Global warming, environmental security and its geo-economic dimensions case study: Caspian Sea level changes on the balance of transit channels

Abstract

Background

Global warming and climate change are considered as important environmental problems. Environmental security is more pronounced with regard to the Caspian Sea. Due to the geopolitical and geo-economic dimensions on the one hand, and its unique characteristics on the other, this large lake is considerably fragile against environmental challenges. In fact, the innate isolation of the Caspian Sea makes its conditions with regard to global warming unique. Using a descriptive-analytical method and library and valid article references, this study seeks to answer the question: “what are the effects of global warming on environmental security and what challenges does it pose to the Caspian Sea from the geo-economic point of view?”

Methods

And Also maps and charts related to the research topic were collected and plotted in the GIS. In the next step, using a descriptive-analytical method based on geopolitical perspectives, especially environmental geopolitical studies and internet searches, we analyze the spatial effects of this universal phenomenon in the context of environmental geopolitical systems.

Results

The findings indicate that global warming will pose a large spectrum of challenges and problems to the Caspian Sea from the destruction of its ecosystems to the complete transformation of its nature. This research has studied global warming and its effects on the sea level changes of the Caspian Sea and particularly the level of water in the transit channels of the Caspian Sea from the geo-economic point of view.

Conclusion

The results show that fluctuations in the water level of the Caspian Sea, in addition to environmental challenges, narrow the balance of its transit channels and threaten the geo-economics and environmental security of the Caspian Sea.

Introduction

Whenever environmental security is discussed, pollution and destruction of the environment by human beings are the first issues which come to mind [37, 40]. Therefore, due to this diversity and placement between different countries and global and regional developments, it needs to pay attention to its political and environmental structure. Anthropogenic activities have had the significant impact on environmental pollution [38, 39, 42, 44]. Meanwhile, global warming and climate change are considered as the most important environmental problems which have turned into important concerns throughout the world) [33]. It is also important when considering a special place with the consideration of environmental security dimension. According to the studies and researches, in the last 100 years the average temperature near the surface of the earth has increased and greenhouse gases have been recognized as one of the most important factors influencing the occurrence of global warming phenomeno n [7]. Increasing temperature throughout the world is one of the most obvious outcomes of global warming which has resulted in the melting of polar ice caps and increased ocean water levels. As a result of this phenomenon, ocean water levels have increased and large parts of coastal regions overlooking open seas have suffered erosive damage and flooding) [25].

Currently, the problem of global warming threatens [3] all ecosystems of the earth on a global and comprehensive scale. Hence, the climatic region of the Caspian Sea is not an exception. In fact, global warming has also affected the climate of the Caspian Sea area along with the occurrence of disastrous phenomena (Kakroodi et al. 2019). Although one of the outcomes of climate change and increasing global temperature, as important environmental problems, is increased sea water levels, a different trend is observed in the Caspian Sea. It is clear that the Caspian Sea is a lake despite its common name. Therefore, global warming and its outcomes on seas must not cause similar worries about this lake. The sinister effects of global warming along with the increased temperature of the earth will evaporate the water of this lake and some have voiced concern about the existential loss of the Caspian Sea.

On the other hand, the Caspian Sea is considered as the largest closed water body on the surface of the earth and its isolation has turned it into a very special ecosystem. Overall, the increased temperature of the earth has had a direct effect on the water levels of the Caspian Sea [21] more importantly, the unique characteristics of the Caspian Sea have resulted in its high vulnerability against external factors such as climate conditions or human-made changes. One should not forget the developing economies around the Caspian Sea which have put economic security above environmental security. In the meantime, the Caspian Sea has been divided among neighbors in a very unbalanced way from various perspectives including resources, depth, and so on. This has caused different inclinations with regard to its environmental security. However, various factors have targeted the environment of the Caspian Sea, each of which may somehow cause erosions and turn into environmental security factors [26]. In general, the effects of global warming on the special and fragile ecosystem of the Caspian Sea should be scrupulously investigated in different scientific fields and from multiple angles such as the effects and challenges created on the geo-economics of the Caspian Sea. The question is “what outcomes has global warming imposed on the environmental security of the Caspian Sea and what challenges has it produced in the Caspian Sea from the geo-economic standpoint.

The hypothesis which is proposed is that global warming will lead to evaporation and will decrease the water levels of the Caspian Sea. As a result of environmental frictions due to global warming along with the challenges of the scarcity of resources in geo-economic dimensions, the environment of the Caspian Sea has somehow become a security concern challenging its geo-economic security.

Materials and methods

Methods

In general, the structure of this research is based on the analysis of the position of global warming and the effects that this phenomenon has on the geopolitical developments in the world system. The research method of this article is descriptive-analytical. The method of collecting data and information is generally based on a library-documentary approach, and the necessary data are collected by reviewing documents and using internal and external books and articles, reputable websites, and reports of relevant institutions. In this regard, in the first step, in order to understand the trends of changes in temperature and sea level change, as well as to better understand the position of global warming in the geopolitical developments of the international system and the case study, especially the Caspian Sea, has attempted to identify the position and previous studies and Also maps and charts related to the research topic were collected and plotted in the GIS. In the next step, using a descriptive-analytical method based on geopolitical perspectives, especially environmental geopolitical studies and internet searches, we analyze the spatial effects of this universal phenomenon in the context of environmental geopolitical systems. In order to answer the research questions, this information is mainly analyzed by qualitative method. The theoretical approach used is a geopolitical approach that combines traditional and modern geopolitical theories, and in particular the use of environmental geopolitics and geo-economic issues. Finally, according to the geopolitical perspective of environmental and environmental security, a conceptual model (Fig. 1) has been drawn to the final results of the research.

