A journey through the Earth's climate history (BBC)

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As world leaders prepare to meet in Copenhagen to discuss climate change - how did the Earth's climate arrive at its current state and how do scientists delve into the secrets of our planet's past?

The layers of ice laid down each year in Antarctica and Greenland store a record of the Earth's climate. Bubbles of air trapped in the ice as it froze can be analysed to give details on temperature at the time it froze, and on atmospheric concentrations of gases.

The oldest ice core so far extracted belongs to the European Project for Ice Coring in Antarctica (Epica). It allows scientists to look back 800,000 years.
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Sources and resources

The data, for the animation , on temperature and carbon dioxide for the 800,000 year time period is taken from the European Project for Ice Coring in Antarctica, Epica. The data can be downloaded using the link on the right and was complied by Dr Robert Mulvaney of the British Antarctic Survey.

For the time period covering the last 1,500 years the CO2 record is from the Law Dome ice core, again in Antarctica. McFarling Meure et al, 2006 is the source. For the past 60 or so years the CO2 source is the readings taken at Mauna Loa by the NOAA.



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more, including sources and downloadable data: http://news.bbc.co.uk/2/hi/in_depth/sci_tech/2009/copenhagen/8393855.stm

Flash animation with graphs: http://news.bbc.co.uk/2/hi/in_depth/sci_tech/2009/copenhagen/8386319.stm