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To get serious about climate change we need to get serious about peat

Want to safely store carbon for 1,000 years? Nothing beats peat. It’s nature’s vault, writes William Booth

Sunday 14 November 2021 00:01 GMT
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Scientist Chris Field of Manchester Metropolitan University measures water temperature and nutrient levels at Winmarleigh and Cockerham Moss, Lancashire’s largest peatland
Scientist Chris Field of Manchester Metropolitan University measures water temperature and nutrient levels at Winmarleigh and Cockerham Moss, Lancashire’s largest peatland (The Washington Post/Simon Bray)

Moor, bog, fen, mire, flush, swamp, slough. Peatlands have gotten a bum rap. They’re inhospitable, useless. Too wet to plough, too dry to fish, the old farmers say.

Slagged off as anaerobic wastelands, dissed in the popular imagination, imagined as the eerie Dead Marshes in The Lord of the Rings or the forbidding Grimpen Mire in The Hound of the Baskervilles. When bad things go down in Charles Dickens, the scene is set in a forbidding moor.

All slander, says Christian Dunn, wetlands scientist at Bangor University in north Wales.

“Peat is the superhero of the natural world,” he says.

These waterlogged, acidic, low-nutrient ecosystems are the world’s most carbon-dense lands. You want to safely store carbon for a thousand years? Nothing beats peat. It’s nature’s vault.

From the boreal north to the tropical south, from Scotland’s grouse moors to the vast tracts recently discovered in the Congo Basin, the Earth’s peatlands store twice as much carbon as all the planet’s forests combined – though they cover only a tenth of the landmass.

“If you’re serious about slowing climate change,” Dunn says, “you must get serious about peat.”

Most people, if they think about peat at all, might think, meh, garden mulch?

Long before the industrial revolution began, farmers were emitting carbon by turning over the peat to plant crops

(Dunn begs you: “Do not buy peat to feed your petunias.” Its sale is being phased out in Britain. In America, availability remained unrestricted.)

Climate scientists have long appreciated the role oceans and forests play to store mega-amounts of carbon. But only now is the power of peat coming into sharper focus – along with the need to preserve the pristine bogs that remain and restore what’s been damaged.

Alongside this new respect comes anxiety among researchers that the carbon buried within these mires can be rapidly released in a warming world.

Peatlands are only 3 per cent of the land surface but store as much as 30 per cent of all the carbon locked in the soil. Release that, and the greenhouse gas concentrations in the atmosphere will go kaboom, accelerating the Earth on its trajectory towards catastrophic warming. It’s scary enough that climatologists have a term for the scenario: a “carbon bomb” hidden in all that peat.

“For centuries, we’ve drained peatlands,” says Dunn. “We’ve degraded the peat – trashed it, burned it, bagged it – and released just staggering amounts of carbon into our atmosphere.”

Long before the industrial revolution began, farmers were emitting carbon by turning over the peat to plant crops. Investigators at France’s Laboratory of Climate and Environmental Sciences have found that this mass conversion could have added 250 billion tons of carbon dioxide into the atmosphere, equivalent to seven years of current emissions from the burning of fossil fuels.

Sheep graze lowland fields in Lancashire. Britain was once covered in peat, but much of that land was converted for agriculture (The Washington Post/Simon Bray)

Huge amounts of peat still exist: in Canada, Russia, Finland, Europe, Alaska and around the tropics. But it is estimated that worldwide, about 15 per cent of peat has already been lost.

In the modern era, farmers have even been paid by governments, encouraged by tax breaks and cash subsidies, to convert peatlands.

There’s a reason Indonesia is one of the top five greenhouse gas emitters in the world – and it is not just coal. It is the clearing of peat for palm oil plantations, with farmers setting fires that burn deep in the fibrous soil and smoulder for months.

“It’s an almost criminal amount of carbon,” Dunn says.

Preserving peat is now considered a powerful tool to counter climbing emissions. It is among what the United Nations considers legitimate “nature-based solutions” – the buzzwords for using woodlands, mangroves, marshes, kelp forests and bogs to soak up carbon.

The idea is that humanity’s greatest ally against climate change can be the Earth itself.

Britain is one of the first countries to put peat at the centre of its strategy to reach net-zero emissions by 2050. At the UN climate summit in Glasgow, the government is highlighting its pledge to spend more than $1bn by 2025 on peat restoration, woodland creation and the management of the two habitats.

