Here’s a climate feedback loop that doesn’t get enough attention: the hotter it gets, the more we cool ourselves, and the more we cool ourselves, the hotter it gets.

A new study in Nature Communications by Hongzhi Zhang, Yuli Shan (University of Birmingham), and colleagues has quantified this problem with uncomfortable precision.

The Numbers

Under a mid-range emissions scenario (SSP2-4.5), cumulative AC-related emissions from 2010 to 2050 could reach 113.3 billion tonnes of CO₂ equivalents. In the worst case, annual emissions from air conditioning alone could hit 8.5 billion tonnes by 2050 — significantly more than the current total US emissions of 5.9 Gt/year.

The additional warming from AC under the mid-range scenario? About 0.05°C. That may sound small, but it’s a self-reinforcing loop on top of everything else.

The Surprise

Only 8.3% of the growth in AC emissions comes from additional cooling demand driven by climate change. The overwhelming driver is economic: as incomes rise in hot countries — India, Southeast Asia, sub-Saharan Africa — more people can afford air conditioning for the first time.

This isn’t a story about irresponsible consumption. It’s about billions of people gaining access to basic thermal comfort. You can’t — and shouldn’t — tell people in New Delhi or Lagos not to buy AC. But you can make sure the systems they buy are efficient and powered by clean energy.

What This Means for CDR

This study is a reminder that carbon removal doesn’t exist in isolation. We need CDR and decarbonized cooling:

  • Heat pumps that cool efficiently and run on renewable electricity
  • Building design that reduces cooling loads (passive cooling, better insulation, reflective materials)
  • Refrigerant transitions away from high-GWP HFCs
  • Grid decarbonization in the countries where AC demand is growing fastest

CDR handles the emissions we can’t avoid. But it’s far cheaper to prevent a tonne of cooling-related CO₂ than to remove it after the fact.

The AC paradox is a perfect illustration of why both tracks — removal and reduction — have to run in parallel.

Source: EurekAlert / University of Birmingham | Nature Communications