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This past July was the hottest recorded month in human history. Heat waves smashed temperature records worldwide and even brought summer temperatures to Chile and Argentina during the Southern Hemisphere’s winter. It’s more than just a matter of sweaty discomfort. In the U.S. alone, it kills more people each year than floods, tornadoes and hurricanes combined. As climate change worsens, access to 1． cooled spaces is rapidly becoming a health necessity.

Yet standard air-conditioning systems have 2． us in a vicious cycle: the hotter it is, the more people use the AC—and the more energy is used as a result. Nicole Miranda, an engineer researching sustainable cooling at the University of Oxford says: “it’s not only a vicious cycle, but it’s a(n) 3． one.” According to 2018 data from the International Energy Agency (IEA), the worldwide annual energy demand from cooling is 4． to more than triple by 2050.

It’s becoming increasingly clear that humans cannot outrun climate change with the same air-conditioning technology we’ve been using. One well-known problem with current AC systems is their reliance on refrigerant 5．, many of which are potential greenhouse gases. About 80 percent of a standard AC unit’s climate-warming emissions currently come from the energy used to 6． it, says Nihar Shah, director of the Global Cooling Efficiency Program at Lawrence Berkeley National Laboratory.

Standard air-conditioning systems 7． cool and dehumidify through a relatively inefficient mechanism: in order to condense water out of the air, they overcool that air past the point of comfort. Many new designs therefore separate the dehumidification and cooling processes, which avoids the need to overcool.

Even with some of the best technologies available, the gains in 8． alone might not be enough to offset the widely expected increase in air-conditioning use. It will not work to simply replace every 9． air conditioner with a better model and call it a day. Instead, a truly cooler future will have to 10． other strategies that rely on urban planning and building design to minimize the need for cooling in the first place.