This interactive visualization describes how climatologists obtain and interpret evidence from the Greenland Ice Sheet in an effort to piece together a picture of Earth's distant climate history. Resource describes how glaciers form and how they can be used to collect ancient atmospheric data. The issues analyzed in the data collection are particularly good in showing how science is done in the field.

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 video describes why tropical ice cores are important and provide different information than polar ice cores, why getting them now is important (they are disappearing), and how scientists get them. The work of glaciologist Lonnie Thompson is featured, with a focus on his work collecting cores of ice from high mountain glaciers that contain significant data about past climate change.

This NBC Learn video features climate scientists doing their research on Mt. Kilimanjaro to study the climate of the past. The scientists put the recently observed changes on the glacier into perspective by comparing past climate fluctuations, stressing that the current observed rate of change is unprecedented.
Note: you will need to scroll down the Changing Planet video page to get to this video.