What can ice cores tell us about the atmosphere millions of years ago?

These cylinders of ice, drilled from glaciers and ice sheets around the world, preserve precious clues about our changing climate and records such as rainfall, temperature and greenhouse gases, even volcanic eruptions. But what can the past tell us about the future?

Host Graihagh Jackson hears from two ice core experts about their icy adventures in Antarctica, the Himalayas and beyond.

Dr Liz Thomas is Head of Ice Cores Research at the British Antarctic Survey and is currently working on an ice core that may be the oldest ever.

Lonnie Thompson is a pioneer in the field whose first ice core finds date back to the 1970s. He is Distinguished University Professor of Earth Sciences. Senior Research Scientist, Byrd Polar Research Center, The Ohio State University. Professor Thompson also appears in a documentary called The Canary.

Presenter: Graihagh Jackson
Producers: Diane Richardson and Nik Sindle
Production coordinator: Maria Ogundele and Sabine Schereck
Sound mix: Tom Brignell and Louis Griffin
Editor: Simon Watts