Editing IPCC:AR6/SROCC/Chapter-3 (section)

===== 3.4.1.2.2 Ground ice =====

Permafrost thaw and loss of ground ice causes the land surface to subside and collapse into the volume previously occupied by ice, resulting in disturbance to overlying ecosystems and human infrastructure (Kanevskiy et al., 2013 <sup>[[#fn:r1405|1405]]</sup> ; Raynolds et al., 2014 <sup>[[#fn:r1406|1406]]</sup> ). Excess ice in permafrost is typical, varying for example from 40% of total volume in some sands up to 80–90% of total volume in fine-grained soil/sediments (Kanevskiy et al., 2013 <sup>[[#fn:r1407|1407]]</sup> ). Ice rich permafrost areas where impacts of thaw could be greatest include the Yedoma deposits in Siberia, Alaska, and the Yukon in Canada, with ice divided between massive wedges interspersed with frozen soil/sediment containing pore ice and smaller ice features (Schirrmeister et al., 2011 <sup>[[#fn:r1408|1408]]</sup> ; Strauss et al., 2017 <sup>[[#fn:r1409|1409]]</sup> ). Other areas including, for example, Northwestern Canada, the Canadian Archipelago, the Yamal and Gydan peninsulas of West Siberia, and smaller portions of Eastern Siberia and Alaska contain buried glacial ice bodies of significant thickness and extent (Lantuit and Pollard, 2008; Leibman et al., 2011; Kokelj et al., 2017; Coulombe et al., 2019). The location and volume of ground ice integrated across the northern permafrost region (5.63–36.55 x 10 3 km 3 , equivalent to 2–10 cm sea level rise) is known with ''medium confidence'' and with no recent updates at the circumpolar scale (Zhang et al., 2008 <sup>[[#fn:r1410|1410]]</sup> ).

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