Earth in balance
Posted by aogTuesday, 11 January 2005 at 15:53 TrackBack Ping URL

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LIKE two bookends of calamity, earthquakes at Bam in Iran and off Sumatra in Indonesia have delineated a year of unusual seismic ferocity - a year, one might say, of living dangerously.

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This year just ending - which the all-too-seismically-aware Chinese will remind us has been that of the Monkey, and so generally much prone to terrestrial mischief - has seen killer earthquakes in Morocco in February and Japan’s main island of Honshu in October. [emphasis added]

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In recent decades, thanks largely to the controversial Gaia Theory developed by the British scientists James Lovelock, it has become ever more respectable to consider the planet as one immense and eternally interacting living system - the living planet, floating in space, every part of its great engine affecting every other, for good or for ill.

Mr. Lovelock’s notion, which he named after the earth goddess of the Ancient Greeks, makes much of the delicacy of the balance that mankind’s environmental carelessness increasingly threatens. But his theory also acknowledges the somber necessity of natural happenings, many of which seem in human terms so tragically unjust, as part of a vast system of checks and balances. The events that this week destroyed the shores of the Indian Ocean, and which leveled the city of Bam a year ago, were of unmitigated horror: but they may also serve some deeper planetary purpose, one quite hidden to our own beliefs.

This isn’t quite as silly as some make out, although it does skirt the edge of claiming “bad spirits make earth move!”. The reference to Chinese folk tales as if they were informative on the subject isn’t a sign of a well grounded opinion.

The main problem is that Gaia theory doesn’t postulate the Earth as an intelligent or purposeful agent, merely as one with significant homeostasis. It’s on par with how mammals keep their internal body temperature constant despite large changes in the external temperature. Earth does the same thing or it would long since have become lifeless. In fact, living organisms are part of the negative feedback cycles that keep the Earth in balance. That’s reasonable. However, that doesn’t imply any necessity to natural happenings, such as Ice Ages or earthquakes. Maybe they are, maybe not, but Gaia theory doesn’t say.

More interestingly, Gaia theory is actually about the stability of the planetary state, not its delicacy. Because there are negative feedback loops that provide a certain level of homeostasis, perturbations that are small don’t matter. Like a ball in a bowl, unless it’s pushed far enough it will just return to someplace close the original position.