Daisyworld – Demonstrating the Gaia Hypothesis
The Gaia hypothesis can be understood through the simple computer model Daisyworld, which was developed for the purpose. Based on a simple scenario, Daisyworld envisages a world with two types of daisies, black and white. When (for whatever reason) the temperature falls below the optimum level for both types of daisy to grow, the black daisies are able to absorb more heat and so grow more quickly, coming to predominate. The black daisies, however, absorb so much heat that the atmosphere eventually warms up. As it becomes warmer the white daisies, with their ability to reflect heat and to keep cool, find that they are better suited to the prevailing conditions. They then begin to predominate – reflecting so much heat that the atmosphere cools and the black daisies again begin to thrive. Daisyworld is, of course, and extremely simple model and the real earth involves far more variables, both in number and in complexity. As the explanation provided by Indiana University notes, what it does is demonstrate the impact of feedbacks and the way in which natural selection can operate to maintain the equilibrium of the earth’s system.
Gaia and the Future
In a world where discussions rage about climate change and the impacts which humans and their activities can have upon the earth’s system and its suitability for life, Lovelock’s position is unambiguous. In an article first published in the Independent newspaper in 2006, he equates himself as the bringer of bad news. He argues that Gaia is quite capable of self-regulation, and that human intervention is taking on a task that is beyond our capabilities. Climate change – and specifically global warming – is a threat: he warns of a possible temperature rise of 8⁰C in temperate regions and 5⁰C in the tropics. His argument is that human interference, through irresponsible use of resources which contribute to self-regulation, will lead to what he calls “a morbid fever that may last as long as 100,000 years.” Gaia is not proven, of course, and there is a strong body of opinion which supports the contention that climate change is itself natural and not anthropogenic. But Lovelock and his supporters continue to argue that human meddling in the natural balance of the earth as a system is potentially disastrous and, as he concludes, “we are responsible and will suffer the consequences.” Sources Gaia Theory. “Understanding Gaia Theory” Accessed 11 May 2011. Indiana University. “Daisyworld or Gaia redux” Accessed 11 May 2011. Lovelock, James. The Earth is about to catch a morbid fever that may last as long as 100,000 years. (2006) Accessed 11 May 2011. Open University. Evolving Life and the Earth (1997).
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