How does rising atmospheric CO2 affect marine organisms?

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Interannual and Interdecadal Climate Variations
Vega, A.J., Sui, C.-H. and Lau, K.-M.  1998.  Interannual to interdecadal variations of the regionalized surface climate of the United States and relationships to generalized flow parameters.  Physical Geography 19: 271-291.

What was done
The authors used a statistical procedure known as Principal Component Analysis to combine 344 separate climate divisions encompassing the conterminous United States into nine different regions for purposes of precipitation analysis, and into five different regions for purposes of temperature analysis.  Annual data for these regions were then analyzed for trends and variability shifts over the period 1895 to 1991, after which they were compared with changes in atmospheric circulation.

What was learned
Precipitation increased in six of the nine precipitation regions from the beginning to the end of the record.  Temperature increased in only one of the five temperature regions (southwest).  In addition, four of the precipitation regions experienced a significant increase in interannual variability through time, while a decrease in interannual variability was reported for three of the temperature regions.  ENSO events were found to contribute to increases in precipitation throughout the eastern United States and the Pacific Northwest, as well as to increases in temperature in the southwest United States.

What it means
"If ENSO frequency is directly linked to hemispheric and/or global temperature variations," the authors note, then "United States regions may become wetter but not necessarily warmer, except for the Southwest, with the advent of future increases in anthropogenic gases."  If, we would also add, greenhouse gases do indeed enhance the atmosphere's natural greenhouse effect, which is probably a bigger "if" than the one they use.

Reviewed 15 May 1999