Earth’s ozone layer faces heightened risk.
A NASA study released on Sunday documented an unprecedented depletion of Earth’s ozone layer above the Arctic last winter and spring.
The amount of ozone destroyed in the Arctic in 2011 was comparable to that seen in the Antarctic where an ozone “hole” has formed each spring since the mid-1980s.
Of critical importance, the stratospheric ozone layer extends from about 10 to 20 miles above the surface and protects Earth from the sun’s harmful ultraviolet rays.
The Antarctic ozone hole forms when extremely cold conditions, common in the winter Antarctic stratosphere, trigger reactions that convert atmospheric chlorine from human-produced chemicals into forms that destroy ozone.
The same ozone-loss processes occur each winter in the Arctic. However, the generally warmer stratospheric conditions there previously limited the impact. This is no longer the case.