Students gain experience using a spreadsheet and working with others to decide how to conduct their model 'experiments' with the NASA GEEBITT (Global Equilibrium Energy Balance Interactive Tinker Toy). This activity helps students become more familiar with the physical processes that made Earth's early climate so different from that of today. Students also acquire first-hand experience with a limitation in modeling, specifically, parameterization of critical processes.

In this activity, learners use the STELLA box modeling software to determine Earth's temperature based on incoming solar radiation and outgoing terrestrial radiation. Starting with a simple black body model, the exercise gradually adds complexity by incorporating albedo, then a 1-layer atmosphere, then a 2-layer atmosphere, and finally a complex atmosphere with latent and sensible heat fluxes. With each step, students compare the modeled surface temperature to Earth's actual surface temperature, thereby providing a check on how well each increasingly complex model captures the physics of the actual system.