There’s an interesting exchange beginning at 41:08 on the YouTube video of the recording of the NASA Hangout: Ask A Climate Scientist on 30 September 2013. The video starts a few seconds before the 41:08 mark:
Below is a transcript (also the best I could accomplish):
Patrick Lynch: Another question from twitter here: “Is there an alternative to reduce global warming without cutting down on emissions?”
Dr. Ralph Kahn: I don’t think there’s an easy way out. The proposals that have been put forward regarding geoengineering and things like that come with large uncertainties and to the extent that people have been able to look at it so far, not only are there large uncertainties, but there are real possibilities that those mechanisms could either backfire–could backfire and actually make conditions worse rather than better.
One of the reasons for this is that the Earth is very diverse. And so any solution you try to make that that might perhaps improve things in one area, you can’t confine those impacts to just one area. In another area it just gets worse. So for example, if you put particles somewhere and it brightens up the clouds there, other changes will take place. There are no clear boundaries that the climate–that the atmosphere–will respect. And the result of that will be that there can be a lot of unintended consequences.
What conflicts could geoengineering cause? What seemed like a good idea at the time might make things far worse. Even if the geoengineering does not cause weather problems in another country, what if random bad weather is interpreted as a consequence of that geoengineering? What if the deleterious side effects are deliberately chosen–and aimed–at another country? If drought or floods or some other negative weather pattern is already causing problems, any conflict might escalate even more quickly. Look at the problems determining what percentage of forest fires or tornadoes or hurricanes are caused by global warming. If geoengineering caused 10% of a drought that destroyed crops, would the geoengineers be responsible for 10% of the crop losses–or blamed for everything? I could also see a corporation or group of individuals attempting some sort of unofficial geoengineering and the geoengineering going wrong–either for them or for someone else.
Controlling Anthropogenic Global warming now might prevent wars being created accidentally–or on purpose.
By the way, I chose the above segment to discuss, but the entire NASA Hangout is worth listening to!