New York: Evidence has been building that the ozone layer of the atmosphere is recovering, and a new paper claims to have directly measured the ozone hole gradually filling back in, according to a report in arstechnica.com.
During the 1970s and '80s, it was reported that a class of industrial chemicals, the chloro-flurocarbons (CFCs), were damaging the ozone layer, a region of the stratosphere rich in this reactive form of oxygen. Ozone is able to absorb UV light that would otherwise reach the Earth, where it’s capable of damaging DNA. The levels of ozone had been dropping, which resulted in a nearly ozone-free “hole” over the Antarctic,
The ozone hole spurred countries and companies into action and the Montreal Protocol codified an agreement to slow down use of CFCs which appears to be working, arstechnica.com reported.Hints of a recovery have often been followed by years in which ozone levels drop again.
But new research shows that the the amount of chlorine over the Antarctic was declining at a rate of 25 parts-per-trillion each year (that’s 0.8 percent), though it may increase in some years due to the weather. This resulted in a 20-per cent drop in ozone destruction, it said.
