Caspian Sea faces catastrophic shrinkage due to climate change Article by Down to Earth

The Indian website Down to Earth has published an article by Rajat Ghai on the threat of the Caspian Sea drying up. Caliber.Az reprints this article. 

Next month, the world will converge on Baku, the capital of Azerbaijan in the South Caucasus, for the 29th Conference of Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC). Ironically though, the Caspian Sea on which Baku is located, is in danger of drying up due to human-induced climate change.

A recent media report quoted an Iranian government official warning that up to a quarter of the Caspian Sea’s water levels may dry up within the next 20 years.

That would be a catastrophe since the Caspian is not just any other body of water. It is the largest enclosed body of water in the world, with no direct connection to the world’s oceans. In other words, it is “endorheic”.

So, what is threatening the Caspian?

The Caspian stretches over a huge area of Eurasia, from Russia in the north to Iran in the south and from Turkmenistan and Kazakhstan in the east to the Caucasus Mountains in the west.

The primary reason for the drying of the Caspian is human-induced climate change, according to research published by Azeri and Kazakh scientists earlier this year.

A crucial factor in the hydrological balance of the Caspian Sea is the rivers flowing into it, according to the 2024 study.

“About 130 rivers flow into the Caspian Sea, but the Volga, Kura, Ural, Terek, and Sulak rivers bring the main volume of runoff to the sea. According to some data, the Volga River accounts for more than 80 per cent of the water brought into the Caspian Sea. However, this share can be noticeably larger in different periods. Therefore, Caspian Sea level fluctuations are largely determined by the variability of the Volga River flow,” the researchers noted.

The Volga is the largest river in Europe, while the Ural is the continent’s third-largest. “The Volga is 3530 km long, and the basin covers an area of 1,360,000 km2…The main source of the Volga River runoff is snowmelt and precipitation falling in its basin,” according to the scientists.

Will the sea vanish?

The Azeri and Kazakh scientists analysed hydrological changes in the Volga and their repercussions on the Caspian Sea level from 1938 to 2020.

They found a strong correlation between high Volga River runoff and increased atmospheric precipitation in its basin until 2005.

“However, in recent years (2005-2020), a significant decline in the runoff coefficient at the Verkhneye Lebyazhie hydrological station, attributable to climate warming surpassing global temperature anomalies, has been observed. This warming’s impact on river flow and sea level was quantified, resulting in a 133 cm decrease in sea level from 1977 to 2020,” the research paper noted.

So, what then is happening?

The scientists stated that various studies have found that over the Caspian Sea, wind speed and direction change periodically.

During periods of decreasing Caspian Sea level, the wind speed was greater than during periods of increase.

“On the other hand, during periods of sea level decrease, the eastern component of the wind direction prevailed, and during periods of sea level rise, the northern component prevailed,” as per the paper.

Unlike the northern winds, the eastern winds blow from Central Asia and bring drier and hotter air masses. This, in turn, increases the intensity of evaporation.

The media report stated that Azerbaijani President Ilham Aliyev had expressed deep concern over the “catastrophic” shrinkage of the Caspian Sea in early October. He had also discussed the matter with Russian President Vladimir Putin.

The Soviet Union oversaw the destruction of the Aral Sea with its lopsided environmental policies. Iran too has witnessed the drying up of Lake Urmia.

If something similar happens to the Caspian, it would be apocalyptic for large parts of Eurasia, not least for India, whose Western Disturbances originate as local storms over the Sea. It is something that delegates at Baku could well take note of. 

By Khagan Isayev