Refrigeration
The most powerful climate lever almost nobody thinks about is the gas hiding inside your fridge and air conditioner — thousands of times more warming than carbon dioxide. Fixing it is a rare good-news story, attached to the most successful environmental treaty in history.
The effect is immediate. This stops an emission that is happening right now.
Origins
The story of refrigerants is the story of solving one crisis and accidentally creating the next — and then, remarkably, solving that one too.
Early refrigerants were often toxic or flammable — ammonia, sulphur dioxide — and the occasional lethal leak was a real hazard. In the 1920s industry produced what looked like a miracle: chlorofluorocarbons, or CFCs, which were stable, non-toxic, and non-flammable. They went everywhere, into every fridge and air conditioner and spray can.
Then, in the 1980s, scientists discovered that those same stable molecules were destroying the stratospheric ozone layer that shields all life from ultraviolet radiation, tearing a hole in it over Antarctica. The response was the Montreal Protocol of 1987 — the single most successful environmental treaty ever written, ratified by every nation on earth, which phased out CFCs and set the ozone layer on a path to full recovery.
But the replacements, the HFCs, turned out to be potent greenhouse gases. So in 2016, in Kigali, Rwanda, the world amended the same treaty again. The Kigali Amendment commits nations to phasing down HFCs on a staggered schedule — wealthy countries first, then most of the world, then the hottest countries last — a phase-down that alone is projected to avoid on the order of half a degree Celsius of warming by 2100. One treaty, revised twice, healing one wound and then the next.
What it actually is
The refrigerant is the working fluid that makes a fridge cold and an air conditioner cool a room — the substance that absorbs heat inside and releases it outside. For decades the chemicals used for this job have been quietly among the most potent greenhouse gases on earth.
The current generation, hydrofluorocarbons or HFCs, do not damage the ozone layer — that was the previous generation’s crime, since solved. But molecule for molecule, HFCs trap heat hundreds to thousands of times more effectively than carbon dioxide. A small leak of refrigerant can outweigh, in climate terms, a great deal of a device’s energy use.
And here is the crucial, counter-intuitive fact that makes this a solution rather than just a problem: most of the damage happens not while the appliance runs, but when it dies. The great majority of refrigerant emissions occur at end of life, when equipment is scrapped and the gas is simply vented to the sky. Which means there are two distinct tasks, and both are winnable: stop using the worst gases in new equipment, and carefully capture and destroy the enormous existing “bank” of refrigerant already installed in the world’s roughly one-and-a-half billion cooling devices before it escapes.
The technology to do both exists. Natural refrigerants — propane, ammonia, carbon dioxide itself — have negligible warming potential. Recovery and destruction of old refrigerant is a solved engineering problem. This is not a case of waiting for invention. It is a case of doing the unglamorous work.
The numbers
The potency. Common HFCs warm the atmosphere on the order of one thousand to several thousand times more than an equal mass of carbon dioxide. This is why a substance present in tiny quantities can matter so much.
Where the emissions happen. Roughly 90 percent of a refrigerant’s lifetime emissions occur at disposal, when old equipment is scrapped and the gas vents. Managing that existing bank is therefore at least as important as changing what goes into new machines.
The scale of the stock. There are on the order of 1.4 billion refrigerators and freezers in the world, plus a fast-growing population of air conditioners — each one a small reservoir of refrigerant, and cooling demand is rising steeply as the world warms and grows richer.
The prize. Full compliance with the Kigali phase-down is projected to avoid close to 0.5℃ of warming by the end of the century, and analyses of managing the refrigerant bank on top of that place the combined climate benefit among the very largest available from any single class of action.
The alternatives. Natural refrigerants carry negligible warming potential — propane sits near a warming potential of a few, ammonia and carbon dioxide near zero — though each brings its own handling requirement around flammability, toxicity, or pressure.
Why it matters
We find this solution genuinely cheering, and it is worth being clear about why, because good news is rare enough in this field that it deserves to be understood rather than just enjoyed.
First, it is proof that the hardest kind of international cooperation is possible. The Montreal Protocol worked. Every country signed, the chemicals were phased out, industry adapted faster and cheaper than it swore it could, and the ozone layer is healing. When people say global environmental action is hopeless, this is the standing rebuttal — and Kigali shows the same machinery can be pointed at the climate.
Second, it does not ask anyone to be colder. In a warming world, cooling is not a luxury; it is increasingly a matter of survival, as heat waves become deadly. The refrigerant solution is beautiful precisely because it does not require us to give up cooling. It asks only that we cool with better gases and clean up the old ones. You keep the fridge and the air conditioner; you just change what is inside.
And third, it rewards the unglamorous. There is no ribbon-cutting for a technician who properly recovers refrigerant from a scrapped air conditioner instead of venting it. There is no headline for a well-run reclamation programme. This is climate work as plumbing and disposal and paperwork — and it may be, ton for ton, among the most valuable work available. We have a soft spot for solutions like that: enormous in effect, invisible in operation, requiring not a breakthrough but simply the discipline to finish the job.
