Scientist Dream of a Future Where Your AC Unit Sucks Carbon Out of the Sky

Air conditioners rule the world.
Air conditioners rule the world.
Photo: Getty

Air conditioners require lots of energy to run, meaning they result in lots of greenhouse gas emissions. But maybe they don’t have to? In a recently published Nature paper, researchers with the Institute for Micro Process Engineering in Germany have dreamt up a world where air conditioners don’t make climate change worse, but rather suck carbon out of the air.


The air conditioners we know and love pull in warm air and release it as cooler air by using coolants to absorb the heat. This wouldn’t necessarily change in a future where AC units fight climate change, but the devices would have to be tweaked to absorb the carbon dioxide in air along with heat. The researchers propose using a special filter to capture carbon and water from the air to convert them into a hydrocarbon fuel that can then be used in the AC owner’s home or office, or even sold.

The idea is essentially a microgrid that runs on the carbon your air conditioner caught, which is pretty cool considering that carbon is warming up our planet and driving humanity toward a cliff. The authors of the paper estimate that, in a specific Frankfurt, Germany, office building, this technology could be capable of producing more than 600,000 gallons of fuel in a year from the carbon captured, reports Fast Company.

Carbon capture technology is still in its early days, and there are a lot of competing ideas for how to scale it up. One of the big challenges is that the technology relies on electricity, which in today’s world is often dirty. To remove more carbon from the air than you’re putting in, folks have proposed running carbon capture plants renewably. As Wired reports, the new paper’s hypothetical air conditioner units would need to run on renewable energy just to break even, because the fuel they produce will also emit greenhouse gases when burned.

We’ll need more air conditioners to survive a warmer future, and it would be nice if they didn’t make climate change even worse. But this is all still, however, incredibly hypothetical. And while carbon capture is cool, it does not address the root cause of this entire mess: our consumption! No technology will save us if we don’t stop emitting copious amounts of carbon and other greenhouse gases into the atmosphere.

Yessenia Funes is climate editor at Atmos Magazine. She loves Earther forever.


Stephan Zielinski

I read the letter. (It’s just a letter, even if the authors did have some of their friends look at it. That’s why it’s published under “Perspective.”) Whooee, was that a big load of “If we had a cart, we’d have a horse and a cart, if we had a horse.”

Yes, if electrical power was carbon-neutral, we could run little synfuel plants wherever convenient, and use the resulting hydrocarbons to power vehicles. (Which we may want to do going forward, simply because hydrocarbon fuel is energy dense.) But the authors are ignoring the inevitable inefficiencies in building a lot of little plants rather than one big one, and starting from carbon-neutral electricity is like discussing how to cook a seven-course meal by assuming the first six courses are already on the table and now the biggest problem remaining is how to get a carton of ice cream open.