Runaway Greenhouse Effect Exercise
This material is replicated on a number of sites as part of the SERC Pedagogic Service Project
"Why is Venus so much hotter than the Earth? You are a group of experts gathered from around the world to solve this long-standing mystery..."
This is a collaborative problem-solving exercise about the greenhouse effect on Venus. Students role-play biologists, coal geologists, space warfare experts, astronomers, pollution-control scientists, and hydrophysicists. Each student gets a copy of the appropriate briefing sheet (there are 6) containing some information important to solving the problem, much of it quantitative.
The purpose of this exercise is to:
- Enable students to work out why Venus is so much hotter than Earth
- Demonstrate the degree to which various atmospheric gases trap heat
- Make lecture material more exciting and memorable for students
- Allow students to work theories out for themselves using data and general principles
Context for Use
The enclosed paper describes a typical exercise as taking about 75 minutes to cover the material ordinarily covered in a 60-minute lecture. The author asks that anyone using the exercises contact him to tell him how it goes.
The 1-sentence explanation of the scenario is on the Role-Playing Collection page : "Why is Venus so much hotter than the Earth? You are a group of experts gathered from around the world to solve this long-standing mystery..." The author provides an MSWord document with complete briefing sheets for the different roles students take on (more info) . Each role set to print onto a different page. A basic astronomy or planetary science textbook will also be needed.
Teaching Notes and Tips
The author stresses the need for the instructor to wander between groups and listen to what they are saying in case of students going horribly off course. According to the Role-Playing Collection page : "This exercise teaches students about the greenhouse effect. I pose the question of why Venus is so ridiculously hot, when it isn't that much closer to the Sun than us: its equilibrium temperature should be around 50C, not 400+C."
Not included, as these are substitutes for lecture
References and Resources
This exercise is only one of eleven in two substantial collections of detailed Role-Playing and Problem-Based Exercises for Teaching Undergraduate Astronomy (more info) . The whole site includes debates and collaborative problem-solving exercises broken into role-playing and problem-based learning exercises collections, with data and equations provided to the students. Topics include the formation of solar systems, the politics of exploration, international space law, and navigation by the stars. The exercises generally involve the students working in teams as experts on part of a problem and sharing their results with the rest of the class to come up with an overall solution. The students are expected to use math, teamwork, and astronomy to overcome the challenge. This site also includes papers on the theory and assessment of role-playing and problem-based learning in education, as well as photos of students role-playing.