"Stopping fossil fuels, moving to renewable and nuclear, using less energy" is great. None of it just doesn't reverse climate change even a little. It just means we have dialed the oven regulator from 3 to 2. The oven will reach maximum temperature anyway, just a little slower.

Geoengineering is not similar thing to the emission reduction initiatives, it is a completely different idea with a completely different result in the end. You can't substitute one for another.