Why would we be any more likely to implement it, relative to the solutions that humans have already figured out for climate change?

Well we can be confident in the knowledge that techbros might finally take the issue seriously if an AI tells them to!

I know this is not an uncommon opinion in tech circles, but I believe an insane thing to hang humanities hopes on. There's no reason to think AI will be omnipotent.

There is not, but there is plenty of historical evidence that scientific and technological progress has routinely addressed humanities crisis du jour.

You mean new and incredibly effective ways to shape public opinion? I guess it might. But then someone would still have to use it for that purpose...