentalists have criticized packaging materials as being wasteful of energy and resources. Recycling bins are being placed in residential areas to facilitate the collection of surplus packaging.             pioneer species those species that are the first to colonize and thrive in new areas. Recently cleared woodland and new roadsides are areas where pioneer species will quickly appear. As the habitat matures other species take over, a process known as succession.             pitfall trap simple trap for trapping small invertebrates. In its simplest form a beaker or jam jar is buried in the ground so that the rim of the jar is flush with the soil. Beetles, millipedes, spiders and other arthropods tumble into the jar and are unable to escape.             PM10 (abbreviation for particulate matter less than 10 micrometers across) clusters of small particles, such as carbon particles, in the air that come mostly from vehicle exhausts. There is a link between increase in PM10 levels and a rise in death rate, increased hospital admissions, and asthma incidence. The elderly and those with chronic heart or lung disease are most at risk.             polluter-pays principle the idea that whoever causes pollution is responsible for the cost of repairing any damage. The principle is accepted in law but has in practice often been ignored; for example, farmers causing the death of fish through slurry pollution have not been fined the full costs of restocking the river.             pooter small device for collecting invertebrates, consisting of a jar to which two tubes are attached. A sharp suck on one of the tubes, while the other is held just above an insect, will propel the animal into the jar. A filter wrapped around the mouth tube, prevents debris or organisms from being swallowed.             population group of animals of one species, living in a certain area and able to interbreed; the members of a given species in a community of living things.             prior informed consent informal policy whereby companies who sell pesticides to developing countries agree to suspend exporting the product if there is an objection from the government of the receiving country and to inform the government of the nature of the pesticide. The situation arises frequently because some pesticides banned in the developed world may be bought by agricultural operations or companies in the Third World, perhaps unaware of any health implications. The policy was adopted by the Food and Agriculture Organization in 1989, and has since been made binding by the European Community on its member states.             pyramid of numbers diagram that shows quantities of plants and animals at different levels of a food chain. This may be measured in terms of numbers (how many animals) or biomass (total mass of living matter), though in terms of showing transfer of food, biomass is a more useful measure. There is always far less biomass at the top of the chain than at the bottom, because only about 10% of the food an animal eats is turned into flesh—the rest is lost through metabolism and excretion. The amount of food flowing through the chain therefore drops with each step up the chain, hence the characteristic "pyramid" shape.             Q             quadrat in environmental studies, a square structure used to study the distribution of plants in a particular place, for instance a field, rocky shore, or mountainside. The size varies, but is usually 0.5 or 1 m/1.6 or 3.3 ft square, small enough to be carried easily. The quadrat is placed on the ground and the abundance of species estimated. By making such measurements a reliable understanding of species distribution is obtained.             R             radiation monitoring system network of monitors to detect any rise in background gamma radiation and to warn of a major nuclear accident within minutes of its occurrence. The accident at Chernobyl in Ukraine in 1986 prompted several

 

 

