Give annotation of the text

Understanding the Environment

The science of ecology is the study of the interactions that determine the abundance and distribution of organisms. In other words, ecology attempts to explain why individuals live where they do and why their populations are the sizes they are.

No population, human or otherwise, can grow indefinitely; eventually, some biotic or abiotic variable will begin to limit population growth. This basic ecological principle was first established in 1840 by German chemist Justus von Liebig and has been called the Law of the Minimum. From a human standpoint, this means that all of the world's physical resources are in finite supply.

Ecologists also have discovered that all species in an ecosystem interact with one another, either directly or indirectly. A classic ecological experiment illustrates this point very well. American ecologist Robert Paine, working in the rocky intertidal region of the Pacific coast, found stable invertebrate communities dominated by 15 species of animals, including starfish, mussels, limpets, barnacles, and chitons. When Paine removed all of the starfish from the area, the community collapsed, and eventually only 8 invertebrate species were common. Although it was not obvious in the undisturbed regions, the starfish were preying heavily on one of the mussel species and keeping its numbers down. With the starfish removed, the population of this mussel increased, and the mussel was able to outcompete many other species of invertebrates. Thus, the loss of one species, the starfish, indirectly led to the loss of an additional six species and a transformation of the community.

Typically, because the species that coexist in natural communities have evolved together for many generations, they have established a balance, and their populations remain relatively stable. Occasionally, when humans introduce a non-native species to an ecosystem, dramatic disruptions occur, often because the natural predators of the introduced species are not present. For example, early sailors routinely introduced goats to isolated oceanic islands, intending for the goats to roam freely and serve as a source of meat when the sailors later came ashore. Free from all natural predators, the goats thrived and, in the process, overgrazed many of the islands. With a change in plant composition, many of the native animal species were driven to extinction. A simple action, the introduction of goats to an island, yielded many changes in the island ecosystem, demonstrating that all members of a community are closely interconnected.

In the 1970s the British scientist James Lovelock formulated the Gaia hypothesis, which has attracted many followers. According to this theory, named after the Greek goddess of the earth, the planet behaves like a single living organism. Lovelock postulated that the earth, like many organisms, can regulate its temperature, dispose of its wastes, and fight off disease. Although the Gaia hypothesis serves as a convenient metaphor for the interconnections among living beings, it does not have any particular scientific merit.

From a scientific viewpoint, the earth is not a single living organism, but it can be viewed as a single integrated system. The National Aeronautics and Space Administration (NASA), using its expertise in planetary and space sciences, is collaborating with other U.S. governmental agencies in the use of artificial satellites to study global change. NASA's undertaking, begun in 1991, is called Mission to Planet Earth. This project is part of an international effort linking numerous satellites into a single Earth Observing System (EOS). EOS is designed to increase knowledge of the interactions taking place among the atmosphere, land, and oceans; to assess the impact of natural and human events on the planet; and to provide the data that permit sound environmental policy decisions to be made.

 

Put 10 questions to the text (alternative, special, general and disjunctive).

Give annotation of the text.

Acid Rain

Acid Rain is a form of air pollution, currently a subject of great controversy because of widespread environmental damage for which it has been blamed. It forms when oxides of sulfur and nitrogen combine with atmospheric moisture to yield sulfuric and nitric acids, which may then be carried long distances from their source before they are deposited by rain. The pollution may also take the form of snow or fog or be precipitated in dry forms. In fact, although the term “acid rain” has been in use for more than a century — it is derived from atmospheric studies that were made in the region of Manchester, England — the more accurate scientific term would be “acid deposition.” The dry form of such precipitation is just as damaging to the environment as the liquid form.

The problem of acid rain originated with the Industrial Revolution, and it has been growing ever since. The severity of its effects has long been recognised in local settings, as exemplified by the spells of acid smog in heavily industrialised areas. The widespread destructiveness of acid rain, however, has become evident only in recent decades. One large area that has been studied extensively is northern Europe, where acid rain has eroded structures, injured crops and forests, and threatened or depleted life in freshwater lakes. In 1984, for example, environmental reports indicated that almost half of the trees in Germany's Black Forest had been damaged by acid rain. The northeastern United States and eastern Canada have also been particularly affected by this form of pollution; damage has also been detected in other areas of these countries and other regions of the world.

Industrial emissions have been blamed as the major cause of acid rain. Because the chemical reactions involved in the production of acid rain in the atmosphere are complex and as yet little understood, industries have tended to challenge such assessments and to stress the need for further studies; and because of the cost of pollution reduction, governments have tended to support this attitude. Studies released by the U.S. government in the early 1980s, however, strongly implicated industries as the main source of acid rain, in the eastern U.S. and Canada. In 1988, as part of the United Nations-sponsored Long-Range Transboundary Air Pollution Agreement, the United States, along with 24 other nations, ratified a protocol freezing the rate of nitrogen oxides emissions at 1987 levels. The 1990 amendments to the Clean Air Act of 1967 put in place regulations to reduce the release of sulphur dioxide from power plants to 10 million tons per year by January 1, 2000. This amount is about one-half the emissions of 1990.

 

1. Fill the gaps with the proper words:

1. Acid Rain is a form of …, currently a subject of great controversy because of widespread … for which it has been blamed.

2. The pollution may also take the form of snow or fog or be … in dry forms.

3. The problem of acid rain … with the …, and it has been growing ever since.

4. The widespread … of acid rain, however, has become evident only in recent decades.

5. … have been blamed as the major cause of acid rain.

6. Because the … involved in the production of acid rain in the atmosphere are complex and as yet little understood, industries have tended … such assessments and to stress the need for further studies; and because of the cost of …, governments have tended to support this attitude.

 

 

2. Answer the questions:

 

1. What do you think of the Acid Rain problem?

2. Which forms of Acid Rain exist?

3. How old is the term “Acid Rain”?

4. How can Acid Rain damage the environment?

5. What is the main cause of Acid Rain?

6. Which actions do people take to liquidate consequences of acid rains?