This unit allows students to investigate past changes in Earth's climate. Students first explore relationships in climate data such as temperature, solar radiation, carbon dioxide, and biodiversity. They then investigate solar radiation in more depth to learn about changes over time such as seasonal shifts. Students then learn about mechanisms for exploring past changes in Earth's climate such as ice cores, tree rings, fossil records, etc. Finally, students tie all these together by considering the feedbacks throughout the Earth system and reviewing an article on a past mass extinction event.

This classroom demonstration illustrates the amount of water stored in various parts of the Earth system in a straightforward manner. Students estimate the proportions of water in the oceans, icecaps and glaciers, groundwater, freshwater lakes, inland seas, soil moisture, atmosphere, and rivers. Then they fill beakers with the actual proportion and discuss what elements of the activity were surprising to them. Information on flash floods and flood preparedness and safety are included.