> Marine cloud brightening could produce meaningful planetary cooling for roughly $5 billion per year at scale (NAS estimate).

Eh. Cloud brightening is a temporary hack, stops working as soon as you stop actively doing it, and isn't an alternative to switching away from fossil fuels. It's probably worth doing to push back the "ice melts and releases more carbon" thing but let's not confuse it with the extent of what needs to be done. You can't actually solve the problem for $5B/year.

> AI investment is private capital chasing returns.

Getting private capital to work for you is a good way to solve the problem. The real problem is politics.

The EV tax credits and the subsidies oil companies get were costing about the same amount of money, but we only got rid of one of them. Nuclear should cost less than fossil fuels, but we're told that fission is scary and Deepwater Horizon is nothing but spilled milk so the one with the much better environmental record has to be asymmetrically regulated into uncompetitiveness.

If we actually wanted to solve it we'd do the "carbon tax but 100% of the money gets sent back to the people as checks" thing, since then you're not screwing everyone because on average the check and the tax cancel out and corporations pay the tax too but only people get the check. Then everyone, but especially the heaviest users, would have the incentive to switch to alternative energy and more efficient vehicles etc., because everybody gets the same check but the people putting thousands of miles on non-hybrid panzers pay more in tax.

The "problem" is that it would actually work, which is highly objectionable to the oil industry and countries like Russia since it would cause their income to go away, hence politics.