Nobody will bet. James Inhofe won't bet. Christopher Monckton won't bet. Tom McClintock, Lubos Motl, Glen Raphael, Onar An, Steve Hemphill, Jim Clarke, other denialist commenters at Prometheus, and others I've surely forgotten won't do honest bets that test the denialist-versus-consensus positions on global warming.
I've come up with a few more bet proposals. I'm especially proud of the offer that warming will accelerate relative to the post-1850 average, but no interest. Kind of makes you wonder.
(If you think you know someone who'll bet, please send him or her my way.)