Analysis Direct air capture
The direct air capture industry got a big boost with the opening of Mammoth, its largest plant yet, but can the technology scale up, asks Madeleine Cuff
HUMANITY has spent the past few centuries releasing ever greater amounts of carbon dioxide into the atmosphere – a state of affairs that must be reversed if we are to get to grips with climate change. Removing CO₂ in a process called direct air capture (DAC) has been on the cards for some time, but finally, after years of research and small-scale pilot projects, giant carbon-sucking facilities are becoming a reality. The question is, will the industry grow large enough, fast enough?
DAC got a big boost this month when Swiss company Climeworks switched on a new plant called Mammoth in Iceland. This can extract up to 36,000 tonnes of CO₂ a year from the atmosphere – living up to its name, at least when compared with its predecessor, Orca, which boasted a maximum capacity of 4000 tonnes per year.
Rapid expansion
The new plant instantly quadrupled global capacity for DAC and is a sign of a step change under way in the industry. Mammoth will only hold the title of world’s largest DAC plant until next year, when the Stratos plant in Texas, built by a subsidiary of energy firm Occidental Petroleum using technology from Canadian DAC company Carbon Engineering, comes online. It will be able to extract half a million tonnes of CO₂ a year.
Steve Smith at the University of Oxford says Mammoth and Stratos are the start of a rapid expansion in global direct air carbon capture and storage (DACCS) capacity. “A dozen or so more DACCS projects are planned to go live in the next couple of years, by various companies,” he says. “If these all materialise, DACCS capacity could be nudging 800,000 tonnes per year.”
Overall, ambitions are high – both Occidental and Climeworks plan to be operating multiple plants with capture capacities of 1 million tonnes apiece by 2035.
This rapid expansion is being driven by two factors. The first is corporate interest in carbon removals, with the likes of Microsoft, Stripe and Coca-Cola buying DAC credits to help offset their own emissions. With the reputation of many traditional carbon offset schemes in tatters, DAC is seen by some large firms as one of the last respectable removal options.
Government policy has also been instrumental, particularly in the US. President Joe Biden’s administration is spending $3.5 billion to support four DAC “hubs” in the US, including Stratos, as part of measures passed in the Inflation Reduction Act to drive carbon removal efforts across the country. US federal tax credits also provide support of up to $180 per tonne of CO₂ trapped and per
