[danbruc]

What is the logic behind this carbon capture process? They repeatedly go through the lime cycle - calcium carbonate, calcium oxyd, calcium hydroxyd and back to calcium carbonate. We are producing millions of tons of calcium oxide per year anyway, would it not make more sense to just capture the carbon dioxide from that instead of going around in a loop?

Each cycle requires heating the calcium carbonate to almost 1000 °C in order to release the carbon dioxide and then you have a gas again, which you have to compress consuming even more energy and store somewhere. The calcium oxide that ends up in concrete would even permanently fixate the same amount of carbon dioxide as released during its production.

And that for 35 billion tons per year just to keep the carbon dioxide concentration constant before we can even start to actually take any carbon out of the atmosphere. Would it not make much more sense to use all that energy, which has to come from renewable sources, to replace some fossil energy?

And who will pay for this? Instead of burning X dollars of carbon and then paying probably roughly the same amount again to get the carbon pulled out of the atmosphere, would it not make more sense to just replace the fossil fuel with renewable energy. And sure, there are complications, availability, storage, and not all fossil fuels are easily replaceable with electricity.

And for scale, if you turn 35 billion tons of carbon dioxide into dry ice, then you haven to safety get rid of 22 cubic kilometers of that stuff each year. Global oil production was 5 cubic kilometers in 2022.

[harpooniker]

"would it not make more sense to just replace the fossil fuel with renewable energy"

What if people don't want to switch? They'll just elect someone who stops the progress.

The carbon capture doesn't require the cooperation of the public, except for funding.

[chii]

> elect someone who stops the progress

but then

> doesn't require the cooperation of the public, except for funding

carbon capture require just as much cooperation. Just of a different form. There's no way around it, since the work to do capture does not directly produce a private benefit. You'd have to regulate it to make it work, for example, force a penalty for emitters that cost more than the capture.

This means you will already need to elect someone to propose and pass the legislation. In which case, those who would end up having to pay will simply elect the opposition.