Seth Baum worries that, in an attempt to geoengineer a solution to climate change, we may end up vulnerable to multiple global catastrophes happening at once:
[I]f we stop putting particles into the atmosphere, we get a very rapid temperature increase, until temperatures finally stabilize at where they would have been without the particles. This rapid temperature increase is many times faster than that of climate change alone and would be very damaging. ..
We’d be fools to impose that rapid temperature increase upon ourselves. However, if a big enough catastrophe occurred, then we could lose the capacity to continue the climate engineering. The catastrophe could be something like a major war or disease outbreak. If this causes society to stop climate engineering, then the rapid temperature increase would hit a population already very vulnerable from the initial catastrophe. The result is a double catastrophe that could be very devastating for humanity.