Curbing a Potent Greenhouse Gas On Dec. 17, the European Union drafted important legislation to cut hydrofluorocarbons, or HFCs, by 79 percent by 2030. This is the most concrete move yet to rein in HFCs, which are potent greenhouse gases used in refrigerators and air-conditioners. In June, the United States and China reached an agreement to reduce these gases, and in September leaders of the Group of 20 nations pledged to do their share. With Europe's move, the goal of a global agreement on the gases is closer than ever. Global support has been growing for tackling HFCs through the Montreal Protocol - which phased out chlorofluorocarbons, or CFCs, that were destroying the ozone layer - rather than through the broader and more cumbersome United Nations Framework Convention on Climate Change. While HFCs, developed to replace CFCs in refrigeration and air-conditioning, do not harm the ozone layer, they are fast becoming a significant contributor to global warming. The United Nations Environment Program projects that HFCs, only 1 percent of greenhouse gases today, will make up 20 percent by 2030 if nothing is done. Eliminating HFCs would be the equivalent of taking 100 billion tons of carbon dioxide out of the atmosphere. HFCs have higher global warming potential than carbon dioxide, but they disappear from the atmosphere much more quickly. Global negotiations on limiting more persistent greenhouse gases must continue, but eliminating HFCs will help. New technologies exist to replace HFCs. The European legislation proposes phasing out consumer refrigerators using HFCs in 2015 and imposing additional bans on a range of commercial refrigeration and air-conditioning products that use the most potent HFCs in 2020 and 2022. With this breakthrough in Europe, India, one of the fastest-growing markets for coolants, is now the last big holdout on reduction of HFCs. Despite joining the G-20 pledge, India has reiterated its opposition to tackling HFCs through the Montreal Protocol. The United States and India should continue bilateral talks to address concerns about costs so that India can join the international effort. The European Union should move quickly now to pass into law the draft legislation to give industry a clear timeline to begin the necessary transition.