Direct Air Capture (DAC): using ‘smart tech’ to remove CO2 from the atmosphere to help stabilise concentrations of this greenhouse gas. What’s not to like?


Let me explain, courtesy of some number-crunching from a guy called Morey Wolfson.

[1] COST

The concentration of CO2 in the atmosphere today is around 420 parts per million (ppm).

To ensure any kind of long-term climate stability, that needs to come back down to around 350 parts per million – and for us to be able to secure that just as soon as possible.

1 ppm of CO2 weighs an astonishing 8 billion tonnes! In other words, that’s the amount of CO2 that would need to be removed to get us back from 420 ppm to 419 ppm.

Currently, it costs anywhere between $600 and $1,000 to remove 1 tonne of CO2 using Direct Air Capture.

DAC evangelists have persuaded lots of politicians who really should know better that if they hurl billions of dollars at DAC over the next 20 years or so, they’ll get that price right down to no more than $100. That’s probably moonshine, but let’s go with it, in order to complete this little exercise in surrealism.

To reduce the concentration of CO2 by just 1 part per million (bearing in mind that we eventually need to find a full 70 parts per million) will cost $100 x 8 billion (the weight, in tonnes, of 1ppm).

That’s $800bn. And that’s the best case!

So, please just bear that in mind next time you hear some thermodynamically-illiterate politician bigging up the prospect of the UK becoming a global leader in DAC.

In its latest plan for scaling up DAC, Carbon Capture and Storage and BECCS, the Government has set aside around £50m over the next few years.

Just last week, it confirmed a £3m grant for a company called CO2CirculAir for a pilot plant in Northern Ireland to use its ‘smart-DAC’ technology to remove precisely 100 tonnes of CO2 per annum.

A snip at around £30,000 a tonne!


I’ve written about this extensively – particularly in relation to Carbon Capture and Storage:

I don’t doubt that various CCS technologies will be needed in the future, particularly in terms of enabling hard-to-abate sectors to transition to Net Zero by 2050.

But it’s my belief that CCS should never be used on either gas-fired or coal-fired power plants – or, for that matter, for the manufacture of so-called ‘blue’ hydrogen. All that’s so obviously a way of keeping today’s fossil fuel companies in business when we should be seeking to put them out of business as soon as possible.

Direct Air Capture is of course different – as a technology that removes CO2 from the atmosphere rather than prevents it from getting up there in the first place.

But given the insane economics, as above, it’s still ridiculous to think that this is going to play a major role in any serious Net Zero strategy any time between now and 2050.

That won’t stop either the illiterate politicians or the fossil fuel industry or those big companies committed to their own Net Zero targets, with stupid amounts of money to throw at stupid technologies – but please don’t get too excited about any of this.