Submarine permafrost warming (medium confidence, WG1-9)Increases in temperature and active layer thickness (WG1-9); near-surface terrestrial permafrost extent will reduce under all scenarios by 2100 (virtually certain, WG1-9) AntarcticRising permafrost temperatures over past three to four decades (high confidence, WG1-9) Lake, river ice ArcticDeclines in seasonal lake ice cover thickness and duration over most Arctic lakes; declines in cold-season river ice extent (high confidence, WG1-12)Many lakes will lose >1 month lake ice cover by 2050