| If we overestimate, then our best efforts may well over-correct, and we touch off a new ice age. If we underestimate, then there is little-to-no remediation
The most important part would be to use remediation technology which has a physical timescale of persistence substantially shorter than the effective residence time of the longest-living and most significant greenhouse gas, namely CO2, which is in the hundreds-to-thousands of years.
If you're using aerosols which have a residence time of a few years, then a mistake will equilibrate out after a few years of doing less.
But I have little confidence that one can ameliorate the effects even modestly precisely as opposed to adding in another perturbation of approximately equal magnitude but perhaps on significantly different axis.
The most important thing is just to stop doing what we're doing, and the most important thing in that is to stop fucking digging up and burning coal.
As it turns out, Germany and Japan which are generally perceived to be responsible, forward thinking nations with renewables are amping up their coal. Not just refusing to turn off coal, but actively increasing their use when they have nuclear infrastructure already paid for to prevent this. Japan does live in a seismically unstable neighborhood, but Germany has no excuse at all. Despite all their wind and solar, when it actually comes to real generation, they are, today INCREASING coal mining and burning, just as all the quantitative scientists said they would when they decided to turn off nukes instead of increasing them.
It's truly irresponsible, much worse than China's attitude, who at least recognizes the problem.