1. KEY IDEA Climate has changed in the past through natural causes, on timescales ranging from millions to hundreds of years AIM To recognise that the world’s climate has changed significantly over time

2. What do you already know about climate change? SNOWBALL!

3. http://www.bbc.co.uk/learningzone/clips/evidence-of-climate-change/1490.html

6. Ice sheets are like a time capsule. They contain layers of ice, oldest at the bottom, youngest at the top. Each layer is one year of snowfall. Trapped in the ice layers are air bubbles. These preserve air from the time the snow fell. Locked in the air bubble is carbon dioxide. Climatologists can reconstruct past temperatures by drilling a core through the ice and measuring trapped carbon dioxide in ice layers.

7. http://www.youtube.com/watch?v=Jxi-OlkmxZ4 Al Gore explains global warming in 10 mins Watch the clip from An Inconvenient Truth. Note 5 key facts that Al Gore explains about our changing climate.

10. McCarty Glacier in Alaska

11. Greenland Ice Sheet melting

12. Larsen B ice shelf Loss of ice

13. Old photographs, paintings and drawings

14. Written records such as books and diaries

15. 1400s Sodium in ice, seas stormier, period of cooler temperatures Use the information from ‘Discovering Antarctica’ to annotate the diagram.

16. Exam-style question Describe some of the evidence that tell us that climate was different in the past. (4 marks)