“…Nevertheless, the cryosphere supports diverse biological communities on the surface of glaciers and continental ice sheets Hotaling et al, 2017a), beneath them (Hamilton et al, 2013), in their meltwater (Hotaling et al, 2019a), in permafrost (Jansson and Tas, 2014), and in sea ice (Boetius et al, 2015). Even though these biotic communities are dominated by unicellular microbial life (e.g., bacteria and algae: Boetius et al, 2015;Anesio et al, 2017;Hotaling et al, 2017a), macroinvertebrates (e.g., ice worms and rotifers; Shain et al, 2016;Hotaling et al, 2019b) and vertebrates (e.g., gray-crowned rosy finches; Rosvold, 2016) are also represented. However, rising global temperatures are driving widespread recession of the cryosphere (Lyon et al, 2009;Notz and Stroeve, 2016;Roe et al, 2017) with profound implications for biodiversity (Hotaling et al, 2017b), human populations (Pritchard, 2017), and ecological feedbacks (e.g., trophic interactions and biogeochemical cycles, Sommaruga, 2015;Milner et al, 2017).…”