How does rising atmospheric CO2 affect marine organisms?

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The Last Thousand Years of Climate Change in Antarctica
Cremer, H., Gore, D., Melles, M. and Roberts, D.  2003.  Palaeoclimatic significance of late Quaternary diatom assemblages from southern Windmill Islands, East Antarctica.  Palaeogeography, Palaeoclimatology, Palaeoecology 195: 261-280.

What was done
The authors reconstructed a history of environmental change in the southern Windmill Islands, East Antarctica, based upon diatom assemblages obtained from two long and well-dated sediment cores removed from two marine bays, comparing their findings with those of studies of several other parts of Antarctica.

What was learned
In the words of the authors, "the diatom assemblage in the upper sediments of both cores indicates Neoglacial cooling from ~1000 cal yr BP," noting that this latest thousand-year period "is generally marked by distinct cooling leading to glacial re-advances, more extensive sea-ice, lower precipitation, and lower bioproductivity."  In addition, they report that "this climatic deterioration is visible in nearly all available Antarctic terrestrial and marine records (e.g. Ingolfsson et al., 1998; Jones et al., 2000; Roberts et al., 2000, and references therein)."

What it means
These observations suggest several different ways of thinking about potential global warming: after a thousand years of cooling in Antarctica, it would seem only (1) natural, (2) normal, and/or (3) preferable for temperatures to start moving in the other direction for a while.

Ingolfsson, O., Hjort, C., Berkman, P.A., Bjork, S., Colhoun, E., Goodwin, I.D., Hall, B., Hirakawa, K., Melles, M., Moller, P. and Prentice, M.L.  1998.  Antarctic glacial history since the Last Glacial Maximum: an overview of the record on land.  Antarctic Science 10: 326-344.

Jones, V.J., Hodgson, D.A. and Chepstow-Lusty, A.  2000.  Palaeolimnological evidence for marked Holocene environmental changes on Signy Island, Antarctica.  The Holocene 10: 43-60.

Roberts, D., McMinn, A. and Zwartz, D.  2000.  An initial palaeosalinity history of Jaw Lake, Bunger Hills based on a diatom-salinity transfer function applied to sediment cores.  Antarctic Science 12: 172-176.

Reviewed 17 September 2003