A warming world is making the need to stay cool more pressing. Hot countries are getting hotter, tipping normal summer temperatures into dangerous territory more frequently. Temperate countries are experiencing heat waves that were once unthinkable.
Globally, an estimated 1.2 billion rural and urban poor are at risk because they lack access to cooling, including refrigeration and air conditioning, according to a 2022 report by the research group Sustainable Energy for All. Meanwhile, 2.4 billion middle-class people are "on the brink" of buying the most affordable cooling appliance available to them, the report found, regardless of its efficiency.
While millions of people buying cheap ACs is a quick fix for a hotter climate, it also stands to complicate the energy transition. More air conditioning puts more strain on local power supplies, and threatens efforts to shift energy sources from fossil fuels to renewables. Indeed, cooling will be "one of the top drivers of global electricity demand over the next three decades," the International Energy Agency said in a 2018 special report. The organization estimates that approximately 10 new air conditioners will be sold every second between now and 2050.
At the moment, space cooling devices -- fans, dehumidifiers and air conditioners -- use more than 2,000 terawatt hours of electricity every year, which is equivalent to two and a half times the total electricity used across Africa, according to the IEA, and about 10% of the global total. Based on current policies and targets, this is set to grow to 6,200 terawatt hours by 2050, with nearly 70% of the increase tied to demand for AC units in homes.
Already, space cooling can take up more than two-thirds of peak electricity demand on hot days in parts of the U.S. and Middle East. In Saudi Arabia, for example, air conditioning accounts for 70% of total annual electricity demand. Countries where demand is expected to grow significantly, particularly India, China and Indonesia, would need to install large amounts of expensive peak power capacity to meet anticipated cooling needs.
Space cooling is also expected to overtake appliances as the largest single user of electricity in buildings globally by 2050. For this, 2,500 gigawatts of additional capacity is needed -- the equivalent of the current total energy generation capacity of the United States, Europe and India combined, according to the IEA.
Part of the challenge is appliance efficiency. Often, new AC converts are just focused on buying the most affordable device they can find. According to the IEA, the average air conditioner sold in 2018 was less than half as efficient as the typical appliance available, and a third as efficient as the best technology on offer. Policies that require or incentivize people to buy more efficient AC units could cut energy demand by 45% and reduce investment and running costs for the electricity network by $3 trillion, the IEA found.
But even in an optimistic scenario that assumes more efficient cooling technology, the required energy demand is likely to exceed IEA estimates for a world warming at no more than 2C, according to separate research from the Center for Sustainable Cooling at the University of Birmingham. If everyone in the world had access to the cooling they need, including refrigerators for food and medicine, as well as air conditioners in cars and homes, the related energy demand would outstrip IEA estimates threefold by 2030, according to the Center for Sustainable Cooling.
To provide enough cooling to keep humans safe and food and medicines from spoiling, the Center for Sustainable Cooling estimates the world will need 14 billion additional cooling devices by 2050, almost four times the 3.6 billion currently in use.
Further, the volume of electricity the Center estimates would be needed to run all of those devices is equivalent to more than 80% of the IEA's projected renewable capacity for 2050. Under the most pessimistic scenario, if new technologies making appliances more efficient are not employed, it could be over 100%.
Even those estimates make the (generally safe) assumption that renewable energy capacity will continue to grow. If that doesn't happen, the impact from millions more air conditioners would be much greater. More than 2 metric gigatons (billion tons) of carbon dioxide equivalent per year by 2030, even in a scenario where AC units become more efficient over time. That's more than the entire emissions of the European Union. in 2021.