Saving a Million Species

How many species may perish as a result of climate change and associated threats?

The research paper 'Extinction Risk from Climate Change' published in the journal Nature in 2004 created front-page headlines around the world. The notion that climate change could drive more than a million species to extinction captured both the popular imagination and the attention of policy-makers, and provoked an unprecedented round of scientific critique. + Full description

Saving a Million Species reconsiders the central question of that paper: How many species may perish as a result of climate change and associated threats? Leaders from a range of disciplines synthesise the literature, refine the original estimates, and elaborate the conservation and policy implications.

Saving a Million Species offers a clear explanation of the science behind the headline-grabbing estimates for conservationists, researchers, teachers, students, and policy-makers. It is a critical resource for helping those working to conserve biodiversity take on the rapidly advancing and evolving global stressor of climate change – the most important issue in conservation biology today, and the one for which we are least prepared.

- Short description


  • Examines the initial extinction risk estimates of the original paper, subsequent critiques, and the media and policy impact of this unique study
  • Presents evidence of extinctions from climate change from different time frames in the past
  • Explores extinctions documented in the contemporary record
  • Sets forth new risk estimates for future climate change
  • Considers the conservation and policy implications of the estimates


Lee Hannah is Senior Researcher in Climate Change Biology at Conservation International and adjunct professor in the Bren School of Environmental Science and Management at the University of California, Santa Barbara.