I'll bite. I think geoengineering is the only way we solve this without going to global governance (which wouldn't happen on time without major wars).
I'd argue that we can put solar sails/shades in the Earth-Sun L1 Lagrange point and reduce incoming sunlight be up to ~0.5%. And that it wouldn't be that risky at all. It'd just be another mega construction project, and not a particularly nasty one even.
But I haven't done the engineering on it. I only speak as someone who did Planetary Science in grad school, and knows a bit about orbital mechanics. I once gave a grad school level presentation on solar sails while wearing a colander on my head, so that's exactly how hard I've thought about it.
If I had Elon's money and needed a redemption arc...