Ice cores taken from deep within the Earth's polar regions hold a hidden secret: the historical record of the Earth's climate.
- Evidence of natural climate changes can be found in landscapes and fossils.
- Studying polar ice shows that our planet's climate has fluctuated over many thousands of years.
- Changes in the Earth's orbit and huge volcanic eruptions can affect these natural variations.
- Today, man-made pollution is driving climate change, and levels of carbon dioxide are increasing.