Glacier-fed streams literally drain the roof of our planet. Climate change and related glacier shrinkage have major yet poorly understood impacts on the glacier-fed streams (Milner et al., 2017; PNAS, 114: 9770-9778). The environment of glacier-fed streams is one of the most extreme on Earth, with temperatures around the freezing point, high hydraulic stress, elevated UV radiation and poor resources, for instance. It is most likely that this extreme environment, home to a rich and specialized assemblage of microbes and animals, is now changing at an unprecedented pace. However, the impacts of this environmental change on the biodiversity and biogeochemistry of glacier-fed streams remain poorly studied and understood. Today, we understand the life in these now vanishing ecosystems less than the life in the most remote and deepest ocean.