Last night, I attended a lecture by James Lovelock, originator of the Gaia Hypothesis, and author of the recent book The Revenge of Gaia. Briefly, the Gaia Hypothesis proposes that the earth functions like a single organism consisting of a number of subsystems which interact in a sustainable way. On Thursday, Lovelock was talking about the problem of global warming and measures to slow down the inevitable escalation of the earth’s temperature in the approaching century – matters he discusses in detail in his book. I am guessing from the title that, the book additionally talks about how the earth (Gaia) is trying to cope by means of occurrences such as forest fires which release more carbon dioxide into the atmosphere in an effort to reach equilibrium at a hotter global temperature. Lovelock didn’t elaborate on this “revenge” of Gaia, focussing instead on what it may mean for the human race.
Lovelock’s picture of the earth’s future is grim, and he seems to be convinced that we are too far along the road to reverse global warming, and the best we can do is to try to slow down the process and adapt to the coming changes. This is not to suggest that the earth is in danger of a runaway greenhouse effect – which has occurred on Venus – but that human beings should be prepared for a dramatic rise in temperature and the consequent changes in their lives. For example:
- He mentioned that, in time, it will become impossible to live or cultivate crops in the tropics. This will cause an exodus of many living species toward the poles – akin to a similar exodus that occurred about 50 million years ago when the temperature of the earth rose by about 8 degrees celsius over a few thousand years. (The implication is that Americans will flee to Canada and the Chinese will flee to Siberia.)
- By 2050, Lovelock believes, the earth’s agricultural produce will be insufficient to feed the population. Extremely hot summers such as the one in Europe in 2003 will, by then, have become the norm.
Lovelock didn’t put a time scale on the first scenario. I admit that it seems slightly far fetched, but given enough time, it seems more and more likely. The second scenario, I’m afraid, is quite possible. In this context, it appears that rising sea levels and the submergence of coastlines seem to be the least of our problems!
Lovelock mentioned a very interesting short term ploy to compensate for the increase in the sun’s intensity, first proposed by a Russian scientist. Airplanes can be made to release sulphate particles into the atmosphere through their fuel exhaust. These would form a haze in the atmosphere which reflects a fraction of the sun’s rays. If the amount of the sulphates is small enough, there is no appreciable risk of contamination. This felt strangely familiar to me, because I remembered reading that such a process occurs naturally on Venus. It routinely rains sulphuric acid on Venus, except that the acid droplets never the surface. The surface of Venus is so hot, that the acid droplets vaporize and rise again into the atmosphere. The dense clouds of sulphuric acid reflect the sunlight. Of course, this cannot prevent Venus from heating up, because 95% of its atmosphere consists of carbon dioxide which absorbs heat. On earth, the suphate particles will be more useful because we have less than 0.05% carbon dioxide.
This is merely a step to buy us time, according to Lovelock. We have then to deal with the process of controlling the amount of carbon dioxide in the atmosphere, which has increased by about 40% in the last 200 years. To do this, Lovelock, controversially again, favors the use of nuclear fuels over fossil fuels and the proliferation of genetically modified crops in order to increase food production. He calls the Kyoto Protocol well-intentioned but impractical, quoting the example of a Chinese official saying that they would have another revolution on their hands if they decided to stop burning coal. (“If [the Chinese] can’t do it, how in blazes can a democracy do it?”)
I was quite impressed by the number of people who attended the lecture, a lot of whom looked like alumni living in the Bay Area. But again, this is to be expected in California and I wouldn’t consider the response representative of the country as a whole. For people who missed the lecture, a large part of Lovelock’s speech overlaps with an interview he gave to the excellent Michael Krasny on Wednesday. An audio stream and mp3 download are available at KQED’s Forum.