Wednesday, April 9, 2014

Who are you going to believe?

Look, ma, no warming!
Talked with a local meteorologist at some length this week for a wrap-up news story on the 2013-14 winter. I had thought the weather was severe, but only by comparison with the past few mild winters. It turns out it was severe, period: we had the fifth-largest snowfall since record-keeping began, and the second-coldest January-March stretch.

It felt only a bit worse than average to me, but my childhood in Pittsburgh and my college years in Chicago tend to bias my reference standard.

It occurred to me that if I were a climate change skeptic, I would view this past winter as a great talking point. "Ha! Global warming, you say? Tell me another one! It's getting so hot that Lancaster County had its second-coldest winter in more than a century."

But that's nonsense, of course. For one thing, plenty of other places were hot this winter; Lancaster County is not the linchpin of the world, whatever some of its citizens may think.

Also, as climate scientists never tire of pointing out, the signal of climate change is very small compared to the noise of short-term temperature variation. If the world warms six degrees over the next century, that works out to ... hang on, "difficult" math here ... six hundredths of a degree a year. One winter can easily be six or seven degrees colder (or warmer) than average, as 2013-14 in fact was. You're not going to see a couple hundredths of a degree in there.

There's that old joke about the woman who finds her lover, who has been proclaiming his fidelity, in bed with her rival. As she pulls out a gun to take revenge, he exclaims, "Who are you going to believe, me or your own lying eyes?" On climate change in particular, but on some other contentious cultural issues, too (evolution comes to mind), the guy has a point. What the average person sees is just a small sliver of a vastly larger data set. If you take that small sliver as dispositive, you're going to be badly misled.

1 comment:

  1. That may be why "global warming" is being replaced with "climate change" - it's easier to convince people that the climate is changing, than that its changing in a particular direction.