Daisy World Simulations with NetLogo

by Ralph Abraham and the Visual Math Institute

Daisy World #1

This is a model based on Watson and Lovelock (black and white daisies), 1983. Our model of 2000 built in Tcl, and older language, is here translated into NetLogo 4.0.2, using its built-in system dynamics editor. If you are interested in this approach, you might download the NetLogo 4.0.2 system, and run our model.
  • The math of the daisyworld model
    This is a summary of the Watson-Lovelock model, based on their original publication.
  • Graphic of the Interface
    This is the interface presented by the applet.
  • Graphic of the Diagram
    This is the NetLogo system dynamics diagram, which is presented by our model when opened in NetLogo 4.0.2.
  • NetLogo model for Daisyworld as Applet
    Just click "setup" and "go".
  • NetLogo model for Daisyworld as Text
    Download this to read the code, or run the model within NetLogo.
    • Notes for this model may be found HERE, as well as within the applet and the model.

    Daisy World #2

    In this model due to James Lovelock and Lee Kump (Nature, 1993) humans pump up atmospheric CO2 (we ignore methane) and thus temperature, while the algal ecosystem in the oceans and the land-plants on land pump it down again. Lovelock and Kump (1993) presented simulatiion results but not the model, the details of which seem to have been lost. We propose to reconstruct this model as a NetLogo System Dynamics model.
  • Graphic of the Diagram
    This is the NetLogo system dynamics diagram, which is presented by our model when opened in NetLogo 4.0.2.
    • Revised 01 January 2008 by Ralph