Will high heatwave risk be the new normal over high-elevation regions of northwestern High Mountain Asia in the future?

Abstract

The rise in temperature as a consequence of climate change has significantly impacted the environmental, social, and economic systems worldwide, especially over complex terrains like High Mountain Asia (HMA). Assessment of the associated climate risks is critical in developing proper adaptation and mitigation strategies and ensuring long-term resilience. In this study, we apply an impact-chain-based climate risk assessment to understand the risk associated with heatwaves in the local communities over northern parts of Afghanistan, Pakistan, and western Tajikistan. Additionally, the elevation dependence of the heatwave severity, population exposure, and its translation to heatwave risk over the region is analyzed. Heatwave events are identified based on five statistically downscaled GCMs under SSP2-4.5 and SSP5-8.5 scenarios. Based on these scenarios, an enhanced warming in the range of 1.6 °C to 6.9 °C is anticipated in the future which will result in more intense and frequent heatwaves over the region. A significant increase in future population exposure over the areas below the elevation of 3000 m, coupled with higher deprivation index will set risk levels from ‘intermediate’ to ‘very high’, conditions that are currently unprecedented for this region. A significant shift in population, compared to the historic period, is anticipated over high-elevation areas (>3000 m) by the end century under the SSP5-8.5 scenario, resulting in ‘very low’ exposure. The occurrence of more severe heatwave events in the future will not manifest as a ‘very high’ heatwave risk owing to the strong influence of exposure on risk. These results emphasize the need to consider all risk components, beyond just the hazard, to effectively assess future climate risk of communities in high-elevation regions like HMA. The study provides insights into the heatwave risk hotspots over the region, providing the stakeholders and local communities with critical information for planning adaptation and mitigation measures.