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The industrialized world has cornered itself into a drastic air conditioning trap: the warmer it gets, the more we use air conditioning. The more we use air conditioning, the warmer it gets. The problem posed by air conditioning resembles, in miniature, the problem we face in tackling the climate crisis. The solutions that we reach for most easily only bind us closer to the original problem.

Because of the combination of population growth, rising incomes, falling equipment prices and urbanization, the number of air-conditioning units installed globally is set to jump from about 1.6 billion today to 5.6 billion by the middle of the century, according to the International Energy Agency.[1]

The US already uses as much electricity for air conditioning each year as the UK uses in total. The IEA projects that as the rest of the world reaches similar levels, air conditioning will use about 13% of all electricity worldwide, and produce 2 billion tons of CO2 a year – about the same amount as India, the world’s third-largest emitter, produces today.

One step towards solving the problem presented by air conditioning – and one that doesn’t require a complete overhaul of the modern city – would be to build a better air conditioner. There is plenty of room for improvement. “Everything is still based on the vapor compression cycle; same as a refrigerator. It’s effectively the same process as a century ago,” says Colin Goodwin, the technical director of the Building Services Research and Information Association. “What has happened is we’ve expanded the affordability of the air conditioner, but as far as efficiency, they’ve improved but they haven’t leaped.”[2]

The US Environmental Protection Agency took a step to force new innovation in this area by recently announcing a rule that would phase out hydrofluorocarbons (HFCs), the potent greenhouse gases that are widely used as refrigerants.[3]

Though HFCs aren’t intentionally emitted in the regular use of refrigerators and air conditioners, they often leak out at various phases in an appliance’s life cycle, from manufacturing through disposal. One of the most widely used HFCs, R-134a, causes 1,430 times more warming than an equivalent amount of carbon dioxide over 100 years. Another that is commonly used in supermarkets, R-404A, has a global warming potential of 3,900. Eliminating the use of HFCs worldwide would reduce emissions enough to avoid up to 0.5˚C (0.9˚F) of warming by 2100.[4]

So what do the solution pathways look like to achieve the innovations in air conditioning necessary to escape this current feedback loop?

Using technology currently in development, AC units in skyscrapers and even your home could get turned into machines that not only capture CO2 but transform the stuff into a fuel for powering vehicles that are difficult to electrify, like cargo ships. The concept, called crowd oil, is still theoretical and faces many challenges. But in these desperate times, crowd oil might have a place in the fight to curb climate change.

The researchers’ analysis found that the Frankfurt Fair Tower in Germany (chosen by lead author Roland Dittmeyer of the Karlsruhe Institute of Technology), with a total volume of about 200,000 cubic meters, could capture 1.5 metric tons of CO2 per hour and produce up to 4,000 metric tons of fuel a year. By comparison, the first commercial “direct air capture” plant, built by Climeworks in Switzerland, captures 900 metric tons of CO2 per year, about 10 times less, Dittmeyer says. An apartment building with five or six units could capture 0.5 kg of CO2 an hour with this proposed system.[5]

The nonprofit RMI has worked with the Indian government and a clean energy initiative called Mission Innovation to launch the Global Cooling Prize, a competition that asked manufacturers to completely redesign air conditioners to shrink the climate footprint.

The competition announced two winners with new prototypes for air conditioners that have five times less climate impact than units that are on the market now. If scaled up, the technologies could help avoid 132 billion metric tons of CO2-equivalent emissions by the middle of the century.

The winning designs, from a major Chinese manufacturer called Gree Electric Appliances with its partner Tsinghua University, and Daikin, an Indian manufacturer that partnered with Japan’s Nikken Sekkei, use proprietary compressors designed to work with refrigerants that aren’t as polluting, as well as optimize how the equipment cools or dehumidifies the air; if the temperature is already low enough but the room is still humid, the equipment can efficiently switch to only lower the humidity. One of the designs senses the outdoor air, so it can let in fresh air when it’s cooler outside; one design can also connect directly to a solar panel, which can shrink the amount of power the unit takes from the grid.[6]

As with many innovations like these discussed above, the upfront cost of new designs will be higher than standard alternatives, but will pay for themselves and save more money over time because the efficiency of the system means consumers will save so much on energy bills. And when it comes to issues like the global air conditioning trap, the phrase “you can pay now or pay later” has never rung truer.

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