September 13, 2021 - 7:00am

“Carbon capture and storage” is the technology of taking carbon dioxide out of the air or from factory emissions, and turning it into something that can be either used or sequestered away. When used to take it out of the air, it’s called “direct air capture” (DAC), and it’s a way of reducing the concentration of atmospheric carbon, not simply slowing the rate of increase.

Last week, it was announced that Orca, the world’s largest DAC plant, had been turned on. It is capable of sucking 4,000 tonnes of carbon dioxide from the air every year, and turning it into deep-underground carbonate rock.

The first thing to admit is that 4,000 tonnes isn’t very much. The average UK citizen is responsible for the emission of nearly six tonnes per year. So this offsets the equivalent of about 700 Britons, or about 0.001% of the population — and, of course, other countries exist.

It’s also pretty expensive. ClimeWorks, the company behind Orca, offers to remove 600kg of carbon per year for £528; that’s £880 a tonne. You can get a return flight from London to New York for about £300, so if you were to offset the emissions (between 600kg and a tonne per passenger, depending on who you ask), it would triple or quadruple the cost.

Nonetheless, I am still quite excited about it.

First, yes, 4,000 tonnes isn’t very much. But the thing about technology is it gets bigger quickly. Literally zero people owned iPhones 15 years ago. Now, there are over one billion active iPhones. Or, perhaps more relevantly, 35 years ago, solar energy produced 0.1 terawatts of energy worldwide; now, it’s 4,300 and accelerating. 

Orca isn’t the only CCS plant in the world. According to the Global CCS Institute think tank, there are operational plants that capture 40 million tonnes annually. That includes “point source” capture, taking it straight from factory emissions: looking at DAC alone, it’s much smaller, 9,000 tonnes in July 2020; with Orca, presumably it’s now about 13,000 tonnes total. But the first million-tonnes-a-year plant is under construction and should open in the mid-2020s.

It’d still be a tiny fraction of global emissions, but the point is the speed of upscaling: something like 1,000% in a few years. Presumably that rate’s not sustainable, but it could easily end up capturing single-digit percentages of global emissions within a decade or two, which would be a massive deal.

And what’s more, this is exciting from a personal point of view. I enjoy heating my house, driving my kid to football training, and flying away on holiday, but the nagging guilt is always there that this is contributing to some serious negative global consequences. Offsetting is probably better than nothing but it’s hard to be sure: if I pay someone to plant some trees, will they be there in 20 years? If I pay them to encourage some Indian factory to use LED bulbs instead of incandescent, might I be paying them to do something they were going to do anyway?

With this, it’s unambiguous. The carbon is literally turned into a rock and buried hundreds of metres underground. It costs more, but it puts an upper limit on how much one tonne of carbon dioxide is worth: like £900. You could fly to New York guilt free if you did it! Surely there’s a market for that? There must be people who feel cash-rich but clean-conscience-poor who would love the chance to straightforwardly, no-arguments-about-it, expunge their carbon guilt. I know I would (and I have now subscribed).

This isn’t the final victory in the battle against climate change. But I get annoyed by people talking it down. We’ll need many things — technology improvements, policy change, behavioural change — to fix the climate. This is one of those things. We need it to work.

Tom Chivers is a science writer. His second book, How to Read Numbers, is out now.