Fig. 1.

Conceptual diagram showing the general determinants of study

Global warming

After the Cold War, the environment became the main focus of worries and political struggles and the international outcomes of environmental erosion found a special place in reviewing environment literature [5]. Today, the problem of global warming comprehensively threatens all the ecosystems of the world. According to the report by IPCC, the average temperature of the earth’s surface has increased about 0.2–0.6 °C. In higher geographical latitudes, this increase has been higher. It is predicted that if the conditions continue as they are, until 2100, the temperature of the earth’s surface will increase about 1.4–5.8 °C. During the twentieth century, the global warming phenomenon has resulted in the melting of polar ice caps and evaporation of oceanic waters [46] As a result of this phenomenon, the water level of oceans has increased and large parts of coastal regions overlooking open seas have suffered erosive damage and flooding.

Recent studies indicate that climate warming will have important regional effects such as the exacerbation of flooding and droughts so that in some regions the amount of rainfall will increase and in other regions including the south and Southeast Asia, Latin Africa, and the Sahara in Africa warming and decreased rainfall will prevail. Increased temperature of the earth and even the melting of a small part of polar ice caps will cause a major part of agricultural lands located on the coastal areas to go underwater [4]. A part of the reason for climate change (at least in the major part of the recent century) is related to the unrestrained activities of man, especially, his industrial ones. Increasing greenhouse gases is a clear manifestation of this. The effects of increasing greenhouse gases along with the greenhouse effect will result in the global warming of the climate and also the destruction of the ozone layer. Undoubtedly, if the trend of climate change continues as it does, all natural and artificial ecosystems will be influenced and the various patterns related to food production activities formed for centuries will change and the structure of human societies will be affected [15].

Environmental security

Traditional studies of security have focused on the military aspects as the only dimension of security. Contrary to the traditional view of security, others disagree with a one-dimensional and limited view of security and expand it to military, political, economic, social, and environmentalaspects [8]. Non-traditional security has a complex nature. It includes hundreds of national and transnational threats and is a vast domain with which a lot of actors (governmental and non-governmental) are engaged. Due to the interaction of common physical, economic, environmental, and social forces violence is produced [36] In this regard, environmental security is in fact a new field in security studies whose literature has been enriched by the oppositions and struggles due to the lack of natural resources, erosion, and environmental pollution and its security affects the sustainability of human life ([49]). Environmental threats target bio-ecosystem and geographical health [14].

Moreover, changes in natural environment can influence economic, political, and demographic factors that affect the geography of power. Limitations in using the resources can be considered as a sign of security threat. Basically, environmental threats in the form of environmental risks (natural or human) have the potential to lead to struggle and conflict in order to gain access to scarce resources. They may also comprehensively threaten the future of life on the planet. Environmental threat of national security is similar to military and economic threats that undermines governments’ material base and may escalate to a degree to threaten the stability of governments and their institutions [50]

Environmental security can be defined as liberation from social instability resulting from the erosion of the environment [19]. New theorists of security believe that such issues as the warming of the earth, erosion of the ozone layer, and other environmental problems are among future threats for humanity and pose a common threat to countries. Determining any security trend is based on signs of the threat. If the threatening forces or elements change, new trends are created to deal with it. The first sign of environmental security threat can be seen in the limitations of using resources. The limitation to access resources leads to conflicts [28].

Geo-economy

The meaning of geo-economy is a combination of the three elements of geography, power, and economy. This does not mean that geo-economy is something other than or against geo-politics. Rather, it is part of geo-politics and is one of the geopolitical thoughts in the present era [9]. Geo-economy is the study of the effects of economic factors or infrastructures in national, regional, or global environments on political decision-making, power competitions, and the whole structure of regional and global geo-politics.

The basis of geo-economics is an argument presented by Edward Lutwak. In the 1990’s, he heralded a new and international order in which economic tools replaced military aims as the chief focus of the governments for consolidating their power and character in the international field and this is the nature of geo-economics [14].

The period of geo-economic thought is a new era in which the role and performance of countries is entirely conditioned on their economic data and resources. Also the roleplaying and place of counties and geographical regions in the large-scale strategy of super powers which determine international policies depend on their economic power [31]. In fact, in the concept of geo-economy, the objectives have been transformed into strategic objectives by changing the economic strategies and making use of the geopolitical context [9].

Results and discussion

Research Exposition: Caspian Geography:The Caspian Sea is the largest lake in the form of a large depression with an area of 360,000 km², referred to as a sea. This lake is five times larger than the second largest lake in the world called Lake Superior, and it has about 50 large and small islands with a total area of 350 km². There are also 150 rivers leading to the Caspian Sea. The volume of this lake is 7600 km³ [10].

The Caspian Sea is almost rectangular. The longitudes of the coastline countries around the Caspian Sea are different, and the coastal lengths of these countries are 1900 km for Kazakhstan, 1355 km for Russia, 820 km for Azerbaijan, 1768 km for Turkmenistan, and 657 km for Iran. [6] The length of the sea varies from 1204 km to 1305 km from north to the south, with a width of 443 km [2].

