One of a suite of online climate interactive simulations, this Greenhouse Gas Simulator uses the bathtub model to demonstrate how atmospheric concentrations of CO2 will continue to rise unless they are lowered to match the amount of CO2 that can be removed through natural processes.

This activity describes the flow of carbon in the environment and focuses on how much carbon is stored in trees. It goes on to have students analyze data and make calculations about the amount of carbon stored in a set of trees at three sites in a wooded area that were to be cut down to build a college dormitory.

This is a multi-step activity that helps students measure, investigate, and understand the increase in atmospheric CO2 and the utility of carbon offsets. It also enables students to understand that carbon offsets, through reforestation, are not sufficient to balance increases in atmospheric C02 concentration.