A framework for assessing threats and benefits to species responding to climate change
1. Current national and international frameworks for assessing threats to species have not been developed in the context of climate change, and are not framed in a way that recognises new opportunities that arise from climate change.2. The framework presented here separates the threats and benefits of climate change for individual species. Threat is assessed by the level of climate-related decline within a species’ recently occupied (e.g. pre-1970s) historical distribution, based on observed (e.g. repeat census) and/or projected changes (e.g. modelled bioclimate space). Benefits are assessed in terms of observed and/or projected increases outside the recently occupied historical range.3. Exacerbating factors (e.g. small population size, low dispersal capacity) that might increase levels of threat or limit expansion in response to climate change are taken into consideration within the framework. Protocols are also used to identify levels of confidence (and hence research and/or monitoring needs) in each species’ assessment.4. Observed and projected changes are combined into single measures of expected decline and increase, together with associated measures of confidence. We weight risk classifications towards information that is most certain. Each species is then placed in one of six categories (high risk, medium risk, limited impact, equivalent risks & benefits, medium benefit, high benefit) reflecting whether climate change is expected (or has been observed) to cause net declines or increases in the region considered, based on the balance of benefits and threats.5. We illustrate the feasibility of using the framework by applying it to (i) all British butterflies (N = 58 species) and (ii) an additional sample of British species: 18 species of plants, bats, birds and beetles.6. Synthesis. Our framework assesses net declines and increases associated with climate change, for individual species. It could be applied at any scale (regional, continental or global distributions of species), and complements existing conservation assessment protocols such as red-listing. Using observed and projected population and/or range data, it is feasible to carry out systematic conservation status assessments that inform the development of monitoring, adaptation measures and conservation management planning for species that are responding to climate change.
Thomas, C. D., J. K. Hill, B. J. Anderson, S. Bailey, C. M. Beale, R. B. Bradbury, C. R. Bulman, H. Q. P. Crick, F. Eigenbrod, H. M. Griffiths, W. E. Kunin, T. H. Oliver, C. A. Walmsley, K. Watts, N. T. Worsfold, and T. Yardley. 2011. A framework for assessing threats and benefits to species responding to climate change. Methods in Ecology and Evolution 2:125–142. doi: 10.1111/j.2041-210X.2010.00065.x.