Fig. 1: Map of the study areas and trends in the ground temperature over the period 2000–2019.

Credits: Map by Sebastian Laboor. Arctic settlements are from the dataset Total Arctic population on settlemental level in 2017 (500+ inhab) by Nordregio¹²², which is used and licensed under CC-BY-SA-4.0, and available at https://doi.org/10.1594/PANGAEA.895745. The spellings of some settlement names were edited. The submarine permafrost extent is from the Submarine Permafrost Map (SuPerMAP), which was modeled with CryoGrid 2, Circum-Arctic by Overduin et al.¹²³, and is used and licensed under CC-BY-4.0 and available at https://doi.org/10.1594/PANGAEA.910540. Trends in permafrost temperature were retrieved via the Center for Environmental Data Analysis from the ESA Permafrost Climate Change Initiative (Permafrost_cci): Permafrost Ground Temperature for the Northern Hemisphere, v3.0, 25 June 2021, by Obu, Westermann et al.¹²¹, which is used and licensed under https://artefacts.ceda.ac.uk/licenses/specific_licences/esacci_permafrost_terms_and_conditions.pdf and available at https://doi.org/10.5285/b25d4a6174de4ac78000d034f500a268. The country borders are from the dataset TM_WORLD_BORDERS by http://thematicmapping.org, which is used and licensed under CC-BY-SA-3.0. The administrative borders are from OpenStreetMap¹²⁴, and are available and licensed under the Open Data Commons Open Database License (ODbL) (openstreetmap.org/copyright) by the OpenStreetMap Foundation (OSMF).