After decades of thinning, Earth's ozone layer is slowing recovering, the United Nations (UN) said in a report released Monday, highlighting how international co-operation can help tackle major environmental issues.
The ozone layer, which protects humans and other species from the sun's highly hazardous ultraviolet radiation, has been declining since the 1970s due to the effect of chemicals such as chlorofluorocarbons (CFCs) and similar gases found in refrigerants and aerosol spray cans.
A new study from the National Oceanic and Atmospheric Administration (NOAA) shows an "unexpected and persistent increase" in global emissions of an ozone-depleting chemical even though an international treaty forced production to completely halt by 2010.
NOAA scientists suggest that emissions are most likely from new, unreported production from an unidentified source in eastern Asia.
The Earth's protective ozone layer is not recovering uniformly from the damage caused to it by industry and other human activities. And scientists are not sure why it isn't.
An international research team says the ozone, which protects humans and other species from harmful ultraviolet radiation, is continuing to recover at the poles. But recovery at lower latitudes, where far more people live, is not.
By Jake Johnson
Hailed as an example of how concerted global action can help solve a planetary crisis, a new study conducted by NASA scientists documented the first direct evidence that an international effort to ban chlorofluorocarbons (CFCs) has led to the recovery of the Antarctic ozone hole.
While the ozone hole is still enormous—measuring about 19.6 million square kilometers (7.6 million square miles, or 2.5 times the size of the U.S.) at its annual peak extent this Sept. 11—that's much smaller compared to the average area of ozone hole maximums since 1991 of roughly 26 million square kilometers (10 million square miles).