The Environmental Protection Agency moved on Monday to sharply reduce the use and production of powerful greenhouse gases central to refrigeration and air-conditioning, part of the Biden administration’s larger strategy of trying to slow the pace of global warming.
The agency proposed to regulate hydrofluorocarbons, or HFCs, a class of man-made chemicals that are thousands of times more potent than carbon dioxide at warming the planet. The proposal is the first significant step the E.P.A. has taken under President Biden to curb climate change.
The move is also the first time the federal government has set national limits on HFCs, which were used to replace ozone-depleting chlorofluorocarbons in the 1980s but have turned out to be a significant driver of global warming. More than a dozen states have either banned HFCs or are formulating some restrictions.
And it is another sign, along with Mr. Biden’s decision to rejoin the Paris climate accord and to host a recent virtual climate summit — that the administration is reinserting the country into the international fight against global warming.
“By taking fast action on these short-lived climate pollutants, of which HFCs are the most potent, we can buy ourselves some time and actually help avoid climate tipping points,” she said.
The regulation would begin to take effect in 2022 and would gradually reduce the production and importation of hydrofluorocarbons in the United States by 85 percent over the following 15 years. About 15 percent of HFCs would still be permitted because they have critical uses for which alternatives do not yet exist.
The E.P.A. estimated that by 2050 the rule would eliminate the equivalent of 4.7 billion metric tons of carbon dioxide, or about three years’ worth of emissions from America’s power sector. That would help put the United States on a path toward meeting Mr. Biden’s aggressive goal of cutting America’s emissions roughly in half by 2035.