Global rural settlement expansion rivals its urban counterpart in biodiversity impact

While the impacts of urban expansion on biodiversity are well-documented, the role of rural settlement dynamics is poorly understood, potentially underestimating global threats. Here we compare the dynamics of urban and rural settlements and model their historical and future differential effects on biodiversity using integrated global datasets. Between 2000 and 2020, compared to urban settlements, rural settlements encroached upon 2.3 times more natural and semi-natural land, expanded 3.7 times more rapidly within Key Biodiversity Areas, and were associated with 3.5 times greater biodiversity decline. Overall, the total biodiversity loss linked to rural settlement dynamics was 1.01 to 1.36 times greater than that from urban dynamics. Future projections indicate continued biodiversity loss under all scenarios, although compact development could mitigate these impacts by 8–14%. Our findings reveal the overlooked but substantial biodiversity impact of rural settlements, highlighting the urgent need for inclusive policies governing both urban and rural land use. Globally, overlooked rural settlement expansion contributes more to biodiversity decline than urban sprawl, according to an analysis that combines data on urban and rural settlements, land use, and species distribution.