“What we have found is that the target we have all been aiming for is a disaster – a guaranteed disaster,” Hansen recently told the Guardian Newspaper in London.

Hansen will give his first major public address since announcing that governments and climate researchers have grossly underestimated the severity of the effects of carbon dioxide emissions next Tuesday at CCAN’s Super Rally.

Since Hansen is coming to DC to talk to us, I figure we have to get him to answer at least one personal question. I kinda want to know what climate catastrophe keeps him up at night, but I’m a little scared to know what that would be. Ideas? Post your questions for Hansen in the comments