30 May 2025

Press Release

For immediate release

WWF and Aviva unveil new saltmarsh research: a blueprint for climate resilience

New report shows the importance of saltmarshes and what these ecosystems do for our climate
Carbon monitoring tower is the first of its kind in the UK to help monitor saltmarsh, revealing how these habitats store carbon
WWF and Aviva are calling for saltmarshes to be included in the Greenhouse Gas Inventory to help meet UK net zero targets

Saltmarshes are ‘significant’ carbon sinks, according to a pioneering report released today (29 March) by WWF, in partnership with Aviva, on the critical role of saltmarsh habitats around the UK in combating climate change, meeting net zero targets, and protecting coastal communities.

The ‘Importance of UK saltmarshes’ report, produced in collaboration with the UK Centre for Ecology and Hydrology and RSPB – presents findings from a ‘carbon flux tower’ funded by Aviva, the UK’s leading insurer, and installed on the Ribble Estuary in Lancashire. This marks the start of a new monitoring network providing vital data on how saltmarshes contribute to the UK’s climate goals.

The solar-powered tower continuously measures the exchange of carbon dioxide between the saltmarsh and atmosphere, capturing how much carbon is absorbed or released throughout the year. This high-frequency, real-time data reveals that saltmarshes are significant carbon sinks, with the amount absorbed during the spring and summer outweighing what is released during the autumn and winter months.

While flux towers have been used to monitor carbon in other vital habitats such as woodlands and peatlands, this is the first time a coastal habitat is being studied in this way – offering a breakthrough in understanding the carbon dynamics of saltmarshes. The insights gained will help refine national greenhouse gas estimates and shape future policy, unlocking the value of these vital coastal ecosystems.

The report also includes early findings from a new network of 48 Surface Elevation Tables across six UK sites. These monitor how saltmarshes respond to sea-level rise. Initial results show a mixed picture - some marshes are adapting, while others including North Norfolk and the Ribble, are struggling - highlighting where restoration is most urgently needed.

Tom Brook, ocean conservation specialist at WWF, said:

“The results are in, and mud matters. Saltmarshes are powerful natural allies in the fight against climate change – storing carbon, protecting our coasts and supporting rich biodiversity.

“As extreme weather and rising sea levels put more people and places at risk, the case for protecting and restoring these habitats has never been stronger.

“This research adds to a growing body of evidence showing that saltmarshes are not just ecologically important but essential to building a resilient, net zero future.”

Claudine Blamey, Aviva Group Sustainability Director, said:

“Aviva supports WWF’s research, which will make a genuine, science-based contribution to the wider understanding of how saltmarsh can help us move towards net zero.

“The Ribble Estuary saltmarsh flux tower has yielded positive results, confirming and strengthening the critical importance of UK saltmarsh in storing carbon. And more broadly the wider benefits of this habitat in supporting biodiversity and offering flood mitigation benefits, helping communities get ready for the impacts of climate change.”

WWF and Aviva are calling for saltmarsh habitats to be included in the UK’s Greenhouse Gas Inventory – the official record of the country’s emissions and removals which is used to track progress toward net zero.

Including saltmarshes would be a major step. Recognising their carbon storage potential would improve national reporting and help unlock funding and policy support for their protection and restoration.

About saltmarshes

Saltmarshes are coastal wetlands found where land meets salt water. Filled with salt-tolerant plants like grasses and shrubs, they are regularly flooded by tides, providing natural flood barriers as well as crucial habitats for diverse wildlife like herons, egrets, otters, and marine life.

However, the UK has lost over 85% of its saltmarshes due to development, pollution, and climate change. With sea levels rising and around 6.3 million properties in England already at risk of flooding - a figure expected to reach 8 million by mid-century - protecting and restoring saltmarshes is more urgent than ever.

Why are saltmarshes important?

• Carbon storage: Saltmarshes are highly efficient at capturing and storing carbon, playing a vital role in mitigating climate change.

• Coastal protection: They act as natural flood barriers, absorbing wave energy and reducing storm impacts – Saltmarshes provide over £1 billion in flood protection benefit for UK homes.

• Biodiversity hotspots: Although they cover only 6% of the Earth’s land surface, 40 percent of all plant and animal species live or breed in wetlands, which includes saltmarshes.

• Water purification: Saltmarshes filter pollutants and sediments, improving coastal water quality and marine health.

• Recreation & wellbeing: These “blue spaces” offer opportunities for walking, birdwatching, and enjoying nature, benefiting mental and physical health.

• Economic & community value: Saltmarshes support local jobs and investment while providing essential ecosystem services that sustain people and nature.

ENDS

About the WWF-Aviva partnership

WWF and Aviva have been working in partnership since 2021 to restore UK landscapes, build healthier, more resilient communities and help transform one of the biggest indirect drivers of climate change: the UK finance sector.

Together, WWF and Aviva have worked with nature to tackle the climate and biodiversity crises, helped to change political policy and public opinion, and connected tens of thousands of people to the natural world across the country through community volunteering, local engagement and events, and educational opportunities.

www.wwf.org.uk/who-we-are/who-we-work-with/aviva

About Aviva:

We are the UK's leading diversified insurer and we operate in the UK, Ireland and Canada. We also have international investments in India and China.
In 2021, we announced our ambition to become Net Zero by 2040, the first major insurance company in the world to do so. While we are working towards our sustainability ambitions, we recognise that while we have control over Aviva’s operations and influence over our supply chain, when it comes to decarbonising the economy in which we operate and invest, Aviva is one part of a far larger global system. Nevertheless, we remain focused on the task and are committed to playing our part in the collective effort to enable the global transition. Find out more about our climate goals at www.aviva.com/sustainability/climate and our sustainability ambition and action at www.aviva.com/sustainability/.