THE idea that the earth’s physical and biological systems adjust to perturbation through feedback systems is central to James Lovelock’s Gaia theory. Let me declare upfront that I don’t subscribe to this theory because I don’t see the earth as a living entity, but rather as a place where life is lived. I do agree, however, that natural systems tend to exhibit strong negative feedback around an equilibrium point. Negative feedback is the opposite of positive feedback. It acts to oppose perturbation on a system and thus to maintain the current equilibrium. [1]
The Gaia theory is very popular including amongst many sceintists concerned about global warming notably Tim Flannery. Professor Flannery was named Australian of the Year in 2007 and is presently chairman of the Copenhagen Climate Council. The Gaia theory underpins his influential book on climate change ‘The Weather Makers’.
Given Professors Lovelock and Flannery believe in feedback systems which seek to maintain an optimal physical and chemical environment for life on earth, Gaia, it is perhaps surprising that they are so concerned about elevated concentrations of carbon dioxide causing a climate crisis.
I understand that this concern, as articulated by Professor Lovelock in his 2006 book ‘Revenge of Gaia’, stems in large part from a belief that Gaia has been so despoiled that the biological systems which would normally buffer, for example the capacity of phytoplankton and forests to draw excess carbon dioxide from the atmosphere, is no longer properly functioning.
But what if there exists a physical system, in addition to these biological systems, to prevent runaway greenhouse?
Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.