Extracting CO2 from the atmosphere

In my last post, I talked about the very interesting process whereby CO2 can be converted into rock.  There is now enough CO2 in the atmosphere  to increase global temperatures by perhaps 2 C.  And yet the ratio of CO2 to the whole (400 parts per million) is so small it's hard to extract and concentrate for storage or conversion into rock or production of methane and e-fuels via the Sabatier process.   However the technology does exist to extract  CO2 from the air, and is already in use on a small scale:

In Squamish, British Columbia, a Canadian town halfway between Vancouver and Whistler where the ocean meets the mountains, a startup led by Harvard physicist David Keith – and funded in part by Bill Gates – is building an industrial plant to capture carbon dioxide from the air.

Carbon Engineering aims to eventually build enough plants to suck many millions of tons of CO2 out of the air to reduce climate change. Its technology could help capture dispersed emissions – that is, emissions from cars, trucks, ships, planes or farm equipment – or even to roll back atmospheric concentrations of CO2.

The Calgary-based company is one of a crop of startups placing bold bets on technology designed to directly capture CO2 from the air. Lately, at least three have shown signs of progress. New York City-based Global Thermostat, which is led by Peter Eisenberger, a Columbia University professor and former researcher for Exxon and Bell Labs, tells me it has recently received an infusion of capital from an as-yet-unnamed US energy company. As part of a demonstration project financed by Audi, Swiss-based Climeworks in April captured CO2 from the air and supplied it to a German firm called Sunfire, which then recycled it into a zero-carbon diesel fuel.

(The Guardian)

(Source; click  to enlarge image)

It prolly isn't sensible  to start extracting CO2 from the atmosphere now, except to make carbon-neutral fuels, as Audi has started to do with e-diesel  and e-methane.  Both processes use concentrated CO2 from exhaust flues or biomass.  The Sabatier process presumably also requires concentrated rather than ambient CO2.   But there will surely come a time when we will need to start extracting CO2 from the atmosphere.  Right now, it would be much cheaper to just switch to renewables than to expensively extract CO2 from the air and turn it into rock, and that switch has started.  In the meantime, though, this process could be used to offset emissions from cement and steel manufacture.

I have no doubt that we will one day have to start removing CO2 from our atmosphere and sequestrating it.  The longer we take to slash CO2 emissions, the more urgent that necessity will become, and the more we will need to do.    As with other ways of preventing runaway global warming, the technologies exist.  Just the willpower is lacking.