If good intentions and good ideas were all it took to save the deteriorating atmosphere, the planet’s fragile layer of air would

admin2009-04-26  40

问题     If good intentions and good ideas were all it took to save the deteriorating atmosphere, the planet’s fragile layer of air would be as good as fixed. The two great dangers threatening the blanket of gases that nurtures and protects life on earth—global warming and the thinning ozone layer—have been identified. Better yet, scientists and policymakers have come up with effective though expensive countermeasures.
    But that doesn’t mean these problems are anywhere close to being solved. The stratospheric ozone layer, for example, is still getting thinner, despite the 1987 international agreement known as the Montreal Protocol, which calls for a phase-out of chlorofluorocarbons (CFCs) and other ozone-depleting chemicals by the year 2006.
    CFCs—first fingered as dangerous in the 1970s by Sherwood Rowland and Mario Molina, two of this year’s Nobel—prizewinning chemists—have been widely used for refrigeration and other purposes. If uncontrolled, the CFC assault on the ozone layer could increase the amount of hazardous solar ultraviolet light that reaches the earth’s surface, which would, among other things, damage crops and cause cancer in humans. Thanks to a sense of urgency triggered by the 1085 detection of what has turned out to be an annual "hole" in the especially vulnerable ozone over Antarctica, the Montreal accords have spurred industry to replace CFCs with safer substances.
    Yet the CFCs already in the air are still doing their dirty work. The Antarctic ozone hole is more severe this year than ever before, and ozone levels over temperate regions are dipping as well. If the CFC phase-out proceeds on schedule, the atmosphere should start repairing itself by the year 2000, say scientists. Nonetheless, observes British Antarctic Survey meteorologist Jonathan Shanklin: "It will be the middle of the next century before things are back to where they were in the 1970s".
    Developing countries were given more time to comply with the Montreal Protocol and were promised that they would receive $250 million from richer nations to pay for the CFC phase-out. At the moment, though, only 60% of those funds has been forthcoming. Says Nelson Sabogal of the U.N. Environment Program: "If developed countries don’t come up with the money, the ozone layer will not recuperate. This is a crucial time".
    It is also a critical time for warding off potentially catastrophic climate change. Waste gases such as carbon dioxide, methane and the same CFCs that wreck the ozone layer all tend to trap sunlight and warm the earth. The predicted results: an eventual melting of polar ice caps, rises in sea levels and shifts in climate patterns.

选项 A、quick responses.
B、energy efficiency.
C、great initiatives.
D、scientific analysis.

答案C

解析
转载请注明原文地址:https://kaotiyun.com/show/tdi4777K
0

随机试题
最新回复(0)