"Betting Over Global Warming
Skeptics and proponents of global warming both accept that due to natural variability, average temperatures in any given year in the future could be either warmer or colder than at the present.[2][3] Global warming proponents generally accept that after ten years, temperatures are much more likely to have increased than decreased, with odds of an increase being significantly greater than 1:1. Skeptics who expect no trend in temperatures would give 1:1 odds of an increase, while skeptics anticipating cooling temperatures would give less than 1:1 odds.
With the exception of two Russian physicists betting $10,000 that temperatures would drop instead of increase in ten years,[4] all other skeptics have either refused to bet on terms that pay out before the year 2100,[5] have refused all bets, or, like Richard Lindzen, have only accepted odds that indicate temperatures are much more likely to increase rather than decrease."
http://en.wikipedia.org/wiki/Global_warming_controversy#Betting_Over_Global_Warming
