Peat Bog, Connemara, County Galway, Ireland.

Stacks of peat, which was traditionally burnt for heating and cooking, dot an Irish bog. Peat cutting has contributed to widespread drying of European peat bogs. Credit: Tim Graham/Getty

Geography

Humans are drying out Europe’s ancient peat bogs

Climate change and peat cutting are altering ecosystems, some of them centuries old.

Peatlands across Europe have experienced substantial drying in the past few centuries and might be on the brink of shifting from carbon sinks to carbon sources.

Around half of the organic carbon in Europe’s soils is stored in bogs and fens. These peatlands formed after the glaciers retreated at the end of the last ice age, some 12,000 years ago. Climate change and direct human interference are now threatening to undermine the conditions needed to maintain the carbon stock that has accumulated over millennia.

Graeme Swindles at the University of Leeds, UK, and his colleagues used fossil amoebae — shell-building organisms abundant in soils — to reconstruct the depth of the water table in 31 peatlands across the British Isles, Scandinavia and Continental Europe. They found that almost two-thirds of sites have dried extensively over the past 300 years from the combined effects of climate warming and peat extraction, draining and burning.

Effective management and restoration are indispensable to prevent Europe’s peatlands from losing their carbon storage capacity irreversibly, the authors say.