Approximately 20 to 30% of plant and animal species are likely to be at increasingly high risk of extinction as global mean temperatures exceed warming of 2 to 3 oC above preindustrial levels, according to Intergovernmental Panel on Climate Change (Fourth Assessment Report). Global warming has already been implicated in hundreds of documented cases of species declines across marine, terrestrial and freshwater ecosystems globally, including in the loss of amphibian species such as the Golden Toad. Climate change will be one of the major drivers of species extinctions in the 21st century.
But which species will be most vulnerable to climate change? Which species, ecosystems and regions should we prioritise for conservation? These questions have become increasingly relevant to scientists, policy and decision makers and the public. IUCN, with funding from the MacArthur Foundation and the Indianapolis Zoo, has initiated a project to identify the species most vulnerable to the negative impacts of climate change.
General Circulation Models (GCMs) predict that climate change will affect different areas of the world to different degrees. But it is also widely recognized that not all species will respond in the same way, even to similar levels of climatic change. In addition, a species’ individual susceptibility to climate change depends on a variety of biological traits, including its life history, ecology, behaviour, physiology and genetic makeup. Species that are in greatest danger of climate-change driven extinction are those with high susceptibility to climatic changes, that also have distribution ranges that will experience large climatic changes and where their adaptive capacity is low.
Based on information from the IUCN Red List (www.iucnredlist.org), as well as on newly collected data, IUCN and our partners have gathered such trait information for the world’s birds (9 856 species), amphibians (6 222 species) and reef-building corals (799 species). Preliminary analyses of life history and ecological traits of these groups suggest that up to 35% of birds, 52% of amphibians and 71% of reef-building corals have traits that are likely to make them particularly susceptibly to climate change.
IUCN plans to utilize the results of species level climate change vulnerability assessments to complement the current IUCN Red List Categories and Criteria. In the medium term, and in combination with climate change spatial models, project results will be used to strengthen the power of the IUCN Red List Categories and Criteria to detect the threat of climate change to global species. By identifying the species that are most vulnerable to climate change before they are severely impacted, we hope to contribute a practical new conservation tool to help prevent extinctions.
