How does rising atmospheric CO2 affect marine organisms?

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A Climate Model Reality Check
Davey, M.K., Huddleston, M., Sperber, K.R., Braconnot, P., Bryan, F., Chen, D., Colman, R.A., Cooper, C., Cubasch, U., Delecluse, P., DeWitt, D., Fairhead, L., Flato, G., Gordon, C., Hogan, T., Ji, M., Kimoto, M., Kitoh, A., Knutson, T.R., Latif, M., Le Treut, H., Li, T., Manabe, S., Mechoso, C.R., Meehl, G.A., Power, S.B., Roeckner, E., Terray, L., Vintzileos, A., Voss, R., Wang, B., Washington , W.M., Yoshikawa, I., Yu, J.-Y., Yukimoto, S., and Zebiak, S.E.  2002.  STOIC: a study of coupled model climatology and variability in tropical ocean regions.  Climate Dynamics 18: 403-420.

What was done
The authors tested the ability of 23 dynamical ocean-atmosphere models to correctly simulate fields of tropical sea surface temperature (SST), surface wind stress, and upper ocean vertically-averaged temperature (VAT) in terms of annual mean, seasonal cycle, and interannual variability characteristics.  Of the models tested, 21 were coupled GCMs, of which 13 used no form of flux adjustment.

What was learned
In the words of the 36 climate modelers who performed the tests and did the evaluations, "in most models without flux adjustment, the annual mean equatorial SST in the central Pacific is too cool and the Atlantic zonal SST gradient has the wrong sign."  They also note that "annual mean wind stress is often too weak in the central Pacific and in the Atlantic, but too strong in the west Pacific."  In addition, they say that "few models have an upper ocean VAT seasonal cycle like that observed in the equatorial Pacific."  On top of these deficiencies, they report that "interannual variability is commonly too weak in the models: in particular, wind stress variability is low in the equatorial Pacific."  Likewise, they say that "most models have difficulty in reproducing the observed Pacific 'horseshoe' pattern of negative SST correlations with interannual Niņo3 SST anomalies, or the observed Indian-Pacific lag correlations."

What it means
The authors rightly conclude, from their results and the results of Latif et al. (2002), that "the equatorial Pacific is still a major problem area for coupled models."  Indeed, they report that "overall, no single model is consistent with observed behavior in the tropical ocean regions," concluding that "understanding and overcoming these shortcomings must be a high priority for the coupled modeling community."

We think that the attainment of these high-priority climate modeling goals should be a high-priority prerequisite for formulating Kyoto-type energy policy; for how can one rationally base such important regulatory decisions on climate models that have such important proven deficiencies in replicating current real-world climate, to say nothing of their ability to accurately predict its future?  Most sensible people would laugh at the thought, were it not so serious and sad a matter.  Which leads us to ask, Where in the world has reason fled?

Latif, M., Sperber, K., Arblaster, J., Braconnot, P., Chen, D., Colman, A., Cubasch, U., Cooper, C., Delecluse, P., DeWitt, D., Fairhead, L., Flato, G., Hogan, T., Ji, M., Kimoto, M., Kitoh, A., Knutson, T., Le Treut, H., Li, T., Manabe, S., Marti, O., Mechoso, C., Meehl, G., Power, S., Roeckner, E., Sirven, J., Terray, L., Vintzileos, A., Voss, R., Wang, B., Washington, W., Yoshikawa, I., Yu, J. and Zebiak, S.  2001.  ENSIP: the El Niņo simulation intercomparison project.  Climate Dynamics 18: 255-276.

Reviewed 10 July 2002