Depth of the Caspian Sea: The depth of this lake is very variable and the shallowest part of the Caspian Sea holds only 1% of the total volume of its water and its maximum portion [47] is about one third of the total volume. The maximum depth of the Caspian Sea near the Iranian coast is 980 m, while the maximum depth near the Russian coast is 50 m. [35] Minimum depth of the Caspian Sea is around 0 to 5 m and its deepest part reaches a maximum of 1046 m (Fig.2).

Fig. 2.

Location map of Caspian Seas; a General location; b The Caspian Sea, Depth and bathymetry (in meters)

Caspian climate: Due to the longitudinal and latitudinal expansion (great length and width of the Caspian Sea), there are different climate zones around the Caspian Sea. The northern Caspian has cold climate, while the middle and southern Caspian have relatively warm climate zones, and this remarkable climatic variation is complete with a desert climate on the eastern coast of the Caspian Sea. The temperature range of the Caspian Sea (Fig. 3) is relatively unusual. On the one hand, in winter, there is a significant temperature difference between the northern and southern Caspian regions and the northern Caspian Sea surface is frozen. However, unlike open seas, this presence of ice cannot be linked to global warming and the phenomenon of rising water levels, as well as the phenomenon of freezing of sea water and melting of ice is repeated in annual cycles. In fact, in the summer, temperatures in the north and south of the Caspian Sea are almost equal, and there is no constant source of ice in this lake.

Fig. 3.

Caspian climate

In the southern Caspian regions, water temperature does not reach below 13 °C in the winter, and in the northern Caspian, the average water temperature in the summer reaches 25 °C. In the shallow eastern parts of the Caspian Sea around the Garabogazköl lagoon, the summer temperatures can reach 35–40 °C. Global warming can have certain implications for the Caspian climate system as a closed body of water, such as increasing the evaporation rate, reducing the water level, changing the precipitation characteristics and the climatic conditions of the Caspian region [51].

In terms of precipitation, the highest annual rainfall occurs on the Iranian southern coast of the Caspian Sea, and the lowest rainfall occurs on the eastern shores of Turkmenistan and Kazakhstan. The highest temperature is measured in the eastern coasts of the Caspian Sea and the lowest temperature in the north of the Caspian Sea on the coast of Russia, so that in the northern parts of the Caspian Sea, freezing occurs and the movement of vessels in this area is only possible by the help of icebreakers. In terms of climatic classification, the coasts of Iran and Azerbaijanhavemoderate Mediterranean climate. The eastern part of the Caspian Sea is warm and semi-arid, and its northern part has a cold and dry climate. Existence of the large Karakum Desert as well as the lagoon of Garabogazköl in the vicinity of the Caspian Sea, increases the amount of evaporation in the eastern part of the Caspian Sea, which is also one of the natural causes of lowering the water level. The Caspian Sea water level is predicted to continue to decline which may result in climate change in the area and threaten the Caspian coastal biota [52].

Geo-economy of the Caspian Sea: The geo-economic significance of the Caspian Sea is mostly due to its energy reserves [45]. However, even in the past this region has been of great economic significance and value. Due to the existence of a vast body of water in this area with all its features, as well as its relationship with other lands, the Caspian Sea has long been considered as one of the most important commercial areas of the world. The Caspian Sea itself is exploited as a source of food and medium of transportation and some of the rare aquatic life forms are found in it. It facilitates transportation of goods and travel between the coastal areas. The strategic location of the Caspian Sea between Europe and Southeast Asia, makes it the main transit route between the coastal states, Europe and South-East Asia. In general, the Caspian Sea is geo-economically important because of its characteristics such as the transportation network, the huge reserves of oil and natural gas, and its biodiversity.

In the twentieth century, during the 1973 oil embargo and during the Persian Gulf War of 1991, the Caspian region showed its political and geographical importance. In recent decades, due to new drilling and exploration as well as offshore fields in the Caspian Sea, the region has become the focus of global attention and has brought many large international companies to the area. A look at the Caspian Sea reservesHistories that the sea has a special place in world energy supply with about 48 billion barrels of crude oil and about 8.76 trillion cubic feet of natural gas. Among them, the largest share of oil belongs to Kazakhstan with 31.2 billion barrels and the largest share of gas with 3 trillion cubic feet belongs to Russia. Based on this data Iran has the smallest share of the Caspian oil and gas.

Considering the growing importance of energy in today’s world and the Caspian Sea’s energy reserves, it has a special significance for countries that rely on imported energy from this area. China, the European Union states, and India are among such countries. However, the EU market has a lower priority for gas exports from the region despite its better geographic access to the Caspian Sea compared to China. The reason is that the European Union has diversified its energy basket and is less dependent on energy imports. On the contrary, due to the higher rate of economic growth and low diversity of its energy basket (as compared to the European Union) as well as greater dependence on energy imports, China is abetter marketthan India and the EU for Caspian Sea energy exports [12].

