A biologist at the University of Connecticut has found evidence that up to a third of all species alive today could go extinct by 2100 if greenhouse gas emissions are not slowed or stopped. In his study published in the journal Science, Mark Urban conducted an analysis of 485 studies carried out over the past 30 years on the ability of species to adapt to climate change.
He found that if global temperatures rise approximately 5.4°C by the end of this century (the worst-case scenario), it would likely lead to the extinction of approximately one-third of all species alive today. He notes that some cases of chain-reaction extinctions could occur, in which a small animal goes extinct and then a larger animal that feeds on it consequently goes extinct. He also notes that some species groups or types are at much higher risk than others, such as amphibians.