Gaia: A New Look at Life on Earth
Alternatively, How Life on Earth is like an Oven.
James Lovelock's look at life on earth is not new any more, in fact it's thirty years old this year. I found it a rather frustrating book. However I'm not sure how much of that is because it's out of its original context and I know little about the disciplines the book is intended to inform.
There's no doubting that the central idea of Gaia is a powerful one. According to the Gaia hypothesis, life on earth plays a major part in regulating the planet's condition to ensure its suitability for life. So, for example, the sun's output has fluctuated a good deal since the start of life on earth. This should have altered the temperature of the planet a lot more than it has - enough to destroy most of the life present. This hasn't happened, Lovelock claims, because life itself has evolved to regulate the temperature. The same applies to the composition of gases in the air, the availability of key chemicals, the levels potentially harmful chemicals, the salinity of the sea and a range of other things.
The analogy is an oven, a very simple cybernetic system. The thermostat senses the temperature and passes on a signal which increases or decreases the generation of heat, as required to keep a constant temperature.
The trouble is that Lovelock can firmly identify only a seemingly small number of cases to demonstrate his point. In the case of temperature, he conjectures that its control may be done in some way through ozone. Even in the cases he does have, he's short of the crucial feedback mechanisms - the means of sensing that there is a problem and responding to it.
In addition, while he states these interlinked systems have come about through evolution, he gives no details as to how this actually happened. It's not implausible, given the intriguing things that can occur in evolution, but early on the book did receive heavy criticism from evolutionary biologists, including Professor Yaffle himself.
Part of the explanation for this is that Gaia, in 1979, is largely a hypothesis and an inspiration for research. To see how well this hypothesis has been verified we have to look at later work. Some of its ideas do seem to have become mainstream, particularly the view of the earth consisting of numerous linked, non-linear systems. These make tracing cause and effect very hard (even impossible), a problem that can be seen when we look at greenhouse gas emissions and global warming.
A surprising feature of Gaia, given its place in the environmental and ecological movements is that it is rather unsympathetic to those movements. To an extent, Lovelock is reacting against more extreme and un- (or even anti-)scientific positions. On top of this, his Gaian perspective means he views life on earth as a much more resilient system than other people. Indeed, he views people as part of this system and part of the regulation. Ultimately, although we have appropriated much of it for our own purposes, we have not significantly harmed the biological productivity of the planet. Lovelock suggests that we have (or at least had) barely touched the areas key to the system, in particular the continental shelves.
Lovelock fails to address a lot of questions that rise out of this. In particular the question of timescales. Gaia may be able to react to changes wrought by humans, but can it react fast enough? And even if we are unlikely to destroy life on earth or even, in the longer-term at least, seriously hurt it, what changes will we cause in the meantime? In contract to this, the book's epilogue is about the plight of the whales and the possibility of their extinction. Is it not all one and the same to Gaia?
James Lovelock's look at life on earth is not new any more, in fact it's thirty years old this year. I found it a rather frustrating book. However I'm not sure how much of that is because it's out of its original context and I know little about the disciplines the book is intended to inform.
There's no doubting that the central idea of Gaia is a powerful one. According to the Gaia hypothesis, life on earth plays a major part in regulating the planet's condition to ensure its suitability for life. So, for example, the sun's output has fluctuated a good deal since the start of life on earth. This should have altered the temperature of the planet a lot more than it has - enough to destroy most of the life present. This hasn't happened, Lovelock claims, because life itself has evolved to regulate the temperature. The same applies to the composition of gases in the air, the availability of key chemicals, the levels potentially harmful chemicals, the salinity of the sea and a range of other things.
The analogy is an oven, a very simple cybernetic system. The thermostat senses the temperature and passes on a signal which increases or decreases the generation of heat, as required to keep a constant temperature.
The trouble is that Lovelock can firmly identify only a seemingly small number of cases to demonstrate his point. In the case of temperature, he conjectures that its control may be done in some way through ozone. Even in the cases he does have, he's short of the crucial feedback mechanisms - the means of sensing that there is a problem and responding to it.
In addition, while he states these interlinked systems have come about through evolution, he gives no details as to how this actually happened. It's not implausible, given the intriguing things that can occur in evolution, but early on the book did receive heavy criticism from evolutionary biologists, including Professor Yaffle himself.
Part of the explanation for this is that Gaia, in 1979, is largely a hypothesis and an inspiration for research. To see how well this hypothesis has been verified we have to look at later work. Some of its ideas do seem to have become mainstream, particularly the view of the earth consisting of numerous linked, non-linear systems. These make tracing cause and effect very hard (even impossible), a problem that can be seen when we look at greenhouse gas emissions and global warming.
A surprising feature of Gaia, given its place in the environmental and ecological movements is that it is rather unsympathetic to those movements. To an extent, Lovelock is reacting against more extreme and un- (or even anti-)scientific positions. On top of this, his Gaian perspective means he views life on earth as a much more resilient system than other people. Indeed, he views people as part of this system and part of the regulation. Ultimately, although we have appropriated much of it for our own purposes, we have not significantly harmed the biological productivity of the planet. Lovelock suggests that we have (or at least had) barely touched the areas key to the system, in particular the continental shelves.
Lovelock fails to address a lot of questions that rise out of this. In particular the question of timescales. Gaia may be able to react to changes wrought by humans, but can it react fast enough? And even if we are unlikely to destroy life on earth or even, in the longer-term at least, seriously hurt it, what changes will we cause in the meantime? In contract to this, the book's epilogue is about the plight of the whales and the possibility of their extinction. Is it not all one and the same to Gaia?