I find this article at Real Climate very interesting, a nice peekhole into potential disaster:

One also has to wonder whether the international treaties and organizations needed to agree on and execute a geoengineering scheme are significantly easier to realize than the agreements needed to decarbonize the energy future, which would offer safer and more durable climate protection. And once you open the Pandora’s box of geoengineered climate, what do you do if nations disagree about what kind of climate they want, or if some poor nation objects to suffering drought in order to cancel heat waves in Chicago? Great fodder for science fiction novels about climate wars, but I’d prefer not to have to think about it happening for real.

Another issue, of course, is political diversion. I have students writing about the issue of climate at the moment and they are thinking about it in interesting ways, measuring carbon footprints, thinking about tax breaks and incentive. Speculation is good, wild, grounded ideas, better. For crises ahead, we need level heads.