The expert opinions that I've seen so far have indicated that geoengineering at any scale that we're realistically able to produce on a short notice is unlikely to have a sufficient effect on climate change. Essentially it's a pipe dream at best, and a way to create additional (localised) disasters at worst.
If the only proper argument for doing it is that "the left" is against it and "the right" is for it, that seems comparatively weak.
That sounds like a critique far more applicable to non-experts arguing that there's no need for any kind of modification to our consumption patterns or energy use, because if "the left" really cared about the environment they'd just set off our nukes or radically change the composition of our oceans instead
It would be strange, if this were truly an emergency, for people who believed it to be an emergency of the highest degree...
To whine and screech "that's too dangerous, don't do that" when other people were proposing solutions. These are the same people who are touted as the experts, mind you. This means that when journalists and talking heads and other jackasses say "but the experts don't even think those things will work", they are talking about the same people who claim that there is an emergency in the first place.
They aren't interested in potential solutions. It's just an attempt to wrestle political power away from those who currently have it and implement economy-murdering policy because they're mad poor people eat meat.
If the only proper argument for doing it is that "the left" is against it and "the right" is for it, that seems comparatively weak.