Day By Day

Tuesday, May 15, 2007

The Climate Consensus Keeps Changing


The NYT notes that "scientists" are backing away from some of their most cherished apocalyptic visions, specifically the supposed results of the collapse of the climate conveyor belt.

OSLO — Mainstream climatologists who have feared that global warming could have the paradoxical effect of cooling northwestern Europe or even plunging it into a small ice age have stopped worrying about that particular disaster, although it retains a vivid hold on the public imagination.

The idea, which held climate theorists in its icy grip for years, was that the North Atlantic Current, an extension of the Gulf Stream that cuts northeast across the Atlantic Ocean to bathe the high latitudes of Europe with warmish equatorial water, could shut down in a greenhouse world.

Without that warm-water current, Americans on the Eastern Seaboard would most likely feel a chill, but the suffering would be greater in Europe, where major cities lie far to the north. Britain, northern France, the Low Countries, Denmark and Norway could in theory take on Arctic aspects that only a Greenlander could love, even as the rest of the world sweltered.

All that has now been removed from the forecast. Not only is northern Europe warming, but every major climate model produced by scientists worldwide in recent years has also shown that the warming will almost certainly continue.

“The concern had previously been that we were close to a threshold where the Atlantic circulation system would stop,” said Susan Solomon, a senior scientist at the National Oceanic and Atmospheric Administration. “We now believe we are much farther from that threshold, thanks to improved modeling and ocean measurements. The Gulf Stream and the North Atlantic Current are more stable than previously thought.”

Read it here.

But..., but..., Al Gore said....

Never mind.

This is the problem with basing your view of the future on computer models. As the parameters change and as new information becomes available the predictions can be significantly modified. Despite their much-vaunted sophistication the principle of GIGO still applies. The result is that anyone who uses the evidence of computer models [snicker] on which to base social or economic policy is building his house on shifting sands.

It might be argued that in a global sense this is a mere detail, but it's a pretty damn big detail and, as the article observes, it has caught hold in the imaginations of the European public [and the Hollywood loons] and will be hard to displace.