nCa Commentary
“ . . by 2100, water levels in the Caspian Sea could drop by another 8 to 30 meters (26 to 98 feet).”
This is an alarming quote from a research paper titled, “The fate of the Caspian Sea under projected climate change and water extraction during the 21st century.”
It was authored by Sifan A Koriche, Joy S Singarayer, and Hannah L Cloke, and published by IOP Publishing on 24 August 2021.
The fate of the Caspian Sea under projected climate change and water extraction during the 21st century
https://iopscience.iop.org/article/10.1088/1748-9326/ac1af5
The Caspian Sea has been shrinking for the past several decades and the scientists have tried to identify the causes. Everyone agrees that the rate of shrinking of the Caspian is quite alarming, full of consequences for not just the region but the entire world. — The climate change is the culprit.
Frank Wesselingh and Matteo Lattuada have dealt with the subject in their paper published by The Conversation on 23 December 2020.
The title of the paper is quite candid: ‘The Caspian Sea is set to fall by 9 metres or more this century – an ecocide is imminent’
The Conversation
Frank Wesselingh and Matteo Lattuada don’t mince their words.
They write:
“By the end of the century the Caspian Sea will be nine metres to 18 metres lower. That’s a depth considerably taller than most houses. It means the lake will lose at least 25% of its former size, uncovering 93,000 sq km of dry land. If that new land were a country, it would be the size of Portugal.
“As we found in our new research, the crisis may well result in an ecocide as devastating as the one in the Aral Sea, a few hundred kilometres to the east. The Caspian’s surface is already dropping by 7cm every year, a trend likely to increase. In five years it might be about 40cm lower than today and in ten years almost one metre lower. Maritime countries worldwide are coming to terms with one metre or so of sea level rise by the end of the century. The Caspian Sea faces a drop of that size – except it will happen within a decade.
“Climate change is the culprit. The Caspian Sea waters are isolated, its surface is already around 28 metres below global oceans. Its level is the product of how much water is flowing in from rivers, mostly the mighty Volga to the north, how much it rains, and how much evaporates away.
“At the end of the century the Volga and other northern rivers will still be there. However, a projected temperature rise of about 3℃ to 4℃ in the region will drive evaporation through the roof.”
As for the reasons for this shrinkage in the size of the Caspian, there is almost unanimity among the experts.
There are many past and ongoing studies focused at the causes of the shrinkage of the Caspian Sea. One of them has been authored by J. L. Chen, T. Pekker, C. R. Wilson, B. D. Tapley, A. G. Kostianoy, J.-F. Cretaux, and E. S. Safarov.
In this research paper, published in 2017 by AGU Publications in its Geophysical Research Letters, the authors contend that the shrinking of the Caspian can, at least in part, be attributed to the decrease in the rainfall, increase in evaporation, and the reduction in the river runoff (rivers discharging their water into the Caspian). The study covers the period 1979-2015.
The Geophysical Research Letters
Peter Dockrill, in an article for Science Alert, elaborates on the findings of the research paper of Chen et al, 2017, and includes the opinion of experts to prove his point.
In his article titled ‘We Finally Know Why The Caspian Sea Is Evaporating Off The Face Of The Planet,’ Dockrill writes:
“The researchers say that hotter surface air temperatures over the Caspian Sea – a total rise of about 1 degree Celsius (1.8 degrees Fahrenheit) since 1979 – have resulted in increased evaporation, and the most likely culprit behind all this is climate change.
“While the overall water level in the Caspian has fluctuated for several hundred years, steepened changes in the last century suggest evaporation caused by warmer temperatures is the greatest influence on the body of water.
[ . . . ]
“Digging into the satellite data along with records of precipitation and drainage into the sea from rivers, the team found the effects of evaporation were greater than any other influences on water level.
“In other words, evaporation has more of an impact than gains made from rainfall or water flowing into the Caspian from rivers surrounding the sea.
“”If the temperature in the Caspian Sea region continues to increase, the evaporation rate is also expected to increase,” explains space geodesist Anny Cazenave from France’s space agency CNES, who wasn’t involved with the study.
“Unless river discharge increases accordingly or precipitation in the Caspian drainage basin increases accordingly, the imbalance is likely to continue.”
Science Alert
All the studies point to three reasons for the shrinking of the Caspian Sea: 1. Increase in the surface temperature; 2. Decrease in the annual rainfall; and 3. Decrease in the volume of water discharged by the rivers into the Caspian Sea.
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Turkmenistan transformed in 2019 its State Enterprise for the Caspian Sea into the Institute of the Caspian Sea. Its structure and mandate were further streamlined under a presidential decree issued in 2021. The institute has a wide mandate including the study of the shrinking of the Caspian Sea.
The state structures related to ecology and environment are also engaged in the study of the challenges facing the Caspian and finding solutions for them.
The newly appointed minister of ecology and natural resources of Kazakhstan is Ms. Zulfiya Suleimenova. At 34, she is the youngest member of the Tokayev cabinet. She announced just a couple of days ago that Kazakhstan will adopt new approaches for dealing with the issue of the shrinkage of the Caspian.
There are several agencies and institutions in Iran that are studying the Caspian issues, including the Department of Environment (ministerial level organization), and the Iranian National Intitute for Oceanography and Atmospheric Science.
The ministry of ecology and natural resources of Azerbaijan has a subsidiary organization devoted to the Caspian environmental issues.
The ministry of natural resources and environment of Russia and its subsidiary and affiliate organizations and institutions are keeping an eye on the Caspian issues.
The summit of the heads of the Caspian states and other bodies of the Caspian also keep an eye on the shrinking of the Caspian.
However, the problem is truly global in nature.
The climate change and its consequences are not limited to anyone’s geographical borders. Everyone needs to play their role with full sense of responsibility.
As for the matter of reduction in the discharge of the river waters into the Caspian, the main responsibility lies with Russia as its Volga River is the main source of water for the Caspian. Russia would need to find the ways to restore the volume of annual discharge of Volga waters into the Caspian to the levels of 1970. /// nCa, 19 January 2023