The White House cautiously endorsed the idea of studying how to block sunlight from hitting Earth’s surface as a way to limit global warming in a congressionally mandated report that could help bring efforts once confined to science fiction into the realm of legitimate debate.
Even if we achieve full decarbonisation, the damage already done won’t go away. This would be a last resort, though because no matter how much research you do, it’ll never be possible to really predict what would happen.
One nice thing about these sorts of countermeasures is that if they turn out to have bad side effects it’s easy to just stop doing them.