Ozone Glee and Gloom

By Josie Glausiusz|Friday, November 01, 2002
RELATED TAGS: GLOBAL WARMING
According to a Japanese study, the ozone hole over the Antarctic may slam shut within four decades. Tatsuya Nagashima of the National Institute for Environmental Studies in Ibaraki simulated the gases seeping into the ozone layer, 10 to 15 miles high in the stratosphere. He found that declining levels of chlorine from recently banned chlorofluorocarbons should enable the ozone to return to early-1980s levels by 2040. But another study, conducted by physicist Drew Shindell of NASA Goddard Institute for Space Studies in New York City, suggests that recovery of the ozone layer will be delayed 10 to 20 years by rising levels of two gases—methane and nitrous oxide—that also contribute to greenhouse warming. At low latitudes, methane in the stratosphere breaks down into hydrogen oxides, which attack ozone. Nitrous oxide can decompose to form ozone-eating nitrogen oxides. "In 60 or 70 years, there should be no more depletion from chlorine, but since there will be all these greenhouse gases, it will not look like it used to in the 1970s," Shindell says. Fortunately, the ozone layer should still be robust enough to provide protection from solar ultraviolet rays.




 
Comment on this article
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT
ADVERTISEMENT
Collapse bottom bar
DSC-JanFeb15
+

Log in to your account

X
Email address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it emailed to you.

Not registered yet?

Register now for FREE. It takes only a few seconds to complete. Register now »