Quantifying sensitivity and exposure to climate change in Western North American species

Background/Question/Methods

Significant changes in climate over the coming century are expected to result in noticeable shifts in species distributions, as species seek habitat favorable to their survival. Not all species will be affected equally, and some may even be driven to extinction due to their inability to keep pace with a changing environment. Understanding which species are most vulnerable to climate change is important to effectively guide conservation efforts and resource management decisions.

This research presents a novel method for assessing species vulnerability to climate change. The method focuses on measuring climate breadth, the amount of climate variability a species experiences across its range.  The climate breadth of 130 different terrestrial species – including plants, amphibians, birds, and mammals – was determined in two ways: using historical climate data to quantify species sensitivity to climate change, and future climate projections to quantify potential exposure to climate change.

Results/Conclusions

Climate breadth as a metric of sensitivity and exposure to climate change was demonstrated to agree with much of our current understanding of species status. Climate breadth was also shown to maintain consistency across different spatial scales, be adaptable to different climate datasets, and give results that are directly comparable between different species. Comparison of climate breadths suggested that certain species may be much more vulnerable to climate change than is currently recognized, and others considerably less so. Larix occidentalis and Juniperus occidentalis scored lowest out of 31 tree and shrub species, indicating vulnerability; in contrast, Corynorhinus townsendii scored relatively high compared to other mammals, indicating greater resilience. The results show that climate breadth can provide valuable insight for assessing species vulnerability to climate change, even when little or no life history information is known.