Ice cores have been collected by the British Antarctic Survey and include samples dating back 800,000 years. Professor Iain Stewart visits the cold store in Cambridge where scientists use these samples to investigate the varying temperatures of the earth. Research shows the changes match the changes in the earth's orbit.

This clip is from:
The Big Freeze
First broadcast:
14 December 2010

Use to introduce the idea of using cores to analyse changes to climatic conditions. Students could carry out similar studies of soil cores or even tree rings.