2015-06-18

Straw Man

I really do try to stay out of the climate change "debate." My core belief, for those interested, is that most of the descriptive models are accurate, but most of the predictive models are inaccurate. That's a nuanced view that doesn't tend to put me on a "side." There shouldn't be a "side." There should only be findings.

But anyway, something called The Committee for Skeptical Inquiry has challenged something called the Heartland Institute to a bet. The details of the bet are as follows:
The Committee for Skeptical Inquiry (CSI) hereby presents to the Heartland Institute a challenge as to whether the Earth’s climate will set a new record high temperature this year. The challenge will be settled using the NASA GISS mean global land surface temperatures for the conventional climate averaging period (defined by the World Meteorological Organization as 30 years) ending on December 31, 2015. If the global average temperature does not exceed the mean temperature for an equal period ending on the same date in any previous year for which complete data exist, CSI will donate $25,000 to a nonprofit to be designated by Heartland. Otherwise, Heartland will be asked to donate $25,000 to a science education nonprofit designated by CSI. It is CSI’s intent to repeat this challenge every year for the next 30 years.

My Claim: I Believe The CSI's Bet Is Disingenuous

Why? Because the only thing that will impact the outcome of the matter being bet upon are global average temperatures for the last half of the year 2015. In other words, if the next six months are hotter-than-average, globally, then CSI will win.

Assuming the Heartland Institute believes that current temperature trends are part of an essentially random walk, that means that their expected probability of winning would be 50%. (Assuming temperature is random and normal, 50% of recorded temperatures will appear above the mean, by definition, give or take. Let's leave aside the possibility that the Heartland Institute believes that global temperatures follow a non-normal distribution. Both possibilities are equally preposterous, anyway.)

Of course, no one who pays attention to global temperatures actually believes they are random. There is, for one thing, seasonality in global average temperature. There are quite certainly a different number of temperature sensors in the Southern hemisphere than the Northern hemisphere, and the urban impact on temperatures will be greater wherever there are more urban sensors. There are seasonal changes in ocean currents and temperatures, which is a fact I have no reason to believe the Heartland Institute disputes.

And finally, six or seven months of temperature readings are insufficient to draw conclusions about the accuracy of climate change models, no matter what happens to those temperatures in that period of time. Duh.

All of these reasons demonstrate that the CSI is basically trolling the Heartland Institute. I don't have a problem with that, but let's not pretend it's a real bet.

But Wait - There's More!

Suggesting that the people at the CSI are trolls is actually a charitable interpretation of this bet. I say this because their press release contains the following quote:
“If anyone really thinks that human-caused global warming is a hoax, and that the climate has stopped heating up, they must also believe that temperatures will now stabilize or drop,” said Mark Boslough, a physicist and CSI Fellow who devised the challenge. “Well, that’s a testable claim, so let’s test it.”
Boslough's "if" is a straw man fallacy. It is not at all true that anyone who disputes the theory of AGW believes "that temperatures will now stabilize or drop" within the next 7 months. For example, one might believe that global warming is occurring for non-anthropomorphic reasons.

I have no idea what the Heartland Institute's position on this matter is, and I don't much care. But Boslough's argument is a preposterous straw man, and his Institute's bet is thoroughly disingenuous.