This short video, adapted from NOVA, explains how Earth's position relative to the Sun might be responsible for the dramatic shift in the climate of what is now the Saharan nation of Djibouti.

This is a lab about evidence for past climate change as captured in ice sheets of Greenland and Antarctica. Students investigate climate changes going back thousands of years by graphing and analyzing ice core data from both Greenland and Antarctica. They use information about natural and human-caused changes in the atmosphere to formulate predictions about Earth's climate.