Boost for Caspian Sea protection as new environmental rules come into force

Geneva, 18 November 2025 – Major new infrastructure planned around the Caspian Sea will be legally required to meet transboundary environmental standards, as a new Protocol enters into force today under the Framework Convention for the Protection of the Marine Environment of the Caspian Sea – known as the Tehran Convention – hosted by the UN Environment Programme (UNEP). 

Upon the request of any Caspian littoral state, the Protocol on Environmental Impact Assessment will require the potential effects of major infrastructure projects in another state to be assessed before they get underway. The types of infrastructure covered include transport, oil and gas extraction, tourism, and urban development. For example, new motorways, major oil refineries and power stations, pipelines, large dams, and major transfers of water resources — other than drinking water — are all covered by the Protocol. 

If requested by an affected littoral state, an impact assessment will be carried out, and its results must be made publicly available. The assessments will be carried out at the national level and will cover the marine environment of the Caspian Sea, including water level fluctuations and pollution from land-based sources. The new infrastructure will then require a green light from the affected country before construction can continue.   

The Caspian region is a major trade artery between Europe and Asia, driving significant new infrastructure development. Between 2014 and 2024, EU imports from China more than doubled and exports grew by 47%, for example — illustrating the importance of strong cross-border environmental safeguards.

“Today marks an important step in protecting the Caspian Sea,” said Arnold Kreilhuber, the UNEP Europe Director. “Through this Protocol, Caspian countries are sending a clear message that economic growth and environmental protection must be balanced – collaboration among states is key to achieving this.”

If the joint Environmental Impact Assessment procedure is triggered by a littoral state, the role of the Tehran Convention Secretariat will be to ensure information flow, prepare reports, and promote cooperation and technical assistance. 

As the Caspian region undergoes rapid economic development, the Protocol brings the region in line with international best practices on impact assessments and ensures that potential cross-border risks are identified and addressed early in the decision-making process. 

The Protocol on Environmental Impact Assessment in a Transboundary Context is the fourth protocol designed to protect the Caspian under the Framework Convention for the Protection of the Marine Environment of the Caspian Sea. In 2011, the littoral states adopted the Protocol Concerning Regional Preparedness, Response and Cooperation in Combating Oil Pollution Incidents (the Aktau Protocol). In 2012, the Protocol for the Protection of the Caspian Sea Against Pollution from Land-based Sources and Activities (the Moscow Protocol) was adopted. The Protocol for the Conservation of Biological Diversity (Ashgabat Protocol) was adopted by littoral states in 2014. A fifth protocol is currently under negotiation and will address monitoring, assessment, and information exchange.

NOTES TO EDITORS

About the Tehran Convention

The Secretariat of the Framework Convention for the Protection of the Marine Environment of the Caspian Sea, also referred to as the Tehran Convention, is provided by UNEP on an interim basis. The Convention is a governance framework that aims to protect the Caspian Sea and its marine environment, and ensure its sustainable development by laying down general requirements and institutional mechanisms. It has been signed by the five Caspian littoral states — the Republic of Azerbaijan, the Islamic Republic of Iran, the Republic of Kazakhstan, the Russian Federation, and Turkmenistan.

About the UN Environment Programme
The UN Environment Programme is the leading global voice on the environment. It provides leadership and encourages partnership in caring for the environment by inspiring, informing and enabling nations and peoples to improve their quality of life without compromising that of future generations.

For more information and to arrange interviews, please contact:
Alejandro Laguna, Head of Communication, UNEP Europe Office