Court, R.; Lattuada, M.; Shumeyko, N.; Baimukanov, M.; Eybatov, T.; Kaidarova, A.; Mamedov, E. V.; Rustamov, E.; Tasmagambetova, A.; Prange, M.; Wilke, T.; Hassall, C.; Goodman, S. J.

The Caspian Sea is the world\'s largest landlocked waterbody, providing habitat for hundreds of endemic and migratory species, along with ecosystem services that sustain millions of people. Global warming is projected to drive declines in water levels of up to 21 m by 2100. Using geospatial analyses, we assessed the impact of sea level decline on habitats, protected areas, and human infrastructure. We show that a water level decline of just 5 to 10 m will critically disrupt key ecosystems, reduce existing marine protected area coverage by up to 94%, and render billions of dollars of civil and industrial infrastructure obsolete. Urgent action is needed to replace traditional static conservation planning with a pre-emptive, dynamic approach that allows protected areas to track shifting ecosystems. This will be essential to help the Caspian Sea\'s endemic biodiversity adapt to these changes, and avoid conflicts with mitigation efforts directed at protecting human activity.