Professor Iain Stewart uses coloured and plain ice cubes to demonstrate the albedo effect. Light surfaces reflect more heat than dark surfaces. This phenomenon is known as the albedo effect, and is a powerful force in driving regular ice ages in Earth’s history.

As the Earth’s temperature drops, induced by the planet’s extreme orbit, this triggers ice sheets to grow. The expanding ice means more of the Sun’s energy is reflected back into space, leading a to further drop in temperature.

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

Students could produce annotated maps or diagrams to show how the albedo effect causes ice caps to increase in size.