September 6, 2006
There has been a growing drumbeat of dire warnings about global warming in the last few months. I tend to be skeptical about the doomsday predictions, but it would be foolish to discount the possibility, given that so many scientists are convinced the phenomenon is a real one. Indeed, melting glaciers in the mountains of Peru and declining populations of tree frogs in the mountains of Costa Rica are clear evidence that something is amiss. The problem is that many of the shrillest alarms are coming from folks like Al Gore, whose scientific credibility is not exactly high. It sounds like "Chicken Little." Saturday's Washington Post featured James Lovelock, the English inventor who in 1969 formulated the concept of "Gaia," named for the Greek goddess who personified the Earth. (It is not a true theory, since it cannot be suitably tested, and in any case involves final causes, i.e., a higher purpose.) In brief, Lovelock's Gaia conjecture holds that Planet Earth is a self-regulating organism whose atmosphere fluctuates so as to maintain healthy conditions for life to flourish. Lovelock has written a new book, The Revenge of Gaia: Earth's Climate Crisis and the Fate of Humanity. He thinks global temperatures will rise by at least ten degrees over the next decade or so, and that much of the planet will become an unhospitable desert. In other words, our terrestial home has a fever, and we are the unwanted pests it is trying to get rid of!
Before we fall into utter panic and start buying land in northern Manitoba, however, it might be a good idea to recall one of the lessons of Chaos theory. In his book The Cosmic Blueprint, Paul Davies reflected on Lovelock's concept of Gaia, noting that Earth's temperature has remained relatively stable over the eons even as the sun's output of energy has climbed by as much as 30 percent. (That factor may well account for most or all of the recent observed increases in temperature.) Chaos theory cautions us not to expect that current trends will continue in a linear fashion, but may rather be nothing more than a temporary fluctuation that is part of a dynamic, self-regulating process. It is not surprising, therefore, that Davies is more sanguine about our future than Lovelock is:
The apparently stable conditions on the surface of our planet serves to illustrate the general point that complex systems have an unusual ability to organize themselves into stable patterns of activity when a priori we would expect disintegration and collapse. Most computer simulations of the Earth's atmosphere predict some sort of runaway disaster, such as global glaciation, the boiling of the oceans, or wholesale incineration due to an overabundance of oxygen setting the world on fire. The impression is gained that the atmosphere is only marginally stable. Yet somehow the integrative effect of many interlocking complex processes has maintained atmospheric stability in the face of large-scale changes and even during periods of cataclysmic disruption. (SOURCE: Davies, p. 132)
I suppose if the Earth really were trying to rid itself of a large portion of its human population, there wouldn't be much we could do about it, so I'll give Lovelock that. Here's a good way to tell if global warming really is imminent: Intelligent people would stop complaining about the price of energy being too high, as if aggregate energy consumption ought to be even greater than it already is.