Large stocks of peatland carbon and nitrogen are vulnerable to permafrost thaw

• DOI: 10.1073/pnas.1916387117
• Publication Date: 2020-08-11T00:25:28Z
• Authors: Gustaf Hugelius; Julie Loisel; Sarah Chadburn; Robert B. Jackson; Miriam Jones; Glen MacDonald; Maija Marushchak; David Olefeldt; Maara Packalen; Matthias B. Siewert; Claire Treat; Merritt Turetsky; Carolina Voigt; Zicheng Yu
• Keywords: 570; northern peatlands; permafrost thaw; hiili; ta1172; ta1171; ikirouta; 630; typpi; turvemaat; Ympäristötiede; Northern peatlands; nitrogen stocks; greenhouse gas fluxes; Greenhouse gas fluxes; ilmastonmuutokset; 15. Life on land; Climate Science; carbon stocks; Carbon stocks; Permafrost thaw; kasvihuonekaasut; 13. Climate action; Nitrogen stocks; Environmental Science; Physical Sciences; Klimatvetenskap

Significance Over many millennia, northern peatlands have accumulated large amounts of carbon and nitrogen, thus cooling the global climate. Over shorter timescales, peatland disturbances can trigger losses of peat and release of greenhouses gases. Despite their importance to the global climate, peatlands remain poorly mapped, and the vulnerability of permafrost peatlands to warming is uncertain. This study compiles over 7,000 field observations to present a data-driven map of northern peatlands and their carbon and nitrogen stocks. We use these maps to model the impact of permafrost thaw on peatlands and find that warming will likely shift the greenhouse gas balance of northern peatlands. At present, peatlands cool the climate, but anthropogenic warming can shift them into a net source of warming.