Coming in from the cold: Potential microbial threats from the terrestrial cryosphere

The terrestrial cryosphere includes >198,000 glaciers and three ice sheets (Pfeffer et al., 2014). The paradigm of cryospheric environments as “germless continents” (Byrd, 1938) has shifted to ecosystems (Kohshima, 1984; Hodson et al., 2008). Indeed, the terrestrial cryosphere constitutes a “forgotten biome” (Anesio and Laybourn-Parry, 2012) with microbial processes influencing the fundamental dynamics of glacial systems (Edwards et al., 2014).