Caspian Sea Level Drop Triggers Multilateral Environmental Governance Talks Among Littoral States

The Environmental Crisis: Scale and Causes

Scientific presentations at the Baku emergency session, delivered jointly by teams from the Caspian Environmental Programme and national research institutes of all five littoral states, confirmed that the sea level has fallen 2.4 metres since 2005, with 0.9 metres of the total decline occurring in just the last three years. The rate of decline is accelerating. The primary driver is reduced freshwater inflow from the Volga River, which historically contributes approximately 80 percent of Caspian inflows and whose flow has been diminished by a combination of increased upstream agricultural abstraction, hydropower reservoir regulation, and below-average precipitation in the Volga catchment related to climate patterns. Secondary factors include increased evaporation from the sea's surface driven by a 1.4°C increase in mean surface temperature since 1980 and, in the eastern Caspian, increasing abstraction for oil and gas operations in the Kazakh and Turkmen offshore sectors.

The physical consequences are already visible and economically significant. Kazakhstan's major Caspian port at Aktau has seen its operational depth reduced by 1.8 metres, requiring ships to load at 60-70 percent capacity and necessitating emergency dredging campaigns. Azerbaijan's Baku port is similarly affected, with the Caspian Shipping Company reporting a 15 percent reduction in cargo throughput due to draft constraints. The northern shallows of the sea, historically the primary habitat for Caspian sturgeon and kilka, have contracted substantially, threatening fisheries that employ tens of thousands of workers across the littoral states and that underpin a $400 million annual caviar and fish export industry.

Governance Responses and Diplomatic Challenges

The 2018 Convention on the Legal Status of the Caspian Sea, negotiated over 22 years, established a legal framework for territorial division, resource exploitation, and environmental cooperation, but was designed primarily to resolve sovereignty disputes rather than to create an operational basin management authority. Its environmental provisions are aspirational rather than binding. The emergency session on October 17 produced an agreement in principle to establish a Caspian Environmental Monitoring Council with a permanent secretariat in Astana, funded by equal contributions from each littoral state, and to share real-time hydrological and meteorological data through a joint platform.

The diplomatic challenge is that the most effective interventions require action primarily by Russia, which controls the Volga catchment and whose agricultural and industrial water management decisions most directly determine Caspian inflow volumes. Russia attended the Baku session but resisted any formulation that would make its Volga management practices subject to review or consultation requirements. The compromise language agreed commits Russia to 'enhanced information sharing on upstream water management' and to 'consulting with the Caspian Environmental Monitoring Council before major changes to Volga basin regulation', a formulation that falls short of binding obligations but represents the limit of what Moscow would accept. Iran, which borders the southern Caspian and whose sea level concerns relate more to coastline erosion than port depths, supported stronger enforcement language but deferred to consensus.

Sources

• Caspian Environmental Programme – Sea level trend report October 2026
• Reuters – Caspian Sea level drop forces emergency talks among five littoral states
• AP – Vanishing Caspian: sea level crisis prompts new environmental diplomacy