Caspian Sea Hits Historic Low as Climate Change Drives Collapse
The Caspian Sea has dropped to a historical low driven primarily by climate change, threatening shipping, fisheries, and coastal tourism across its five littoral states. According to researchers, the world’s largest enclosed body of water is experiencing a sustained decline that outpaces human intervention alone.
The Volga River and the Limits of Dam Control
Climate change is the dominant force behind the falling water level, outweighing human intervention such as upstream damming, according to Anoush Nouri Esfandiari, secretary of the Iranian Water Policy Research Institute. While water abstraction from rivers feeding the basin affects the sea, the Volga River—which supplies more than 80 percent of the Caspian’s inflow—mostly features dams that function for navigation, with limited total abstraction.
Iran has built numerous dams on rivers feeding the Caspian, particularly the Sefidroud and its tributaries, bringing a large portion of local flow under control. However, the share of those rivers compared to the Volga is small, meaning domestic conservation measures have a limited effect at the scale of the entire sea.
Russian Agricultural Expansion and Volga Pressures
Russia has expanded irrigation along the Volga basin since 2022 to boost domestic grain production following trade disruptions and food import restrictions tied to its invasion of Ukraine. That increased agricultural use has intensified demand for water upstream, limiting outflow to the basin.
Sewage Challenges and Northern Population Growth
Zaur Shiriyev, a nonresident scholar at the Carnegie Russia Eurasia Center, noted that pollution of coastal waters remains a severe challenge for the region. Schemes to collect and dispose of sewage have dragged on for years without reaching full operation, compounding pressures from rising populations in northern provinces like Mazandaran.
Tehran Conference and Littoral Treaty Debates
Against the backdrop of environmental decline, regional actors are pushing for closer institutional coordination. During a conference dedicated to Caspian Sea Day in Tehran, diplomats addressed ongoing ecological challenges, while the Turkish Ambassador to Turkmenistan called for deeper cooperation among neighboring nations. Meanwhile, the five littoral states—Azerbaijan, Iran, Turkmenistan, Kazakhstan, and Russia—continue debates over the legal treaty meant to divide the shrinking water body.