As it is shown in the (Fig. 4), in 2015 there was no gas exports to India. In this year, the Caspian Sea region exported 1.61 and 0.45 of million barrels of oil equivalent gas to the EU and China markets, respectively. Therefore, with regard to the Caspian region, it is far from optimal in terms of securing its demand for gas. The reason is the shadow of political issues on economic priorities and the lack of progress in building gas pipelines to other markets. However, the economic problems of the countries in the path of the pipelineand the danger of terrorism have prevented the development of the pipeline. In addition to the above reasons, it is important to note that in short-term the creation of a new marketfor gasis very difficult, and the addition of each new market even in India is very costly and requiresthe development of pipelines [11].Global Warming and hydraulic behavior of the Caspian Sea: Given the importance of the Caspian Sea to coastal countries, there are serious concerns about the impact of global warming on greater evaporation of the Caspian Sea waters. The containment of the Caspian Sea and the increase in evaporation rate due to global warming, along with climate change, and lower precipitation on the Caspian Sea and its catchment area, has presented researchers with an important problem [20]. Some researches consider the fate of this lake to be a lesson for the rest of the world claiming that the Caspian Sea is on the path to destruction. Often, these concerns and predictions are raised by the northern Caspian states, especially Russia. These factors further increase the need for more in-depth studies on Caspian water fluctuations.In this regard, the particular hydrological behavior of the Caspian Sea has attracted the attention of many scientists and experts in the field of marine sciences. Rapid water fluctuation is one of the most important hydrological properties of the Caspian Sea. Comparing the rate of changes in Caspian Sea water level with the oceans indicates greater fluctuations in Caspian Sea water levels which under certain conditions has more than 100 times greater fluctuations compared to the oceans [53]. However, the water level of the Caspian Sea has fluctuated in different periods; during some periods this level has been very low while it has risen in other periods. This process which takes a long time has caused changes in the environment and economic activities around the sea. One of the long periods of the reduction in Caspian Sea water began in the 1930s at a time when the Soviet Union started to implement many of its agricultural and industrial projects. Also, changing the bed of some rivers, creating artificial lakes, dams, waterways and increased human activities in these areas led to the reductionof Caspian Sea water to its lowest level (19 m below ocean level) in 1977. But since 1978, contrary to previous forecasts for the continuation of the decline in water levels, the sea level began to increase, with an average of 15 cm added annually to the water level until the year 1995. Since 1995 Caspian Sea water level has been in another negative trend [54].

Fig. 4.

Caspian oil and gas exports in 2015

Water balance is an important factor in the natural activities of water bodies. Basin water volume and surface, and the shape of the coastlines are a function of the basin water balance. The balance of water basins changes over time. The fluctuations of water levels in closed water bodies occur in shorter time periods, and in addition to the above factors, human factors also quickly show their effects.In general, numerous factors influence the fluctuations of the water balance in closed water basins.Variations in water volume is among the factors affecting the Caspian Sea water level, and temperature fluctuation is one of the most important factors that influence sea water volume.

If the water volume and the Caspian Sea area at the 26-m level are 78,845 km³and 405*103 km², respectively, (assuming a vertical coastal slope at this level), with 1 °C increase in temperature, the water level will rise 4 cm. The process of evaporation is affected by various factors such as water surface temperature, salinity, cloudiness, air humidity, and wind. Among these parameters, the water surface temperature plays a more important role [34]. At lower surface temperatures, less evaporation is expected. With a drop of 1 °C in the surface temperature of the water, evaporation rate decreases up to 6%. The total time of the Caspian Sea water replacement is 250 years, and its rate rises from north to south. By comparing the isotopic water samples from different regions of the Caspian Sea since the beginning of the 1980s and 1990s, it was determined that deep waters rise at a rate of 13 m per year. Comparing the results of experiments in different periods with intervals of eight years showed that the speed of Caspian Sea water turnover has increased. In the early 1980s and 90s, deep water percentage in the 0–15 m depth increased from 17% to 83%. Therefore, at the beginning of the twenty-first century, the Caspian Sea water cycle will change again and water level will cease to rise.

However, one of the unique features of the Caspian Sea is its faster changes compared to the ocean levels. These rapid changes have had significant effects on the coastal morphology. Nevertheless, the effects of pre-registration changes of the water balance is ambiguous and various findings have been presented. Therefore, prediction of the balance is very complicated and often involves mistakes [22]. In fact, recent changes in the Caspian Sea balance has surprised everyone. While, according to the measurements between the years 1850 and 1929, the sea level was about −25, it decreased by about three meters to 1977. While researchers were concerned about the relatively fast water level decline imposing heavy burdens on industrial and port facilities, suddenly and over the course of eighteen years, the water level increased by about three meters and caused heavy damage, especially in lower areas [23]. Meanwhile, it is worth noting that with the increase in the period of the North Atlantic climate cycles that accompanied the increase of the Volga River discharge by 25–30%, and the warming of the air during 1978–1995 with a thermal anomaly of about 0.32 °C, the fluctuating behavior of the Caspian Sea was reversed. During the warm-up period, the Caspian Sea went up and the level of its surface increased by 2.5 m. During this time, the amount of northern waters flowing to the Caspian Sea increased, and over the course of the 17 years a large part of the low altitude northern areas of the Caspian Sea went underwater, and many economic infrastructures suffered serious damage [32].

Also, the variation in the oscillatory acceleration of the sea level in the Caspian Sea is indicative of certain events occurring in the catchment area. Tracking of available weather signals indicates that during the years 1930 to 1978 the amount of atmospheric precipitation decreased and during the summer periods the evaporation process increased which is in turn the result of global warming and climate change. However, acceleration rate of sea level variation is not fully correlated with changes in climatic factors, and at this time, another factor, that is human intervention in the catchment area, has caused a sharp drop in the level of the Caspian Sea [27].

