High in the West Pennines, thousands of carefully designed holes are being dug into Holcombe Moor—not by miners seeking coal or lead, but by conservation teams with a very different goal: storing carbon beneath the soil to help fight climate change. What looks like simple excavation is actually the latest chapter in restoring one of Britain's most crucial carbon reserves, erasing decades of industrial damage with a surprising solution: Sphagnum moss.
The Pennine hills carry the scars of centuries. Roman lead mining gave way to coal extraction that fueled the mills of Manchester, Leeds, and Sheffield during the industrial revolution. The smoke that blackened those cities drifted back across the hills, carrying arsenic and lead that poisoned the soil, stripping it of all vegetation. What remained were moonscapes of exposed peat—erosional gullies that destroyed in decades what had taken over 8,000 years to form. Those blanket peatlands, the slow accumulation of partially decayed plant matter, held something precious: over 3 billion tonnes of carbon, about ten times more than all UK woodland carbon stocks combined.
But damaged peatlands don't just stop storing carbon—they become carbon sources themselves, releasing greenhouse gases into the atmosphere. About 15% of the world's peatlands have been drained, making restoration urgent. On Holcombe Moor, Natural England's Nature for Climate Peatland Grant Scheme began a novel approach: in 2021, teams created 3,000 water-retention structures called scallop bunds—crescent-shaped pools dug into the peat surface using low-impact excavators. In 2024, they added another 700. Five years on, those original bunds tell a success story: they're now carpeted with grasses and lined with pools brimming with Sphagnum moss, transformed from bare peat into natural-looking bog.
Sphagnum moss is the real engineer here. This specialized species can hold up to 20 times its own weight in water, maintaining the saturated conditions needed to suppress decomposition and build peat. In a healthy bog, new Sphagnum grows up through older moss, raising the water table and leaving the deeper moss partially decayed and preserved. Bogs grow only millimeters per year, but over millennia they accumulate meters of carbon-rich organic matter. Industrial pollution had erased Sphagnum from these hills entirely, but restoration teams have spent decades reseeding bare peat and replanting the moss, watching barren moonscapes return to vibrant green.
The bunds solve a specific challenge: on flatter moorland plateaux, restoring the wet conditions that allow Sphagnum to re-establish is difficult. By capturing surface water that would otherwise run off after rainfall, the shallow pools maintain the moisture levels these plants need to thrive. It's an elegant solution grounded in simple hydrology—making the bog wet again so that the moss that builds peat can return.
As the UK faces more extreme temperatures and the risk of increased wildfires, restored wetlands offer another benefit: protection through saturation. But the deepest value lies in what's happening underground. Each pool filled with recovering moss is a carbon store being rebuilt, bit by bit, in landscape that looked beyond recovery just a few years ago. The holes appearing across the Pennines aren't signs of damage—they're the beginning of healing.