Researchers led by the University of Leeds examined 31 peatlands across Britain, Ireland, Scandinavia and continental Europe to assess changes in peatland surface wetness during the last 2,000 years.
They found that nearly half of the study sites are the driest they have been for the last 1,000 years.
While changes to temperature and rainfall have significantly contributed to peatland drying, 42 percent of the sites had been significantly damaged by human activities. The peatland sites in Britain and Ireland had the most extensive degradation compared to the other sites, with cutting, drainage, burning and grazing all contributing to peatland drying.
Study lead author Dr Graeme Swindles from the School of Geography at Leeds said: "Our study sites include some of the least damaged peatlands in Europe, but it is clear that almost all European peatlands have been affected by human activities to some extent.
"The combined pressure of climate change and human impacts may push these vitally important carbon storing ecosystems into becoming a global source of carbon emissions.
"It is more important than ever that we safeguard peatlands with effective management and active restoration."