This activity from NOAA Earth System Research Laboratory introduces students to the scientific understanding of the greenhouse effect and the carbon cycle. The activity leads them through several interactive tasks to investigate recent trends in atmospheric carbon dioxide. Students analyze scientific data and use scientific reasoning to determine the causes responsible for these recent trends. By studying carbon cycle science in a visual and interactive manner, students can learn firsthand about the reasons behind our changing climate.

In this activity, students explore the role of combustion in the carbon cycle. They learn that carbon flows among reservoirs on Earth through processes such as respiration, photosynthesis, combustion, and decomposition, and that combustion of fossil fuels is causing an imbalance. This activity is one in a series of 9 activities.