26 January, 2009

Science writer and broadcaster Richard Hollingham meets Dr Robert Mulvaney at the British Antarctic Survey, who explains how collecting ice cores from all over Antarctica gives scientists a unique window into the Earth’s past climate.

Dr E.C. Pasteur removing an ice core from the core barrel during drilling on an ice dome on Berkner Island. The collaborative drilling programme with the Alfred-Wegener-Institut, Bremerhaven, Germany recovered ice cores to study the climate and atmospheric conditions of the Weddell Sea region over the past millenium.

Ice cores collected from thousands of metres beneath the Antarctic ice cap contain tiny bubbles of air trapped when snow fell on the continent hundreds of thousands of years ago. By extracting the bubbles, scientists can measure the levels of carbon dioxide and methane in the atmosphere as far back as three quarters of a million years ago.

Throughout this time, they have found temperature has followed carbon dioxide closely. As carbon dioxide levels rose, so did temperature.
Listen to the podcast on NERC’s Planet Earth Online

Related link

Planet Earth online podcast