Letting nature back in

The national parks and coastlines of the UK are a familiar and well-loved sight to those who live, work and visit them throughout the year.

What might not be as familiar is that some of these environments could play a vital role in the fight against global warming — or that these natural solutions are being undermined by urban and agricultural development or damage caused by air pollution.

Essentially, humans are helping to cause climate change while also removing and damaging potential solutions.

Two examples of these natural remedies are peatland and salt marshes. These habitats act as huge stores of carbon in the world’s atmosphere. Peatlands are a type of wetland that occur in almost every country in the world, while salt marshes form when mud settles and plants grow in sheltered places along the UK’s coastline, particularly in major river estuaries.

Now, research from Manchester Met is showing the true benefits of peatlands and salt marshes in the fight against climate change, and it’s also providing evidence for why it’s crucial that we preserve, restore and create these landscapes.

Dr Chris Field, an environmental ecologist at Manchester Met, explained: “When we first started working in this area, the story wasn’t about carbon storage — it was about habitat restoration.

“It began with us looking at a large area of peatland in the Peak District, which had essentially become a dead ecosystem due to the polluted air blowing across from Manchester and various ways the land had been managed.”

Peatland plays an important role in global climate regulation and is home to a range of highly specialised flora and fauna. While peatlands in the northern hemisphere cover only three to five per cent of the total land area, they store around 33% of global soil carbon.

Therefore, peatlands have a strong natural potential to save carbon, playing a significant role in nature-based solutions for climate change.

Dr Field said: “It’s about showing the benefit to everyone in terms of the climate, the biodiversity gains, and the economic gains of managing land effectively.

“We first looked at how we could encourage plants and vegetation to grow again on the land, and it was at this point we noticed that sphagnum moss was beginning to fare quite well in the conditions.”

Sphagnum moss is a plant that has existed for millions of years and has been found to have huge climate benefits. It is known to be excellent at capturing carbon, taking carbon dioxide out of the atmosphere, and storing it as deep layers of peat.

But the actions of humans mean peatlands are too often turned into carbon emitters rather than
carbon stores.

“When peatlands are drained, the stored carbon is released as greenhouse gases to the atmosphere,” explained Dr Field. “That is why it is important to keep peatlands wet. Unfortunately, many peatlands are degraded and emit rather than store carbon.

“The global annual greenhouse gas emissions from drained organic soils are twice that from aviation. We need to act now to prevent further degradation and encourage more recovery of our remaining peatlands.”

As part of the EU-funded ‘Care-Peat’ project, Dr Field’s research is helping to find innovative solutions for peatland restoration involving national and international stakeholders.

Care-Peat is an Interreg North-West Europe project with 12 partners working together to reduce carbon emissions and restore the carbon storage capacity of different types of peatlands.

Peatland restoration

“We began working with partners, including BeadaMoss, to reintroduce sphagnum moss into areas of peatland in Northwest England,” said Dr Field.

“Working with Lancashire Wildlife Trust at the Winmarleigh Moss Carbon Farm near Preston, we are saving around 20 tonnes of carbon dioxide emissions per hectare per year in comparison to a neighbouring drained peatland that is grazed by sheep.

“It’s exciting that projects like Care-Peat are able to provide the evidence that this type of land management works.”

For the partners involved in the project, Manchester Met’s research has provided the data they need to evidence their work’s impact and potential future impact.

“We’re demonstrating alternative, sustainable land use for peat soils that can hopefully benefit the
climate, people and wildlife,” said Sarah Johnson, Lancashire Peatland Initiative Project Manager at the Lancashire Wildlife Trust.

“What makes this model special is that it’s really targeted at areas that are marginal and difficult to manage, and once the carbon farm is set up, it doesn’t need to be harvested. And it’s low maintenance, so it can really fit as an intermediate between restoration in a conventional sense and intensive land management.”

Building on the success of the Care-Peat project, Manchester Met researchers are now working in collaboration with the National Farmers Union to survey farmers to understand their perceptions of climate change and how altered land management practices, particularly on peat, can help to tackle climate change.

