Glacier Environment and Climate Change in Bhutan—An Overview

Bhutan, a part of the Eastern Himalayas, is a tiny land-locked country hosting rich biodiversity apart from glaciers and snow capped mountains. With similar to 70% of Bhutan under forest cover, this water-rich country promises to maintain at least 60% of the landmass under forest in perpetuity at any given point of time. Yet, climate change hasn't pardoned this carbon-neutral nation. This article conveys a brief idea about the dent that climate change is leaving on the glacier environment in Bhutan. Bhutan is undergoing warming at an unprecedented rate with evidences suggesting higher warming trends during winter months and also at higher altitudes (>4000 m.a.s.l.) (Sharma et al., 2009). With large diversity of glaciers in the region, comprehensive field-based studies have been difficult due to rugged terrain, political issues and limited manpower and financial aid. Yet several remote sensing based have suggested glaciers in Bhutan are melting. Evidences suggest oldest stage of glaciers in Bhutan extended down to 2600 m.a.s.l. (Mool et al., 2001); whereas in the present day, they are found only above 4000 m.a.s.l. Glacial retreat in Bhutan has been extensive (Karma et al., 2003; Rupper et al., 2012; Naito et al., 2012; Bajracharya and Shrestha, 2011; Bajracharya et al., 2014; Veettil et al., 2015) leading to formation of supra-glacial, pro-glacial and moraine dammed lakes. Particularly in Bhutan and Eastern Himalayas, threat from glacial lake outburst floods is high. With 22 potentially dangerous glacial lakes, there is high risk and hazard potential to the regions lying downstream from outburst. In spite of being an environmentally sustainable country with a conservative approach, Bhutan is at the frontline of climate change-related threats. Future water security is not warranted under this scenario. This can have serious implications on water-dependent-economy of Bhutan that thrives on hydropower, agriculture and tourism. Extensive research is called for in Bhutan, apart from efforts to adapt and mitigate climate change.