The only type of geoengineering I would endorse without much hesitation is sucking CO2 back out of the atmosphere. But I don't think that the weather system is sensitive enough that we can't try nudging it with measures that are easy to stop and whose effects only last a couple of years (e.g. injection sulphur into the atmosphere).
AdrianN was responding to a comment about "crazy consequences" to messing with the weather. His point was that thus far there haven't been any, despite centuries of human-driven weather changes.