Exposure of mammal genetic diversity to mid?21st century global change

Accelerating climate and land-use change are rapidly transforming Earth's biodiversity. While there is substantial evidence on the exposure vulnerability of biodiversity to global at species level, intraspecific genetic diversity (GD) still unknown. Here, we assess mitochondrial GD mid-21st century in terrestrial mammal assemblages grid-cell bioclimatic region scales under alternative narratives future societal development. We used predictions distribution based thousands georeferenced genes for hundreds species, latest generation models from ongoing sixth phase Coupled Model Intercomparison Project (CMIP6), projections prepared CMIP6. found that more than 50% genetically poorest geographic areas (grid-cells), primarily distributed tundra, boreal forests/taiga temperate regions, will be exposed mean annual temperature rise exceeds 2°C compared baseline period all considered scenarios. also show least 30% most rich tropical, subtropical montane regions an increase > less optimal Genetic these predicted severe reductions primary vegetation area increasing human activities (an average loss 5–10% their total sustainable scenarios). Our findings reveal a combined effects change. Meanwhile post-2020 conservation goals overlooking diversity, our study identifies both poor highly diverse severely change, paving road better estimate geography