09 Jun 2021
Value in Nature – a green stairway to heaven
Natural peatlands provide some of the most effective stores of carbon in the world. But these great organic wetlands are constantly under threat and thousands of years worth of carbon capture is in danger of being lost. In this week's blog entry, Harold explores the benefits of preserving the UK's peatlands, both for environmental and economical reasons.
Peatlands consist of partially decomposed plant and animal remains, the haunting burial ground for the Tollund Man and Elling Woman. Their wet, acidic conditions allow organic material to accumulate over centuries to form peat deposits. They account for nearly three million hectares or around 12% of the UK’s land area.
These lands potentially provide some of the greatest stores of carbon available on Earth (over three billion tonnes in the UK alone – 20 times more than the nation’s forests, and roughly equivalent to the carbon stored in the forests of the UK, Germany and France combined), built up patiently by nature over thousands of years.
They also offer rich habitats to support biodiversity, supply over 25% of the UK’s drinking water, and moderate the flow of rainwater from mountainous areas, lowering flood risks. They are major tourist attractions, none more so than at the ‘Stairway to Heaven’ trail at Cuilcagh Mountain on the border between Counties Fermanagh and Cavan.
In the UK, there are three main types of peatland, distinguished by their location and vegetation. The first is the blanket bog of our rainy and cloudy uplands. Fine examples can be found from the Flow Country in the North of Scotland, through Wales to Dartmoor in the South West. Then we have the fen peatlands, fed primarily by ground and river water, found in hollows or near the edge of open water. Wild fens once stretched for hundreds of miles across Eastern England. But a lot of this land has now been drained.
Carbon stores are a reminder that nature operates on long cycles that need to be understood properly before engaging in short-cycle human engineering. Perhaps the most important lesson is that there are times when it is best to leave nature to its own rhythms.
Finally, we have raised bogs. Sometimes these started life as fens and are now amongst the rarest habitats on our islands. Like fens, they are found in lowland areas. Unlike fens, they are now principally nurtured by rainfall. Ballynahone Bog in Northern Ireland provides just one of many examples on the Emerald Isle, with its hummock and hollow pool complexes nesting the magical cinnamon bracket, green tiger beetle and round-leaved sundew.
A natural bog can remove around 3.5 tonnes of carbon dioxide per hectare per year, and natural fen over five tonnes. However, peatlands can also be a source of methane. Therein lies both risk and opportunity. Over the longer term, the climate cooling effects of CO2 sequestration outweigh the warming impact of methane emissions, for peatland in good condition. However, with nearly 80% of our peatlands impaired by human activity, nature’s balance has been upset and this arithmetic reversed.
Tragically, net annual GHG emissions from peatland in the UK are now estimated at 23 million tonnes, as we carelessly unlock what Seamus Heaney might have called a door into the dark, in this case, to meet a dangerous climate foe.
It need not be this way if we reconnect to nature and its values. In purely economic terms, the ONS estimates that to restore all UK degraded peatland, it would cost £8-22bn over 100 years, but would save £109bn in terms of reduced carbon emissions. In other words, the benefits are approximately 5-10x the costs. That seems like an attractive investment in almost any scenario, given our Net Zero greenhouse-gas emission target.
Beyond economics, there are other resonances. Carbon stores are a reminder that nature operates on long cycles that need to be understood properly before engaging in short-cycle human engineering. Perhaps the most important lesson is that there are times when it is best to leave nature to its own rhythms. Maybe then, to paraphrase Led Zeppelin, if we all call that tune, the piper will lead us to reason.
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