Annett Bartsch^1,2, Guido Grosse^3,4, Sebastian Westermann⁵, Tazio Strozzi⁶, Claude R Duguay^7,8, Frank Martin Seifert⁹, Jaroslav Obu¹⁰, Andreas Kääb⁵, Ingmar Nitze¹¹, Birgit Heim¹¹, Antonie Haas¹², Barbara Widhalm¹³, Sebastian Laboor¹¹, Sina Muster¹⁴, Andreas Wiesmann⁶, Gustaf Hugelius¹⁵, Reynald Delaloye¹⁶, Heidrun Matthes¹¹, Marina O Leibman¹⁷ and further members of the ESA DUE GlobPermafrost and ESA CCI+ Permafrost teams, (1)Austrian Polar Research Institute, Vienna, Austria, (2)B.Geos, Korneuburg, Austria, (3)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Potsdam, Permafrost Research, Potsdam, Germany, (4)University of Potsdam, Institute of Geosciences, Potsdam, Germany, (5)University of Oslo, Department of Geosciences, Oslo, Norway, (6)Gamma Remote Sensing, Guemligen, Switzerland, (7)University of Waterloo, Department of Geography & Environmental Management and Interdisciplinary Centre on Climate Change (IC3), Waterloo, ON, Canada, (8)H2O Geomatics, Waterloo, ON, Canada, (9)Corvallis, OR, United States, (10)University of Oslo, Oslo, Norway, (11)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Potsdam, Potsdam, Germany, (12)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Bremerhaven, Bremerhaven, Germany, (13)Zentralanstalt für Meteorologie und Geodynamik, Climate Change Impacts, Vienna, Austria, (14)Alfred Wegener Institute for Polar and Marine Research, Potsdam, Germany, (15)Stockholm University, Department of Physical Geography, Stockholm, Sweden, (16)University of Fribourg, Fribourg, Switzerland, (17)Russian Academy of Sciences, Earth Cryosphere Institute, Tyumen Scientific Centre (Siberian Branch), Moscow, Russia