Carbon removal is the latest way to fight climate change — but will it take off in time to save the planet?
A handful of companies have begun to pull carbon dioxide out of the air and store it underground in an effort to fight climate change. But challenges remain in ramping up the technology to a large enough scale that will make it affordable and effective enough to start to halt the rise of global temperatures.
How carbon removal works
Like giant stationary vacuum cleaners, machines suck CO2 from the air.
At the Orca plant operated by Climeworks in Iceland, the gas is then mixed with water and added to porous rocks underground, where it transforms into carbonate minerals.
At the new Heirloom plant in California, calcium oxide powder is combined with the extracted carbon dioxide to make limestone.
Offsets vs. carbon capture vs. carbon removal
Carbon offsets, like those people buy to mitigate carbon-intensive activities like air travel, claim to reduce CO2 through measures such as protecting forests or planting trees, but many have been exposed for inflating claims of averted emissions.
Carbon capture and storage, or CCS, refers to capturing CO2 emitted from smokestacks.
Carbon removal, known as “direct air capture” or DAC, isn’t tied to an emissions source and can be built anywhere. Unlike offsets, it provides a precise, easily measurable carbon reduction.
“I buy the gold standard of funding Climeworks to do direct air capture that far exceeds my family’s carbon footprint,” Bill Gates said when asked about his private jet use in February.
How to purchase carbon removal
Climeworks sells a range of monthly subscriptions, the cheapest of which costs $28 per month and removes as much carbon every month as roughly 11 grown average trees (20 kg of CO2), and they can create customized plans.
“We wanted to make our technology available to everyone,” Anna Ahn, a spokesperson for Climeworks, told Yahoo News.
The Orca plant removes roughly 4,000 tons of CO2 annually and the service is so popular it is sold out. If you buy a credit from Climeworks, you are prepaying for carbon removal that will occur when a new plant opens next year that will remove 30,000 tons of CO2 per year.
In 2021, the U.S. emitted 6.34 billion metric tons of carbon dioxide equivalents.
Heirloom is selling custom plans, mainly to companies. Both companies also have major corporate customers, including Microsoft.
“Carbon removal can be a lot more expensive than offsets, but what you’re paying for in terms of climate impact is radically different,” Brian Marrs, Microsoft’s senior director of energy and carbon, told the New York Times.
Recommended reading
Reuters: Climate tech company Heirloom opens U.S. commercial carbon capture plant
Independent: Carbon capture startup Climeworks removes CO2 from open air in ‘industry first’
Yahoo News: What Iceland's landmark carbon removal project means for the fight against climate change
But will it solve climate change?
Heirloom’s plant removes just 1,000 tons of CO2 per year, about 200 cars’ worth.
Heirloom says it wants to grow to millions of tons annually, and Climeworks says its goal is a gigaton per year by 2050.
Worldwide, scientists project the need for 10 billion gigatons of carbon removal per year by 2050.
Last week, Climeworks announced a partnership with Canadian firm DeepSky to build plants in Canada capable of removing up to 1 million tons per year of CO2, with the first to open before 2030.
The Biden administration has earmarked $3.5 billion for developing direct air capture hubs around the country, with the first grant recipients — a Texas project led by Occidental Petroleum and a Louisiana project from a technology contractor — announced in August.
Canada is looking at a package of carbon removal subsidies worth $20 billion over five years.
Carbon removal may be impractical because of its high costs: Experts estimate that DAC costs more than $600 per ton of CO2 today and needs to drop below $200/ton by mid-century to adequately address climate change.
Heavy energy demands reduce environmental benefits, unless the electricity used to power carbon removal is all renewable (as it is in Iceland and at the Heirloom plant in California).
Fossil fuel companies could try to remove the carbon they produce to stay in business. ExxonMobil is investing in carbon removal.
Climeworks predicts that the cost will come down as the industry achieves economies of scale, just like the costs of solar energy and battery storage have dropped dramatically.
“There's a big, big scale-up that lies ahead of us,” Ahn said. “And with the scale-up, the costs will also reduce due to economies of scale, due to technology development.”
