Matthias Fuchs^1,2, Torsten Sachs², Gustaf Hugelius³, Gerald V Frost Jr⁴, Mikhail Grigoriev⁵, Benjamin M Jones⁶, Ingmar Nitze¹, Juri Palmtag⁷, Pier Paul Overduin¹, Chien-Lu Ping⁸, Elizaveta Rivkina⁹, Lutz Schirrmeister¹, Georg Schwamborn¹, Matthias B. Siewert¹⁰, Jens Strauss¹, Alexandra Veremeeva⁹, Sebastian Zubrzycki¹¹ and Guido Grosse^12,13, (1)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Potsdam, Potsdam, Germany, (2)GFZ German Research Centre for Geosciences, Potsdam, Germany, (3)Stockholm University, Department of Physical Geography, Stockholm, Sweden, (4)ABR, Inc. - Environmental Research & Services, Fairbanks, United States, (5)Melnikov Permafrost Institute SB RAS, Yakutsk, Russia, (6)University of Alaska, Fairbanks, Water and Environmental Research Center, Institute of Northern Engineering, Fairbanks, AK, United States, (7)Northumbria University, Department of Geography and Environmental Sciences, Newcastle-Upon-Tyne, United Kingdom, (8)University of Alaska Fairbanks, Palmer, AK, United States, (9)Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino, Russia, (10)Umea University, Department of Ecology and Environmental Science, Umea, Sweden, (11)Universität Hamburg, Center of Earth System Research and Sustainability (CEN), School of Integrated Climate System Sciences, Hamburg, Germany, (12)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Potsdam, Permafrost Research, Potsdam, Germany, (13)University of Potsdam, Institute of Geosciences, Potsdam, Germany