Scientists warn: Tackle global river delta changes through adaptation and policy

New research identifies the key causes of changes affecting river deltas around the world and warns of an urgent need to tackle them through climate adaptation and policy.

Deltas are low-lying areas that form as rivers and empty their water and sediment into another body of water, such as an ocean, lake, or another river.

Some of the largest in the world, such as the Rhine, Mekong, Ganges-Brahmaputra-Meghna, and Nile, are threatened by climate change, facing rising sea levels and increasing frequency of extreme events.

With approximately 500 million people today living within or adjacent to delta systems, this is a major issue.​

Most local, human-induced causes show measurable impacts within years and the framework provides a clear basis for prioritising timely, locally grounded action with a deeper understanding of the systems that shape these complex and dynamic environments.

Publishing their findings today in Nature Climate Change, the team includes scientists from the Universities of East Anglia (UEA), Southampton and Oxford in the UK, and Deltares, TU Delft, Wageningen University and Utrecht University in The Netherlands.

Effective adaptation requires more than isolated measures, that often overlook an important step in deeper assessments of the system as a whole.

The diagnostic framework links these drivers of change with their direct and indirect impacts across scales in time and space (divided in centuries, decades or temporal scales). It is intended to support policymakers, technocrats, engineers, and stakeholders in developing locally grounded adaptation strategies that are both realistic and resilient.

It aims to help identify and understand the interconnectivities within the biophysical system, from source to sink, and how these link with local/regional/transboundary socio-economic structures.

While climate change threatens the world’s deltas, anthropogenic drivers - largely reflected in sediment starvation and resource extraction, profound land-use change and hydrological regime shifts - can outpace climate change in the short to medium term.

Nearly all local anthropogenic drivers result in measurable impacts within years or decades, emphasising the significance and relevance of local and regional causes for effective and timely climate adaptation and policy development.

“By promoting system-level thinking, this framework encourages more critical and collaborative approaches to adaptation. It helps identify the solutions with the highest chance of being implemented successfully, especially when embedded in a longer-term vision.”

The diagnostic framework can also foster constructive dialogue among stakeholders and ensure that adaptation efforts are both science-based and socially relevant.

“But this framework helps to disentangle these dynamics and diagnose the challenges in a delta, which is a fundamental first step in defining adaptation solutions that tackle the root causes of the impacts felt.”

The research was inspired by the work of the Rise and Fall Project, a collaboration between Deltares and the Utrecht University, and also involved researchers from the University of Cologne and University of Padova.

Over a period of nearly three years, the team combined decades of knowledge on vulnerabilities in deltas and adaptation efforts to develop a framework that can facilitate diagnosing the key processes and interactions shaping a delta system. The goal: to offer a holistic foundation for planning effective, context-sensitive adaptation strategies.

‘A systems perspective for climate adaptation in deltas’ is published in Nature Climate Change on July 7, 2025.