THE CASPIAN SEA WATER LEVEL DECLINE: A COMPREHENSIVE REVIEW OF CLIMATE-DRIVEN IMPACTS ON ECOSYSTEMS,BIODIVERSITY, AND INFRASTRUCTURE

Abstract

The Caspian Sea, the world's largest landlocked water body, is experiencing unprecedented water level decline driven primarily by climate change. This review synthesizes recent scientific evidence on the causes, consequences, and projected impacts of this environmental crisis. Analysis of satellite data reveals that water levels have declined by approximately 2 meters since 1996, with rates accelerating to 30 cm per year since 2020. Climate modeling projects potential declines of 9 to 21 meters by 2100 under medium to high emission scenarios, which would result in complete desiccation of the northern Caspian basin and conversion of up to 143,000 km² of water to land. Such declines critically threaten endemic species including the endangered Caspian seal (Pusa caspica) and six sturgeon species, while potentially reducing marine protected area coverage by up to 94%. Coastal communities, industrial infrastructure, and fisheries face billions of dollars in economic losses. The review identifies increased evaporation driven by rising temperatures as the primary driver, with anthropogenic water abstraction and dam construction on the Volga River exacerbating natural fluctuations. Effective mitigation requires adaptive, dynamic conservation planning, transboundary cooperation, and immediate policy interventions to protect both biodiversity and human livelihoods. The findings emphasize the urgent need for coordinated international action to address this environmental catastrophe, which serves as a critical test case for managing climate change impacts on major landlocked water bodies worldwide.