Is Earth's ozone layer recovering?
In the steamy city of Mumbai, India, one citizen, Geeta Vittal, told the International Herald Tribune that when she first got an air conditioner she thought it was an extravagance. Now she has five. "All my friends have air conditioners now," she said "Ten years ago, no one did." (Photo by Jantik)
In recent years, experts have believed that Earth’s ozone layer was on the road to recovery. But the 2006 ozone hole broke records for area and depth.
Is the ozone layer in Earth’s stratosphere recovering? The experts we contacted said there’s still a consensus that it is, due to a successful global effort to reduce chlorofluorocarbon emissions.
But, they said, there are some contradictions in part because of the rising standard of living in India and China. Some scientists point to air conditioning in Asia as one factor. Satellite observations have shown extremely high levels of chlorine chemicals in the atmosphere…
And these chemicals – mostly coolants that leak from air conditioners – are known to destroy ozone. These particular coolants are banned or are being phased out in the U.S., Europe and other industrialized countries. But they’re not against the law in the developing countries of Asia, including India and China.
The air conditioning business is booming across Asia. And many of these air conditioners contain the ozone-depleting chemical HCFC-22. There’s also another factor at work here. Scientists agree that Earth’s lower atmosphere is warming. This warming appears to have caused a cooling of the upper atmosphere, and it’s thought that this cooling will delay the eventual recovery of the ozone.
Our thanks today to NASA : explore, discover, understand.
The Price of Keeping Cool in Asia; Use of Air-Conditioning Refrigerant Is Widening the Hole in the Ozone Layer, from the New York Times (requires registration)
India, China’s AC prompts ozone worries, from ScienceDaily
Our thanks to:
Jack Fishman
Senior Research Scientist
Chemistry and Dynamics Branch
NASA Langley Research Center
Hampton, VA
Dork Sahagian
Director, Environmental Initiative and Professor, Earth and Environmental Sciences
Lehigh University
Bethlehem, PA
Additional Teacher Resources
NASA: Ozone Resource Page
This NASA web page provides an explanation of ozone and links to ozone video, images, resources, and articles.
NASA: Ozone Hole 101
Learn more about why ozone can be good or bad, depending on where it is found. This NASA web page provides an overview of ozone.
NASA: Ozone Hole Watch
Visit the NASA Ozone Hole Watch web site, where you can check on the latest status of the ozone layer over the South Pole. Satellite instruments monitor the ozone layer, and NASA uses the data to create images that depict the amount of ozone.
