Global temperature reconstructions of the Holocene indicate a warm period typically between 10-5 ka BP, the Holocene Thermal Maximum (HTM). During the HTM, temperatures across the Arctic region are estimated to have been 1-3 Celsius degrees warmer than present, sea-ice cover was reduced, and the Greenland Ice Sheet retreated beyond its present-day margin. Although not globally synchronous, the HTM is a particularly interesting period to investigate the impacts of a warming climate and a dwindling cryosphere on Arctic ecosystems. This session is organized by the PAGES working group ACME (Arctic Cryosphere Change and Coastal Marine Ecosystems). We welcome observational (proxy-based) and/or modeling studies offering new insights into the timing, magnitude and impacts of the Holocene Thermal Maximum on the Arctic region. Studies from marine as well as terrestrial settings are welcome, and we encourage multi-proxy studies as well as studies combining classical and emerging approaches (e.g. microfossils, stable isotopes, biomarkers, eDNA, proxy-model comparison).