Fossil-calibrated predictions of local and global extinctions

Climate change poses a significant threat to global biodiversity, yet predicting species extinctions remains challenging. Most projections rely on species distribution models (SDMs), which estimate realized niches based on modern occurrences and climate and extrapolate them into future habitat using climate projections. However, the predictive accuracy of SDMs for extinction risk remains unverified due to limited ground-truthing; in contrast, the fossil record offers an independent benchmark that can be used to both validate and forecast extinction predictions. Here, we use fossil data of planktonic foraminifera to estimate species’ past thermal niches and assess extinction risk under climate change. We show that past climate-driven extinctions over the last ~66 million years were largely predictable from these niche characteristics. Projecting our niche estimates into the future reveals spatiotemporal extinction risk patterns that complement traditional SDMs, highlighting severe threats to biodiversity under anthropogenic warming, particularly in the polar oceans.