How does rising atmospheric CO2 affect marine organisms?

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The Little Ice Age in the Caribbean
Winter, A., Ishioroshi, H., Watanabe, T., Oba, T. and Christy, J. 2000. Caribbean sea surface temperatures: Two-to-three degrees cooler than present during the Little Ice Age. Geophysical Research Letters 27: 3365-3368.

What was done
The authors determined likely sea surface temperatures for the periods 1700-1705, 1780-1785 and 1810-1815 from a study of oxygen isotope data obtained from coral skeletons of Montastrea faveolata located on the southwestern shore of Puerto Rico. Similar isotope data obtained for the period 1983-1989 and contemporary direct sea surface temperatures measured at the University of Puerto Rico's marine station at La Parguera were used to calibrate the temperature reconstruction technique and provide a current baseline against which to compare the Little Ice Age results.

What was learned
It was determined that sea surface temperatures at the site studied were significantly cooler during the three Little Ice Age periods investigated than they are currently. In fact, the authors say their results "indicate the Caribbean experienced cooling during the Little Ice Age with temperature estimated to be at least 2-3 cooler than found during the present decade."

What it means
These results continue to add to the accumulating evidence that the Little Ice Age was indeed real and widespread, in contradiction of the ongoing attempt to rewrite climate history and relegate this significant climatic event to something so small and localized that it does not even appear on the global temperature record of the past millennium (see our Editorial of 2 August 2000 ). The data presented in this paper, however, as well as data contained in other papers cited by the authors, lead them to state that "the Little Ice Age may have been more global in extent than previously expected." It may also have been much colder than believed; for they state that the cooling suggested by their data "represents about half of the sea surface temperature cooling recorded in Barbados corals during the Last Glacial Maximum." Such cooling, equivalent to half an ice age, is pretty impressive. It cannot be hid and will ultimately result in the climate reconstructionists having to recant.

Reviewed 25 October 2000