Scientists at MIT and elsewhere have identified the first fingerprints1 of healing of the Antarctic ozone2 layer, published today in the journal Science. The team found that the September ozone hole has shrunk by more than 4 million square kilometers -- about half the area of the contiguous United States -- since 2000, when ozone depletion3 was at its peak. The team also showed for the first time that this recovery has slowed somewhat at times, due to the effects of volcanic4 eruptions5 from year to year. Overall, however, the ozone hole appears to be on a healing path.The authors used fingerprints of the ozone changes with season and altitude to attribute the ozones recovery to the continuing decline of atmospheric6 chlorine originating from chlorofluorocarbons . These chemical compounds were once emitted by dry cleaning processes, old refrigerators, and aerosols7 such as hairspray. In 1987, virtually every country in the world signed on to the Montreal Protocol8 in a concerted effort to ban the use of CFCs and repair the ozone hole.We can now be confident that the things weve done have put the planet on a path to heal, says lead author Susan Solomon, the Ellen Swallow Richards Professor of Atmospheric Chemistry and Climate Science at MIT. Which is pretty good for us, isnt it Arent we amazing humans, that we did something that created a situation that we decided9 collectively, as a world, Lets get rid of these molecules We got rid of them, and now were seeing the planet respond.Solomons co-authors include Diane Ivy10, research scientist in the Department of Earth, Atmospheric and Planetary Sciences, along with researchers at the National Center for Atmospheric Research in Boulder11, Colorado, and the University of Leeds in the U.K.
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1 fingerprints n.指纹v.指纹 参考例句： Everyones fingerprints are unique. 每一个人的指纹都是与众不同的。 They wore gloves so as not to leave any fingerprints behind . 他们戴着手套，以免留下指纹。 来自《简明英汉词典》
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