Collaborative Research: Climate controls on carbon accumulation in upland permafrost at millennial scales

Organic-rich surficial materials of the Arctic are a storehouse of frozen carbon (C) of global consequence. Climate ultimately controls the exchange of carbon between this reservoir and the atmosphere, but the long-term relation between climate and permafrost carbon is highly uncertain. This study draws from climate changes that occurred during the recent geologic past (late glacial and Holocene), which serve as natural experiments, to quantify the long-term (millennial-scale) relation between climate and the mass of carbon that accumulated under distinctly different climate states. Whereas previous studies of the effects of climate changes on permafrost carbon have generally focused on lakes and peatlands of low-lying terrain, this study provides complementary information from upland deposits that mantle hilly terrain, possibly the least-well known component of the arctic frozen organic carbon inventory. The project applies and develops new approaches to investigating the relation between climate and carbon sequestration in an understudied setting and at long time scales by bringing together expertise in Arctic paleoecology, paleoclimatology, surficial geology, geochronology and quantitative geomorphology. This paleo perspective provides a unique approach to help infer how permafrost and its C reservoir may react in the future.