I suppose I should talk a bit about Bjorn Lomborg, who is taking a bit of a beating from the "scientific" community. (Actually, I'll let Goldberg tell the tale, since he's obviously forgotten more about Galileo than I ever knew. Do click through to Nick Schulz's TCS piece, not to mention Lomborg's own defense -- both linked in this piece.) Lomborg proves the point that it's hard to be an optimist, even when you have evidence that things are getting better. Far easier to predict doom and offer "scientific" models that take a worst-case scenario as a baseline.
And, hey, anyone who still buys into global warming can come shovel my "coldest winter on record" patio right now. Bring heavy gloves.