Pedro Domingos

Geoengineering cheaply takes care of the tail risk. Its likely side effects are minor and easily reversed. Greater uncertainty means lower likelihood that humans are a major cause of warming. Overall, it weakens the case for decarbonization.

What do you think of this analysis? https://scholar.harvard.edu/files/weitzman/files/fattaileduncertaintyeconomics.pdf … For given average level of climate change, if the effects of GHG are less certain, that means more risk of catastrophe (since costs grow disproportionately with more warming)

How does this paper conflict at all with what I said? Geoengineering caps the tail risk. More uncertainty also means lower likelihood that GHGs are a major problem a at all. Overall, less of a case for decarbonization, which would be massively disruptive for unclear gain.

More uncertainty about the effects of GHGs and the various feedback mechanisms means that there’s *more* of a chance that GHG‘s are a catastrophic risk.

But we can use geoengineering to cheaply cap that risk. And on the other side, it means more of a chance that they're not a problem at all (in fact, they may even lower the temperature, depending on cloud effects, etc.). So overall, less of a case for (high-cost) decarbonization.

OK so your argument is almost the opposite of how I interpreted your original tweet. You think that there’s little uncertainty about the risks of GHG because we understand the models of climate and Geoengineering very well and can cap the risk. Am I understanding you correctly?

No! Uncertainty about the effects of GHGs is very high, but we can cap the upper tail risk by geoengineering, so overall increasing uncertainty decreases the expected utility of decarbonization.

I think I get it now. Your argument for not worrying much seems to hinge mainly on your high confidence in the models of large scale climate change geoengineering in case of looming catastrophe, not in your lack of confidence in climate change models generally.