Editor's Summary

15 May 2008

Message in a bubble: Antarctic ice-core greenhouse-gas record goes back 800,000 years


The air bubbles trapped in the Antarctic Vostok and EPICA Dome C ice cores provide composite records of levels of atmospheric carbon dioxide and methane covering the past 650,000 years. Now the record of atmospheric carbon dioxide and methane concentrations has been extended by two more complete glacial cycles to 800,000 years ago. The new data are from the lowest 200 metres of the Dome C core. This ice core went down to just a few metres above bedrock at a depth of 3,260 metres. Two papers report analyses of this deep ice, including the lowest carbon dioxide concentration so far measured in an ice core. Atmospheric carbon dioxide is strongly correlated with Antarctic temperature throughout the eight glacial cycles, but with significantly lower concentrations between 650,000 and 750,000 years before present. The cover shows a strip of ice core from an Antarctic ice core from Berkner Island, this slice from a depth of 120 metres. Photo by Chris Gilbert, British Antarctic Survey. Elsewhere in this issue, we move from climates past to future plans for climate prediction.

News and ViewsPalaeoclimate: Windows on the greenhouse

Data laboriously extracted from an Antarctic ice core provide an unprecedented view of temperature, and levels of atmospheric carbon dioxide and methane, over the past 800,000 years of Earth's history.

Ed Brook

doi:10.1038/453291a

LetterHigh-resolution carbon dioxide concentration record 650,000–800,000 years before present

Dieter Lüthi, Martine Le Floch, Bernhard Bereiter, Thomas Blunier, Jean-Marc Barnola, Urs Siegenthaler, Dominique Raynaud, Jean Jouzel, Hubertus Fischer, Kenji Kawamura & Thomas F. Stocker

doi:10.1038/nature06949

LetterOrbital and millennial-scale features of atmospheric CH4 over the past 800,000 years

Laetitia Loulergue, Adrian Schilt, Renato Spahni, Valérie Masson-Delmotte, Thomas Blunier, Bénédicte Lemieux, Jean-Marc Barnola, Dominique Raynaud, Thomas F. Stocker & Jérôme Chappellaz

doi:10.1038/nature06950

EditorialsThe next big climate challenge

Governments should work together to build the supercomputers needed for future predictions that can capture the detail required to inform policy.

doi:10.1038/453257a

NewsThey say they want a revolution

Climate scientists call for major new modelling facility..

Olive Heffernan

doi:10.1038/453268a