More species may become extinct as a result of climate change than previously thought, a modelling study suggests.

As the climate warms, many species are predicted to shift their ranges to stay within comfortable temperature zones. However, some species will be better able to do so than others. Mark Urban at the University of Connecticut in Storrs and his colleagues have created a model that takes into account the competition that species face for habitats when they move to new ecosystems. They modelled the effect of 4 °C of warming over 100 years on 40 simulated species, and found a much higher number of extinctions than did models that do not account for species competition and species' differing dispersal abilities.

Even species with broad heat tolerances might be outcompeted — either by the arrival of newcomers in their current habitats or by native species in ecosystems that become habitable to them in future.

Proc. R. Soc. B http://dx.doi.org/10.1098/rspb.2011.2367 (2012)