Brian at Backseat Driving has been challenging people to bets about global warming, and it looks like I’m the latest to be challenged.
In general, I like the idea of betting on propositions, because it forces people to put their money where their mouth is, as well as to think carefully about what they really believe. That said, I’m not sure Brian’s proposed bets really get to the heart of the matter.
You’ll notice that many of his proposed bets are about whether the world is getting warmer, without any reference to causes. As I’ve said before, I’m reasonably convinced that the world is getting warmer; I’d say it’s about 95% likely. That means I’d require at least 19-to-1 odds in order to bet that global temperatures will stay the same or get cooler. If Brian is willing to offer those odds, I’ll take them. But I would fully expect to lose the bet, having agreed only because of the high payout in the unlikely event of winning. I hardly think any loss-of-face would be on the line.
As far as I can tell, only one of Brian’s proposed bets raises the issue of the human contribution to global warming, as opposed to other hypotheses such as increased solar activity. Brian is willing to bet that the IPCCC report of ~2016 will conclude that anthropogenic global warming “likely intensified tropical storm damage in the 1995-2005 period.” So in other words, this is a bet about what a politically charged committee will conclude about the causes of events that have already occurred. Again, is this really the issue? I thought the point of bets like these was to arbitrate among hypotheses by reference to objectively measurable future facts of the world. Even a sincere global-warming-denier (and I’m not one) could reasonably reject this bet because he strongly suspects the IPCCC will continue to espouse the conventional wisdom, whether that wisdom is correct or not.
And, as far as I can tell, none of Brian’s proposed bets raises the issue of the extent of global warming, which is the main issue that separates alarmists like Al Gore from the scientific consensus. None of them relate to the extent of resulting harms. None of them relate to the existence or extent of benefits from global warming. None of them relate to the effectiveness of policies aimed at limiting global warming. In short, none of the proposed bets really addresses the main points being raised by those who admit that some global warming is taking place but doubt the desirability of enacting major policy initiatives to deal with it.