With their breathtaking serenity, beauty and rich biodiversity, mountain ecosystems have long been hailed as guardians of nature’s services. Covering almost a third of the planet’s land surface, they provide a plethora of vital ecosystem services by regulating climate and hydrological cycles that sustain life locally and globally. This case study is part of the publication “Adaptation Gap Report 2023: Underfinanced. Underprepared. Inadequate investment and planning on climate adaptation leaves world exposed” (ISBN No: 978-92-807-4092-9). Suggested citation: United Nations Environment Programme (2023). Mountains in silent thaw: Losses and damages from the disappearing “frozen heartbeat” of Earth. An online resource of Adaptation Gap Report 2023: Underfinanced. Underprepared. Inadequate investment and planning on climate adaptation leaves world exposed. Nairobi. https://doi.org/10.59117/20.500.11822/43796