Ozone hole: Going, going, gone?

NASA satellite shows direct evidence of ozone hole recovery

It's long been known that the hole in the ozone layer is shrinking, but a new study has provided greater insight into the improving health of the ozone layer by analyzing the chemicals around the hole over the last decade or so.

From article, (To check that the CFC ban is contributing to the recovery of the ozone layer hole, a team of researchers studied data gathered by a satellite-mounted instrument called the Microwave Limb Sounder (MLS), which measures trace gases in the atmosphere. Using MLS data gathered every winter between 2005 and 2016, the team was able to determine the daily changes in ozone levels during the entire winter season of each year – from early July to mid-September.

Sure enough, the researchers found that the rate of ozone loss decreased by 20 percent over that time period.

As encouraging as the result is, we're not out of the woods yet. New CFCs aren't being pumped into the atmosphere, but the existing ones will still be around for a long time.

"CFCs have lifetimes from 50 to 100 years, so they linger in the atmosphere for a very long time," says Anne Douglass, co-author of the study. "As far as the ozone hole being gone, we're looking at 2060 or 2080. And even then there might still be a small hole.")