Landslide Hazard Is Projected to Increase Across High Mountain Asia

High Mountain Asia has long been known as a hotspot for landslide risk, and studies have suggested that landslide hazard is likely to increase in this region over the coming decades. Extreme precipitation may become more frequent, with a nonlinear response relative to increasing global temperatures. However, these changes are geographically varied. This article maps probable changes to landslide hazard, as shown by a landslide hazard indicator (LHI) derived from downscaled precipitation and temperature. In order to capture the nonlinear response of slopes to extreme precipitation, a simple machine-learning model was trained on a database of landslides across High Mountain Asia to develop a regional LHI. This model was applied to statistically downscaled data from the 30 members of the Seamless System for Prediction and Earth System Research large ensembles to produce a range of possible outcomes under the Shared Socioeconomic Pathways 2-4.5 and 5-8.5. The LHI reveals that landslide hazard will increase in most parts of High Mountain Asia. Absolute increases will be highest in already hazardous areas such as the Central Himalaya, but relative change is greatest on the Tibetan Plateau. Even in regions where landslide hazard declines by year 2100, it will increase prior to the mid-century mark. However, the seasonal cycle of landslide occurrence will not change greatly across High Mountain Asia. Although substantial uncertainty remains in these projections, the overall direction of change seems reliable. These findings highlight the importance of continued analysis to inform disaster risk reduction strategies for stakeholders across High Mountain Asia. Landslides have posed a major risk in the Himalaya and other ranges of High Mountain Asia. Some previous researchers have suggested that the changing climate will make landslides more common, due to more intense rainstorms. We have looked into whether this will happen across a vast swath of Asia that includes the highest mountains and plateaus in the world. Because the future climate depends on human decisions and activities, we mapped these potential changes under two scenarios: development along current lines and development that is heavily dependent on the use of fossil fuels. We found increasing hazard in both cases, but the change is much greater under the latter. Furthermore, we found that the hazard from landslides triggered by rainfall will increase in every major mountain range at some point in the twenty-first century. This result implies the need for continued vigilance by engineers, planners, and emergency responders across High Mountain Asia. New model analyses suggest that landslide hazard will increase in most parts of High Mountain Asia over the coming decades Even in regions where landslide hazard is projected to decline by end of the century, it will first increase by the middle of the century The landslide season may shift or intensify in some locations, but a major regime change is not expected