After four years of inaction, the EPA is finally regulating this superpollutant


Sales of air conditioners are soaring. Regulating the heat-trapping hydrofluorocarbons in them is crucial.

Carbon dioxide gets the fame and attention, out of the greenhouse gases. But there are others that are even more effective at trapping heat; they just exist in much smaller concentrations, so they don’t usually face the same level of scrutiny or regulation.

The United States is finally taking aim at an important type of these lesser-known superpollutants: hydrofluorocarbons, or HFCs, which are used in air conditioners and refrigerators. The Environmental Protection Agency announced a rule on Monday, first reported by the New York Times’s Lisa Friedman, that it will phase out the coolant’s use by 85 percent over the next 15 years. The EPA estimates the rule would cut down on the equivalent of 4.7 billion metric tons of carbon dioxide from 2022 to 2050 — about equal to three years of US power sector pollution.

HFCs have only been used in appliances since the 1990s, as a replacement for ozone-depleting chemicals, but their use has grown at a terrifying rate. While HFCs still only comprise about 1 percent of total greenhouse emissions, they are thousands of times better at trapping heat than carbon over a 20-year period.

Left unregulated, global HFCs would add another half-degree Celsius of warming by 2100, according to the EPA. That half-degree is crucial to avoid — it’s the difference between the world we have today and the one we will have soon at 1.5 degrees Celsius, and means crop failures, Arctic ice-free summers, and cities facing unmanageable flooding.

And it’s especially important to start phasing out HFCs now, since the global stock of air conditioners is rising rapidly in a warming world: According to United Nations’ Climate and Clean Air Coalition, there will be 10 AC units sold every second for the next 30 years. The alternative chemicals all have some impact on global warming, but natural (meaning not human-made) options have a much smaller footprint, according to Project Drawdown. Ammonia, for example, has almost zero impact.

That’s why the EPA’s new proposed regulation that sets the first cap for manufacturing and importing HFCs in the US is very good news.

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Vox, 4 May 2021