In fact, human activities around the Caspian Sea in general have jeopardized the balance of its fragile ecosystem [24]. A major concern is the gradual drying up of the Caspian Sea similar to the fate of the Aral Sea. In the 1960s, the Soviet government erected large dams to exploit the water flowing to the Aral for the cultivation of cotton and rice. Over the next thirty years, the Aral Sea shrank dramatically and lost its economic value. The rivers flowing into the Caspian Sea are also subject to diversion and exploitation for similar purposes or their upstream reserves are evaporating [1].

Based on statistical study of the Caspian Sea level, from 1835 to 1930 the level of water gradually decreased at a moderate and slow speed of about 1.9 cm per year. However, from 1930 to 1941, with an accelerated rate of about 14.7 cm per year, Caspian Sea water level dropped by 1.8 m, and from 1941 to 1978, during 37 years, its level fell at a slower rate of 3.8 cm per year (Fig. 5) (Buzan 2018).

Fig. 5.

Caspian Sea level record between1835 and 2015 Blue line illustrates four parts of fluctuation [23]

The results of the data analysis in the hydrological year of 2017–2018 indicate that the average sea level has reached −27.01 m, and this was about 4 cm below the previous year (2016–2017). The lowest level of water observed in this period was in the first half of December at-27.41 m and the highest water level was in August of 2018 at −26.63 m. The fluctuation range of waterlevel during this year was more than 34 cm.

Overall, the trend of seasonal changes in this year compared to the previous two years shows a decline in water levels during the last autumn and summer seasons, which has a major impact on the average annual water fluctuations in this hydrological year, and can be attributed to the severity of the inflow reduction from the draining rivers.

The total area of the Caspian drainage basin is 3.5 million square kilometers, distributed among the countries of Iran, Turkmenistan, Azerbaijan, Russia, and some areas in Turkey. (Fig. 6).

Fig. 6.

a The Caspian Sea and surrounding water resources. b Caspian Sea catchment (Kakroodi2012)

Important rivers entering the Caspian Sea from different coastal areas are: the Volga River, Ural, and Amba in the northern part providing 87% of the basin water. The Volga River alone accounts for 1.4 million square kilometers of the entire catchment area. The rivers of the western part include the Kura, Terek, Sulak accounting for 7% of the water entering the Caspian Sea. The rivers of the southern shores of the Caspian Sea, such as Sefid-Rud, Haraz, and Aras account for about 5% of the catchment.

As it was mentioned, Caspian water is isolated and it is only lost due to evaporation. Caspian Sea is detached from open seas and below the ocean level and as a result its advance and retreat largely depend on the amount of rainfall in drainage basins of the Volga and other rivers. [15, 16] In fact, the climatic phenomena in the vast drainage basin of this lake and its effects on the flow of rivers are among the most important factors influencing changes in the balance of water. Volga is the most important river that provides 80% of the river inflows to the Caspian Sea. In the current year, Volga water contribution to the Caspian Sea was below the recent 50 years average (1961–2016). It should be noted that last year its water flow was greater than the long-term average. However, reduction in the balance of water recorded in September 2018 was significantly high. The reason for this was the early occurrence of widespread rainfall in the spring in the Volga Basin and early onset of the flood season. Due to the lower inflow of this river compared to the long-term average, the beginning of the declining trend of water balance started in September with a greater intensity. Also, this decline was expected to continue with the same intensity during the fall of 2018 (Fig. 6.b).

It is worth noting that the volume of water behind the Volga River dams is more than 200 cubic kilometers, which is roughly equivalent to the amount of water that Volga is supposed to discharge into the Caspian Sea duringthe low rainfall season. Now, if the climatic conditions prevent the increase of the water volume of the river and withdrawal rate is increased, the Caspian Sea level fluctuation will pose a serious challenge. So far, droughts have affected large parts of the northwest to the northeast and the western parts of the Caspian Sea.

Long-term reduction in the balance of water results in the drying of a vast area of ​​marginal gulfs and wetlands. The ecological damage caused by this event is huge, and remedy of such environmental disasters may be impossible. Moreover, as a result of this decline, the balance of maritime transportation channels will also be in jeopardy. The destruction of residential areas and natural vegetation cover, damage to oil wells, difficulty of cargo ships for entering ports, and the destruction of coastal habitats and ecosystems are some issues that could be caused by an increase in the balance of the Caspian Sea water.

According to the latest UN economic plan report, during the last phase of the Caspian Sea surface level rise during the years 1978–1995, over $ 15 billion in damage was inflicted on coastal countries around it. Today, the rapid decline in the balance of the Caspian Sea water is considered as a major concern in the region. (Khoshravan2018). Therefore, from the geo-economic standpoint, fluctuations in the Caspian Sea surface level has caused constraints and problems at various levels, including ports and the maritime transportation industry. These challenges manifest themselves in thelevel of the Caspian transit channels, the fragility of the Caspian environmental security as well its geo-economic security.

