Ancient Permafrost and a Future, Warmer Arctic

Abstract

Climate models predict extensive and severe degradation of permafrost in response to global warming, with a potential for release of large volumes of stored carbon. However, the accuracy of these models is difficult to evaluate because little is known of the history of permafrost and its response to past warm intervals of climate. We report the presence of relict ground ice in subarctic Canada that is greater than 700,000 years old, with the implication that ground ice in this area has survived past interglaciations that were warmer and of longer duration than the present interglaciation.

A reconstruction of atmospheric carbon dioxide and its stable carbon isotopic composition from the penultimate glacial maximum to the last glacial inception

“…Studies on northern permafrost regions concerning amount and age of stored organic carbon suggested permafrost soil pool sizes of up to 1700 Gt C (Tarnocai et al, 2009), with 88 % being perennially frozen. Permafrost in the central Yukon region in Canada revealed ages older than 740 000 yr BP (Froese et al, 2008), showing that a long-term accumulation is possible. Also Reyes et al (2010) claimed the persistence of deep discontinuous permafrost during the last 200 000 yr.…”

“…4. Such a range may still be realistic in the framework of the permafrost reconstructions by Froese et al (2008), Tarnocai et al (2009) and Reyes et al (2010). In contrast, if we assume a change in biomass in low and middle latitudes with a typical δ 13 C terr signature of −22 ‰ for the LGM (Francois et al, 1998), thus significantly heavier than carbon locked in permafrost, the total amount of additional stored terrestrial carbon required to explain the δ 13 C anomaly in the PGM for 25 % preservation increases to more than 2000 Gt C (not shown).…”

PERMAFROST AND PERIGLACIAL FEATURES | Yedoma: Late Pleistocene Ice-Rich Syngenetic Permafrost of Beringia

“…Perhaps their most distinctive property, however, is the pungent odor they give off from the incompletely decomposed organic matter that is exposed as they thaw. Although these deposits are largely of late Pleistocene age, the presence of distal, dateable volcanic ash (tephra) within some of them indicates a middle Pleistocene age (Froese et al, 2008(Froese et al, , 2009Reyes et al, 2010).…”

Late Quaternary environmental and landscape dynamics revealed by a pingo sequence on the northern Seward Peninsula, Alaska

“…Therefore, permafrost deposits are increasingly used as an archive of late-Quaternary environmental and climatic conditions in the high latitudes of the northern hemisphere (e.g. Matthews, 1974a;McDowell and Edwards, 2001;Murton, 2001;Schirrmeister et al, 2002Schirrmeister et al, , 2008Muhs et al, 2003;Hubberten et al, 2004;Sher et al, 2005;Froese et al, 2008;Kienast et al, 2008;Kuzmina et al, 2008;Wetterich et al, 2008;Meyer et al, 2010;Andreev et al, 2011).…”