Mountain regions are known as the “water towers of the world” for their capacity to store freshwater in glaciers. River basins with glaciers on their headwaters benefit from water stored as ice, representing a regulating water source for downstream river flow, particularly during the summer and in dry periods, especially in times of drought. However, human-induced global warming has caused glaciers to retreat, meaning the ice mass that has formed over many years melts faster than snowfall can replace. Currently, glaciers are melting at double the speed they have in the past two decades, with ever decreasing water availability for those that depend on glacial meltwater for their lives. This technical background report for the 2023 edition of the Interconnected Disaster Risks report analyses the root causes, drivers, impacts and potential solutions for the mountain glaciers melting risk tipping point our world is facing through an analysis of academic literature, media articles and expert interviews.