Climate change threatens many plant and animal species not only when their habitats disappear as climatic conditions change, but also when those habitats shift. In a new study, a team of University of Potsdam researchers found that whether a species' habitat disappears or shifts has a significant impact on how accurately different models can predict its risk of extinction. However, this distinction is not reflected in the current standard methods used to assess extinction risk. Because identifying vulnerable species early is essential for timely conservation action, the researchers argue that these methods urgently need to be revised.
Researchers Raya Keuth, Susanne Fritz, and Damaris Zurell systematically evaluated the current IUCN Red List guidelines for assessing climate-related extinction risk. Since 1964, the International Union for Conservation of Nature (IUCN) Red List of Threatened Species has documented the global status of biodiversity and has recently expanded its guidelines for assessing extinction risk under climate change. To evaluate these guidelines, the researchers simulated virtual species with different rates of dispersal, reproductive capacity, and adaptation to warm and cold conditions. Their results show that the models most commonly used today — species distribution models (SDMs) — consistently underestimate extinction risk for range-shifting species. This is because the models assume a linear relationship between population size and habitat loss, an assumption that is not supported by empirical evidence. Instead, the researchers found that even small habitat losses can lead to sharp population declines in range-shifting species.
The study also found that the current quantitative extinction risk thresholds, which can be estimated using spatially explicit population models (SEPMs), are too conservative and therefore provide warnings too late for effective conservation action. Overall, the findings reveal fundamental weaknesses in the current IUCN Red List approach to assessing extinction risk under climate change.
The researchers emphasize that the IUCN Red List guidelines should be updated to improve future assessments of climate-related extinction risk. They propose recommendations for better integrating the existing modeling approaches and identify more informative metrics that would provide more meaningful assessments.
"Our research highlights the urgent need to improve the IUCN Red List guidelines so that conservation measures can be planned and implemented in time," says Raya Keuth of the Institute of Biochemistry and Biology at the University of Potsdam, the study's lead author. "Only more accurate predictions will enable us to effectively counter the ongoing loss of biodiversity."
Published study: Raya Keuth, Susanne A. Fritz, Damaris Zurell. Models used for Red List assessments underestimate climate-related extinction risk of range-shifting species. Nature Ecology & Evolution (2026). https://doi.org/10.1038/s41559-026-03125-y
