I'm not ready to predict, but based on what I saw in Europe in 2015[0] and how things[1] are developing[2] lately[3], I see this as a very plausible outcome.
The US and EU countries get more migrants than they can handle; resentment grows; attempts to solve the problem with bureaucracy and policing fail spectacularly; calls for outright violence grow louder; and the well-meaning citizenry agrees that Something Must Be Done!
Geo-engineering is something, and it will be done.
- we make an AGI or find a human genius that figures out a way to make it work, in which case we're all good
- we try it with known methods, it fails and we possibly go extinct faster in the worst case scenario
Fun times. No pressure.
On the bright side I suppose it only makes sense to plan for success though, since if we fail then we're dead anyway.