To the relief of millions of Mexicans, Hurricane Patricia turned out to be much less fearsome than had been forecast. There may still be more damage to come, as the remnants of the storm head across the already soaked plains of Texas and up towards the Great Lakes, but for a storm that was briefly being described as the strongest ever recorded, it turned out to be, well, not all that.
Patricia's sudden burst of strength -- it went from a depression to a strong Category 5 hurricane in less than 24 hours -- was clearly due to the powerful El Nino in the Pacific, but that hasn't stopped meteorologists from drawing links to climate change. Maybe the most panicky weather guy of all, and the one most shameless about attributing individual weather events to climate change, is Eric Holthaus over at Slate. Here's what he wrote just before the storm started to weaken.
If I were to cite a one-off event, say the fact that last February was the coldest ever recorded in southern Ontario (you could look it up) to proclaim that climate change was a myth, I'd be quickly and condescendingly put in my place by an army of self-appointed experts, telling me that climate and weather aren't the same thing. Holthaus and others don't seem to be governed by the same rules, but that doesn't save them from withering sarcasm from the internet when their dire predictions turn out to be wrong -- just check out the comment string on the linked article.
Of course, that criticism in turn brings out the acolytes of climate science to silence the dissent. If you care to scroll through the comments on the article, you'll find one skeptic asking why the storm weakened sharply even before hitting land. This prompted one "expert" to respond: "Cooler water near the shore. Next question?", At this point I was foolish enough to get involved, wondering why nobody had suggested that might happen until after it actually did. This got me into a minor scrap with a guy posting under the charming handle "Fetus Gerulaitis", who challenged my suggestion that climate science is much better at coming up with explanations for what just happened than at providing useful predictions of what will happen.
I'm not a climate scientist and I'm not a climate change denier. I'm truly agnostic about the whole thing, but tend to think a version of Pascal's Wager is the best way to proceed -- better to be safe than sorry. However, the fact that I may not be able to cite chapter and verse from peer-reviewed academic papers on the subject doesn't disqualify me from using my logical faculties to express an opinion on it. Let's give it a try, assuming you're still with me.
The most famous proposition in modern climate science is the Hockey Stick graph of global temperatures, most closely associated with Professor Michael Mann. Now of course, in looking back many centuries for climate trends, Mann did not have access to actual temperature records, so he had to use a proxy, and the main one he chose was tree rings. So far, so good, although there seems to be some dispute about whether the size of the rings in bristlecone pines is really a good indicator of temperature changes.
Within the last couple of centuries, actual temperature measurements have become available, so the researcher has the opportunity to splice that data onto the older, tree-ring derived stuff. In doing that, however, you'd surely want to check that for the period for which you have both sets of data, there's some degree of congruence between the two measurements. One of the main criticisms of Mann's work is that on finding that the tree ring data for recent decades did not match the rise in temperatures he discerned from actual measurements, he went ahead and spliced the two series together anyway.
The other major criticism of Mann's work (and others on similar lines) is that the tree ring data seem to imply no natural variance in temperatures for many centuries, until a sudden upward trend emerges as fossil fuel burning leaps higher after the Industrial Revolution. What about the well-documented Medieval Warm Period and the subsequent Little Ice Age? Well, guess what -- climate scientists are busying themselves in proving that those things never happened. All that well-documented evidence of the River Thames freezing over every winter, of Europe-wide crop failures and the rest of it is apparently invalid when compared to studies prepared by academics using unverifiable proxy measurements of their own devising. (Unverifiable because if actual temperature data were available, there'd be no need to use proxy measurements in the first place).
One more thing and I'll stop! Climate change skeptics have been claiming for some time that the most recent data were showing a "pause" in the global warming trend, starting around 1998. Climate scientists, including the aforesaid Dr Mann, have come up with a number of explanations for this, mostly focusing on the theory that the deep oceans were somehow absorbing the extra energy. Needless to say, this possibility was never mooted until it became necessary to come up with an explanation of the pause.
But here's the thing -- the NOAA, usually seen as the go-to source on climate measurement, has gone back and adjusted the supposedly historical data and....there never was a pause at all! As the Church Lady would say, "isn't that conVEENient?' Well actually, not really. If the new NOAA data are correct, then all of the highly confident theories that Prof Mann and others concocted to explain away the "pause" are wrong, aren't they?
I very much doubt if Fetus Gerulaitis will ever read this, but I'd like to thank him for getting me to think these things through again. The science isn't settled: it never is.
No comments:
Post a Comment