We examine how change in a species' geographic range size over time influences that species' extinction risk. We analyze instantaneous range size and range size change and how these terms relate to extinction risk in marine microplankton. We find that both the instantaneous range size and the change in range size are informative predictors of extinction. Using predictive models, we also assess extinction probability in four extant groups.

Biodiversity is under threat from the effects of global warming, and assessing the effects of climate change on areas of high species richness is of prime importance to conservation. Terrestrial and freshwater rich spots have been and will be less affected by climate change than other areas. However, marine rich spots of biodiversity are expected to experience more pronounced warming.