So that's the purpose of this post - designing a fair bet that I can explain in a 15-second sound bite, a test that my existing bet completely fails.
Here it is:
Rush, I'll bet you that the next decade will warm at least twice as fast as the per-decade warming rate in the 20th Century. If you believe it's just been natural warming so far that'll reverse itself, you have no reason to expect this dramatic acceleration, and you should clean up in the bet.
That should be enough for talk radio. We'd have to get details out of the way - I'm thinking the best/quickest way to resolve it is to compare 1998-2007 to 2008-2017. The temp rise in the 20th Century was .6C, so a per-decade doubled rate is .12C. I take the risk of a massive volcanic eruption skewing my decade when none occurred during his, but .12C provides a good comfort margin.
We'll see what happens.