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Too hot for the cold blooded

Are Lizards Toast?
Raymond B. Huey, Jonathan B. Losos, Craig Moritz

Lizards should be relatively invulnerable to warming: They are very good at evading thermal stress, tolerate high body temperatures, and resist water loss. Nevertheless, Sinervo et al. document extinctions of lizard populations on five continents and argue that global warming is responsible. They use a simple biological model, validated against observed extinctions, to predict that warming will drive almost 40% of all global lizard populations extinct by 2080.


Erosion of Lizard Diversity by Climate Change and Altered Thermal Niches -- Sinervo et al. 328 (5980): 894 -- Science
..compares recent and historical surveys for 48 Mexican lizard species at 200 sites. Since 1975, 12% of local populations have gone extinct. We verified physiological models of extinction risk with observed local extinctions and extended projections worldwide. Since 1975, we estimate that 4% of local populations have gone extinct worldwide, but by 2080 local extinctions are projected to reach 39% worldwide, and species extinctions may reach 20%. Global extinction projections were validated with local extinctions observed from 1975 to 2009 for regional biotas on four other continents, suggesting that lizards have already crossed a threshold for extinctions caused by climate change.

Evolutionary biologist Professor Barry Sinervo said: "Our research shows the ongoing extinctions of lizards are directly due to climate warming from 1975 to the present. Most of these species currently registering local extinctions will be completely extinct by 2080, unless we change and limit the carbon dioxide production that is driving global warming,"

Note how a suggestion here and a model there suddenly become a certainty that CO2 is killing the lizards off.
I haven't seen the evidence behind the paywall but would be intrigued to see the warming and extinction correlation graph.

Comments

seems to me a bit like the tree ring hypothesis- just as there are many many things affecting the growth rate of trees and hence the width of tree rings (including apparantly the perception of the particular person measuring them) there are many many things affecting lizard population- one thinks food availability, imported rival species, imported predators, the ability of the researchers to actually find them,, etc. etc.
I wish the general public, instead of wondering "how do they know that" in wonderment of their cleverness, would instead wonder "how do they know that" as an expression of doubt. If you don't understand how knowledge has been gained- assume it has been gained fraudulently!

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