Sphagnum moss is analysed to assess water and carbon retention (The Washington Post/Simon Bray)

Prime Minister Boris Johnson in October promised to restore at least 86,000 acres of degraded peatlands in England by 2025 – and 690,000 by 2050, an area slightly larger than the size of Cheshire. The Scottish government is even more ambitious (it has less land, but more peat) and aims to repair 618,000 acres by 2030.

Peatlands are wetlands, with a twist.

“Watch your step,” says Sarah Johnson, a peat project manager with the Lancashire Wildlife Trust, which protects a bog in northeast England called Winmarleigh and Cockerham Moss.

When you tread upon healthy peat, the ground can feel squishy. Your step is bouncy, like walking on a mattress, except that bounce comes from layers of plants and moss that have been laid down, at one millimetre a year, since the last Ice Age.

Johnson explains that these waterlogged ecosystems are unique, because they slow decomposition way down – and so the dead plants remain, but they don’t really rot, and they keep storing the carbon they removed from the atmosphere via photosynthesis.

Water channels run between established sections of peat bog, and direct water toward newer areas, at Winmarleigh and Cockerham Moss (The Washington Post/Simon Bray)

Unlike a forest, where trees fall and decompose, recycled by insects and fungi, peat accumulates year after year. It’s like the carbon cycle stops, says Chris Evans, a biogeochemist at the UK Centre for Ecology and Hydrology.

“The really interesting thing about peat is that it’s been storing this carbon for thousands of years. It’s been doing this before there were human beings,” he says. “And if you can keep it wet, peat can keep storing carbon for a very, very long time.”

A recent study by Moors for the Future Partnership in Britain examined a single blanket bog in Derbyshire and found the amount of carbon locked up was equivalent to the annual emissions of eight coal-fired power stations.

Britain was once covered in peatlands. London is built on a former one. Now, most lowland peat is gone.

Netting helps keep the bog intact (The Washington Post/Simon Bray)

In Holme Fen north of Cambridge, a landowner in 1848 had a post driven through 22 feet of peat until it hit the clay substrate. As the land was drained over the next 170 years, the surface of the peat subsided by 13 feet – like a shrinking sponge sitting on a kitchen countertop.

Today, just 20 per cent of the United Kingdom’s peatlands are considered “near natural”. Much of the disturbed peat is no longer a net sink, storing carbon. It is now a source of greenhouse gases, an emitter.

Scientists calculate that peatlands in Britain are releasing approximately 23 million tons of carbon dioxide equivalent each year, making them one of the top contributors to the country’s greenhouse emissions from land use.

“The first thing you have to do in a leaky spaceship is plug the hole,” says Richard Lindsay, a specialist in peatland ecosystems at the University of East London.

Stop draining peatlands and start repairing them by keeping them wet, he says.

Yet, there is an inherent tension in Britain’s strategy to reach net zero emissions by the middle of the century, in part through nature-based solutions. Until recently, when the government wanted to grow trees in Britain to store carbon, where did it plant them? “On the cheapest, most marginal land,” Lindsay says. On peat.

Wild mushrooms grow within the bog (The Washington Post/Simon Bray)

And because waterlogged trees would die, he says, “you have to drain the peat to plant the trees.”

Out at Winmarleigh and Cockerham Moss, they’re testing a new idea: “carbon farming”. In which the “crop” is the carbon a farmer is locking into the peat. Mike Longden, a peatland initiative officer with the Lancashire Wildlife Trust, stood on a berm and explained the farm.

The team took five aces of an unloved degraded peatland, drained in the 1970s, and rebuilt the dykes, pumps and plumbing. They stripped off the top four inches of nutrient-rich topsoil, left over from when sheep grazed the pasture, and planted 150,000 plugs of the new cover crop, sphagnum moss. Then they brought the water level back to the field to re-wet the new moss and existing five feet of unoxidized peat below.

The newly planted moss is looking happy and healthy. As it grows, it will carpet the site, and the bottom of the moss will just sit there in watery acidic conditions, to form – presto! – new peat.

Who will pay for it? Rob Stoneman, director of landscape recovery at the Wildlife Trusts, says very soon the government will probably pay land managers a few hundred pounds an acre to store carbon in a reclaimed peat bog. Corporations, too, might buy even more for credits from the carbon farmers of the future to offset their greenhouse gas emissions.

“The thinking is, that if you are going to get to net zero as promised in Britain, somebody is going to subsidise this,” Stoneman says.

For a thousand years?

“At least for a while,” Stoneman says.

© The Washington Post

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