Page 346         western European countries to begin installation of such systems locally, and in 1994 work began on a pilot system to provide a gamma curtain, a dense net of radiation monitors, throughout eastern and western Europe.             Red Data List report published by the World Conservation Union (IUCN) and regularly updated that lists animal species by their conservation status. Categories of risk include extinct in the wild, critically endangered, endangered, vulnerable, and lower risk (divided into three subcategories). The list was updated in 1996.             reuse multiple use of a product (often a form of packaging), by returning it to the manufacturer or processor each time. Many such returnable items are sold with a deposit which is reimbursed if the item is returned. Reuse is usually more energy- and resource-efficient than recycling unless there are large transport or cleaning costs.             S             seabird wreck the washing ashore of significantly larger numbers of seabirds than would be expected for the time of year. In February 1994 around 75,000 birds were washed up along the east coast of Britain. They were mostly fish-eating species, such as guillemots, shags, and razorbills, and appeared to have died of starvation. The cause of seabird wrecks is unknown though overfishing could be a contributory factor.             sere plant succession developing in a particular habitat. A lithosere is a succession starting on the surface of bare rock. A hydrosere is a succession in shallow freshwater, beginning with planktonic vegetation and the growth of pondweeds and other aquatic plants, and ending with the development of swamp. A plagiosere is the sequence of communities that follows the clearing of the existing vegetation.             sewage disposal disposal of human excreta and other waterborne waste products from houses, streets, and factories. Conveyed through sewers to sewage plants, sewage has to undergo a series of treatments to be acceptable for discharge into rivers or the sea, according to various local laws and ordinances. Raw sewage, or sewage that has not been treated adequately, is one serious source of water pollution and a cause of eutrophication.             Single European Act 1986 update of the Treaty of Rome (signed in 1957) that provides a legal basis for action by the European Union in matters relating to the environment. The act requires that environmental protection shall be a part of all other Union policies. Also, it allows for agreement by a qualified majority on some legislation, whereas before such decisions had to be unanimous.             slash and burn simple agricultural method whereby natural vegetation is cut and burned, and the clearing then farmed for a few years until the soil loses its fertility, whereupon farmers move on and leave the area to regrow. Although this is possible with a small, widely dispersed population, it becomes unsustainable with more people and is now a cause of deforestation.             slurry form of manure composed mainly of liquids. Slurry is collected and stored on many farms, especially when large numbers of animals are kept in factory units. When slurry tanks are accidentally or deliberately breached, large amounts can spill into rivers, killing fish and causing eutrophication.             soil depletion decrease in soil quality over time. Causes include loss of nutrients caused by overfarming, erosion by wind, and chemical imbalances caused by acid rain.             soil erosion the wearing away and redistribution of the earth's soil layer. It is caused by the action of water, wind, and ice, and also by improper methods of agriculture. If unchecked, soil erosion results in the formation of deserts (desertification). It has been estimated that 20% of the world's cultivated topsoil was lost between 1950 and 1990.             standing crop the total number of individuals of a given species alive in a particular area at any moment. It is sometimes measured as the weight (or biomass) of a given species in a sample section.             succession series of changes that occur in the structure and composition of the vegetation in a given area from the time it is first colonized by plants (primary succession), or after it has been disturbed by fire, flood, or clearing (secondary succession).             sustainable capable of being continued indefinitely. For example, the sustainable yield of a forest is equivalent to the amount that grows back. Environmentalists have made the term a catchword in advocating the sustainable use of resources.             sustained-yield cropping the removal of surplus individuals from a population of organisms so that the population maintains a constant size. This usually requires selective removal of animals of all ages and both sexes to ensure a balanced population structure. Taking too many individuals can result in a population decline, as in overfishing.             T             TBT abbreviation for tributyl tin, a chemical used in antifouling paints that has become an environmental pollutant.             TRAFFIC the arm of the World Wide Fund for Nature that monitors trade in endangered species.             transboundary pollution pollution generated in one country that affects another country, for example as occurs with acid rain. Natural disasters may also cause pollution; volcanic eruptions, for example, cause ash to be ejected into the atmosphere and deposited on land surfaces.             tributyl tin (TBT) chemical used in antifouling paints on ships' hulls and other submarine structures to deter the growth of barnacles. The tin dissolves in sea water and enters the food chain. It can cause reproductive abnormalities—exposed female whelks develop penises; the use of TBT has therefore been banned in many countries.             trophic level the position occupied by a species (or group of species) in a food chain. The main levels are primary producers (photosynthetic plants), primary consumers (herbivores), secondary consumers (carnivores), and decomposers (bacteria and fungi).             Tullgren funnel device used to extract mites, springtails, fly larvae, and other small invertebrates from a sample of soil.             U             urban ecology study of the ecosystems, animal and plant communities, soils, and microclimates found within an urban landscape.

 

 

