Friday, September 28, 2012

Strained Silver and strange predictions on climate

It's not the usual lopsided intellectual battle we discuss here at Eli's.  This is Michael Mann criticizing Nate Silver's somewhat skeptical take of climate prediction capability in Silver's new book:
It's not that Nate revealed himself to be a climate change denier; he accepts that human-caused climate change is real, and that it represents a challenge and potential threat. But he falls victim to a fallacy that has become all too common among those who view the issue through the prism of economics rather than science. Nate conflates problems of prediction in the realm of human behavior -- where there are no fundamental governing 'laws' and any "predictions" are potentially laden with subjective and untestable assumptions -- with problems such as climate change, which are governed by laws of physics, like the greenhouse effect, that are true whether or not you choose to believe them.
As usual, I'll leave the heavy lifting to someone else, Mann in this case.  Also as usual, I haven't read Silver's book, so maybe there's more to it.  What I can add, however, is that it's helpful to look at climate predictions by Silver himself and by a denialist he credulously supports.

Three years ago, Nate offered to bet climate denialists on a monthly basis over whether the temperature in their hometown was one degree above or below the historical average.  As I said at the link, this was a somewhat aggressive bet offer that could've been vulnerable to letting his opponents rely on a short-term seasonal prediction of colder temps to game the system against him.  It would be interesting to see if he discusses his past bet offer and why he's critical of predictions that are much less affected by random noise.

Second is Silver's enthusiasm for the discredited Scott Armstrong, a crackpot climate denier.  In that case, there was a prediction and a betting market created by Armstrong's fans at InTrade, a skewed and unfair prediction that they still managed to lose spectacularly (link goes to a series of posts on Armstrong and the bet).

Like Mann, I'm a Fan of Nate, but he whiffed on this one.

One more thing:  Nate apparently wrote something about Gavin Schmidt (no relation) and his unwillingness to get involved in betting over climate models.  As someone who is willing to bet over climate, here's my response about climate denialists who won't bet over their predictions:
Of course any particular skeptic might honestly not be interested in betting, but the widespread lack of interest tells you something.
There's a difference between an individual's disinterest in betting versus the widespread disinterest among denialists as a community (with honorable skeptic exceptions) in putting their money where their mouths are.