When they are dug up for fuel or compost, or drained and ploughed for farming and forestry, it causes a surge in emissions of carbon dioxide, the most important of the climate changing greenhouse gases.
In Britain more than 45 per cent of the original peatland has been damaged by man, according to the report from Exeter University's Wetland Ecosystems Research Group. Its scientists estimate that exploitation of the bogs results in carbon dioxide (CO2 ) emissions which amount to 40 per cent of the CO2 produced by all of the UK's cars, buses, lorries, trains and aircraft. Bog plants absorb CO2 from the air as they grow, then when they die the carbon is locked away in organic chemicals in the soaking peat for thousands of years. They act as vast carbon stores, as do oil, coal and gas fields.
Burning fossil fuels recombines the carbon stored in them with oxygen in the air to give off CO2 . Their combustion is reckoned to be the most important cause of man- made global warming, which is expected to change climate and raise sea levels in the next century. But when peat is drained for agriculture or dug up, the organic carbon stored within it for hundreds of thousands of years is also converted to CO2 gas.
Paradoxically, rotting vegetation in peat bogs gives off methane, sometimes known as marsh gas, which is a more powerful, but less common, greenhouse gas than CO2 .