Air Conditioning as a Climate Solution
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AC Has Been A Climate Scourge. Could It Become A Climate Solution?

The world needs more air conditioning. If we do it right, it could even reduce emissions
August 3, 2022

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Wildfires grab the headlines but extreme heat that claims the most lives—over 350,000  worldwide in 2019. As the planet warms and dangerous heat waves become common, air conditioning will shift from being a rich world luxury to a global humanitarian need.

Air conditioners have long been energy hogs, contributors to urban heat islands, and sources of greenhouse gases: a toxic feedback loop that tarred them as climate villains. But in a world where whole populations need artificial cooling to thrive, can new AC technologies actually help our climate targets? 

• • •

Cooling Is Cooking Us

1. A legacy of harm. The core technology inside most air conditioners sold today hasn’t changed much in over a century. Only around one in twenty meets the bare minimum of performance standards, and many use hydrofluorocarbon (HFC) refrigerants that are thousands of times more potent than CO2 as a greenhouse gas.  

2. A problem that keeps getting bigger. The Rocky Mountain Institute (RMI) predicts that by mid-century, there will be as many air conditioners in the world as there are cellphones today. Expect billions of new units as, according to a new study from Peter Sherman at Harvard, 99 percent of the urban population in India and Indonesia will need air conditioning by 2050. Even in temperate countries such as Germany, over 90 percent of people will require AC to cope with deadly heat waves.

India AC electricity demand

Source: Projected global demand for air conditioning associated with extreme heat and implications for electricity grids in poorer countries. Energy and Buildings, 2022.

3. A dangerous Band-Aid. “People in poorer countries largely do not have the luxury of widespread availability of AC units in their households,” Sherman notes. 90 percent of people in the US have access to AC, compared to 9 percent in Indonesia and a mere 5 percent in India. Rich countries can just turn up their cooling instead of making the tough, institutional changes needed to tackle climate change.

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AC Is The Gateway Drug to Decarbonization

1. Cutting the carbon cord. That temperate countries are also suffering from heat could be a blessing in disguise, as it could encourage home-owners to embrace multi-purpose heat pumps. About half the energy consumed in American homes goes on space heating, mostly using fossil fuels. Replacing oil or gas furnaces with an electric heat pump removes all their direct emissions, and gives consumers cooling during the summer. And because heat pumps are about three times more efficient than the best gas furnaces, there is a carbon benefit even if the utility power is not yet fully renewable.  

2. Boosting efficiency. AC tech desperately needs a reboot, and there are many options being explored, including personal cooling, and innovative radiant systems. Last year, the Global Cooling Prize announced winners of its $1m prize, whose prototypes had five times less climate impact than standard air conditioning units.

3. Accelerating the transition to solar. Solar intensity and air temperatures are closely linked, and photovoltaics will generally produce the most electricity when it is most in demand for cooling. India, Kenya, Bangladesh, and Rwanda are among those developing nations embracing solar projects – as well as China, of course.

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What To Keep An Eye On

1. Regulation gearing up. Should Biden’s Inflation Reduction Act pass, there will be more incentives to make the switch to heat pumps, as well as increased domestic investment in solar and other green technologies. Widely available, cheaper, better AC units could ultimately benefit the whole world, not just America.

2. The HFC phase down. Less ambitious but perhaps more realistic than a complete phaseout, hundreds of countries have committed to phasing down HFC use to 15 percent of baseline levels. This move got a huge boost last year when India signed up. This effort alone is hoped to avoid 0.5 degrees Celsius of warming by 2100.

3. A very cool paint. Researchers at Purdue have formulated a heat-rejecting white paint that can keep surfaces 8 degrees Celsius cooler than the ambient temperature in the day – and 19 degrees at night. By reflecting ultraviolet rays, the paint rejects the heat to space, without contributing to local heat islands.

Image: ©Anthropocene Magazine

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