Postdoctoral Fellowship: OPP-PRF: Assessing the Contribution of Permafrost-derived Trace Gases in Greenhouse Warming since the Last Glacial Maximum

University Of Alaska Fairbanks Campus, Fairbanks AK

Investigators

Abstract

Permanently frozen ground (permafrost) in the northern regions of the world holds about twice as much carbon as what currently exists in Earth’s atmosphere. As climate warms, this carbon may be released as greenhouse gases. Rapid warming events, which occurred during the end of the last Ice Age, provide useful “natural experiments” for understanding how much permafrost-derived greenhouse gases will exacerbate ongoing warming. Paleoclimate proxy records provide insight on the timing, intensity, and location of past warming events in permafrost-laden regions and valuable context for past episodes of permafrost thaw. Evidence of past permafrost thaw is preserved in several different forms, i.e., in cave deposits, lakes that formed from thawing permafrost, and in erosional patterns. This climate and landscape history can be compared to data derived from ice cores, which detail the sources and concentrations of atmospheric greenhouse gases. This project combines data from permafrost thaw records, paleoclimate evidence, and ice core-based greenhouse gas concentrations to better understand the effects of warming and permafrost thaw on the deglacial carbon cycle. This project synthesizes existing records of permafrost thaw and evaluates them alongside paleoclimate records in the NSF-funded Rapid Arctic Warming (OPP-1947981, OPP-1948005) database to better understand how warming and permafrost instability influence the global carbon cycle. Previous research has largely focused on “bottom-up” records of permafrost thaw or on “top-down” ice core-based greenhouse gas reconstructions. Here, these disparate approaches are integrated and evaluated alongside the climatic context of deglacial warming and greenhouse gas increases. Records from the Rapid Arctic Warming database provide quantitative constraints on climatic conditions which the PI will use in permafrost modelling experiments. This work advances understanding of threats to permafrost stability and resulting impacts on atmospheric greenhouse gases. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.