In Kigali, 197 nations agree to phase down the coolants replacing the last banned chemicals

For nearly three decades, the Montreal Protocol had been hailed as the rare environmental treaty that actually worked, phasing out the CFCs that tore holes in the ozone layer. But the chemical industry's replacement, hydrofluorocarbons, had a different problem: some trapped heat thousands of times more effectively than carbon dioxide. On October 15, 2016, at the Twenty-Eighth Meeting of the Parties in Kigali, Rwanda, 197 nations amended the treaty to phase down HFCs, committing to cut production and consumption by at least 85 percent from 2011-2013 levels. UNEP estimated the deal could avert up to 0.5 degrees Celsius of warming by 2100…