Last updated: April 2015
Peatlands and carbon
Dr Rob Stonemanon on the importance of peatlands in the fight against climate change
A squelch across the upland moors of Britain is the nearest you’ll get to walking on water. At well over 90% water, peat is less solid than milk, yet the mat of sphagnum mosses, heathers and sedges allows a relatively easy walk above sometimes 30 foot of wet peat.
Peat banks Yorkshire, photo credit: Andrew Bowden
Most of the peat is composed of the dead remains of sphagnum mosses that grow from their tip leaving the bottom of the plant to only partially rot away in the waterlogged conditions. The sunshine that allowed the plants and mosses to grow, and the carbon dioxide from the atmosphere that was absorbed in the plant and converted into leaf material via photosynthesis, is locked into the peat.
Over thousands of years, a dense store of carbon forms. Today peat represents an enormous store of carbon – 550 gigatonnes of carbon, the equivalent of three-quarters of all the carbon in the atmosphere and twice all the carbon stored in the world’s forests. Given forest land covers 20% of the world land surface and peatlands only 3%, this is a very concentrated store, part of the essential workings of the Earth’s carbon system, taking carbon dioxide out of the atmosphere and laying it down as peat keeping Planet Earth in its Goldilocks balance – not too hot, not too cold.
That function is now in disarray given widespread damage to peatlands especially in NW Europe (Britain and Ireland in particular), North America and SE Asia. Land drainage, afforestation of temperate bogs, logging of tropical peatlands (that are covered in rainforest), fires both deliberate and accidental, and conversion to agricultural soils have all conspired to damage perhaps as much as half the world’s peatlands.
In SE Asia, the palm oil industry has drained many millions of acres of pristine peat swamp forest. Out-of-control burning, often deliberately lit, has created regular bouts of haze – smoke from burning peat swamps – that is now a major problem in SE Asia. The particularly severe fires of 1997-98 accounted for nearly a quarter of all fossil fuel emissions that year and caused several billion dollars of economic losses, for example shutting Singapore airport on numerous occasions.
Today, instead of taking carbon out of the atmosphere, peatlands are the cause of 8% of all human-related carbon emissions. However, peat restoration is doable and cheap; simply a case of blocking drainage channels and restoring natural vegetation types. In Yorkshire for example, the Yorkshire Peat Partnership has restored 17,000 ha of peatland over the last four years, nearly half of all the damaged peatland in Yorkshire. If we could replicate that work across the globe and restore the world’s peatlands, we could very cheaply reduce carbon emissions by 8% and suddenly we can begin to grasp the climate change issue.