Think of some questions to review the contents of Text 6A and ask each other.

21. Read the text below to find answers to the given questions:

Text 6 B

Environmental Problems of the Earth

1. What is environment?

The environment is our physical surroundings. This includes both human (man-made), social and physical (natural) features. Natural features include soil, the atmosphere, vegetation and wildlife. Human features include housing, transport and industry. Social features include things such as culture, language and political systems.

A variety of environmental problems now affect our entire world. As globalization continues and the earth’s natural processes transform local problems into international issues, few societies are being left untouched by major environmental problems.

Many people are concerned about human action in the environment. Human interference with the environment causes many environmental problems. Some of the largest problems now affecting the world are acid rain, air pollution, global warming, hazardous waste, ozone depletion, smog, water pollution, overpopulation, and rain forest destruction. Every environmental problem has causes, numerous effects, and most importantly, a solution.

2. What causes acid rain?

Acid rain is caused by the burning of fossil fuels. Burning oil, gas and coal in power stations releases sulphur dioxide (SO ) into the atmosphere. Burning oil and petrol in motor vehicles puts nitrogen oxides (NO ) into the atmosphere. These gases mix with water droplets in the atmosphere creating weak solutions of nitric and sulphuric acids. When precipitation occurs these solutions fall as acid rain.

3. What problems are caused by acid rain?

Acid rain increases the acidity levels of rivers, lakes and seas. This can kill aquatic life. Acid rain increases the acidity levels of soils. This can kill vegetation. Acid rain from the UK has been found to destroy the roots and leaves of forests in Germany and Scandinavia. Acid rain can erode buildings and monuments (particularly if they are made from limestone).

4. What is global warming?

Global warming is the worldwide warming of the atmosphere. Global warming is caused by the increases in the amount of carbon dioxide and other gases being released into the atmosphere by the burning of fossil fuels. These gases add to the natural greenhouse effect.

5. What is the greenhouse effect?

To understand global warming you first need to know about the greenhouse effect. The greenhouse effect is a natural phenomenon that controls the balance of heat within the earth’s atmosphere. It is the process whereby the natural layer of gases in our atmosphere traps a small percentage of the sun’s radiation reflected from the earth’s surface. Without the greenhouse effect, the average surface temperature would be about -18 degrees Celsius.

6. What problems are caused by global warming?

Sea levels will rise due to the melting of the ice caps. This will cause flooding in many low-lying areas of the world. These areas include Bangladesh, East Anglia (England) and The Netherlands.

7. What is water pollution?

Water is necessary to life on earth. All organisms contain it; some live in it; some drink it. Plants and animals require water that is moderately pure, and they cannot survive if their water is loaded with toxic chemicals or harmful microorganisms. If severe, water pollution can kill large numbers of fish, birds, and other animals, in some cases killing all members of a species in an affected area.

Pollution makes streams, lakes, and coastal waters unpleasant to look at, to smell, and to swim in. Fish and shellfish harvested from polluted waters may be unsafe to eat. People who ingest polluted water can become ill, and, with prolonged exposure, may develop cancers or bear children with birth defects. The major water pollutants are chemical, biological, or physical materials that degrade water quality. Pollutants can be classed into eight categories, each of which presents its own set of hazards.

8. What is the harmful effect of petroleum products?

Oil and chemicals derived from oil are used for fuel, lubrication, plastics manufacturing, and many other purposes. These petroleum products get into water mainly by means of accidental spills from ships, tanker trucks, pipelines, and leaky underground storage tanks. Many petroleum products are poisonous if ingested by animals, and spilled oil damages the feathers of birds or the fur of animals, often causing death. In addition, spilled oil may be contaminated with other harmful substances.

9. What is the harmful effect of pesticides and herbicides?

Chemicals used to kill unwanted animals and plants, for instance on farms or in suburban yards, may be collected by rainwater runoff and carried into streams, especially if these substances are applied too lavishly. Some of these chemicals are biodegradable and quickly decay into harmless or less harmful forms, while others are not biodegradable and remain dangerous for a long time.

10. What are environmental engineers?

Environmental engineers develop solutions to environmental problems using the principles of biology and chemistry. They are involved in water and air pollution control, recycling, waste disposal, and public health issues.

Environmental engineers conduct hazardous-waste management studies in which they evaluate the significance of the hazard, advice on treatment and containment, and develop regulations to prevent mishaps. They design municipal water supply and industrial wastewater treatment systems. They conduct research on the environmental impact of proposed construction projects, analyze scientific data, and perform quality-control checks.

Environmental engineers are concerned with local and worldwide environmental issues. They study and attempt to minimize the effects of acid rain, global warming, automobile emissions, and ozone depletion. They may also be involved in the protection of wildlife. Many environmental engineers work as consultants, helping their clients to comply with regulations and to clean up hazardous sites.

TEXT AND VOCABULARY EXERCISES

22. Find in the text the words or phrases which mean the same as: