As concerned about climate change as I am, I'd balk, too, at geoengineering. Climate change was created from unintentional geoengineering. There isn't enough known about earth and its interwoven climate to risk making it worse. I do what I can to mitigate my impact but I'm fully against deliberate "geoengineering"; we have no way of knowing potential side effects. We're just not that smart...