Review and synthesis of climate change studies in the Himalayan region

There are a few regions in the world, where climate change impacts are more intense than other regions of the world, and Himalaya is the case. The Himalaya, one of the biodiversity hotspot regions and provider of ecosystem services to billion of people all across the world. Present study reviewed and synthesized climate change studies in the Himalayan region in general and Indian Himalayan region (IHR) in particular. Analysis of the literature indicates exponentially increase in climate change studies 2005 onward in the IHR, and maximum are from Jammu and Kashmir (105) followed by Uttarakhand (100) and Himachal Pradesh (77). Among the subject types, maximum climate change impact was studied on water resources/glacier retreat (141 studies) followed by agriculture (113) and forests/biodiversity (86). Increasing temperature, frequent drought spells, erratic rainfall and declining snowfall are commonly reported indicators of climate change. For instance, temperature is reported to increase by 1.5 °C in the Himalaya than an average increase of 0.74 °C globally in last century; however, it varied in eastern (0.1 °C per decade and western Himalayas (0.09 °C per decade. An increase in temperature between 0.28 and 0.80 °C per decade was reported for North-western Himalaya and 0.20–1.00 °C per decade for Eastern Himalaya. The higher altitude of Himalayan and Trans-Himalayan zone are reported to be warming at higher rates. Many of the glaciers were reported to be retreating in both eastern and western Himalaya. Heavy rainfall is becoming very common in the region often accompanied by cloudbursts that aggravate flood situation many times. Perception-based studies of the region reported to provide firsthand and detailed descriptions of climate change indicators and impacts from rural and remote areas, where no instrumental data are available.