Impact of Climate Change on the Glaciers of Spiti River Basin, Himachal Pradesh, India

People living in Spiti river basin, located in the north-eastern part of Himachal Pradesh, depend heavily on seasonal snow and glacier melt for their water requirements. The basin is more susceptible to climate change, as it indicates a higher rise in temperature than other parts of Himachal Pradesh. This work assesses glaciers' current health and projects future changes under RCP 4.5 and RCP 8.5 (Representative Concentration Pathway) climate change scenarios. The total glaciated area in Spiti basin is 550.5 sq. km containing 21.42 +/- 3.86 Giga-tonnes (Gt) of stored water. The basin has observed a mass loss of 8.89 Gt from 1985 to 2013. The future projection for the worst-case scenario (RCP8.5) suggests, 4.1 degrees C rise in temperature and 3.4% increase in winter precipitation by 2070 (average, 2065-2075), from 1985 to 2005 baseline period. Under this climate change scenario, the Spiti basin is likely to experience 84.8% loss in glacier stored water, 71.8% reduction in glaciated area from observed values of 2014. Besides, 76% of total glaciers may disappear by 2070 under RCP 8.5 scenario, which will alter the village communities' water security status, thereby highlighting the urgency to develop an adaptation strategy for the region.