INDEED, ARGUMENTS QUESTIONING THE USEFULNESS OF GAIA: IS IT ALL PISS AND WIND?
STRONG AND WEAK GAIA
Of Coevolutionary Gaia, it can be argued that Lovelock simply restates the obvious and well documented fact that life influences the environment. There are numerous examples, dating as far back as 1844 that illustrate the premise that biological processes alter the physical environment. Is it true that “An observation that is so widely recognised lacks the tentative character of a true hypothesis.”
The Gaia thing may be divided into two separate forms: the weak and the strong.
WEAKGAIA: The weak form of Homeostatic Gaia states that “the dominant interactions between the biotic and abiotic worlds are stabilising.”
STRONG GAIA: The strong form states that “these dominant interactions make the Earth’s physical
environment significantly more stable than it would have been without life.” But surely climatic homeostasis alone is not evidence for Gaia because it is impossible to determine whether the climate is stable as a result of biological processes or regardless of them. The feedback mechanisms of Gaia because it unclear whether such mechanisms are stabilising or destabilising. Without the ability to determine which mechanisms are destabilising, or tend to weaken homeostasis, it may be impossible to understand an organism’s homeostatic regulatory function.
So, maybe Homeostatic Gaia is unfalsifiable. Take Lovelock’s explanation of the oxygen crisis, the switch from oxidising to 'reducing' conditions in the Precambrian atmosphere. Lovelock cites the fact that terrestrial life survived the oxygen crises as evidence for Gaia’s ability to adapt to changing conditions. In response one of his many critics states:
If the most destabilising biotic event in Earth’s history can be construed as evidence for Gaia, and the relative stability since then can also be cited as evidence for Gaia, one wonders what
conceivable events could not be interpreted as supporting the Gaia hypothesis. If there are none, Gaia cannot be tested against the geologic record…If Gaia stabilises and Gaia
destabilises…is there any possible behaviour which is not Gaian?
Perhaps the use of Gaia as an “Earth-asorganism” metaphor and the application of the same to terminology to Gaia and to recognised biological organisms is both unwise and potentially misleading.
