“Prediction is hard, especially of the future.“ Willis Eschenbach tries to convince us that “problems” with 20 year-old computer models mean that we can’t trust the new ones.

Did Hansen, et. al.’s 1992 prediction Potential climate impact of Mount Pinatubo eruption really “miss the mark”? After all, they did predict a “3 sigma” event and the result was only a “2.1 sigma” event… It seems that they correctly predicted the temperature drop duration but over-estimated the scale. Not too shabby for 20 year-old model run with 20 year-old computer horsepower.

Of course Willis doesn’t give any hard numbers for his suggestion that their prediction “failed”. Couldn’t find an Excel formula for that, Willis?

And how did the much more relevant climate model prediction, 20 more years of increasing global temperatures, work out? Oh yeah, that’s what we’ve had. Willis’ insights are no better that Yogi Berra’s.

This is all just an attempt to prop up denialist obstructionism by suggesting that since we can’t predict the future perfectly we should never take any kind of preventative action at all.