Mountains are complex social-ecological systems and natural laboratories in which to explore global change. We invite contributions examining past, present, and future environmental change and associated societal impacts in global mountain environments. This session is open to measurement and modelling studies of mountain climate, cryosphere, ecology, hazards, and hydrology, including coupled societal resources and risks. Mountain terrain is difficult to resolve in climate models, and many areas of the world lack high-elevation monitoring infrastructure. We particularly welcome contributions addressing such knowledge gaps, including high-elevation monitoring efforts, measurements across altitudinal gradients, climate downscaling strategies, and remote sensing innovations. This session is supported by the Mountain Research Initiative (MRI).