Brussels, 08 Jul 2004
Peat bogs around the world are releasing huge amounts of carbon dioxide (CO2) into the atmosphere, and the process could be feeding off itself, creating a snowball effect, a researcher in the UK has warned.
Peat bogs contain a huge quantity of organic carbon, with some estimating that the bogs of Europe, Siberia and North America together hold the equivalent of 70 years worth of global industrial CO2 emissions. The fear is that these bogs are releasing more and more of their carbon into rivers in the form of dissolved organic carbon (DOC).
The man who carried out the research, Dr Chris Freeman from the University of Wales at Bangor, UK, says: 'The world's peatland stores of carbon are emptying at an alarming rate. It's a vicious circle. The problem gets worse and worse, faster and faster.'
Levels of DOC in rivers have been on the rise for as long as 40 years, and current figures put the annual rate of increase at around 6 per cent. The crucial question is: why are peat bogs releasing their stores of carbon? Dr Freeman's belief is that increased levels of carbon dioxide in the atmosphere could be the cause.
Originally testing another theory, Dr Freeman grew plants on peatland soil under enclosed glass domes, some of which contained normal air and others with a CO2 rich atmosphere. He observed that those plants growing in the CO2 rich domes were absorbing much larger amounts of CO2, which in turn were released into the soil. Once there, it feeds bacteria which break down the soil and release the stored carbon into rivers, where further bacteria can convert the DOC into CO2 that bubbles into the atmosphere.
After three years, the amount of DOC in the soil of the CO2 rich domes was 10 times higher than in the normal air domes. 'This shows that even without global warming, rising CO2 can damage our environment. The peat bogs are going into solution,' said Dr Freeman.
'On these trends, by the middle of the century, DOC emissions from peat bogs and rivers could be as big a source of CO2 to the atmosphere as burning fossil fuels,' he concluded.