From the rocky outcrops of Iceland to the to the sunny plains of Texas, engineers are building giant machines to suck carbon dioxide out of the atmosphere. It sounds like science fiction, but the companies behind this technology insist it could be a secret weapon in the fight against climate change.
This month, the UK government pledged £1bn for the creation of four industrial carbon capture clusters, which will trap emissions from industry.
Trees absorb CO2, but there isn’t enough land on the planet to create a carbon sink the size humanity needs. So while we need to plant trees and protect the world’s remaining forests to tackle climate change, we will also need technology to help us remove excess carbon from the atmosphere.
Enter direct air capture (DAC). It is an offshoot of carbon capture and storage, whereby pollution from factories and power plants is trapped and stored underground. DAC takes that one step further, focusing on pulling the gas directly from the air. That is a tougher ask, because CO2 in our air is at much lower concentrations than in the flue gases of a power plant. But if DAC technology can scale, it could give humankind the power to control global pollution levels.
There are signs a breakthrough might be close. Swiss firm Climeworks has built a handful of DAC plants across Europe. Orca, under construction in Iceland, will be the world’s biggest facility when it opens next year, capable of removing four million tons of CO2 every year. Canadian rival Carbon Engineering, meanwhile, is building a plant that could suck away a million tons a year.