Modern landscape change in High Mountain Asia (1950-present)

<p>High Mountain Asia (HMA) &#8211; the Tibetan Plateau and surrounding high Asian mountains &#8211; is now experiencing amplified climate change, glacier melt, and permafrost thaw. The rapid climate change and melting and thawing of the cryosphere are not only affecting the water cycle but also causing landscape instability and mountain hazards, potentially threatening over 2 billion people in the downstream river basins. Glacier retreat and permafrost thaw are accelerating associated with frequent rockfalls, landslides, and debris flows. Lake outburst floods from (pro)glacial- and landslide-dammed lakes have potential runout distances of hundreds of kilometers. Moreover, greater amounts of sediment are mobilized, and fluvial sediment fluxes are increasing. Such mountain landscape instability can be largely attributed to climate change and is threatening infrastructure and livelihoods. We suggest that policymakers and stakeholders in the Himalaya countries must be urgently and fundamentally aware of these increasing threats in a changing climate. Adaptation measures should be based on extensive and continual monitoring of the glaciers, permafrost, unstable paraglacial landscapes, and sediment transport, to better understand compound and cascading hazards.</p>