The Montreal Protocol, the international treaty adopted to restore Earth’s protective ozone layer in 1989, has significantly reduced emissions of ozone-depleting chemicals from the United States. In a twist, a new study shows the 30-year old treaty has had a major side benefit of reducing climate-altering greenhouse gas emissions from the U.S.
That’s because the ozone-depleting substances controlled by the treaty are also potent greenhouse gases, with heat-trapping abilities up to 10,000 times greater than carbon dioxide over 100 years.