Air scrubbing machines are gaining traction, but still in research phase

On a field ringed by rolling green hills in Iceland, fans attached to metal structures that look like an industrial-sized Lego project are spinning. Their mission is to scrub the atmosphere by sucking carbon dioxide from the air and storing it safely underground.

Just a few years ago, this technology, known as “direct air capture,” was seen by many as an unrealistic fantasy. But the technology has evolved to where people consider it a serious tool in fighting climate change.

The Iceland plant, called Orca, is the largest such facility in the world, capturing about 4,000 metric tons of carbon dioxide per year. But compared to what the planet needs, the amount is tiny. Experts say 10 billion tons of carbon dioxide must be removed annually by mid-century.

“Effectively, in 30 years’ time, we need a worldwide enterprise that is twice as big as the oil and gas industry, and that works in reverse,” said Julio Friedmann, senior research scholar at the Center on Global Energy Policy at Columbia University.

Leading scientific agencies including the United Nations Intergovernmental Panel on Climate Change say that even if the world manages to stop producing harmful emissions, that still won’t be enough to avert a climate catastrophe. They say we need to suck massive amounts of carbon dioxide out of the air and put it back underground — yielding what some call “negative emissions.”

At Climeworks’ Orca plant near Reykjavik, fans suck air into big, black collection boxes where the carbon dioxide accumulates on a filter. Then it’s heated with geothermal energy and is combined with water and pumped deep underground into basalt rock formations. Within a few years, Climeworks says, the carbon dioxide turns into stone.

It takes energy to build and run Climeworks’ plants. Throughout the life cycle of the Orca plant, including construction, 10 tons of carbon dioxide are emitted for every 100 tons of carbon dioxide removed from the air. Carbon Engineering’s plants can run on renewable energy or natural gas, and when natural gas is used, the carbon dioxide generated during combustion is captured.

Their plans call for scaling up to remove several million metric tons of carbon dioxide annually by 2030. And Eggers said that would mean increasing capacity by a factor of 10 almost every three years.

It’s a lofty, and expensive, goal.

Estimates vary, but it currently costs about $500 to $600 per ton to remove carbon dioxide using direct air capture, said Colin McCormick, chief innovation officer at Carbon Direct, which invests in carbon removal projects and advises businesses on buying such services.

As with any new technology, costs can decrease over time. Within the next decade, experts say, the cost of direct air capture could fall to about $200 per ton or lower.

For years, companies bought carbon offsets by doing things like investing in reforestation projects. But recent studies have shown many offsets don’t deliver the promised environmental benefits. So McCormick said companies are looking for more verifiable carbon removal services and are investing in direct air capture, considered the “gold standard.”

Worldwide, industrial facilities capturing carbon dioxide from their operations had a combined capacity to capture 40 million tons annually, triple the amount in 2010, according to the International Energy Agency.

But that’s less than 1% of the total emissions that could be captured from industrial facilities globally, said Sean McCoy, assistant professor in the department of chemical and petroleum engineering at the University of Calgary.

If governments created policies to penalize carbon dioxide emissions, that would drive more carbon removal projects and push companies to switch to lower-carbon fuels, McCoy said.

“Direct air capture is something you get people to pay for because they want it,” he said. “Nobody who operates a power plant wants (carbon capture and storage). You’re going to have to hit them with sticks.”