With all the ink-spilling about “pause” or “no pause”, it’s nice to have a clear and simple bet to take a look at.

It’s my bet with fellow economists Bryan Caplan and Alex Tabarrok, and it’s about whether the average temperature anomaly over the next 15 years will be above or below the gray bar in the graphic below. (The red bars show 15-year historic temperature anomalies going back to 1880.)


Details on the bet are below—together with a clean version of the NOAA temperature record—but why don’t you first check out the back-to-back pieces in the Seattle Times (this column and this op-ed) about the revenue-neutral carbon tax ballot measure campaign I’m part of in Washington State?


Details: We’ve agreed to use this NOAA dataset of global land-ocean temperature anomalies, and the bet (which Bryan and I made in June, see more here) is pretty simple: We look at the average temperature anomaly for the 15-year period 2000-2014, and then we look at the average temperature anomaly for the follow 15-year period (2015-2029), and if the difference is more than 0.05C then I win $333.33; if it’s equal to or less than 0.05C then Bryan wins $1000. Ditto for Alex, except he talked me into odds of 5-1 instead of just 3-1, so it’s $1000 from me against only $200 from Alex.

We now have the baseline data for the period 2000-2014, so we can express the bet graphically in terms of an over/under: the red bars show the historic 15-year averages, and the gray bar shows what a 0.05C increase would look like over the next 15 years. If you prefer words, the bet is about whether avg(2015-2029) – avg(2000-2014) <= 0.05C, and we now know that avg(2000-2014) = 0.59. (Note, however, that NOAA does occasionally make small changes to historical data, something that also happens with economic data.)

More Twistory below, stay tuned for an update in January 2016!