Nobody plants a peat bog for a photo opportunity. Tree-planting has schoolchildren and shovels; a rewetted moor has blocked ditches and standing water. Yet on the carbon ledger the bog wins by a distance, and the UK, which holds a striking share of the world's blanket bog, has spent recent years discovering that its least glamorous terrain is among its most important.
Peat is plant matter that never finished rotting. In waterlogged ground, oxygen cannot reach dead vegetation, so each year's growth compresses into a dark, carbon-dense layer that accumulates at roughly a millimetre a year. A deep bog is thousands of years of stored photosynthesis. Per hectare, peatland holds several times the carbon of mature woodland, and UK peat in total stores an estimated three billion tonnes, more than the forests of Britain and France together.
The problem is the condition of it. Around four fifths of UK peatland is degraded: drained for agriculture and grazing, cut for fuel and horticulture, burned for grouse-moor management, or planted, in a mid-century policy misfire, with commercial conifers whose roots dry the ground. Drained peat meets oxygen, and the half-finished rotting resumes. The land physically deflates, and the carbon leaves as carbon dioxide, steadily, every year, from millions of hectares. Estimates put UK peat emissions at roughly twenty million tonnes of CO2-equivalent annually, comparable to a noticeable slice of national emissions, from land officially counted as nature.
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Restoration is conceptually simple: put the water back. Blocking historic drainage ditches with peat or stone dams, reprofiling eroded gullies, removing planted conifers and re-establishing sphagnum mosses raises the water table and halts the oxidation. The tonnes of avoided emissions per pound spent compare favourably with almost any engineered climate measure, and the side payments are substantial. Wet moors slow storm runoff, easing flooding in valleys below. They filter drinking water, cutting treatment costs for the utilities that own large upland catchments, which is why water companies fund much of the work. Rare habitat returns with the moss.
The friction points are human. Rewetting lowland peat collides with productive farmland, especially the drained fens that grow a large share of England's vegetables, where the honest conversation is about new wet-farming crops and compensation rather than simple restoration. Retail gardening still runs on bagged peat compost, whose phase-out has been repeatedly promised and repeatedly delayed. And burning on moorland remains contested ground between land managers and ecologists.
None of these frictions changes the core arithmetic. A hectare of healthy bog quietly banks carbon every year and asks for nothing but wetness. Britain has more of this asset than almost anyone, and for once the climate to-do list item is not invention but plumbing.
