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Daisyworld: Stella Mac or PC

This Activity was developed by Dave Bice, Carleton College Geology Department. Starting Point page organized by R.M. MacKay.
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This activity was selected for the On the Cutting Edge Reviewed Teaching Collection

This activity has received positive reviews in a peer review process involving five review categories. The five categories included in the process are

  • Scientific Accuracy
  • Alignment of Learning Goals, Activities, and Assessments
  • Pedagogic Effectiveness
  • Robustness (usability and dependability of all components)
  • Completeness of the ActivitySheet web page

For more information about the peer review process itself, please see http://serc.carleton.edu/NAGTWorkshops/review.html.

This page first made public: Jul 19, 2005

This material was originally created for Starting Point:Introductory Geology
and is replicated here as part of the SERC Pedagogic Service.


Daisyworld is a very simple planet that has only two species of life on its surface - white and black daisies, and bare ground. Daisyworld is a good example of homeostasis and was first proposed by James Lovelock as a plausible example of his Gaia hypothesis. With guidance, students build a Stella model of Daisyworld from scratch. After constructing the model they perform guided experiments to explore the behavior of Daisyworld to changes in model parameters and assumptions.

Learning Goals

Students explore:
  • Concepts and terms such as:
    • Stefan-Boltzman's radiation law
    • albedo, emissivity, blackbody
  • Basics of Stella and Model construction in the Stella environment
  • The concept of homeostasis
  • Learn how surface albedo changes can influence local and global temperature
  • Use a plausible plant growth factor as a function of local temperature

Context for Use

Appropriate for introductory geoscience courses with an Earth Systems approach.

Description and Teaching Materials

The complete activity is located at Dave Bice's Daisyworld ( This site may be offline. ) using Stella II.

Teaching Notes and Tips

This activity will likely take about 3 to 4 hours for students to work through assuming some introduction and discussion about Daisy world and the Stella environment in lecture. If you do not have Stella at your school you can download a free demo version of Stella from High Performance Systems, Inc.


Grading completed activity is a good measure of assessment. Also a follow-up in class discussion can help assess student understanding of key concepts.

References and Resources

Here is a link to Daisy World Model (more info) written by R.M. MacKay.

More on Daisy World: a feedback perspective.