The transition to new air conditioning refrigerants will involve difficult tradeoffs.
Air conditioning (AC) has transformed life in hot and humid countries including the US, Japan and Korea. Over 85 to 90% of homes have air conditioners in these countries. The developing world is rapidly following suit. AC sales are skyrocketing in India, China, Southeast Asia and elsewhere. Sales aren’t just gradually climbing as average incomes increase. Instead, AC sales are taking off very quickly as households move into the middle class, a point made in research by Catherine and colleagues.
Access to air conditioning has produced enormous benefits to human health, happiness and productivity. Over the next decades, hundreds of millions more people, if not billions, will enjoy the benefits of air conditioning.
That’s the good news. Unfortunately, the spread of air conditioning is also harming the environment.
These harms come in two forms. First and foremost are the greenhouse gases and health-harming pollutants produced by the fossil fuelled power plants that make electricity for air conditioners. But a close second are harms caused by the refrigerants—the chemicals that enable an air conditioner to absorb heat from an indoor space and then expel it to the outdoors. These chemicals have been escaping into the atmosphere. In the atmosphere they’ve eaten away at the life-protecting ozone layer and are adding to the climate change challenge. The most common refrigerants have 2000 times the global warming potential of an equal mass of carbon dioxide. One study estimates that refrigerants account for a quarter of the greenhouse gas emissions associated with air conditioning. While there is uncertainty around that estimate, atmospheric measurements remove any doubt that these chemicals are, in fact, entering the atmosphere.
Choosing Safety over the Environment
There’s a good reason why the air conditioning industry relies on chemicals that are bad for the environment—they’re safe for consumers. The development of a safe refrigerant, Freon, in the 1930s led to the widespread adoption of AC by US households. Before Freon came along, the industry had been experimenting with toxic and flammable options. These higher-risk options were acceptable for industrial refrigeration, but not for household use.
Unfortunately, decades later, Freon, a type of chlorofluorocarbon (CFC), was found to be depleting the ozone layer. Countries came together in the 1980s and developed the Montreal Protocol, a plan to phase out CFCs and replace them with less harmful alternatives. The industry settled on options that maintained safety but didn’t harm the ozone layer. These are known as hydrofluorocarbons (HFCs). HFCs solve the ozone layer problem, but are still quite bad for the climate. A kilogram of the most common HFC in air conditioning is 2,000 more potent as a greenhouse gas than a kilogram of carbon dioxide.
To put the climate damage caused by HFCs in dollar terms I did a back-of-the-envelope calculation for two common AC units, assuming a social cost of carbon of $50 per ton of carbon dioxide-equivalent. I found that if all the refrigerant leaked out of a mini-split air conditioner that is popular in India, the climate change damage would be about $120. For a 2-ton, central AC unit, a common size in the US, the damages would be over $300.
In 2016, countries gathered once again under the auspices of the Montreal Protocol to find a way to phase down HFCs. They developed a new agreement, known as the Kigali Amendments, that would phase down the climate impact of refrigerants over the next 30 years. Sixty-nine countries have ratified the amendments. Notably, today’s two largest producers and consumers of HFCs, the US and China, have not signed on. Neither has India, the country likely to lead global air conditioning use in the future given the country’s hot, humid climate and large population. India’s likely in no rush since they negotiated a phase down that doesn’t begin until 2028.
The Kigali Amendments bring back to the forefront the consumer safety versus environment trade-off. Based on current air conditioning technologies, there’s a direct trade-off between addressing climate change and refrigerant flammability. Lower global warming potential refrigerants such as R-32 and propane are more flammable. In the near-term, to phase down HFCs, countries will need to squarely confront this trade-off.
Striking the Right Balance
There are several approaches a country could take to balancing consumer safety and the climate in this case.
One option would be to maintain that consumer safety is paramount and no flammability risk is acceptable when it comes to air conditioning. This implicitly says that the perceived cost in terms of safety is too high relative to the climate change benefit. A government holding this position would want to keep all flammable refrigerants off the market. Such a country would be depending on the development of new air conditioning technologies and refrigerants to meet its Kigali phase down goals. Hopefully, countries in this camp would also be committing serious resources to innovation. If new technologies don’t appear this view could lead a country to conclude that phasing out HFCs just isn’t worth the cost and continue relying on existing non-flammable options. The US is currently in this camp.
Another option is for a country to allow more flammable refrigerants to enter the market, with significant regulatory safeguards. Japan, Europe and Australia are taking this approach. An alternative refrigerant, R-32, which is classified as “mildly flammable”, has entered the market and captured a large market share. R-32 has been well known for decades but has been rarely adopted due to its flammability. These governments have, in effect, reconsidered the prudent balance between consumer safety and climate change and concluded a riskier refrigerant is needed given the costs of climate change.
As with many climate policies, this trade-off presents the challenge that the “winners” and “losers” are different. The “winners” are people around the world, now and in the future, who benefit from less climate change. The “losers” are the households who now have a flammable chemical in their home. Another difficulty is that the actual risk posed by flammable refrigerants is hard to quantify in neat, cost-benefit terms and communicate to the public. This is reflected in government and industry websites that explain the rationale of the decision to the public.
From a climate perspective, a transition to R-32 may not be enough. It’s only one-third as potent a greenhouse gas as the refrigerant that it replaces, but is still a significant greenhouse gas. It won’t be sufficient for countries to meet their longer-term Kigali goals. To go further new refrigerants are needed. Ironically, a fossil fuel, propane, is a leading contender for this role due to its climate-friendliness relative to the alternatives. While propane is already used widely in the developed and developing world for heating and cooking, it’s flammability is put forward as a barrier to its use in air conditioning.
As efforts to address climate change progress, difficult trade-offs will likely become more common. It will be more important for policymakers to recognize the trade-offs and carefully balance them. Maybe in some cases new technologies will save the day and make the transitions easy. This was the story with the elimination of ozone depleting refrigerants. A near-equivalent alternative was found that didn’t harm the ozone layer. In other cases, these trade-offs will remain and society will need to work through them. This is where the HFC phase-down sits today.
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Suggested citation for this blog post:
Campbell, Andrew. “Weighing Consumer Safety versus Climate Action.” Energy Institute Blog, UC Berkeley, April 22, 2019, https://energyathaas.wordpress.com/2019/04/22/weighing-consumer-safety-versus-climate-action/