The world’s mountains are warming faster than anyone expected

Mountain regions around the world are heating up faster than the lands below them, triggering dramatic shifts in snow, rain, and water supply that could affect over a billion people. A major global review finds that rising temperatures are turning snowfall into rain, shrinking glaciers, and making mountain weather more extreme and unpredictable. These changes threaten water sources for huge populations, including those in China and India, while also increasing risks of floods, ecosystem collapse, and deadly weather events.