Warming peat could release megatonnes of carbon

Environmental Research Web: A one-degree warming of the world's northern peatlands could increase respiration enough to release 38–100 megatonnes of carbon each year. Such a rise is much higher than previously believed and would offset much of the European Union's target for greenhouse gas emissions cuts under the Kyoto Protocol, which is currently 92 megatonnes of carbon per year.

"Northern peatland soils store about one-third of the world's total amount of soil carbon, which has accumulated during centuries to millennia owing to the strongly adverse conditions for the breakdown of organic plant remains," Ellen Dorrepaal of the VU University Amsterdam in the Netherlands told environmentalresearchweb. This storage is equivalent to more than half the carbon in the atmosphere.

Together with colleagues from the Royal Swedish Academy of Sciences and the University of Sheffield, UK, Dorrepaal found that an increase in spring and summer temperature of around 1 °C stimulated ecosystem respiration rates by as much as 52–60%. "One of the striking results was that this strong stimulation was sustained for at least eight years (which was the last time we performed these measurements)," she said, "and therefore did not decline as has been observed in warming studies in other ecosystem types."...

A peat bog in Ireland, shot by Amos, Wikimedia Commons via Flickr, under Creative Commons Attribution 2.0 License