An international research team led by the University of Birmingham has calculated that surging global demand for air conditioning could generate 113.3 gigatons of carbon dioxide equivalent emissions between 2010 and 2050, enough to raise Earth’s average temperature by roughly 0.05 degrees Celsius on its own. The findings, published in Nature Communications on Feb. 25, 2026, frame air conditioning as a feedback loop: hotter temperatures and rising incomes drive more cooling, which in turn accelerates the warming that created the demand. With regulators in the United States already wrestling over how fast to phase out potent refrigerant chemicals, the study sharpens a tension between protecting vulnerable populations from deadly heat and keeping climate targets within reach.
How 113 Gigatons of Emissions Add Up
The study modeled AC-related greenhouse gas output, covering both the electricity consumed by cooling units and the refrigerant gases they leak, across five Shared Socioeconomic Pathway and Representative Concentration Pathway scenario combinations. Under the moderate SSP245 pathway, the researchers estimated cumulative emissions of 113.3 GtCO2e from 2010 to 2050, with an associated global mean temperature increase of about 0.05 degrees Celsius and a range spanning 0.03 degrees Celsius upward depending on the scenario. That temperature bump may sound small in isolation, but it compounds on top of all other warming drivers at a moment when governments are struggling to hold total warming below 1.5 degrees Celsius.
A key part of the analysis focused on how rising incomes in low-income regions will multiply AC demand. As households in tropical and subtropical countries gain purchasing power, millions of first-time buyers will install cooling systems, concentrating new emissions in areas that historically contributed least to climate change. The study frames this as an equity problem as much as an engineering one: denying affordable cooling means more heat-related illness and death, yet supplying it with today’s technology locks in decades of additional emissions.
NASA Climate Data Driving the Projections
To map where and when cooling demand will spike, the researchers drew on NASA’s NEX-GDDP-CMIP6 dataset, which provides future daily temperature and near-surface humidity projections at roughly 0.25-degree spatial resolution under multiple SSP scenarios. That granularity allowed the team to calculate population-weighted cooling degree days at the local level rather than relying on national averages, which can mask extreme regional heat exposure. The dataset covers SSP experiments from 2015 through 2100, giving the model a long enough time horizon to capture slow-moving demographic and climate shifts.
Population growth patterns fed into the model through NASA SEDAC’s 1-km gridded projections, which align population estimates from 2010 to 2100 with the same SSP frameworks. By layering high-resolution climate data on top of fine-grained population grids, the study could identify hotspots where fast-growing urban populations will collide with intensifying heat. That spatial precision matters because aggregate global figures can obscure the reality that a handful of rapidly urbanizing regions in South Asia, sub-Saharan Africa, and Southeast Asia will account for a disproportionate share of new AC installations and the emissions they produce.
Refrigerant Rules Face Political Headwinds
On the regulatory side, the U.S. Environmental Protection Agency finalized rules restricting the use of high-global-warming-potential hydrofluorocarbons in residential and light commercial air conditioning and heat pumps, with key compliance dates beginning January 1, 2025. Those restrictions were designed to push manufacturers toward lower-impact refrigerants, but the transition comes with a price tag. Units built with newer refrigerant chemicals are expected to cost 20 to 25% more, which could put cleaner cooling out of reach for lower-income households in the United States and, by extension, in developing countries where price sensitivity is even greater.
Those rules now face additional uncertainty. An AP report has described political and industry pushback around HFC restrictions, raising questions about how aggressively the rules will ultimately be implemented and enforced. If federal HFC policy weakens, the refrigerant leakage pathway modeled in the Nature Communications study could track closer to its higher-emission scenarios rather than the moderate SSP245 baseline. The United Nations has separately warned that AC electricity use will surge in a warming world, reinforcing the study’s conclusion that both the energy and chemical sides of the equation need simultaneous attention.
Why Efficiency Alone Will Not Close the Gap
Improving the efficiency of air conditioners is often presented as the most straightforward way to curb future emissions, and the new modeling does assume steady gains in performance. Yet the Nature Communications team, drawing on an assessment of technology and policy options, found that efficiency improvements on their own cannot neutralize the combined effect of population growth, urbanization, and rising temperatures. Even aggressive standards still leave billions of additional units entering service, each contributing to higher peak electricity demand and adding to the risk that grids will lean on fossil fuel generation during the hottest hours.
The study instead points toward a portfolio of measures that go beyond the appliance box. Building design that prioritizes passive cooling, expanded use of district energy systems, and rapid decarbonization of electricity all emerge as critical levers alongside better equipment. Without cleaner power, the researchers warn, even the best-performing air conditioners will lock in substantial emissions over their lifetimes. At the same time, policies must ensure that low-income communities gain access to safe cooling, or the world will face widening inequality in climate impacts as heat waves intensify.
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*This article was researched with the help of AI, with human editors creating the final content.
