Julie Loisel Sarah Chadburn Robert B. Jackson Miriam C. Jones Glen MacDonald Maija Marushchak David Olefeldt Maara S. Packalen Matthias B. Siewert Claire C. Treat Merritt Turetsky Carolina Voigt Zicheng Yu Gustaf Hugelius 2020 <div class="executive-summary"><p id="p-5">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.</p></div> application/pdf 10.1073/pnas.1916387117 en Proceedings of the National Academy of Sciences Large stocks of peatland carbon and nitrogen are vulnerable to permafrost thaw article