Chapter 21. Climate Control on Daisy World

Imagine a planet inhabited by only two plants -- white daisies and black daisies. The white daisies have a high albedo. The planet surface covered by white daisies tends to reflect much of the incoming solar luminosity. The black daisies have a low albedo. The surface covered by the black daisies tends to absorb much of the incoming luminosity. Consequently, the mix of daisies on the planet influences the absorbed luminosity and the planet's temperature. Now imagine that the planet's temperature influences the rate of growth of the daisies. If the temperature is close to the optimum value for flower growth, the flowered areas will spread across the planet. But if the temperature is too high or too low, the flowered areas will recede over time.

This imaginary world is called Daisyworld. It was created by Andrew Watson and James Lovelock to illustrate a world with close coupling between the biota and the global environment. Lovelock used daisyworld to counter criticism of his Gaia Hypothesis.