http://www.msnbc.msn.com/id/3032619/vp/32634348#34050658
The reporters make it sound a little cheesy, but it is still so exciting! Ice cores give a carbon record of the atmosphere (by looking at the tiny air bubbles in the ice and measuring carbon dioxide). The best records are from cores taken from Greenland (camp century, and currently GRIP and GISP) and Antarctica (Vostok and currently EPICA). They can measure up to about 800,000 years ago (ice cores from Antarctica can measure this far back).
Kate that was a great news story. How does the carbon dioxide in the air bubbles indicate temperature?
ReplyDeletegood question! The simple answer is by looking at oxygen isotopes. More in next post...
ReplyDeleteI saw this on the news and thought it was amazing! Is it as accurate as tree rings?
ReplyDeleteOh yeah, probably more accurate. Tree rings are influenced by local climate factors that can skew data, but they can tell more about what the local climate was like. Isotopes give a more accurate temperature reconstruction on a global scale. The carbon dioxide bubbles tell carbon dioxide amount (a greenhouse gas), which is related to temperature, but really is analyzed to show carbon dioxide level in the atmosphere - relates now to global warming.
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