In what Senate leaders are hailing as the single biggest victory in the fight against climate change to pass the U.S. Congress in a decade, Democratic and Republican lawmakers approved bipartisan legislation that will dramatically reduce greenhouse gas emissions and further provide incentives for renewable energy developments.

The climate provisions were contained in a sweeping $900 billion pandemic stimulus bill that passed late Monday night. The legislation provides billions of dollars in research and development funds for renewable energy and energy storage initiatives. It also extends key tax credits for wind and solar power projects.

Among the bill’s significant climate provisions is a mandatory phasedown of hydrofluorocarbons (HFCs), chemical refrigerants used in air conditioners and refrigerators that are hundreds to thousands of times more effective at warming the planet than carbon dioxide. 

“It’s a big step,” said David Doniger, director of the climate and clean energy program with the Natural Resources Defense Council, in reference to ongoing efforts to fight climate change. “It doesn’t get you to the goal line, but it keeps you on the field.”

The phasedown will require reductions in HFC production and use in the United States by 85 percent over the next 15 years. The reductions are similar to those required as a part of a larger international agreement that will reduce additional global warming by as much as 0.5 degrees Celsius by the end of the century.

The international agreement, known as the Kigali Amendment to the Montreal Protocol, was negotiated in 2016 with strong backing from John Kerry, then U.S. Secretary of State, who was recently appointed climate envoy to the Biden Administration. 

More than 120 countries have already signed the amendment, but three of the largest HFC producers and consumers, the United States, China and India, have yet to ratify the agreement. 

“To make it work, all the big countries have to be involved,” Doniger said, noting that China and India have both started the transition away from HFCs but are waiting for the U.S. to formally ratify the agreement before doing the same.  

Durwood Zaelke, president of the Institute for Governance & Sustainable Development, said the legislation is a key step in reducing “short-lived climate pollutants”—things like methane and black carbon that cause tremendous warming but only remain in the atmosphere for a relatively short period of time.

“Cutting these climate pollutants in the next decade can cut the rate of climate warming by half, a critical strategy for keeping the planet safe as countries pursue the goals of net zero climate emissions by 2050,” Zaelke said in a written statement.

The HFC phase down legislation gained broad support among Republicans at the urging of U.S. chemical manufacturers who have developed hydrofluoroolefins (HFOs), a new generation of synthetic chemicals with lower global warming potentials. 

HFOs can be blended with HFCs to produce low global warming potential refrigerants that are only several hundred times more potent than carbon dioxide as a greenhouse gas, as opposed to HFCs alone, which are in the high hundreds to thousands of times more potent than carbon dioxide.

A 2018 report by two U.S. air conditioning and chemical manufacturing industry trade groups found that by 2027, the Kigali amendment would increase U.S. manufacturing jobs by 33,000 and increase U.S. exports by $5 billion by requiring the manufacturers to produce new refrigerants.

Mark Roberts, an environmental consultant at ECO Policy Advisors and the former senior counsel for the Environmental Investigation Agency, a non-profit environmental organization, praised the legislation, but said it is not enough to rapidly reduce greenhouse gas emissions from refrigerants.

Alternative refrigerants that are much less potent as greenhouse gases already exist but have been largely sidelined from the U.S. market. Propane, for example, a promising refrigerant for air conditioning, is only 3 times more potent as a greenhouse gas than carbon dioxide.   

Roberts said consumer and industrial safety standards, which will play a leading role in determining what alternative refrigerants can be used in place of HFCs, need to be updated.  

A recent Inside Climate News investigation found that an effort funded by the United Nations to encourage the production of propane-based air conditioners in China has been stymied by restrictive U.S. safety standards established by UL, formerly known as Underwriters Laboratories, which the U.N. suggests are biased in favor of U.S. chemical manufacturers.

“Safety standards need to be changed to allow U.S. companies to develop the next generation of AC [air conditioning] and refrigeration technologies,” Roberts said.  “Hydrocarbons, CO2, ammonia, air and water all have been proven safe, effective, and energy efficient in various AC and refrigeration applications. Consumer and industrial standards need to be updated so that they do not hamper American creativity or impede the production of all possible AC and refrigeration technologies.”

UL, a private U.S. company that sets consumer safety standards, declined a request to comment but said recently that “as technology continues to advance, we continue to revise our standards not only to keep people safe but also to protect our planet as we live out our mission to make the world a safer, more secure and sustainable place.”