More wet peatlands than expected
New study in Nature
The global loss of wetlands is smaller than previously assumed, according to the recent study Extensive global wetland loss over the last three centuries in the internationally renowned scientific journal Nature. Peatland scientists from the University of Greifswald, partner in the Greifswald Mire Centre, have contributed data from their Global Peatland Database and from the historical holdings of the local peatland library. The results now help to better assess the climate impact of peatlands, e.g. to quantify the change in carbon storage and in methane emissions. It also allows conclusions to be drawn about the impact of wetland loss and how wetland restoration can be better planned .
The study by an authors' collective led by Standford University shows that only 21-35% of the world's wetlands have been lost since 1700, instead of 50-87% as previously thought. In a historically first reconstruction, the scientists combed through thousands of records of drainage and land-use change in 154 countries for the study to compare them with the current distribution of drained and altered wetlands to get a picture of the state since 1700.
"In terms of area, the loss is not as great as is often claimed. What seems to be good news at first glance, however, should not deceive us. Worldwide, about four million km² of wetlands have disappeared, of which about 0.5 million km² are wet peatlands. However, drained peatlands are responsible for 4-5% of global greenhouse gas emissions: they are relatively small areas but with huge consequences!" says Prof. Dr. Dr. Hans Joosten, emeritus professor and co-author of the study.