国家地理-2008-10-04 北极陷入“死亡螺旋”(在线收听) |
According to scientists from the National Snow and The levels of perennial, or year-around sea ice, have been dropping rapidly. According to NASA, the drop in ice levels has averaged nearly 10% each decade since NASA began satellite imaging in 1979. Between the winters of 2005 and 2007, the amount of perennial ice that was lost was equivalent to an area the size of Perennial sea ice is the thick ice that remains solid throughout the year and provides important habitat and hunting grounds for polar bears, while the surrounding seasonal ice melts and reforms each year. This data further reinforces previous evidence that the minimum level of perennial sea ice in the An Arctic climate expert at the National Snow and Sea ice works as a mirror, reflecting the Sun's rays. The more sea ice that exists, the more the Sun's rays are reflected off the Earth’s surface. But when sea ice levels decline, more of the Sun's rays can be absorbed by the seas and by land. This can then lead to a rise in global temperatures and disrupt the fragile equilibrium of the world's climate. Worse yet, this can result in what scientist called, ice-albedo feedback, meaning the more the sea ice declines, the more likely it will continue to decline.
Equivalent to: having the same value, purpose, job etc as a person or thing of a different kind; and here it refers to the same size. Habitat: the natural home of a plant or animal Ramification: A subordinate part extending from a main body; a branch Equilibrium: a balance between different people, groups, or forces that compete with each other, so that none is stronger than the others and a situation is not likely to change suddenly
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原文地址:http://www.tingroom.com/lesson/gjdl2008/63499.html |