c. The amount of solar energy absorbed or radiated by Earth is modulated by the atmosphere and depends on its composition. Greenhouse gases— such as water vapor, carbon dioxide, and methane— occur naturally in small amounts and absorb and release heat energy more efficiently than abundant atmospheric gases like nitrogen and oxygen. Small increases in carbon dioxide concentration have a large effect on the climate system.

In this experiment, students will observe two model atmospheres: one with normal atmospheric composition and another with an elevated concentration of carbon dioxide. These two contained atmospheres will be exposed to light energy from a sunny window or from a lamp. The carbon dioxide is produced by a simple reaction and tested using bromothymol blue (BTB).

In this activity, 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). While becoming more familiar with the physical processes that made Earth's early climate so different from that of today, they also acquire first-hand experience with a limitation in modeling, specifically, parameterization of critical processes.

In this activity, students learn about the relationship between greenhouse gases and global warming through a simple teacher demo or hands-on lab activity. Everyday materials are used: beakers, baking soda, vinegar, candle, thermometers, heat source such as a goose-necked lamp, etc. Students shine a light onto three thermometers: a control, an upside down beaker w/ a thermometer and air, and a beaker in which CO2 had been poured.