"As the Caspian Sea is a closed basin, there are periodic changes in the level. However, one of the unique features of the Caspian Sea is that the reasons for this are still not fully and unambiguously assessed by scientists. Rasim Sattarzadeh, head of the Ecological Policy Department of the Ministry of Ecology and Natural Resources, said that the main factor in changing the level of the Caspian Sea is the climate of its basin. :
"Analysis of long-term data shows that the level of the Caspian Sea has fluctuated between -20 and -34 meters. In 1977, the sea level dropped to -29 meters, the lowest level observed in the twentieth century.
However, during 1977-1995, the water level increased by 2.5 meters and reached -26.5 meters. Since 1995, the sea level has been declining again. The most noticeable decrease (about 1 meter) occurred in 2006-2015. Although the level partially stabilized in 2015-2017, it began to decline again. According to the ministry official, it is impossible to make a long-term forecast of sea level dynamics. Because none of the long-term level forecasts made so far has proved itself:
"Given that the level of the Caspian Sea depends on many factors, there must be a clear forecast and scenario of changes in these factors. I think it is necessary to be skeptical of such a long-term forecast, as there are many uncertainties in the factors that lead to level fluctuations. It should be noted that there have been recent reports of ice cover in the Caspian Sea.