Future of Freshwater Supply: Himalayan Glacier and River Systems - Summer Rupper, Brigham Young University
Glacier Changes and Regional Climate – Past and PresentSummer Rupper, Brigham Young UniversityThe pattern of glacier changes across the Himalayas and Tibetan Plateau has often been cited as direct evidence of patterns of climate change. At face value, glaciers appear to be among the most straightforward natural indicators of climate change: a glacier simply reflects the difference between accumulation of snow and ablation (i.e., mass loss via melt) and will change its size in response to changes in climate. Where glaciers within an entire region are behaving in the same way (i.e., advancing or retreating synchronously), there can be confidence that local environmental factors specific to any single glacier are not dominating the response, and that regional-scale climate variations are at work. This regional glacier-climate relationship will be discussed and used to help explain the past and present pattern of glacier changes in the Himalaya, as well as the sensitivity of these glaciers to future climate scenarios. Glacier changes in response to current and future climate change will directly impact local and regional freshwater resources. However, it is currently debated whether meltwater from these glaciers constitutes a significant percentage of local freshwater resources. A simple approach to quantifying the contribution of glacier meltwater to local water resources, using the climate-glacier relationship derived from the study of past and present glacier changes, will be presented. Quantifying the sensitivity of Himalayan glaciers to climate change and the contribution of glacier meltwater to freshwater resources is a crucial step in climate impact assessments and resource planning in the most populous region of the world.