Abstract: Environmental changes driven by human activities are posing severe threats to global biodiversity. In conservation biology, the IUCN Red List is often used as a critical benchmark for assessing species extinction risk. However, significant gaps remain in the evaluation of extinction risks for certain taxa, such as insects. China, with its rich butterfly diversity, currently relies heavily on historical data for its IUCN Red List assessments, without incorporating projections of future survival risks. This study integrated 247,248 distribution records of 1,920 butterfly species in China, among which the current distribution records for 598 species are insufficient for modeling, and these 598 species are categorized as Data Deficient. For the 1,322 species with sufficient data, we simulated potential distribution changes from the present to 2070 using ensemble species distribution models, incorporating future climate and land-use data. By quantifying changes in distribution area and applying the IUCN Red List Categories and Criteria (using the A3c criteria), we systematically evaluated the threat levels to these species. The findings reveal significant differences in the threats to butterfly species across future scenarios, with the highest number of threatened species (277) under the high forcing pathway SSP5-8.5, along with an average range reduction of 55.0%. Compared to previous IUCN Red List assessments, this study newly identifies multiple species susceptible to future climate changes. It provides the first future scenario-based IUCN Red List assessment for butterflies in China, highlights the severe threats to biodiversity under high-emission pathways, identifies key groups requiring priority conservation, and offers a scientific basis for developing proactive conservation strategies.

Key words: climate change, land-use change, IUCN Red List, extinction risk, butterfly diversity