Weather prediction is a guessing game

Today’s column is about global warming. Sitting down to write it made a nice break from all the hard physical chores we’re tackling thanks to the unseasonably cool weather.

Yes, unseasonably cool. As the July 16 Citizen reported, “Ottawa’s summer was supposed to be sticky and dry, and June passed the test with flying colours. But now the hot weather has taken a summer holiday of its own, with clouds and rain seemingly stuck in a holding pattern over the city.” In addition to almost constant rain, the paper added “Vacationers and cottage-goers might disagree, but July temperatures have only been slightly below normal. The average high has been 24 C; the average low, 13.4 C. Both are just two degrees cooler than usual. June was scorching by comparison. Eight days of 30plus temperatures were recorded, topping out at 34.2 on the 26th.”

I’m trying to be level in head and tone here. June was hot, July was cold, the predictions were wrong and as a result we know … not much. Other than that weather, like climate, fluctuates in weird ways because it is complex. A cool summer no more proves the Earth is not heating up or that humans are not causing it than a warm decade in the 1990s proved it is and they are. So I consider it unfair that when temperatures are “just” two degrees above average Al Gore starts holding rock concerts, David Suzuki is all over the billboards and arcane computer models acquire a degree of infallibility at which the Pope can only gaze in envy. But when they’re down by that much, an Environment Canada meteorologist dismisses the variation as “not extreme” and says, what the heck, computer models aren’t that reliable.

It’s also unfair that almost every story on global warming ratchets up the alarm. I’ve previously cited Patrick J. Michaels of the Cato Institute, who says that “It is highly improbable, in a statistical sense, that new information added to any existing forecast is almost always ‘bad’ or ‘good’; rather, each new finding has an equal probability of making a forecast worse or better. Consequently, the preponderance of bad news almost certainly means that something is missing, both in the process of science itself and in the reporting of science.”

A case in point is the new study saying that global warming will make places that are too wet even wetter and those that are too dry even drier. Maybe it will. But is that really what the record shows to be normal? Or, like historians and social scientists who seem to discover in any place they examine at any period in history that the rich are getting richer and the poor are getting poorer, is it just what you know they’d say regardless?

I take a similarly skeptical view of widespread insistence that a warmer Earth must spell disaster. Again, maybe it will. But our limited reliable evidence, from history, not fanciful cybernetic projection, is that it didn’t 12,000 years ago when the last Ice Age ended. And we know that the last time global temperature rose, in the “Medieval Warm Period,” (a) man didn’t cause it and (b) the effects were for the most part beneficial. That doesn’t mean it would be this time, let alone that we should encourage or ignore it on that basis. It means that claims to know the opposite so strongly that you refuse to tolerate dissent are hysterical and obnoxious.

OK, that was a bit snarky. So let me say on the other side that for skeptics to whine about the cost of fighting global warming is feeble-minded. The Klingon proverb that only a fool fights in a burning house goes double, in my view, for trying to turn a profit in one. (You might, after all, fight to get out of the house, or for that matter fight the fire.)

I concede that if global warming is as bad as they say, if humans are contributing seriously to it and if Canada meeting its Kyoto commitment would help significantly, then almost no price is too high to pay. But in return I ask that we be permitted an intelligent, courteous debate on all three links in that chain of argument, including what constitutes solid evidence.

I note that Environment Canada forecast a singularly hot dry summer across Canada in 2004. That August their senior climatologist, David Phillips, said “Never have we been so wrong for so long in so many parts of the country.”

Then it predicted it again, and again. Of course if weather is variable and you keep predicting the same thing you will be right about half the time. But reasonable people won’t treat your predictions as useful evidence.

Look out the window and tell me, are you cool with that?

[First published in the Ottawa Citizen]