DaisyWorld

When the temperature raises 5 degrees Celsius, all seeds will germinate. During the first season, dark daisies will grow better than light ones because they will absorb more sunlight and be warmer. Dark daisies would be the fittest species because clusters of them create local warm spots that favour the growth of more daisies.

At the end of the first season, there will be more dark than light daisy seeds. Dark daisies will therefore dominate after the new season opens. There growth will warm, not just themselves, but there locality. With an explosive positive feedback, the population of dark daisies and the temperature of the planet will both rise rapidly. Soon the planet would be covered by dark daisies, and their collective effect would be to increase the global temperature above what it would have been in the absence of life. [See figure 2, (time A)]

When the dark daisies had established a comfortable temperature, grey and white daisies would begin to take advantage of the pleasant conditions. At first, grey daisies would do better than light ones because clusters of daisies would not be able to keep the local temperatures warm enough for survival [see time B]. But the temperature cannot rise indefinitely, overheating also limits growth. Eventually the Sun`s output would exceed the maximum point tolerable to daisies [see time C]. It is at this point where light daisies become the fittest.
Light coloured competitors are now at an advantage; through there ability to reflect sunlight, they cool themselves. As light coloured daisies spread, their collective effect would be to decrease the global temperature well below what it would have been in the absence of any life forms [see time D].

The competitive growth of daisies can keep the mean temperature of the planets surface close top that most comfortable for daisies. In this way, individual daisies, without knowledge or of concern for the planet as a whole, would have acted to control the global environment. NB If we add mutations, for example - slight random changes of the albedo in the growth process. We can run a simulation with mutants, the solar radiation can be significantly increased until the vegitation breaks down.

Finally, the heat produced by the sun would be so great that neither type of daisies would be able to moderate the temperature and all the species would die out
When Lovelock made the Daisyworld model he was ignorant of population biology and unaware that models of more than two species competing simultaneously are almost unvariably unstable. He then made a Daisyworld where there were between three and twenty different species of daisies of different colours competing for space on the planet, and unconsciously regulating their world as they did so. These models included grey daisies whose colour is the same as that of the bare planetary surface.
Lovelock then modelled temperature regulation by ten species of daisy growing in competition . It is as stable as the two species model, and temperature is regulated more accurately.
By including the physical environment in the model, something no theoretical ecologist has ever done, the inherent instability of a multi species ecological model vanishes. Indeed rabbits can be added to graze the daisies and foxes too, to cull the rabbits, without losing stability.
Much more independently we have, for the first time, a theoretical justification for diversity. Diversity is greatest when temperature regulation is most efficient and least when the system is stressed: when growth has just started or when the daisies are about to die from overheating.
Daisyworld is just a model and not a prescription for planetary air conditioning. But the model is full of insight. It is also a general model which is not limited to daisies and climate Lovelock then made models of the earliest eras on earth - the two divisions of the Precambrian, the Archaean and Proterozoic - with microorganisms alone regulating the composition of the atmosphere and the climate simultaneously. Daisyworld provides a plausible explanation of how Gaia works and why foresight and planning are not required for planetary regulation.

Gaian feedback mechanisms The Daisyworld model is absurdly simple, but are there any real Gaian feedback mechanisms on Earth?
One possible Earthly example is dimethyl sulphide (DMS) production by phytoplankton in the oceans. Studies in the North Atlantic have shown that DMS becomes oxidised in the atmosphere to create sulphate and particles that act as cloud condensation nuclei. The latter increase in the cloudiness with the end result that areas of the ocean where these phytoplankton occur are cloudier than elsewhere, conditions that favour the growth of more phytoplankton. In a sense, they are making an umbrella for themselves, and because they are the base of the oceanic food chain, this has profound implications globally on Earth.

[Bjornerud, M. 1996]