Sea ice in plays a central role in the polar climate system. In recent decades, the rapid decline of Arctic sea ice has triggered cascading effects the albedo effect and gas/heat transfer in polar regions. Investigations of earlier warming events, such as the Preboreal/Early Holocene (PB/EH, 11–8 kyr B.P), Bølling-Allerød (B/A, 14.7–12.9 kyr B.P), and Dansgaard Oeschger event 3 (DO-3, 28–27.5 kyr B.P), likely hold clues on climate system responses to changes in Arctic sea ice. This study explores the history of sea ice over the Southern Lomonosov Ridge and its potential relation to permafrost carbon remobilization. Sea ice conditions over the last 27 kyrs were reconstructed through a combination of the sea ice biomarker IP₂₅(Ice-proxy 25) and marine phytoplankton biomarkers (brassicasterol and dinosterol) from the chronologically well-constrained core 31-PC, sampled at the Southern Lomonosov Ridge during the SWERUS-C3 expedition in 2014. The reconstruction allowed for a direct comparison with previously published terrestrial organic carbon (terrOC) remobilization history from the same core. Our findings revealed a seasonal sea ice cover between 27–26 kyr B.P after the DO-3 warm event, which likely caused more heat and moisture transport from ocean to land and strengthened permafrost thawing along the nearby coastline. A perennial sea ice cover then developed and persisted throughout the Last Glacial Maximum (LGM) to the Younger Dryas (YD), including over the entire B/A warm period. Due to sea-level rise during Meltwater Pulse 1A (MWP 1A, 14.7–13.5 kyr B.P), terrOC remobilization during B/A was rapid but its magnitude smaller when compared to PB and DO-3 in 31-PC, and other records from the Arctic. These records collectively suggest that sea-level rise, rather than sea ice conditions, exerts the primary control on coastal erosion during B/A, while we propose that the perennial sea ice cover may have limited wave-induced coastal erosion on the continental shelf bordering the southern Lomonosov Ridge. A sharp reduction and breakup of the perennial sea ice was observed from the PB to the Early Holocene. Contrary to the B/A, Meltwater Pulse 1B during PB triggered significant coastal erosion and massive terrOC remobilization concurrent with the sea ice decline. The absence of sea ice in parallel to larger coastal erosion compared to B/A implies the role of waning sea ice in enhancing permafrost carbon mobilization along the coastline in this period. In accordance with sea ice records from other Arctic seas, the Holocene record exhibited a period of gradual sea ice expansion. Taken together, these findings highlight sea ice extent as a possible factor regulating coastal permafrost carbon remobilization during the last deglaciation.