I'm stunned, but according to this report by Seth Borenstein--who's highly trustworthy--Obama's science adviser John Holdren has said that the prospect of geoengineering the climate has "got to be looked at. We don't have the luxury of taking any approach off the table." A while back, I mused about when the geoengineering issue would "tip" and begin to draw more mainstream attention. This is certainly the biggest opportunity yet for that to happen. I'm not aware of any more high level figure in U.S. government ever raising this issue before in such a serious way, or indeed, in any way at all.