5. Why is the ozone layer so important for all living on the earth?
6. What are the most dramatic predictions of NASA concerning the problem?
7. What steps should be taken to avoid the situation?
• Topics for discussion.
1. Scientists' responsibility for atmospheric pollution.
2. People should avoid overusing:
a) all kinds of sprays;
b) air-conditioning wherever possible;
c) fridges whenever possible.
CLASSWORK
READING (3B)
• Read the passage carefully and discuss the following idea: "How can scientists so confidently predict what will occur in the next 100 years when we can't even predict the weather for tomorrow?"
IS THE EARTH GETTING HOTTER?
It sounded like nature's own apocalypse (апокалипсис). *"The earth's temperature would rise, melting the icecaps, raising the seas, flooding the land. Arisona would turn into a rain forest and the agricultural Midwest would become a desert." At least, that was how TV weathermen interpreted a report by the Environmental Protection Agency (EPA) on the "greenhouse effect" that would begin altering the earth'sclimateby the 1990s. *The EPAprcdicted "catastrophic consequences" if contingency (непредвиденное обстоятельство) plans weren't made with "a sense of urgency".
Fortunately, the news improved later when the National Academy of Sciences said that although the greenhouse effect was very real, "caution (осторожность) not panic" was in order.
In fact, the science ofthe phenomenon is more interesting than frightening. *Thc greenhouse effect results when CO, and certain othergascs in the atmosphere allow the sun's ultraviolet rays to penetrate and warm the earth but then absorb the infrared energy the earth radiates back into space — much as glass in a greenhouse effect does — forming a kind of "thermal blanket" around the planet. By burning huge amounts of fossil fuels, which release C02 into the atmosphere, man has raised the C02 level from 280 to 340 parts per million since 1860. And continued use of coal and other fossil fuels is expected to double the concentration of CO, by the year 2050, elevating the earth's temperature by 3 to 9 degrees Fahrenheit. The greenhouse effect will mean much more than hotter summers and milder winters. It may alter rainfall, affect crop yields (урожай) and eventually— as glaciers begin to melt — raise the level ofthe sea.
Both reports predict that the temperature change will be greater in the polar regions than near the equator. In general, they speculate that snowfall will begin later, the growing season will lengthen and higher latitudes will get less rain. *The EPA says that the sea level will probably rise at least two feet before the year 2100, which could flood "many of the major ports of the world, disrupt transportation networks, alter ecosystems and cause major shifts in land development patterns".
Although use of fossil fuels is the main cause ofthe CO, increase, the government agencies don't advocate any sweeping changes in energy policies. Even a total ban on the burning of fossil fuels in the United States wouldn't have much impact, because the United States accounts for only 25 percent of the world's total man-made C02 emissions. * A worldwide coal ban instituted in 2000 would delay the warming by about 15 years but is considered economically and politically unfeasible.
If we can't prevent the greenhouse effect, we can prepare forit. Suggestions include breeding (выводить) plants that need less water, improving irrigation systems, and many others.
However not all experts are convinced that the heat is coming. Some think that the use of primary energy sources such as coal could decline 60 percent by 2050 and, perhaps, "the opposite of the EPA scenario is true. If the rate of fossil-fuel use is going down, the amount of C02 we add to the air is getting less every year".
• Try to guess the meaning of the words given in italics in the text.
• Translate the sentences marked with an asterisk.
• Answer the following questions.
I. Is there a 100 per cent agreement on our planet's future climatic conditions?