The Island of Doubt

Anyone who uses Google's personalized home page service and never bothered to delete the default quote of the day was greeted this morning with one of third-rate sci-fi author Michael Crichton's more inane utterances."Whenever you hear the consensus of scientists agrees on something or other, reach for your wallet, because you're being had." Just think about that for a moment as you consider the latest news on the possibility that global warming could stop what is somewhat inaccurately but widely known as the Gulf Stream from keeping Europe as warm as it is today.

According to Crichton, real science doesn't produce a consensus on anything. Never mind useful equations like F=ma, E=mc² and those annoying laws of thermodynamics. If scientists all agree on them, they must all be deluded. This may explain why Crichton hasn't written a decent novel since 1973's Andromeda Strain. (Even the promising 1999 offering, Sphere, was just a rehash of the dramatic premise from The Andromeda Strain overlaid on a plagiarized plot from Andrei Tarkovky's 1972 film Solaris, but I digress). The poor guy just doesn't get science. Especially climatology, which is the context for his little gem of quote.

Here's another quote, this time from someone Crichton likes to lambaste for his enthusiastic embrace of the consensus on climate change:

The planet has a fever. If your baby has a fever, you go to the doctor. If the doctor says you need to intervene here, you don't say, well I read a science fiction novel that tells me it's not a problem. If the crib's on fire, you don't speculate that the baby is flame-retardant.

That was Al Gore, taking aim at Joe Barton and other members of Congress who cling to the notion that everything's hunky-dory with the climate.

So keep that all in mind when you read the New York Times account of the evolving thinking on the fate and influence of the global thermohaline, or deep-ocean conveyor, which is widely, and somewhat inaccurately, thought to allow the Gulf Stream to keep Europe warm enough to grow decent wine.

After consulting 23 climate models, the United Nations Intergovernmental Panel on Climate Change said in February it was "very unlikely" that the crucial flow of warm water to Europe would stall in this century. The panel did say that the gradual melting of the Greenland ice sheet along with increased precipitation in the far north were likely to weaken the North Atlantic Current by 25 percent through 2100. But the panel added that any cooling effect in Europe would be overwhelmed by a general warming of the atmosphere, a warming that the panel said was under way as a result of rising concentrations of carbon dioxide and other heat-trapping gases.

"The bottom line is that the atmosphere is warming up so much that a slowdown of the North Atlantic Current will never be able to cool Europe," said Helge Drange, a professor at the Nansen Environmental and Remote Sensing Center in Bergen, Norway.

The use of the phrase "very unlikely" is important because its antithesis, "very likely" is what the IPCC uses to describe its consensus that humans are responsible for jacking up Earth's thermostat. So if we accept their reasoning on anthropogenic global warming, we should also accept two ideas: First, that the Gulf Stream isn't about to shut off; and second, even if it did, winds have as much to do with Europe's warm-for-its-latitude character as anything else.

[I am hereby dropping the sequence depicting a halt in the thermohaline conveyor from the climate change slide show I occasionally present on behalf of Gore. I had been framing that sequence, which comes with some sweet animation, with so many caveats that it really didn't belong, anyway.]

Now, Crichton and his ilk will undoubtedly use this development to support their contention that there is no consensus on climate change. They will do this because they refuse to look at the big picture. The real story here is that global warming is thought to be such a powerful trend that it will swamp most local countervailing trends. More from the NYT piece,

If the North Atlantic Current weakened 25 percent this century, fractionally offsetting the effect of global warming, Britain in 2100 would still be about 4 degrees warmer than today, the United Nations panel estimated. In France, the net warming would be 5 degrees and here in Norway a bit more, depending on latitude.

When climate modelers simulate a 50 percent slackening of the North Atlantic Current, they still see a net warming in those countries. It is when they completely switch off the current, as they say nature is disinclined to do, that the European climate cools to a level below that of today.

More on the very complicated subject of the thermohaline conveyor at RealClimate.