A San Diego scientist says a surge in outlawed ozone-depleting gasses appears to be easing.
Scripps Institution of Oceanography researcher Ray Weiss says levels of chlorofluorocarbons (CFCs) in the atmosphere began rising a few years ago, even though they had been outlawed by the Montreal Protocol.
The chemical was once used as a refrigerant and in the manufacture of foam, but CFCs were outlawed more than a decade ago.
The ozone-eating chemical is particularly damaging to the planet’s ozone layer.
When CFC levels started rising in 2013 researchers concluded the chemical was being made clandestinely. Scientists tracked the chemical to rogue plants in China that have been shut down.
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CHC levels are now falling again.
About two dozen atmosphere monitoring stations around the world helped scientists track down the source of about 60% of the increase.
“It shows you that by measuring what actually goes into the air and making that information widely known that the problems can be solved,” Weiss said.
Two studies in the current edition of the journal "Nature" tracked the rise and fall of the ozone-eating chemical in the air.
Weiss said the are lessons for scientists who may soon need to monitor greenhouse gas emissions because of the Paris Climate Accord. The treaty requires every country to reduce emissions to keep climate warming from getting worse.
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“Now that we are moving more and more into a regulatory world where we need to keep track of things, there’s an increased need to have additional stations in places like those islands east of China,” Weiss said.
Weiss says there are about two dozen existing monitoring stations.
He thinks that the system could be rapidly expanded if monitors were added to stations that already track nuclear particles that are created when nuclear weapons are made or nuclear accidents happen.
Weiss said that adding 80 monitoring stations relatively quickly would make it easier to monitor the emission of greenhouse gasses.
