Ports, oil drilling rigs and coastal settlements will be marooned kilometres from the shore as climate change drives water loss in the Caspian Sea, according to a study that highlights the huge economic threat global warming poses to Azerbaijan, the host of the COP29 climate summit.
Water levels are already falling fast in the Caspian, the world鈥檚 largest inland body of water, in part because Russia is diverting water from the Volga river for agriculture. In 2023, the average level dropped by 30 centimetres compared with the previous year, , a local meteorological service.
As global temperatures rise, evaporation rates over the Caspian Sea are expected to increase, accelerating the rate of decline. sea levels there could drop by 15 metres by the end of the century if there is 2掳C of warming. With higher levels of carbon emissions, there could be a fall of up to 21 metres.
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鈥淎s the world warms, that is going to drive increased evaporation rates,鈥� says at the University of Leeds, UK. 鈥淭his evaporation rate is outstripping that inflow and accumulation of water within the Caspian Sea.鈥�
While this decline in sea level is well established, few studies have looked at the real-world impact of such a dramatic loss of water. Goodman and his colleagues used geospatial data to map how a change in water levels across the Caspian would affect key ecological areas and infrastructure.
鈥淓ven under the most optimistic scenarios, you鈥檙e probably looking at something like 9 to 14 metres [of sea level reduction],鈥� says Goodman. 鈥淚t was really important to have a risk assessment of what the potential implications could be.鈥�
The results suggest that as water levels recede, billions of dollars of economic infrastructure could be at risk across the five nations that border the Caspian Sea: Russia, Iran, Azerbaijan, Turkmenistan and Kazakhstan.
Out of 22 industrial infrastructure facilities included in the analysis 鈥� including ports, oil refineries and gas processing plants 鈥� eight will see their distance to the shoreline increase by more than 5 kilometres if sea levels fall by 10 metres.
The north-eastern basin of the Caspian is especially shallow and therefore is likely to see the most extreme impacts. It is also home to two of the region鈥檚 most important fossil fuel production sites, the Kashagan and Filanovsky oil fields, controlled by Kazakhstan and Russia respectively. These currently extract from offshore rigs, which will become landlocked if sea levels fall by 5 metres or more, the team found.
Already, parts of the seabed to allow the offshore oil rigs to continue production. Fishing communities could also become stranded far from the shoreline they depend on, according to the research.
The ecological threat, too, is vast, with the loss of vital habitats for insects, marine life, migratory birds and the Caspian seal (Pusa caspica), which is found only in this region. 鈥淚t is mass habitat loss,鈥� says lead researcher , also at the University of Leeds.
Goodman stresses that the assessment 鈥� which hasn鈥檛 yet been peer reviewed 鈥� is relatively simplistic and doesn鈥檛 take into account water depth or the response of ecosystems to shifting conditions. 鈥淲e鈥檙e cautious about saying this is a crystal ball that is going to foretell an exact kind of future,鈥� he says.
Nevertheless, it is clear that a change in water levels of this scale would have devastating consequences, says at environment and human rights group Crude Accountability. 鈥淚t鈥檚 a disaster for all of those living and depending on the Caspian Sea for their livelihood.鈥�
The COP29 climate summit is currently taking place in Baku, the capital of Azerbaijan, which lies on the western shore of the Caspian Sea. The country鈥檚 economy is highly dependent on fossil fuels, accounting for 90 per cent of its exports, and its president, Ilham Aliyev, told world leaders at the summit that oil and gas are a 鈥済ift from God鈥�. The burning of fossil fuels is the primary driver of global climate change.
In Azerbaijan, 鈥渢here鈥檚 a huge, not only economic dependence on fossil fuels and extraction and development and all of that, but also a political addiction to fossil fuels鈥�, says Watters.
So far, the COP presidency is doing little to advance discussions on ending global fossil fuel use, says at campaign group 350.org, speaking from Baku. At last year鈥檚 COP summit in Dubai, countries agreed to start 鈥渢ransitioning away鈥� from fossil fuel use, and strengthening this commitment is a key priority for some nations at COP29.
Yet despite the presidency鈥檚 reluctance to discuss the topic at COP29, it is in Azerbaijan鈥檚 long-term interests to reduce its reliance on fossil fuels, says Sieber. The European Union, one of its main customers, has to cut its use of natural gas by 30 per cent by the end of the decade.
鈥淚t鈥檚 in the interests of Azerbaijan to diversify their economy,鈥� says Sieber. 鈥淎nything else seems pretty unwise from an economic point of view.鈥�
Biorxiv
