How big is the energy and climate cost of air conditioning?
The scale is enormous and growing fast. In China, a study of 343 cities found that for every extra day with an average temperature above 30°C, weekly air conditioner sales jump by 16.2% [2]. Under a high-emissions scenario, AC sales in the Pearl River Delta could rise 71% by mid-century, and per capita electricity demand for cooling across China could increase by 28% [2]. That's a massive new demand on the power grid.
In the United States, if commercial floorspace grows as expected, total energy use from buildings could increase by 65-71% by 2100, driven largely by more cooling in the warmest climate zones [7]. Even in Japan, future climate scenarios show annual cooling loads rising by 7-12% in major cities like Tokyo and Osaka [4]. These aren't small changes—they represent a fundamental shift in how much energy we need just to stay comfortable.
How does AC make climate change worse?
The core problem is that most air conditioners run on electricity, and much of that electricity still comes from burning fossil fuels. More AC use means more carbon emissions, which trap more heat, which drives more AC use. In the Pearl River Delta region, researchers found that while climate change has reduced the need for dehumidification (slightly cutting emissions there), the increase in cooling demand has been larger, leading to a net rise in carbon emissions [3].
This feedback loop is especially tight in hot, humid climates. A study of office buildings in Guangzhou, China, found that climate change over 60 years raised the outdoor temperature used for AC design by 0.4-0.7°C, and that alone increased building energy consumption by about 4.6% [1]. The study also showed that the biggest driver of cooling energy use is the indoor temperature set point—meaning the cooler we try to make it inside, the more energy we burn, and the more emissions we create.
Can we break the cycle without giving up AC?
Yes, but it requires smarter design and technology, not just turning down the thermostat. The same Guangzhou study found that multi-objective optimization—adjusting things like set points, air infiltration, and window properties—could cut cooling energy by 10.6-16.8%, enough to offset the climate-driven increase [1]. In New York City, raising thermostat set points and installing reflective roofs could reduce energy burden by up to 20% in the most affected neighborhoods [5].
Other innovations go further. One study demonstrated a fabric that passively cools indoor spaces by reflecting sunlight and emitting heat into space, achieving sub-ambient cooling of about 12°C with no energy input [9]. Another showed that green roofs can cut HVAC energy demand by 10-24% depending on the climate, with the biggest savings in cooler temperate zones [6]. And simple heat recovery systems that pre-cool incoming air using exhaust air can save up to 200 watts of power and pay for themselves in 1.5 years [8]. These solutions show that we don't have to choose between staying cool and protecting the climate—but we do have to choose smarter cooling.
About These Sources
This answer is built on 9 peer-reviewed studies — published from 2021 to 2024, 3 from 2024 or later, 6 in Q1 journals, collectively cited 243 times — selected as the most relevant from 10 studies that passed quality screening, drawn from 64 papers retrieved from a database of over 500 million.
Sources used in this answer
Climate change's effects on the amount of energy used for cooling in hot, humid office buildings and the solutions
Climate change increased the outdoor design temperature for AC in Guangzhou by 0.4-0.7°C, raising office building energy consumption by about 4.6%; multi-objective optimization could cut cooling energy by 10.6-16.8%.
China’s adaptive response to climate change through air-conditioning
Across 343 Chinese cities, an extra day above 30°C boosts weekly AC sales by 16.2%; under a high-emissions scenario, per capita AC electricity demand in China could rise 28% by mid-century.
Responses of air-conditioning loads to climate change and its impact on carbon emissions in the hot summer and warm winter climate
In the Pearl River Delta, cooling design loads increased 1.83-5.56% over 20 years while dehumidification loads decreased, but the net effect was a weak increase in total carbon emissions.
Impact of future climate change on energy consumption in residential buildings: A case study for representative cities in Japan
Using future climate data for Japan, annual cooling loads in residential buildings are projected to rise 7-12% in four major cities, while heating loads fall 5-9%.
Energy burden and air conditioning adoption in New York City under a warming climate
In New York City, low-income households could face AC energy burdens of up to 6.1% of income, rising to 8% by 2100; raising set points and using reflective roofs could cut burden by up to 20%.
Simulation-based study on the role of green roof settings on energy demand reduction in seven Australian climate zones
Green roofs can reduce HVAC energy demand by 10.1-23.7% across Australian climate zones, with the largest savings in cool temperate climates (Canberra) and smallest in humid warm climates (Darwin).
How will United States commercial building energy use be impacted by IPCC climate scenarios?
For US commercial buildings, total energy use by 2100 could increase 65-71% when accounting for urban growth, driven by increased cooling in warm zones and decreased heating in cold zones.
Heating/Cooling Fresh Air Using Hot/Cold Exhaust Air of Heating, Ventilating, and Air Conditioning Systems
A heat recovery system that pre-cools fresh air with exhaust air can save up to 200 W of power, reducing CO2 by about 1 ton per year, with a payback period of 1.5 years in hot conditions.
A Zero‐Energy, Zero‐Emission Air Conditioning Fabric
A cellulose-based fabric achieves passive radiative cooling of about 12°C below ambient with no energy input, while also dehumidifying indoor spaces and generating small amounts of electricity.