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Starting Point-Teaching Entry Level Geoscience > Mathematical and Statistical Models > Mathematical and Statistical Models Examples > Daisyworld: Interactive On-line PC and Mac

# Daisyworld: Interactive On-line PC and Mac

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

This material is replicated on a number of sites as part of the SERC Pedagogic Service Project

#### Summary

Students use a JAVA interface design by R.M. MacKay to explore the Daisy World model described by Mike Barnsley of the Department of Geography, University of Wales Swansea, Singleton Park, Swansea, SA2 8PP (see resources) . The JAVA interface comes with a link to a student activity page in PDF format.

The following is a direct excerpt from University of Wales model description. "The Daisy World model is intended to illustrate a mechanism through which - according to the Gaian hypothesis - biota might optimize their abiotic environment by means of negative feedback. The model does not attempt to describe all of the possible mechanisms and feedbacks which might influence the ways in which the plants and climate develop. Instead, it is an heuristic model - one that seeks to describe the ways in which this mechanism might work. The original model was developed by Watson and Lovelock (1983)."

## Learning Goals

Students:
• Explore the concept of homeostasis in Daisy World;
• Use Excel to graph and analyze results from Daisy World simulations
• Global temperature vs Solar luminosity for Daisy World;
• Area of Black and White daisies vs. Solar Luminosity
• Area of Black and White daisies vs. average planetary temperature
• Planetary Albedo on the Y axis vs. Solar Luminosity L on the X- axis
• In their own words describe how Daisy growth on Daisy World results in homeostasis;
• Compare and contrast Daisy World to a dead planet (no daisies);

## Context for Use

This activity is designed for introductory geoscience courses with an Earth Systems approach and is appropriate for course with minimal mathematics or science prerequisites. Students should have some experience with either Excel, another graphing program, or making graphs by hand. Since the graphical analysis is introductory and fairly qualitative, the activity is appropriate as a beginning graphing exercise.

## Teaching Materials

Here is a link to Daisy World Model

More on Daisy World: a feedback perspective.

## Teaching Notes and Tips

The activity will take students about 4 hours to complete and, since Model and Activity are available on-line, it can be given as a home work assignment. One approach could be to start students out in a lab setting for a hour or so and then let them finish as a homework assignment.

This JAVA activity works best on a PC but it has also worked on Macs (OS 10.2) and Mozilla Browser. Sometimes the reload button had to be used on the Mac.

## Assessment

Grading the activity is a good assessment of student performance and understanding. A follow-up classroom discussion can also be useful to get a sense of student comprehension.

## References and Resources

More on Daisy World: a feedback perspective.

Sea Floor Spreading I or World Population Activity I are good introductory lessons on how to use Excel and how to make graphs with Excel.

Another good reference for students is: Resources Graphing Tutorial: Graphing with Excel . Basics: Data input into cells, Creating a scatter plot and line graph. Advanced: Bar graphs and histograms, Importing text files, Final formatting, Regression lines, Superimposing graphs, Descriptive statistics, Selecting data for display.

A slide show discussion of Daisy World by Mike Barnsley of the Department of Geography, University of Wales Swansea, Singleton Park, Swansea, SA2 8PP.

JAVA Daisy World by Ginger Booth This is a great Flash application which gives students huge flexibility in manipulating input and output. JAVA simulations are also available from the web page. Questions and homework come with this activity.

Andrew Ford's Daisy World Flight Simulator This is a Stella Model flight simulator based on chapter 21 of Fords Modeling the Environment book

Dave Bice's Daisy World Using Stella. Dave has developed a great Stella modeling activity here. Students build the Stella model by following clear instructions and then use it to perform experiments on the behavior of Daisyworld. The Basic equations are identical to those used in the JAVA Daisy World Model (which are also the equations described at the University of Wales Swansea site).

## Subject

Biology:Ecology:Abiotic Relations, Environmental Science:Global Change and Climate:Climate Change:Climate feedbacks, Greenhouse effect, Environmental Science:Global Change and Climate:Climate Change, Geoscience:Atmospheric Science:Climate Change:Greenhouse effect, Environmental Science:Ecosystems:Biogeochemical cycling, Geoscience:Atmospheric Science:Climate Change:Climate feedbacks, Geoscience:Atmospheric Science:Climatology :Atmospheric gases, Climate sensitivity and feedbacks

## Resource Type

Activities:Lab Activity

College Lower (13-14):Introductory Level

## Earth System Topics

Earth's Cycles:Carbon Cycle, Climate, Biosphere, Ecology, Atmosphere

## Topics

Climate, Biosphere

## Theme

Teach the Earth:Teaching Environments:Intro Geoscience, Teach the Earth:Course Topics:Biogeoscience, Atmospheric Science, Teach the Earth:Incorporating Societal Issues:Climate Change, Teach the Earth:Course Topics:Environmental Science

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