Page 347         W             Waldsterben (German "forest death") tree decline related to air pollution, common throughout the industrialized world. It appears to be caused by a mixture of pollutants; the precise chemical mix varies between locations, but it includes acid rain, ozone, sulfur dioxide, and nitrogen oxides.             Washington Convention alternative name for CITES, the international agreement that regulates trade in endangered species.             weedkiller, or herbicide, chemical that kills some or all plants. Selective herbicides are effective with cereal crops because they kill all broad-leaved plants without affecting grasslike leaves. Those that kill all plants include sodium chlorate and paraquat. The widespread use of weedkillers in agriculture has led to an increase in crop yield but also to pollution of soil and water supplies and killing of birds and small animals, as well as creating a health hazard for humans.             wilderness area of uninhabited land that has never been disturbed by humans, usually located some distance from towns and cities. According to estimates by the U.S. group Conservation International, 52% (90 million sq km/35 million sq mi) of the earth's total land area was still undisturbed in 1994.             wildlife corridor passage between habitats. See corridor, wildlife.             World Wide Fund for Nature (WWF) (formerly the World Wildlife Fund) international organization established in 1961 to raise funds for conservation by public appeal. Projects include conservation of particular species, for example, the tiger and giant panda, and special areas, such as the Simen Mountains, Ethiopia.             World Wildlife Fund former and U.S. name of the World Wide Fund for Nature.             WWF abbreviation for World Wide Fund for Nature.             Further Reading           Adams, Douglas, and Carwardine, Mark Last Chance to See (1990)           Begon, M.; Harper J. L.; and Townsend, C. R. Ecology (1990)           Blackmore, Roger Global Environmental Issues (2nd edition 1996)           Bode, Carl (ed.) The Portable Thoreau (1980)           Brown, M. The Toxic Cloud (1987)           Budiansky, Stephen Nature's Keepers (1995)           Carson, Rachel Silent Spring (1962)           Caufield, Catherine In the Rainforest (1984)           Colinvaux, Paul Why Big Fierce Animals Are Rare (1980)           Commoner, B. The Closing Circle: Nature, Man, and Technology (1971)           Crosby, Alfred W. Ecological Imperialism (1993)           Dickinson, Gordon, and Murphy, Kevin J. Ecosystems (1998)           Durning, Alan Thein How Much is Enough? (1992)           Few, Roger Atlas of Wild Places (1997)           Foley, Gerald The Energy Question (1992)           Fowler, Cary, and Mooney, Pat The Threatened Gene: Food, Politics and the Loss of Genetic Diversity (1990)           Galdikas, Biruté M. F. Reflections of Eden (1995)           George, Susan How the Other Half Dies-The Real Reasons for World Hunger (1976)           Goodall, D. W. (ed.) Ecosystems of the World (1977)           Groombridge, Brian (ed.) Global Biodiversity: The Status of the earth's Living Resources (1992)           Kural, Orhan (ed.) Coal: Resources, Properties, Utilization, Pollution (1995)           Lear, Linda Rachel Carson: Witness for Nature (1997)           Lovelock, James Gaia: A New Look at Life on earth (1979)           Lovins, Amory Soft Energy Paths: Towards a Durable Peace (1977)           Luoma, J. R. Troubled Skies, Troubled Waters: The Story of Acid Rain (1984)           MacArthur, Robert, and Wilson, Edward O. The Theory of Island Biogeography (1967)           McNeely, Jeffrey A.; Miller, Kenton R.; et al Conserving the World's Bological Diversity (1990)           Mann, Charles C., and Plummer, Mark L. Noah's Choice (1995)           Meadows, Donella L.; Meadows, Dennis L.; Randers, Jorgen; and Behrens III, William W. The Limits to Growth (1975)           Myers, Norman The Sinking Ark (1979)           Norse, Elliott A. (ed.) Global Marine Biological Diversity (1993)           Noss, Reed F., and Cooperrider, Allen Y. Saving Nature's Legacy (1994)           Pahl-Wostl, Claudia The Dynamic nature of Ecosystems: Chaos and Order Entwined (1995)           Pepper, David Modern Environmentalism: An Introduction (1996)           Ponting, Clive The Green History of the World (1991)           Priest, Joseph Energy (1984)           Pringle, Peter, and Spiegelman, James The Nuclear Barons (1981)           Reaka-Kudla, Marjorie (ed.) Biodiversity II (1997)           Schaller, George D. The Last Panda (1992)           Schumacher, E. F. Small Is Beautiful (1973)           Shiva, Vandana Biodiversity: Social and Ecological Consequences (1992)           Tudge, Colin Last Animals at the Zoo (1991)

 

 

Page 348       Whitley, Edward Gerald Durrell's Army (1992)           Wilson, Edward O. The Diversity of Life (1992)           World Commission on Environment and Development, chaired by Gro Harlen Brundtland Our Common Future (1987)