Security of the Caspian Sea transit channels ‘water level

Maritime transportation can be considered as the most economical type of transportation. A large fraction of commercial goods are transported by giant ships between different countries. It should be noted that in this system the speed of transportation is low and it is suitable for carrying heavy and cheap loads. In international trade, this method has many uses, because a variety of products, such as car parts, food products, clothing, and other goods, can be carried in high volumes and at low costs. Considering that maritime transportation is the most cost-effective means of transportation in international trade, it is beneficial for any country to make use of it. Currently in international trade, more than 95% of the goods are transported through the sea. Therefore, ports are of great importance in the economies of the countries and the development of port infrastructures and increasing the number of ports equipped with facilities to transfer materials with suitable storage space is vital to benefit from this economic means of transportation. The Caspian coastal countries are aware of this advantage, and each country uses this potential, based on their specific economic strategies. Around the Caspian Sea, numerous ports, anchorages and piers have been constructed. More than half of the harbor and industrial facilities are located in the Volga area. Development of ports such as Anzali, Nowshahr, Guryev, Baku, Turkmenbashi, and Astrakhan has facilitated the transportation of goods and, consequently, the development of the region. Of course, along with several ports around the Caspian Sea, different shipping lines are also active. Due to the Caspian Sea’s limitation in accessing other seas, some of these shipping lines are of special importance from the geo-economic point of view. Some of the most important routes include:Caspian-Volga-Baltic Line: This shipping line starts from ports in the Caspian Sea and enters the Volga in the north of the Caspian Sea and continues along the river into the Baltic Sea at the coast of Finland. In fact, the Caspian-Volga-Baltic Line connects the northern European countries to the ports in the Caspian Sea.

Mediterranean-Caspian Line: This waterway starts from one of the ports in the Caspian Sea and continues through the port of Astrakhan on the northwest of the Caspian Sea, from where it enters the Volga River and then continues along the Volga- Don Canal toward the Black Sea.

Baltic-Danube Line: This line begins at one of the ports in the Caspian Sea and enters the Volga in the north. After passing through the Volga-Don Canal and the Black Sea it continues toward the Danube. Using this shipping line, Northern and Southern European countries as well as the countries along the Danube River are connected with the Caspian states. (Barayi 2009). In this regard, the other characteristic of the lake is, in fact, its isolation or connection constraints. As it is shown in (Table. 1), the Caspian Sea does not have access to the open waters of the world except through the Volga-Don and Volga-Baltic routes. This issue becomes more important when it is considered along with other Caspian biological factors such as the low depth and moderately cold climate of the Caspian Sea. This feature, coupled with the different oscillatory behavior of the Caspian Sea, has increased its risks due to the evaporation of the Caspian Sea waters and the apparent effects of lower water levels on this channel.

Table 1.

Distribution of the Caspian Basin in different regions

Rivers	Drainage Basin Area(KM2)	country
Volga	1,402,010	Russia, Kazakhstan
Sulak	57,499	Russia
Terek	13,370	Russia
Rivers Between Sulak and Samur	9020	Russia
Samur	4430	Russia, Azerbaijan
Rivers Between Samur and Kura	15,980	Azerbaijan
Kura	188,040	Azerbaijan, Iran, Turkey, Armenia
Rivers Between Kura and Astra	12,280	Azerbaijan
River Between Astara and Anzali	3200	Iran
Rivers of the Anzali Lagoon	3350	Iran
Sefid-Rud	67,000	Iran
Rivers Between Sefid-Rud and Gorgan-Rud	28,500	Iran
Gorgan-rud	13,200	Iran
Atrac	26,700	Iran - Turkmenistan
Basin Between the Volga -Terek	129,800	Russia
Basin between Terek - Sulak	4200	Russia
Atrakbasin - Ural	822,040	Turkmenistan, Uzbekistan, Kazakhstan
Basin between Ural - Volga	150,400	Kazakhstan, Russia

The most important geographical and political constraints of the Caspian Sea’s isolation are as follows:

• The Volga Channel is the only way to enter the Caspian Sea

• Low width and depth of the channel and limitations on the dimensions of the vessels for passing through.

• Freezing of the channel for 6 months of the year

• The existence of bureaucracy and political problems for obtaining permission to pass through the channel (Barayi 2009).

Therefore, threats to the Caspian environmental security combine challenges in water balance security with various variables including evaporation from global warming as well as competition for maritime transportation, access limitations, and relative advantages of some of the neighbors so that the challenge of changing the balance of the Caspian transit channel becomes more evident.

In general, for most developing countries, economic development is of paramount importance and they tend to erode and destroy the environment as an undesirable, yet tolerable, economic, and industrial consequence. These countries prioritize continuous economic growth, emphasizing the economic aspects of development, and consider it as an essential requirement for the development and preservation of the environment. Based on the economic development index, Caspian Sea neighboring countries can be considered as developing economies. However, as it was mentioned before, environmental security is important in this region because it directly correlates with the possibility or impossibility of having shipping access to open waters. Therefore, although environmental security is often marginalized and less prioritized by many countries, especially less developed ones, considering the interdependence of environmental security with other dimensions of security, in particular geo-economic security (specially for these countries), there remains little excuse to ignore this perspective.

As mentioned before, the five countries of Iran, Russia, Azerbaijan, Turkmenistan, and Kazakhstan have surrounded the Caspian Sea, and the Caspian Sea is of special importance to these countries for various environmental, commercial, and economic reasons. If we review the specifics and characteristics of the Caspian region again, we will notice the differences in access and exploitation possibilities among these neighbors. Therefore, it is clear that the most sensitive and concerned countries are those that have the most benefits from the transit channels ‘water level.

In the eastern and northern parts of the Caspian Sea the slopes of the coast and the sea are low due to the sediments from the Volga River, therefore with a rise or fall of one meter of sea level, water will advance or retreat around 200 km in the flat plains of this area while this is not the case for Iran and Azerbaijan. (Sedghi andiikss 2015). Perhaps the other important factor is the dependence of these countries to the Caspian Sea for transit purposes. Around the Caspian Sea onlyIran and Russia have direct access to open waters. Turkmenistan, Azerbaijan, and Kazakhstan lack access to open waters and therefore consider the Caspian Sea as a great opportunity for maritime transit.

