How does rising atmospheric CO2 affect marine organisms?

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There isn't a Human Influence on Climate
Karlén, W.  1998.  Climate variations and the enhanced greenhouse effect.  Ambio 27: 270-274.

What was done
The author examined proxy climate data related to changes in summer temperatures in Scandinavia over the last 10,000 years.  The proxy temperature record - derived from analyses of changes in the size of glaciers, changes in the altitude of the alpine tree-limit, and variations in the width of tree-rings - was then compared with contemporaneous solar irradiance data derived from 14C anomalies measured in tree-ring records.

What was learned
The data revealed both long- and short-term temperature fluctuations; and it was noted that during warm periods the temperature was "about 2°C warmer than at present."  Furthermore, the temperature fluctuations were found to be "closely related" to changes in solar irradiation.

What it means
In the words of the author, "the similarity between solar irradiation changes and climate indicate a solar influence on the Scandinavian and Greenland climates."  In addition, the author concludes that "the frequency and magnitude of changes in climate during the Holocene do not support the opinion that the climatic change of the last 100 years is unique."  In fact, he bluntly states that "there is no evidence of a human influence so far."

Reviewed 15 January 1999