This is a classroom activity about the forcing mechanisms for the most recent cold period: the Little Ice Age (1350-1850). Students receive data about tree ring records, solar activity, and volcanic eruptions during this time period. By comparing and contrasting time intervals when tree growth was at a minimum, solar activity was low, and major volcanic eruptions occurred, they draw conclusions about possible natural causes of climate change and identify factors that may indicate climate change.

In this activity, students are guided through graphs of surface air temperature anomaly data and Vostok ice core data to illustrate how scientists use these data to develop the basis for modeling how climate is likely to change in the future.