Among the Caspian countries, Iran is less sensitive and vulnerable to water level fluctuations than Turkmenistan, Azerbaijan, and Kazakhstan, considering several factors such as the lesser impact of water level fluctuations on Iranian coastal ports due to the deepening of the Caspian Sea in the south and access to other transit routes through the Persian Gulf and the Sea of Oman, as well asthe priority of other transit routes for this country. On the other hand, Iran considers competition in Caspian Sea shipping to be unfair due to the bureaucracy and political problems in obtaining permission to pass the canal and thus is less inclined to invest in this area.

What distinguishes Russia in the field of maritime transportation is the fact that this country is surrounded by numerous seas, most notably the Baltic Sea and the Gulf of Finland in the west, White Sea, Kara Sea, Barents Sea, Laptev Sea, the East Siberian Sea, Chukchi Sea, and the Arctic Ocean in the north, the Bering Sea, Sea of Okhotsk, Sea of Japan, and the Pacific in the East, the Black Sea and the Caspian Sea in the south. Russia’s access to waters has made it one of the countries with advanced maritime transportation infrastructures.

A look at the statistics shows that Russia has 102 thousand kilometers of waterways, 33 thousand kilometers of which can be navigated. There are about 120,000 rivers in the country, the lengths of which reaches 230,000 km. It has about 42 thousand kilometers of shores with three oceans, which greatly help Russia in international shipping. The ports of Arkhangelsk, Rostov, Murmansk, St. Petersburg, Astrakhan, Kaliningrad, Vladivostok, Sochi, and Novorossiysk are the most important ports in Russia. (EFDIR2018). In the Caspian Sea, the Volga- Don Shipping canal is an important waterway in the European part of Russia, and currently helps in supply transit in the inner waterways of Southern Russia, which is on the “North-South” International shipping corridor. The canal also plays an important role in transit of cargo within the Azov-Volga-Don-Astrakhan regions. With the start of the operation of this canal, the deep sea water system in the European part of Russia was also created that linked these five seas: the Baltic Sea, the White Sea, the Caspian Sea, the Azov Sea, and the Black Sea. [17]. Russia is arguably the country with the most sensitivity and at the same time the country with the greatest initiative and influence in this area, because the Russians have built the canal to connect the Caspian Sea to the Baltic Seaand the Mediterranean Sea. The importance of shipping for the Russians makes them unwilling to allow the Caspian Sea levels to go lower.

As it was mentioned, the depth of the Caspian Sea in the northern ports is about five meters, therefore with one meter of reduction in the water level, the capacity of the ships should also be reduced, which will also affect the cost of goods. The northern ports of the Caspian Sea do not have a lot of depth so canals have been built to facilitate shipping. Also the traffic of ships in this area is done through certain paths. Moreover in some months of the year the surface of the water is frozen. Under these conditions adding the problem [18] of water level reduction will greatly increase transportation costs.

Therefore, reducing water level has negative consequences for the maritime transportation industry and shipping in the Caspian Sea [48]. We may simply argue that as much as the sea level is reduced, the capacity of the ships should be reduced as well, because as water levels decrease, the draft of the ships in northern ports of the Caspian Sea must decrease. As a result if the load of the ships is more than a certain limit, they will not be able to travel to those ports. In short, when water level drops, maritime transit in shallow areas of the Caspian Sea is challenged and due to the lower draft of the ships, sea transportation may lose its economic advantage. This is a great problem for shipping industries around these coastal waters (MEWRI 2018).

It should be noted that the Volga channel is a national waterway for Russia, so the water level of the Volga channel is the basis for the construction of ships in this area. In other words, ships are built based on the depths of 4.20 and 4.30. However, the allowed draft is variable, and since there is no accurate information, ships are frequently in trouble. On the other hand, due to access to open waters and the Black Sea, owners of Russian ships can leave the area and adjust the type of their ships to the depth of water they intend to navigate. Russians also have river ships that do not suffer from fluctuations in the Volga water level. But with a lack of dredging by the Russian government, the owners of other ships face a big problem in this canal because its depth may hit 310 and 330. Some ships are grounded in the canal and should wait for favorable wind to help them leave the area. [30].

Evidence suggests that nowadays the ports in this area demonstrate worse performance indicators. Looking at the performance of the ports in Caspian littoral countries in recent years, we realize that the scale of their operation has been greatly reduced. [29]. This problem undermines the Caspiangeo-economicimportance in the maritime transportation sector, especially the Caspian Sea transit channel, which will negatively impact the geo-economic security of the region.

From the viewpoint of balancing the Caspian Sea level and confronting the challenge of fluctuations in the water level of the Caspian transit zone, the Soviet Union and after its collapse Russia has taken the most significant measures. In addition to the superior economic and technological potential of this country, Russia has greater vulnerabilities in this area that need to be addressed.

In the 1950s, the withdrawal of water was attributed to building dams on the Volga (Fig.7) and other rivers, and diversion of water to agriculture and other human uses. It started the first movement during the Soviet era to save the Caspian Sea. [1] During the drought of the 1980s, the Soviet government decided to construct a dam on the mouth of the Garabogazköl lagoon to balance the level of the Caspian Sea water by preventing the one way flow of the Caspian Sea water to the Garabogazköl lagoon.

Fig. 7.

