Predictions that climate change alone could lead to the extinction of more than one-fifth of plant and animal species before the end of the century have often come under fire, and not just from climate-change deniers. Some biologists are sceptical because the predictions are largely based on theoretical models.

Lounging in the shade may sound soothing, but it could be the death of many lizards if global warming continues at current rates. As temperatures inch upward, the reptiles rest more and hunt less. As a result, 20 percent of lizard species could go extinct by 2080, a new study says.

Many species are experiencing sustained environmental change mainly due to human activities. The unusual rate and extent of anthropogenic alterations of the environment may exceed the capacity of developmental, genetic, and demographic mechanisms that populations have evolved to deal with environmental change.

Fossil fuels have a new crime to live down. A frenzy of hydrocarbon burning at the end of the Permian period may have led to the most devastating mass extinction Earth has ever seen, as explosive encounters between magma and coal released more carbon dioxide in the course of a few years than in all of human history.