The Montreal Protocol banned the use of trichlorofluoromethane (CFC-11) in 1987 after CFCs were linked to ozone depletion. New atmospheric data shows that the protocol has been effective and the hole in the ozone is on schedule to close within the next 50 years.
Researchers were concerned after detecting a spike in CFC-11 emissions from 2014 to 2017, but after cracking down on illegal emissions from eastern China, emissions are once again on the decline.
Analyzing data from atmospheric research centers around the world, the researchers found that emissions declined from 69,000 metric tons from 2014 to 2018 to 52,000 in 2019. Another research group that tracks emissions specifically from China found that the region emitted 10,000 metric tons less of CFC-11 in 2019 than averages from previous years.
Researchers credit increased regulation in China as well as other underregulated areas for the continued success of the Montreal Protocol. So far, it is one of the most successful examples of international environmental collaboration and continues to protect humans from the dangerous effects of overexposure to UV rays.