Halting predicted vertebrate declines requires tackling multiple drivers of biodiversity loss

Abstract

Anthropogenic threats are reshaping Earths biodiversity at an unprecedented rate and scale1-3. Conservation policies often prioritise threats like habitat loss and exploitation based on their global prevalence. However, these assessments rarely quantify the impacts of individual or interacting threats, potential masking the true effects of the Anthropocene4-6. Here, we quantitatively analyse the trends of 3,129 vertebrate populations worldwide with documented exposure to specific and multiple threats. Populations impacted solely by habitat loss or exploitation, the most prevalent threats, do not show the fastest declines. Rather, populations exposed to disease, invasive species, pollution, and climate change decline more rapidly. However, habitat loss and exploitation - along with climate change - do act as additive interactive threats, amplifying population declines. Notably, these interactive threats contribute to population declines, more than temporal or spatial sources of variation. Finally, counterfactual scenarios show that to achieve global non-negative vertebrate population trends, we need to mitigate the effects of multiple threats. These findings underscore the urgency of addressing the compounding effects of multiple threats to halt biodiversity loss and suggest that the local-scale impacts of climate change may be more severe than previously recognized.