Since October 2016, 100 governments have ratified a historic international climate accord, one that then-Secretary of State John Kerry called “likely the single most important step we could take at this moment to limit warming of our planet.”
This treaty entered into force on January 1, 2019, and has sharper teeth than the more famous Paris Agreement, with consequences for ratifying nations that don’t abide by it. It could lower global carbon emissions at a scale and speed never seen before.
It’s called the Kigali Amendment, and it doesn’t address agriculture, forest conservation, or renewable energy. It’s about refrigerants.
“Refrigerants” refer to the class of chemicals needed in any mechanical cooling and heating system or appliance. Your refrigerator, freezer, and air conditioner use them. So do grocery store cold cases, pharmaceutical facilities, refrigerated trucks and train cars, data center cooling systems, poultry farms, and the entire global manufacturing industry. The list of buildings and machines that need refrigerants to function is almost endless.
The Kigali Amendment is an update to 1987’s Montreal Protocol, which many experts consider the world’s most successful international environmental treaty. The goal of the original pact was to phase out worldwide use of hydrochlorofluorocarbons, or HCFS, the refrigerants that had ripped a hole in Earth’s ozone layer (which blocks many forms of harmful UV light from traveling through the atmosphere). In the 1970s, a class of chemicals called hydrofluorocarbons, or HFCs, began to replace HCFCs, and after 1987 that process sped up.
The Montreal Protocol succeeded: The ozone layer hole is shrinking. However, we’ve discovered that HFCs have become some of the most potent, omnipresent greenhouse gases in the world, which is why nations banded together to ban them under the Kigali pact.
In the U.S., ratification of Kigali was expected in late 2018, and it enjoyed unusual and vocal support from both Republicans and HVAC&R (heating, ventilation, air conditioning, and refrigeration) manufacturers. Despite this, 2019 came and went, and the U.S. didn’t sign the Kigali Amendment. Some speculate that since the treaty’s logic rested on climate change action, the Trump administration sacrificed 33,000 American jobs and $5 billion in exports rather than acknowledge the need for it.
Since 2018, 16 states have enacted their own legislation on super-emitting refrigerants. This has kept U.S. research and development in this area from completely dying out. Since most of the country’s HFC use is still unregulated, though, innovative HVAC&R companies compete with each other in limited markets rather than help shift technology across the whole sector.
HFCs are thousands of times more harmful than carbon dioxide and hundreds of times worse than methane. The GWP of CO2, the leading driver of climate change, is 1, while methane’s is 34. The most common HFCs have “global warming potential” values, or GWP, of between 1,400 – 3,500.
But they are also cheap, well-understood by heating and cooling system engineers, and both safe and easy for technicians to use. Thus synthetic HFCs have become so ubiquitous that other types of coolants are known as “alternative refrigerants,” and until recently were considered a niche specialty product for boutique customers.
In 2019, I went to a U.S. conference about alternative refrigerants. Scanning the hundreds of participants, I saw no earnest young climate activists or Silicon Valley aspirants in sustainable footwear. Instead it was a sea of middle-aged white men. Most were HVAC&R salesmen or technicians, mechanical engineers, or executives from privately-owned grocery store chains and industrial companies.
As I watched the presentations by business people, academic researchers, and state regulators, it became clear that HFCs in the U.S. are dealt with ad hoc, depending on the availability of grant or tax break programs that vary wildly from place to place. Practical engineering choices also vary wildly from facility to facility.
It’s deceptive to treat alternative refrigerants as one category because there are a lot of them, and you can’t just grab one and switch it in for an HFC. Each type and use case presents unique design challenges. Refrigerants also differ in ease of use and safety – some types, for example, have an alarming tendency to burst into flames. These engineering problems are solvable. However, whether you sell air conditioners, groceries, or industrial chemicals, the market won’t drive you to spend money for problem-solving that isn’t strictly required.
At one point during the conference, attendees participated in a live poll of just one question: If you make HVAC&R purchasing decisions, what would motivate you to choose alternative refrigerant tech? The selection of answers included operational cost savings and environmental values, but the winning answer, by a huge margin, was “regulatory pressure.” Market forces will not fix refrigerant emissions on their own.