Discharge of the Volga River (km³) during 2016–2018

Because the decrease in the Caspian Sea waterlevel caused ecological problems in the shallow northern waters and created problems for the traffic of ships to the waterways and ports.

Also in 1984, the Russians decided to demolish the dam (Fig. 8) built at the mouth of the Garabogazköl lagoon in order to control the Caspian Sea water balance by increasing the evaporation capacity of the sea through this lagoon. Other areas of the Caspian Sea were also seriously damaged at this time, most notably the oil wells in Kazakhstan and Azerbaijan and a large part of Iranian coastal areas. As mentioned before, more than $ 15 billion in damage was inflicted on the Caspian littoral states [43].

Fig. 8.

Dam building on the Volga Riverin 1934 and up to present time (b)

Overall, the problems caused by fluctuations in water levels during the Soviet Union led to a number of efforts to prevent the reduction of water levels. Diverting and transferring water from rivers that flow to the Arctic Ocean toward the south and the Caspian Sea, closing the waterway to the Garabogazköl lagoon [41] (this lagoon is close to the hot Karakum Desert. It is connected to the Caspian Sea by a small strait and its evaporation rate is very high and it is lower than the Caspian Sea level), and finally using mechanical coatings and drying up parts of the shallow east and northern coasts to reduce the evaporation surface. After the collapse of the Soviet Union and the emergence of new states around the Caspian Sea, new definitions of these countries for national interests created complicated conditions in this area. Considering that a legal regime has not yet been agreed upon by all coastal states of the Caspian Sea, these countries have tried to assume the Caspian Sea as an open sea because it is connected to the Baltic Sea and the Black Sea through the Volga- Don canal, and thus it may be treated under open water laws.

Also, in order to deal with the advancement of sea water, various plans and views have been put forward by other neighbors. For instance, Uzbekistan and Kazakhstan have offered a joint plan to construct a 300-km canal between the Caspian Sea and the Aral Lake to transfer water to it. Unlike the Caspian Sea, the Aral Lake suffers from severe water shortage and has lost about 40% of its original area. Also Iranian experts have apparently presented similarsolutions for the transfer of water from one of the coastal areas to the Namak Lake or Dasht-e Lutor other dry areas through thick pipes and strong pumping and creation of artificial lakes. [3] Another suggestion is to create a direct channel between the Caspian Sea and the Black Sea. (Figure 9). Thus, the problems of the balance of the Caspian Sea level will be eliminated. In this way it will no longer be an isolated lake and will have access to open seas.

Fig. 9.

The plan to build a canal between the Caspian Sea and the Black sea

Although this idea was seriously considered in the 1930s and was recently reiterated by the President of Kazakhstan, so far it has not been realized due to numerous issues, including lack of economic profitability. Of course, what has been mentioned here is merely a part of practical or actual efforts or suggestions to address the issue of the Caspian Sea water balance and surely many efforts have been made in the field of environmental co-operation, such as the Tehran Convention, which are outside the scope of this paper.

Conclusion

However, over the years studies have shown that Caspian hydraulic behavior is unpredictable and very variable. On the other hand, the effects of climate change, especially on the balance of water, are strongly influenced by the volume of water entering the Caspian Sea through discharging rivers, especially the Volga. Considering that if the climatic conditions prevent the increase of the water volume of the river and an increased amountwater is diverted for other purposes, the Caspian Sea water level fluctuation will become a serious challenge. This issue is even more important when it is accompanied by droughts in a large part of the northwest to the northeast and the western part of the Caspian Sea. These conditions have certaingeo-economic implicationsfor the Caspian Sea. It is argued that the challenges and damage caused by the Caspian Sea water level fluctuations are numerous.For instance, the level of maritime shipping channels has encountered problems. Considering the importance of transit of goods, especially for the neighbors which have no access to other sea routes, by escalation of the dangers, important ports will lose their economic potential due to the reduction in the level of ship draft height which will have serious negativeimpact on the maritime industries located in coastal waters.

In general, the isolation and constraints of the Caspian Sea, along with the importance of Volga as the only transit channel to open seas, has led to special geo-economic conditions (Fig. 10) for the Caspian Sea. The features of Volga-Don canal in terms of its depth and specific climate of the northern Caspian Sea have increased its sensitivity to fluctuations in the balance of the Caspian Sea water and has become a major geo-economic challenge in the field of maritime transportation. Such limitations hinder economic growth in the area. This will in turn undermine the geo-economic security of the Caspian Sea in the maritime transportation sector, and in particular the Caspian Sea transit channel. It could also reduce the sensitivity and significance of the Caspian Sea. Among the Caspian Sea neighboring countries, Russia has the least vulnerability due to its ownership of the Volga Channel and the adaptation of its maritime transport industry. Russia has also the greatest potential for action against fluctuations in water levels.In reality, the ownership of the Volga channel by Russia and the prominence of this country as a regional hegemonic power as well as its superiority in economic and military dimensions, leaves little room for other neighbors to bargain. However, applying neofunctionalist theories and emphasizing regional economic cooperation as well as creating common and interdependent economic interests are better solutions than relying on legal conventions. In this way, the challenge of water level fluctuations caused by the reduction of water volume will be a concern which is moreseriously addressed by all neighbors, and each of them in their own capacity, will prevent the reduction of water discharged into the Caspian Sea.

Fig. 10.

Conceptual Model ofGlobal warming, environmental and geo-economic security of the Caspian Sea.

Compliance with ethical standards

Conflict of interest

Competing interests the authors declare that they have no competing interests.