Fossils predict oceans to rise more than expected

Fossil corals have been used to examine how temperature changes in the past have promoted melting of polar ice sheets, showing that sea levels may rise higher than expected.

Coral fossils from around the world from the last interglacial period, 125,000 years ago, were logged in a database and modelling found that during the last interglacial period sea levels peaked at 5.5 to 9 metres above present sea level.

For the period studied, the poles were said to be three to five degrees warmer than present; temperatures we are expected to reach this century. This implies that the polar ice sheets may be more sensitive to small increases in temperature than first thought.

Read more at Australian National University

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3 Comments sorted by

  1. Marc Hendrickx

    Geologist

    Have requested a copy of the paper from the ANU Media Office. Another analogy is with the Holocene Climate Optimum. This saw temps just 5-9000 years ago at the poles similarly elevated, with higher sea levels that present. Not aware of any collapse of ice shelves associated with the HCO so perhaps, ice shelves not as sensitive as this new study would imply. Should make for an interesting read though.

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    1. David Arthur

      n/a

      In reply to Marc Hendrickx

      Holocene Climate Optimum was peak of a fairly weak interglacial period, the Holocene. Previous interglacial period (Eemian?) was a bigger, stronger interglacial period than the Holocene.

      No surprises in any of this: Pleistocene climate was predominantly glacial conditions, with chaotic advent of interglacial periods due to ice thaw (predominantly initiated by Milankovich cycling), with the intensity of the interglacial period depending on a couple of factors.
      1) How much CO2 is released from…

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  2. Lincoln Fung

    Economist

    What were the main reasons for the higher temperature during that period?

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