Current CCS rates are about $60/ton. Given that each PPM represents about 8 billion tons of atmospheric CO2, that's $480B for each PPM reduction. Obviously not great.
But what if that number drops to $30 per ton? $10? If we get the best minds in the world on it, it might be possible. At $10, a $1T investment takes us down 12.5 ppm. That's five years worth of emissions.
It's a monstrous challenge. But it's not completely unimaginable.
Followup. Your comment gave me a crazy idea. I've now thought about it enough to share.
To incentivize carbon removal, the US Treasury commits to spending 10 megabucks per year to buy carbon bricks synthesized via CCS.
Brick price is 10 megabucks / number produced.
Starting spot price (ceiling) is for bricks is somehow determined. Plus whatever sane market rules are deemed appropriate.
The provenance of these bricks is easily confirmed. By some combo of isotopes, inspections, and affidavits. So that sellers can't easily use non-atmospheric carbon.
Some kind of practical form factor is determined for the carbon bricks.
Carbon bricks become yet another currency.
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Said another way:
US Treasury mints gold coins from gold bullion.
Compute farms mint bitcoin from electricity.
Carbon scrubbers will mint carbon bricks from atmospheric carbon.
Whereas bitcoin is inflationary, bricks are deflationary. Like US dollars.
Harness the Cobra Effect. Since all bricks produced will be bought, more production is incentivized.
Another aspect of this is that it could maybe exploit modern monetary policy. Price of bricks getting too high? Maybe 'ease' a few more into circulation by buying them with new dollars.
But what if that number drops to $30 per ton? $10? If we get the best minds in the world on it, it might be possible. At $10, a $1T investment takes us down 12.5 ppm. That's five years worth of emissions.
It's a monstrous challenge. But it's not completely unimaginable.