»Jede sechste Tierart dürfte den Stress des Klimawandels nicht verkraften und aussterben«

We critically need to know how climate change will influence species extinction rates in order to inform international policy decisions about the biological costs of failing to curb climate change and to implement specific conservation strategies to protect the most threatened species. Current predictions about extinction risks vary widely, suggesting that anywhere from 0 to 54% of species could become extinct from climate change. Studies differ in particular assumptions, methods, species, and regions and thus do not encompass the full range of our current understanding. As a result, we currently lack consistent, global estimates of species extinctions attributable to future climate change.

To provide a more comprehensive and consistent analysis of predicted extinction risks from climate change, I performed a meta-analysis of 131 published predictions (table S1). I focused on multispecies studies so as to exclude potential biases in single-species studies. I estimated the global proportion of species threatened in a Bayesian Markov chain Monte Carlo (MCMC) random-effects meta-analysis that incorporated variation among and within studies and with each study weighted by sample size. I evaluated how extinction risk varied depending on future global temperature increases, taxonomic groups, geographic regions, endemism, modeling techniques, dispersal assumptions, and extinction thresholds. I used credible intervals (CIs) that do not overlap with zero and a deviance information criterion (DIC) greater than four to assess statistical support for factors. The majority of studies estimated correlations between current distributions and climate so as to predict suitable habitat under future climates. A smaller number of studies determined extinction risks by using process-based models of physiology or demography (15%), species-area relationships (5%), or expert opinion (4%). Species were predicted to become extinct if their range fell below a minimum threshold. An important caveat is that most of these models ignore many factors thought to be important in determining future extinction risks such as species interactions, dispersal differences, and evolution.

Overall, 7.9% of species are predicted to become extinct from climate change; (95% CIs, 6.2 and 9.8). Results were robust to model type, weighting scheme, statistical method, potential publication bias, and missing studies. This proportion supports an estimate from a 5-year synthesis of studies. Its divergence from individual studies can be explained by their specific assumptions and taxonomic and geographic foci. These differences provide the opportunity to understand how divergent factors and assumptions influence extinction risk from climate change.

[...]

In 1981, Hansen and colleagues predicted that the signal of global climate change would soon emerge from the stochastic noise of weather. Thirty years later, we are reaching a similar threshold for the effects of climate change on biodiversity. Extinction risks from climate change are expected not only to increase but to accelerate for every degree rise in global temperatures. The signal of climate change–induced extinctions will become increasingly apparent if we do not act now to limit future climate change.

Die vollständige Studie finden Sie hier.