Hydrofluorocarbons (HFCs) are on the way out:
The coolant phase-down would be one of the most significant federal policies ever taken to cut greenhouse gas emissions, according to an analysis by the Rhodium Group, a research and consulting firm.
By 2035, the law would help avoid the equivalent of 949 million tons of carbon dioxide, the group estimated, which is similar in scope to the extra expected emissions from Mr. Trump’s climate policy rollbacks on vehicle pollution and methane from oil and gas operations.
Read that bottom part again. One of the biggest and most important steps we could take, but it merely offsets some of the damage Trump did to our efforts to deal with climate change. Here's a short history of the EPA's efforts to control this chemical:
To address HFC emissions and their projected effect on climate change, EPA promulgated changes to the regulatory requirements for HFCs under Title VI of the CAA. The 2015 and 2016 rulemakings, discussed further below, have been subject to legal challenges to EPA’s authority to regulate HFCs under CAA Title VI. (For more about EPA’s authority to regulate HFCs, see CRS Legal Sidebar LSB10155, D.C. Circuit Rejects EPA’s Efforts to Ban Hydrofluorocarbons: Part2.)Title VI also implements U.S. international responsibilities under the Montreal Protocol on Substances that Deplete the Ozone Layer (and its amendments).
International cooperation to phase down CFCs and other ODS has been effective under the Montreal Protocol.Given the global nature ofHFCs and other GHGs emissions, efforts to effectively address climate change will likely need to occur on a global scale.In 2016, nearly 200 nations, including the United States, agreed to the Kigali Amendment to the Montreal Protocol, which contains commitments to phase down global production and consumption of HFCs because they are potent GHGs that substitute for ODS controlled under the protocol.The United States is a party to the Montreal Protocol. As of May 2020, the United States is not party to the Kigali Amendment.
Absent mitigation actions, global HFC emissions and consumption are projected to increase, especially in developing countries as demand is expected to rise for cooling services that would use HFCs. In developed countries, projected emissions increases are driven primarily by the aging and replacement of existing ODS-using equipment (EPA, Global Non-CO2GHG Emission Projections and Mitigation, 2015-2050, 2019).
Bolding mine, because warming planet = more air conditioning. Which you might consider obvious, but it is critical to include that in discussions. The sooner an alternative is developed, the better. And this time we can't let industry rob Peter to pay Paul: HFCs were an alternative to CFCs, which were attacking the ozone layer. And they never should have been approved. Back to the OP and the Kagali Agreement we haven't signed:
In a 2016 accord signed in Kigali, Rwanda, in the last days of the Obama administration, 197 nations agreed to phase out HFCs in favor of alternatives that are less dangerous to the climate. The Kigali agreement was an amendment to the Montreal Protocol, the landmark 1987 treaty designed to close the hole in the ozone layer.
Once the Kigali amendment is implemented by all nations, scientists say it would stave off an increase of atmospheric temperatures of nearly one degree Fahrenheit. That would be a major step toward averting an atmospheric temperature increase of 3.6 degrees Fahrenheit, the point at which many experts think the world will be locked into a future of rising sea levels, severe droughts and flooding, widespread food and water shortages, and more powerful hurricanes. But the Trump administration never ratified the Kigali pact, and instead has proposed to roll back federal regulations curbing the use of HFCs in the United States.
Now, Mr. Trump is about to sign a bill that will require the United States to follow the terms of the Kigali agreement, which requires companies to phase down production and consumption of HFCs to about 15 percent of 2012 levels by 2036. The phase-down will be administered by the Environmental Protection Agency.
And that may be why Trump is now questioning this bill, even though he says he wants to give people bigger relief checks. Perhaps this story could have waited a few more days before hitting the headlines...