How does rising atmospheric CO2 affect marine organisms?

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The Warming of the Deep-Blue Sea
Lindzen, R.S.  2002.  Do deep ocean temperature records verify models?  Geophysical Research Letters 29: 10.1029/2001GL014360.

Levitus et al. (2001) and Barnett et al. (2001) recently documented a modest warming of the planet's deep oceans over the past half-century.  With respect to this accomplishment, Lindzen notes that "the fact that models forced by increasing CO2 and tuned by nominal inclusion of aerosol effects to simulate the global mean temperature record for the past century roughly matched the observed deep ocean record was taken as evidence of the correctness of the models and of the anthropogenic origin of the deep ocean warming," an inference that he feels is unwarranted and which he effectively rebuts in this article.

What was done
Assuming the deep-ocean temperature measurements and their analysis are correct, Lindzen used a highly simplified coupled climate model (an energy balance model with a mixed layer diffusive ocean) "to examine whether deep ocean temperature behavior from 1950 to 2000 actually distinguishes between models of radically different sensitivity to doubled CO2."

What was learned
Lindzen found that the warming of the deep oceans "is largely independent of model sensitivity," concluding that "the behavior of deep ocean temperatures is not a test of model sensitivity, but rather a consequence of having the correct global mean surface temperature time history."  In this regard, he also noted that "we are dealing with observed surface warming that has been going on for over a century" and that "the oceanic temperature change over the period 1950-2000 reflects earlier temperature changes at the surface."

Further to this point, we note that according to the data of Esper et al. (2002), the earth began to warm in the early 1800s, so that the warming of the 20th century, as Briffa and Osborn (2002) have described it, was "a continuation of a trend that began at the start of the 19th century."  Hence, it can be appreciated that the earth had achieved the majority of its post-Little Ice Age temperature rebound well before the bulk of the Industrial Revolution's CO2 emissions had ever entered the atmosphere, i.e., by approximately 1930.

What it means
In light of the observations noted above, it should be clear that the warming of earth's deep oceans over the past fifty years is a far cry from the smoking gun climate alarmists have portrayed it to be.  The modest rise in deep-water temperatures tells us nothing about the sensitivity of earth's climate to atmospheric CO2 enrichment, nor does it link the warming to anthropogenic CO2 emissions.

Barnett, T.P., Pierce, D.W. and Schnur, R.  2001.  Detection of anthropogenic climate change in the world's oceans.  Science 292: 270-273.

Briffa, K.R. and Osborn, T.J.  2002.  Blowing hot and cold.  Science 295: 2227-2228.

Esper, J., Cook, E.R. and Schweingruber, F.H.  2002.  Low-frequency signals in long tree-ring chronologies for reconstructing past temperature variability.  Science 295: 2250-2253.

Levitus, S., Antonov, J.I., Wang, J., Delworth, T.L., Dixon, K.W. and Broccoli, A.J.  2001.  Anthropogenic warming of Earth's climate system.  Science 292: 267-270.

Reviewed 11 December 2002