The Caspian Sea to shrink by a third due to global warming

The Caspian Sea to shrink by a third due to global warming
The Caspian Sea could go the way of the Aral Sea thanks to global warming. The sea level is already falling, but could drop by up to 18 metres if it continues to evaporate at the current pace and the northern section could disappear entirely say scientists. / NASA
By Seymur Mammadov in Baku June 5, 2024

The Aral Sea has gone. The Caspian Sea may be next. Global warming will see its level fall by up to 18 metres and reduce its surface area by a third thanks to global warming. Azerbaijan’s capital will no longer be a port if that happens and the Northern Caspian will disappear entirely.

The sea level in the Caspian has been falling at an alarming rate. Shippers are concerned as ports are already having to be dredged as they become shallower each year. Although fluctuations in the level of the largest inland body of water on the planet are quite natural, many scientists say that the recent drop in the Caspian Sea level is unprecedented.

In ancient times, the Caspian Sea splashed at the foot of the iconic Maiden Tower, which still stands on the seafront in Baku. For the last two hundred years it hasn't returned to that level.

According to several European scientists, by the end of the 21st century, the Caspian Sea level may drop by 9-18 metres. As a result, Baku will no longer be a port, the Kara-Bogaz-Gol Bay in Turkmenistan will disappear. In the northern part of the sea water will recede to expose vast new fields of land.

In a study published by the scientific journal Communications Earth & Environment, scientists attempted to determine how global warming will affect all major lakes and continental seas of the world, including the Caspian Sea. Based on data from recent years, scientists have created a computer model of the Caspian and other large lakes worldwide. According to their calculations, the Caspian Sea will suffer the most. This is because the water from its surface will evaporate faster, and in the northern part of the reservoir, the ice cover will disappear in winter. The level of the Caspian Sea is heavily dependent on changes in the average annual surface temperatures and the amount of water flowing into it from rivers like the Volga, Ural and others. Over the past few years scientists have observed a slow but constant decrease in its level, caused by global warming. Thus, if global warming stops, the Caspian will drop by only 9 metres; otherwise, it will drop by 18 metres or more, reducing its area by a third.

Since 2005, the Caspian Sea level has been decreasing by about 20 centimetres per year. The situation is particularly serious in the northern part of the sea. Photos taken from space are alarming, showing significant areas of the seabed have already been exposed in the Russia and Kazakhstan sectors.

The northern parts of the Caspian Sea are already starting to disappear

Over the past 120 years the sea level has fluctuated from minus 25 metres (according to the Baltic system) to minus 29 metres. Currently, the Caspian Sea level is at minus 28.6 metres. Note that the Baltic Height System (BHS) is a geodetic coordinate system used to determine height relative to sea level in the Baltic region and neighbouring countries.

Almost 90% of Caspian water comes from the Volga River. According to experts, the restoration of the Caspian level after the next drop does not occur due to the nine reservoirs built on the Volga during Soviet times. The Upper Volga, Ivankovo, Uglich, Rybinsk, Gorky, Cheboksary, Saratov, Volgograd reservoirs and one of the world's largest, Kuybyshev, are filled with river water for irrigation purposes, which has noticeably affected the Caspian level in recent decades.

Russian scientists are sounding the alarm, noting that over the past 20 years, the water surface area has shrunk by more than 23,000 square kilometres. The Institute of Water Problems at the Russian Academy of Sciences believes that the continuation of the current situation will lead to the disappearance of the Northern Caspian. Experts from the institute suggest negotiating with Turkmenistan to build a structure that regulates water flow into the Kara-Bogaz-Gol Bay.

Kazakhstan has proposed establishing an Institute for the Study of Caspian Sea Problems, involving representatives from all Caspian states. Kazakh experts believe that the Volga River has the most significant impact on the problem and that negotiations and problem-solving need to happen at the international level.

The most negative forecasts also come from Kazakhstan. The Caspian is predicted to face the same fate as the Aral Sea if the Caspian countries do not urgently address the problem. In the 1960s, the Aral was the fourth-largest lake on the planet, but due to active water withdrawal from the Amu Darya and Syr Darya rivers, the sea began to rapidly dry up.

The Aral Sea has almost entirely disappeared.

The drying of the Aral inflicted irreparable damage on the flora and fauna of the reservoir and surrounding areas. One can imagine the enormous damage the drying of the Caspian will cause to the coastal countries in terms of both the natural environment and the economy. It will affect the ecological balance of the entire region with the coastal zone becoming swampy, and many species of marine flora and fauna will die out. Russia’s legendary beluga caviar comes from sturgeon fish that largely live in the shallow northern part of the Caspian Sea, where stocks of the fish are already in crisis.

Meanwhile, Azerbaijan is taking a calmer approach to the problem. According to the Institute of Geography at the National Academy of Sciences of Azerbaijan, over the last 4,000 years, the Caspian Sea level has decreased every 250 years, then increased over the same period. Since 1837, there have been three sharp changes in the Caspian level. From 1837 to 1930 the level dropped by about 1 metre, from 1930 to 1977 by 3 metres, and from 1978 to 1995 it rose by 2.5 metres. Then the sea began to recede again. Since 1995 the Caspian Sea level has dropped by 2 metres. This decline will continue until 2040, according to the Institute of Geography.

Some Russian specialists do not consider the situation critical and suggest leaving the Caspian alone and focusing on limiting destructive human activities and the squandering of water resources instead of measuring the water level.

As we mentioned earlier, the main problem that reduces the flow of water into the sea is the numerous reservoirs along the Volga River. Additionally, large industrial enterprises also draw water from this artery. Even before the sea level began to fall, the river itself started to shallow. This also creates problems for river navigation. According to Russian media, the riverbeds of the Volga and Ural are polluted, and no one is engaged in cleaning and deepening them.

Experts believe that the main cause of the problems of the Caspian is the mismanagement of water in Russia, which leads to reduced runoff.

If this is the case, the Russian side must urgently address this problem and stop draining the sea. It is clear that Russia has many other problems, and it is a vast country surrounded by many seas and oceans. However, for the other four countries in the region, the Caspian is, one might say, a source of life. The lives of the people in these territories have always been connected to the Caspian Sea. Russia's Caspian neighbours need to move from simple discussions and measurements to active measures.

When the Caspian level seriously fell in the 1960s-70s, Soviet authorities considered diverting Siberian rivers south to fill the sea. It was a crazy project, fortunately not implemented. To save the Caspian Sea, there is no need to reinvent the wheel. The Caspian is a unique body of water. Even its ability to cyclically rise and fall is of great scientific interest. But in this situation, leaving everything to the whims of nature is unlikely to be wise because, in addition to natural factors affecting sea level fluctuations, human activity has also contributed.

The time has come for humans, not nature, to rectify the situation.