TCS Daily


News Flash! We're In For 'NAS'ty Weather

By Philip Stott - December 14, 2001 12:00 AM

A couple of days ago, the New York Times blared out in a dramatic headline that Drastic Shifts in Climate Are Likely, Experts Warn.

It was a classic piece of virtual risk ecohype, emulated widely by other newspapers, such as the Washington Post, as well as scores of television news stations around the U.S. You will notice at once that the climate change involved has to be drastic, it is, moreover, likely -- although no immediate date is given -- and that they are expert Cassandras who are calling the shots.

Interestingly, this virtual risk parallels many other recent natural terrorist threats including meteor strikes and flooded islands in the Pacific Ocean

The source of the dire prediction was a new report issued by the National Research Council, the research arm of the National Academy of Sciences (NAS), in which a panel of 11 scientists examined the possibilities of abrupt climate change. The scientists, inevitably, are much more cautious than their journalistic counterparts. Dr. Richard B. Alley, Professor of Geosciences at Pennsylvania State University, wisely commented that "there is no need for undue alarm" and indicated that societies have managed to adapt to serious climate change in he past. Maybe the Times missed Alleys comments.

We have known that climate changes both gradually and suddenly for a very long time. It is nothing new. In fact, a far more worrying observation was made about such potential shifts by one of the fathers of chaos theory, the climatologist Edward Lorenz, way back in 1964. Lorenz had been experimenting with toy weather since the early 1960s, and he was already asking the fundamental question: "Does a climate exist?" In other words, does the weather have a long-term average?

Lorenz soon began to regard climate as an almost-intransitive system. This is a system that exhibits a kind of average behavior for a period of time but which then, for no apparent reason, shifts into a totally new sort of behavior, still fluctuating, but producing a completely different average. The sudden shift from a White Earth Climate of glaciation, with snow on the continents and ice over the oceans, to a Green Earth Climate of trees and grasses would be a case in point.

As James Gleick writes in his excellent little book on Chaos (1987), "...it takes no great imagination for a climatologist to see that almost-intransitivity might well explain why the earth`s climate has drifted in and out of long Ice Ages at mysterious, irregular intervals. If so, no physical cause need be found for the timing. The Ice Ages may simply be a byproduct of chaos."

Now, the role that random chaos plays in climate change is indeed a cause for thought. But there is something wrong with it for many people. After all, if its true, then you can`t blame the human race for causing the problem, and, oh, how we want to be able to do that! Hence the deep desire to play down such uncontrollable prognostications in favor of those through which we can implicate humans, arguing that greenhouse warming and other alterations of the earth system may increase the possibility of large, abrupt, and unwelcome regional or global climate events.

In this, at once, we have the obvious explanation for the blaring headlines in those media outlets that desperately want President Bush to re-engage with the Kyoto Protocol on curbing the emissions of greenhouse gases.

But it won`t wash. As the scientists rightly point out in their report, such abrupt shifts in climate scar the geological record from eons before there was ever a Homo Sapiens sharpening a flint blade on the plains. Moreover, humans experienced a particularly nasty shift themselves in what we call the Younger Dryas cold interval, around 12,800 years ago, when temperatures dropped by anything from 5 to 10 degrees Celsius to remain very cold for more than 1,000 years. The earth then warmed again by up to 15 degrees in a decade. This, of course, all rather puts in the shade the tiny bit of warming we have been experiencing over the last 150 years (0.6 degrees Celsius) following the Little Ice Age which ended around 1880.

And the alarm won`t wash for other powerful scientific reasons. Recent paleogeological research has clearly indicated that carbon dioxide has largely risen following temperature rises, reversing the supposed cause and effect. And that water vapor -- the most important greenhouse gas of all, though you wouldn`t guess it from most newspapers -- is far more implicated than carbon dioxide, although water vapor is a devil to model in any meaningful way.

What, therefore, can we conclude from all this? This rediscovery that climate might change abruptly tells us more about our society at the start of the new Millennium than it tells up about climate or climate change. Climate has always changed both gradually and abruptly, and it will no doubt continue to do so whatever we do about greenhouse gas emissions. For all we know, not emitting such gases may be worse in this respect than actually emitting gases.

So let`s not flip too much over climate change. The way forward is to maintain the strongest and most flexible economies possible so that we can cope with whatever chaos and nature throw at us. Sadly, the Kyoto Protocol undermines this basic necessity.

Philip Stott is Emeritus Professor of Biogeography in the University of London. His latest book, with Dr. Sian Sullivan, is Political Ecology: Science, Myth and Power (Arnold and OUP, 2000). Philip also hosts the `AntiEcohype` Web Site.
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