Outlook on climate change adaptation in the Hindu Kush Himalaya

Impacts of climate change on key sectors and associated risks

As demonstrated in the previous section, the effects of climate change can already be seen throughout the HKH region. These changes are manifesting themselves through severe natural events often with destructive consequences (i.e. rapid and slow onset disasters) and are also having transformative effects on climatic processes that regulate and influence ecosystem services, agricultural outputs and water availability, among others.This section further explores these impacts on several key sectors for the HKH, as well as any current and future risks they may face. Water Climate change will increase both water stress and water-related hazards. Amajor concern for the region is that the amount of water in its rivers will reduce, due to retreating glaciers in the long-term. There are over 54,000 glaciers in the HKH region, covering an area of more than 60,000 km 2 , with an ice reserve of 6,000 km 3 . There is general agreement among scientists that most HKH glaciers are retreating and have lost mass since the mid-nineteenth century. However, there is one significant exception in the western Himalayas – known as the Karakoram anomaly – where some glaciers in the highest areas of the central Karakoram region have remained stable and even gained mass in the past decades 4 (Gautam et al., 2013; Shrestha et al., 2015a). Most studies that have assessed the future impact of climate change on glaciers in the region predict that glaciers will continue to decrease and lose mass. Lutz

and Immerzeel (2013) found that glacial area in five important upper river basins in the HKH will decrease significantly. Studying the same river basins, Lutz et al. (2014) found that while there will likely be no significant decrease in run-off until 2050, the contribution of water sources (glacial meltwater, snowmeltwater and rainfall) will change and there may be some minor changes to the seasonality of the water flow. However, as glaciers continue to melt, run-off will eventually decrease, especially in river basins that receive substantial amounts of water fromglaciers, such as the Indus river

basin. This is less likely to impact rivers that are more dependent on rainfall, especially as these areas may see an increase in precipitation (Miller et al., 2012). Nonetheless, the increase in evapotranspiration due to warmer temperatures in some areas may outweigh the increase in summer precipitation. For example, in the Koshi basin, evapotranspiration is predicted to increase 4–10 times more than the estimated increase in precipitation. Under such conditions, it is very likely that the frequency of droughts will increase (Tsering et al., 2010).

Water is a valuable resource in the region

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