Large parts of (sub-)Arctic Siberia, Alaska and the Yukon Territory are covered by ice-rich silts that are penetrated by large ice wedges, resulting from syngenetic sedimentation and freezing. Accompanied by wedge-ice growth, the sedimentation process was driven by cold continental climatic and environmental conditions in unglaciated regions during the late Pleistocene (Schirrmeister et al. 2013) inducing the accumulation of the unique Yedoma deposits up to 50 m thick. Because of fast incorporation of organic material into permafrost during sedimentation, Yedoma deposits are supposed to include low-degraded organic matter. Moreover, ice-rich permafrost deposits like Yedoma are especially prone to degradation triggered by climate changes or human activity. When Yedoma deposits degrade, large amounts of sequestered carbon as well as other nutrients are released to the geosystem, which is of global significance for the climate system. In particular, several new estimates have emerged for carbon that accumulated in yedoma deposits in Siberia and Alaska. The current estimates range from 83±12 (Strauss et al. 2013) to 129±30 Pg (Walther et al. 2014) for organic carbon in Yedoma deposits. The yedoma region, including degraded Yedoma deposits and Holocene accumulation, is now thought to contain between 213±41 Pg carbon (Strauss et al. 2013) and 456±45 Pg frozen carbon (Walter Anthony et al. 2014), still supporting earlier accounts of several hundred billion tons of carbon stored deep in the permafrost, even when recalculated with new observations. The major uncertainties for estimating the Yedoma carbon stock that remain are (1) Yedoma coverage, (2) Yedoma thickness, and (3) Yedoma ground ice (wedge and segregated ice) content.