Daisyworld Model: Climate Regulation and Feedback Loops

Premises of the Daisyworld Model

• Star and Planet: A sun-like star and an Earth-like planet.
• Solar Evolution: The sun's heat output increases over time.
• Albedo Neutrality: The planet is initially color-neutral regarding albedo.
• Habitability: The planet has water and nutrients to support life.
• Flora: The only life forms are black and white daisies.
• Growth Conditions: Seeds germinate above 5°C, with an optimum of 22°C. Plants die if the temperature exceeds 40°C.

Feedback Loops and Developmental Phases

The model distinguishes six distinct phases of planetary development:

Phase 0: Dormancy

When solar radiation keeps the temperature below 5°C, all seeds remain dormant.

Phase 1: Exponential Growth

As temperatures reach 5°C, seeds germinate. Black daisies absorb more light, creating a positive feedback loop that increases local temperatures. This continues until the local temperature exceeds the optimum.

Phase 2: Stabilization

An opposing mechanism emerges, favoring white daisies. The system stabilizes near the optimum temperature with a balanced population of black and white daisies.

Phase 3: Global Expansion

As solar radiation rises, daisies colonize the poles. At this stage, black and white daisies are evenly distributed at the equator, while black daisies predominate at the poles.

Phase 4: White Daisy Dominance

Equatorial temperatures approach 40°C. Black daisies disappear, leaving only white daisies, which use their high albedo to cool the local environment.

Phase 5: Planetary Extinction

Solar radiation exceeds the threshold where even white daisies can survive. The process spreads from the equator to the poles until all life on the planet ceases.