Long-term climate warming substantially reduces global soil microbial richness

Soil microbes buffer ecosystems against climate perturbation by regulating carbon storage, greenhouse gas fluxes, and nutrient cycling. Yet, predicting their long-term, global-scale responses to warming remains challenging due to the short duration and limited geographic scope of existing studies. Here, we conducted a global meta-analysis of 2,786 paired observations to assess the impacts of warming on soil microbial diversity and abundance. Overall, soil microbial diversity and abundance consistently declined with increasing warming magnitudes and mean annual temperatures. Long-term warming (≥5 years) is projected to reduce global soil microbial richness by 7%–9% under the Paris Agreement-aligned scenario SSP1-2.6. These findings reveal global patterns of microbial diversity and abundance loss under warming, thereby improving predictive models of ecosystem responses. They enhance our ability to assess the sustainability risks of climate change and highlight the urgent need for mitigation strategies to protect the soil microbiome.