You can't see them, smell them or hear them, but hydrofluorocarbons are all around you.
Anytime you stand with the fridge door open or crank your car's AC, you interact with these compounds.
And they float among other places too. Hydrofluorocarbons (HFCs) are used in fire suppression and cleaning solvents, and they are critical for commercial food preservation and large-scale data storage.
HFCs are the backbone of modern refrigeration and air-conditioning. And while they're great at keeping you — and your stuff — cool, scientists have proven they are making the planet hotter.
Like carbon dioxide, HFCs trap heat within the atmosphere. While they comprise a minority of total greenhouse gas emissions, they still pack quite a punch.
"[HFCs] have global warming potentials that are hundreds to thousands of times as potent as carbon dioxide," said Luke Hall-Jordan, a branch supervisor in the Stratospheric Protection Division of the Environmental Protection Agency.
Hall-Jordan added that the market for these refrigerants is growing rapidly as temperatures climb and more air-conditioning units are installed across the world.
In 2016, over 100 countries, including the U.S., entered an international agreement to phase down the use of HFCs in an effort to curb their emissions.
Hall-Jordan said that assuming everybody complies, that global phase-down is expected to prevent up to 0.5 degrees Celsius of warming by 2100.
Recovering from harmful refrigerants
This isn't the first time the world of cooling has undergone an overhaul. An earlier generation of refrigerants called chlorofluorocarbons (CFCs), commonly known as Freon, used to be the main player in air-conditioning.
When they came onto the market, they were highly effective, non-toxic and non-flammable.
They did have one drawback though: they nearly blew a hole in the Earth's ozone layer.
"Without the ozone layer, we wouldn't be able to stand outside in the sun for a minute. Our skin would burn. And not just us, but any kind of life," said Eric Dean Wilson, author of After Cooling: On Freon, Global Warming, and the Terrible Cost of Comfort.
The international community passed the Montreal Protocol, one of the rare legally binding climate agreements, in order to curb the use of CFCs.
But the ozone layer has yet to fully recover. At certain times of the year, the part of the stratosphere depleted by CFCs is only as thick as a single dime.
"The lesson there is that there's a real lag time with the massive transition that we're making on the human level, and how the atmosphere reacts to it," Wilson said.
"So all of that suggests that we need urgent action [on HFCs]," he said. "Because once we're feeling the most acute effects of the climate crisis, it will be far too late to walk that back."
Is the industry ready to pivot once again?
The AIM Act, adopted in 2020, lays out a three-pronged approach for the U.S. to reduce HFCs.
"We often think of it like a three-legged stool," Hall-Jordan said.
The first approach is to gradually reduce new production and importation of HFCs. So far, Hall-Jordan said that initiative has brought down the use of these refrigerants to about 60% of their historical levels.
Next, the EPA will be placing a series of restrictions on the purchasing of new equipment that uses HFCs between 2025 and 2028. That means the refrigeration and air-conditioning industry will need to have new substitutes ready to go.
Chris Bresee manages government affairs for the Air-Conditioning, Heating, and Refrigeration Institute. He said that new refrigerants are commercially available, and in many cases, already in use.
According to Bresee, the trickier part of the transition has been updating the patchwork of state building codes to ensure contractors can stay in compliance with both state and federal regulations.
Hawaiʻi joins the effort
State lawmakers passed a measure to address that challenge this legislative session. Bresee said that Hawaiʻi was one of the last states to do so.
"This is really just a band-aid to deal with timing, to allow the states to update their building codes, and also to allow these products to enter the market," Bresee said.
The EPA has yet to finalize the last phase of its HFC regulation strategy, but Hall-Jordan said it would likely set further emission requirements for installed air conditioning and refrigeration units in order to prevent leaks.
Hall-Jordan is careful to call the approach to HFCs a "phase-down" rather than a "phase-out." HFCs will likely still be used for specialized purposes.
And while the latest generation of refrigerants may cut the global warming potential of our cooling systems in half, they are still far more potent than carbon dioxide. Before too long, those products could be outdated as well.
"We could see further transition in the future," Hall-Jordan said.
