Glaciers and ice sheets harbour active microbial communities. These communities play an important role in the cycling of carbon and other elements within the cryosphere, and may be analogues for life on other icy planets. Interactions between ice, meltwater, sediment and microbial communities in these extreme environments determine nutrient export from glaciers and ice sheets. This multidisciplinary session will share recent findings on biogeochemical functions, and the wider impacts of these processes in glaciated regions.