What it actually takes
Capture the bank at end of life. Because most emissions happen at disposal, the highest-value action is ensuring that refrigerant in old and scrapped equipment is recovered and destroyed rather than vented. This is a matter of regulation, incentives, and trained technicians — not new science.
Phase down HFCs on schedule. Honour and accelerate the Kigali commitments, and resist the temptation to backslide as cooling demand rises.
Adopt natural refrigerants. Move new equipment to propane, ammonia, carbon dioxide, and other low-warming fluids, with the safety engineering each requires.
Make cooling efficient at the same time. Every unit of electricity saved by a more efficient air conditioner is emissions avoided on top of the refrigerant benefit — the two gains compound, which is why Kigali is paired with cooling-efficiency programmes.
Build reclamation infrastructure. Recovery only happens if there is somewhere for the gas to go and someone paid to take it there. The systems, certification, and markets for reclaimed refrigerant are the unshowy backbone of the whole solution.
Where it matters most
Refrigerant management matters most where cooling demand is exploding — the hot, humid, fast-growing regions where an air conditioner is becoming a necessity rather than a luxury.
Across the Western Ghats and the wider Indian subcontinent, air-conditioner ownership is projected to multiply many times over in the coming decades, making the choice of refrigerant there one of the most consequential climate decisions being taken anywhere.
The North China Plain anchors both the world’s largest manufacturing base for cooling equipment and one of its largest and fastest-growing markets — which means the gases chosen there ripple worldwide.
Across the deserts of the American Southwest — the Sonoran, Mojave, and Chihuahuan — cooling is already life-sustaining infrastructure, and the vast installed base of equipment is a correspondingly vast bank of refrigerant to manage carefully at end of life.
And across the Sahel, where lethal heat is rising fastest against the thinnest cooling infrastructure, the coming build-out is a chance to leapfrog straight to low-warming refrigerants rather than repeat the rich world’s mistakes.
How to tell it’s being done well
Is the old gas captured, or vented? Since most emissions happen at disposal, the single most important question is whether refrigerant is recovered and destroyed when equipment dies. A programme that ignores end-of-life is missing the main event.
What refrigerant does new equipment use? Low-warming natural refrigerants are the goal; high-GWP HFCs are the legacy to leave behind.
Is efficiency addressed alongside the gas? The best cooling solutions cut both the refrigerant emissions and the electricity, because the two gains reinforce each other.
Is there real reclamation infrastructure? Recovery requires trained technicians, certification, and a market for reclaimed gas. Without that backbone, good intentions vent to the sky anyway.
Does it honour the Kigali schedule? Progress here is measured against a clear international timetable. Meeting or beating it is the benchmark.
Where this matters most
Who is working on this
We are researching which organizations in our directory of 8,493 actively work on this solution, and we only list an organization once we have verified it. That research is ongoing. In the meantime, search the directory yourself:
Questions
Why are refrigerants such a big deal for the climate?
The gases used in fridges and air conditioners, hydrofluorocarbons, trap heat hundreds to thousands of times more effectively than carbon dioxide. A small leak can outweigh a device's entire energy use in climate terms, which is why a substance present in tiny quantities matters so much.
Do I need to stop using air conditioning?
No, and that is what makes this solution so appealing. In a warming world cooling saves lives. The answer is not less cooling but better refrigerants and careful cleanup of the old ones. You keep the fridge and the air conditioner; you change what is inside and how it is disposed of.
Why does disposal matter more than daily use?
Around 90 percent of a refrigerant's lifetime emissions happen at end of life, when old equipment is scrapped and the gas is vented to the atmosphere. That is why capturing and destroying the existing bank of refrigerant is at least as important as changing what goes into new machines.
What is the Kigali Amendment?
A 2016 amendment to the Montreal Protocol, agreed in Kigali, Rwanda, that commits nations to phasing down high-warming HFCs on a staggered schedule. That phase-down alone is projected to avoid close to half a degree Celsius of warming by 2100.
What replaces HFCs?
Natural refrigerants such as propane, ammonia, and carbon dioxide, which have negligible warming potential. Each requires its own safety engineering around flammability, toxicity, or pressure, but all avoid the enormous climate cost of HFCs.
Sources
- Project Drawdown - Deploy Alternative Refrigerants Framework and classification. Cited, not reproduced.
- UNEP - Kigali Amendment to the Montreal Protocol
- IPCC Sixth Assessment (AR6) - short-lived climate pollutants
- Velders et al. (2022) - future HFC emissions under Kigali
The solution taxonomy follows the framework popularised by Project Drawdown. The analysis above is our own; for their carbon modeling and rankings, visit them directly.