Range retractions and extinction in the face of climate warming.

Until recently, published evidence for the responses of species to climate change had revealed more examples of species expanding than retracting their distributions. However, recent papers on butterflies and frogs now show that population-level and species-level extinctions are occurring. The relative lack of previous information about range retractions and extinctions appears to stem, at least partly, from a failure to survey the distributions of species at sufficiently fine resolution to detect declines, and from a failure to attribute such declines to climate change. The new evidence suggests that climate-driven extinctions and range retractions are already widespread.