How does rising atmospheric CO2 affect marine organisms?

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Arctic-Breeding Geese
Jensen, R.A., Madsen, J., O'Connell, M., Wisz, M.S., Tommervik, H. and Mehlum, F. 2008. Prediction of the distribution of Arctic-nesting pink-footed geese under a warmer climate scenario. Global Change Biology 14: 1-10.

Citing contentions of the Arctic Climate Impact Assessment (ACIA, 2005), the authors state that "global climate change is expected to shift species ranges polewards, with a risk of range contractions and population declines of especially high-Arctic species."

What was done
Jensen et al. built species distribution models for the Svalbard-nesting pink-footed goose (Anser brachyrhynchus) in order to "relate their occurrence to environmental and climatic variables," after which they used the most parsimonious of these models to "predict their distribution under a warmer climate scenario," based upon "mean May temperature, the number of frost-free months and the proportion of moist and wet moss-dominated vegetation in the area," the latter of which factors is "an indicator of suitable feeding conditions."

What was learned
"Contrary to recent suggestions regarding effects of global warming on Arctic wildlife (ACIA, 2005)," in the words of the six scientists, they report their model predicts that global warming "will have a positive [our italics] effect on the suitability of Svalbard for nesting geese in terms of range expansion into the northern and eastern parts of Svalbard which are currently unsuitable." And they note that this result does not even consider the likelihood that glaciers will decrease in size and expose still more potential nest sites.

What it means
Jensen et al. conclude their paper by stating that increased temperatures could release the population of pink-footed geese from the "present density-dependent regulation during the nesting period," and that "an elongation of the frost-free season in Svalbard may relax their dependence on the acquisition of body stores before arrival (so-called 'capital' breeding, sensu Drent and Daan, 1980), so that geese will have more time to acquire the necessary resources upon arrival and still breed successfully," noting that "both factors are likely to have a positive effect on the population growth."

ACIA. 2005. Arctic Climate Impact Assessment. Cambridge University Press, New York, New York, USA.

Drent, R.H. and Daan, S. 1980. The prudent parent: energetic adjustment in avian breeding. Ardea 68: 225-252.

Reviewed 23 April 2008