Salt marshes

Dr Hannah Mossman is a Senior Lecturer in Ecology at Manchester Met, specialising in the restoration of coastal habitats. Her pioneering research has shown that salt marshes have huge potential in helping the UK to capture more carbon from the atmosphere, especially if more are created.

“New salt marsh is made by taking a piece of low-lying land by the coast and, broadly speaking, making a hole in the sea wall to allow the tide to come in. It could have been a farmer’s field or meadow,” explained Dr Mossman, “After that, it’s entirely natural regeneration to become a salt marsh.”

In a similar way to peatland restoration, it is the multiple benefits of creating salt marshes that are key to their future.

“This idea of multiple benefits is key,” said Dr Mossman. “In the early 2000s, it was only the government making these sites in order to compensate for habitat that had been lost for reasons like development.

“But now it’s become much more about making these sites for people, for biodiversity and for flood defence. This idea that salt marshes have multiple benefits makes projects more attractive for public and private finance in the development of these areas across the country.

“Rather than just being about biodiversity, these places are huge carbon stores and can also help tackle flooding problems because they can store so much water.”

In a groundbreaking study, Dr Mossman and her team revealed that one restored coastal salt marsh in the UK stores as much carbon over four years as just over one million new trees grown over ten years.

The findings resulted from a study at Steart Marshes in Somerset, a working wetland managed by the Wildfowl and Wetland Trust (WWT).

It provides flood defence for local homes and businesses, showcases productive farmland, and is home to a thriving nature reserve.

“Before this study, we didn’t fully appreciate just how well certain salt marshes with the right
conditions like Steart Marshes can perform in terms of storing carbon,” said Tim McGrath, Head of Project Development for Nature-Based Solutions at the WWT.

“These exceptional findings could indicate that the carbon storage potential of restoring salt marsh around the UK coast has been underestimated. The study sends a clear message to policymakers that creating salt marsh shows huge promise as a significant tool in the fight against climate change.”

In 2019, a government-commissioned report identified 22,000 hectares of land around the UK coast that could be restored to salt marsh.

If this happened, the report says over 425,000 tonnes of carbon could be trapped yearly instead of being released back into the atmosphere.

“We’ve probably lost around 50% of our salt marshes in the UK over the years as they’ve been
used for urban and agricultural developments,” said Dr Mossman. “So far, we’ve only created around 3,000 hectares of salt marsh.”

While targets of tens of thousands of hectares of new habitat are ambitious, Manchester Met’s research results have shown how coastal wetlands like Steart Marshes are cost-effective and land efficient.

Unlike peatlands, carbon credits — a kind of permit that a company or person can buy to make up for carbon emissions — are not available on salt marshes, and the areas are not in the UK’s Greenhouse Gas Inventory.

“I think the scenario that will take salt marshes forward is the concept of multiple benefits,” said Dr Mossman. “We can present a package of things that salt marshes can provide, and the funding from different partners may cover one or two of these elements in different areas across the country.”

Future challenges

It is the future challenges that Manchester Met researchers are now turning their attention to. For Dr Field, the recognition of the importance of peatland is there, but many challenges remain if their full potential is to be realised.

“While the government is aware of the work going on in this area, it is a real challenge to finance projects to the huge scales needed within the next five to ten years to meet some of the net zero targets,” he explained.

“We know where the peatlands are, but we’d like to create a comprehensive map of these areas to properly understand the potential climate benefit and the finance needed on a nationwide scale.”

And for Dr Mossman, while the opportunities to create salt marshes are there, it is tackling people’s perceptions of letting the sea flood land previously used for agriculture.

“There are around 17,000 kilometres of sea defences in the UK with a lot at the end of their
lifetime,” said Dr Mossman. “We can’t afford to renew and maintain this amount of sea defences, so the idea of salt marshes protecting the coast from flooding comes into play. This shows that the potential is there, but one of the main problems is the people’s perception of these habitats and what it means for them.

“It’s not about building something green, but re-greening something we’ve already lost.”