How does rising atmospheric CO2 affect marine organisms?

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Beating the Heat: How Do Tropical Lizards Do It?
Logan, M.L., Huynh, R.K., Precious, R.A. and Calsbeek, R.G. 2013. The impact of climate change measured at relevant spatial scales: new hope for tropical lizards. Global Change Biology 19: 3093-3102.

The authors write that "much attention has been given to recent predictions that widespread extinctions of tropical ectotherms, and tropical forest lizards in particular, will result from anthropogenic climate change." However, they note that most of these predictions "are based on environmental temperature data measured at a maximum resolution of 1 km2, whereas individuals of most species experience thermal variation on a much finer scale."

What was done
"To address this disconnect," in the words of Logan et al., they "combined thermal performance curves for five populations of Anolis lizard from the Bay Islands of Honduras with high-resolution temperature distributions," which allowed them to take another - and more refined - look at the situation.

What was learned
The four U.S. researchers report that, "whereas studies conducted to date have made uniformly bleak predictions for the survival of tropical forest lizards around the globe, our data show that four congeneric species, occurring in the same geographic region, differ markedly in their vulnerabilities to climate warming." And, moreover, they find that "none appear to be on the brink of extinction." Indeed, they state that of the five populations they studied, two species "are unlikely to experience a significant decline in performance," one of them "should experience reduced activity time as a result of warming," and that the open-habitat populations they studied "may actually benefit from predicted warming for many decades."

What it means
In light of these encouraging findings, Logan et al. declare, in the concluding sentence of their paper's abstract, that "global-scale predictions generated using low-resolution temperature data may overestimate the vulnerability of many tropical ectotherms to climate change."

Reviewed 18 December 2013