Since I’m an environmental engineer and climate activist, sometimes people ask me what fridge I “want” them to buy. It’s true that there are a few manufacturers, mostly in California, who would be glad to sell them an expensive way to ease some guilt. However, when any of us goes to the hospital or anywhere large and air conditioned, or buys anything that had to be kept cold somewhere along the supply chain, then we’re contributing to demand for HFCs. It doesn’t matter much where we keep our own ice cream. We need to tackle refrigerants collectively.
Phaseout of HFCs is not the only front in the refrigerant emissions battle. There are also HFCs and leftover HCFCs in existing machines. Every air conditioner, industrial heat pump, and refrigerator in the world is not going to be replaced overnight, and the old units won’t just disappear. Leaks and disposal have to be handled.
Existing refrigerant management is crucial. In theory, a vapor compression cycle (like the one in the coils of the average refrigerator) is a closed system. In reality, these systems are notoriously leaky.4 Also, discarded systems languish in landfills leaching HFCs that eventually make their way into the atmosphere. Without government oversight, these legacy HFCs and HCFCs could continue to raise global temperatures for decades to come, even if they are completely eliminated from new products.
The U.N. has just released a new report on climate emissions from cooling technologies. In it, alternative refrigerants were combined with energy efficiency into one vision for “efficient and climate friendly cooling,” or “sustainable cooling,” in the face of rising global temperatures.
I couldn’t agree more with the UN’s vision. Global demand for HVAC&R is going to skyrocket as temperatures go up, and we need to address the associated demand for electricity. In the U.S., energy bills hit poor communities of color harder than elsewhere, so efficiency is an important justice issue as well as a practical one7.
However, as an American engineer, I am concerned by rhetorical frames that link energy efficiency to alternative refrigerants. In the U.S., commercial operations budgets and government contracting norms frequently use energy savings, translated into cost savings, as the only metric of success. For example, in 2019 the Department of Energy awarded $819 million in Energy Savings Performance Contracts, or ESPCs8. These contracts’ central logic is that they are free, in theory, since the government will save more long-term than they’ll spend short-term according to complex calculations. In practice, contractors have to value cost cutting above all else, including the health of the planet.
Energy efficiency in HVAC&R systems is also a solvable engineering problem, but it’s often separate from the refrigerant fluid choice. We need to decouple those issues when emissions require it. Alternative refrigerant technology won’t make it into actual buildings if it has to compete with costing nothing. Technicians won’t fix leaks in existing systems and dispose of spent ones properly if they have to do it for free.
When the U.S. House Select Committee on the Climate Crisis recently released its new plan, I was elated to read a section titled, “Phase Down the Production and Consumption of Hydrofluorocarbons in the United States,” which included recommendations for regulation, enforcement, education, and grants for replacing equipment. Congress must act on this section of the plan as fast as they can. Management strategies like leak repair could pull emissions out of the air right away, while technology shifts to non-HFCs in new machines, which would yield huge climate benefits within a few years.
Project Drawdown’s 2020 Review ranked climate solutions by gigatons of prevented CO2-equivalent emissions. Combined, managing legacy refrigerants and switching from HFCs to non-polluting alternative refrigerants get the highest ranking on the list, higher than expanding solar photovoltaics or wind turbines or electric cars9. But Project Drawdown’s experts are quick to emphasize that all the listed strategies are essential, and I agree. I don’t want to pit refrigerant management and HFC phaseout against other environmental strategies. I want the electrical grids that cooling and heating systems plug into to be powered by renewables rather than fossil fuels.
Still, I would despair to see a facility switch to solar electricity, then plug in an old HVAC&R that spews HFCs. I don’t understand why this is difficult to explain to many environmentalists. When it comes to emissions, some in the climate action community seem to be staring at the forest but missing the tallest tree.
We will need to cool down even more people and perishables as the world gets hotter. If we don’t start contending with HFC emissions, we’ll propel another feedback loop into our global climate emergency. We’re in a race to reduce emissions, and refrigerants offer some of the quickest decarbonization paybacks in the world. It’s time to attack refrigerant emissions, before we run out of time.