Increasing precipitation due to climate change could partially offset the impact of warming air temperatures on glacier loss in the monsoon-influenced Himalaya until 2100 CE

Ann Rowan , Anya M Schlich-Davies, Andrew N Ross, Duncan J Quincey, Vivi K Pedersen

Glacier volume in the Himalaya is projected to shrink by 53–70% during this century due to climate change. However, the impact of changes in precipitation amount and distribution on future glacier change remains uncertain because mesoscale meteorology is not represented in current models that project glacier change. We explored the combined effects of past and future changes in air temperature and precipitation amount and distribution on the evolution of Khumbu Glacier in the Everest region of Nepal—a benchmark glacier in the monsoon-influenced Nepal Himalaya—using a climate-glacier modelling approach that forces an ice-dynamical glacier evolution model with a surface mass balance forcing that includes mesoscale meteorological variables derived from downscaling of Regional Climate Model outputs. Our simulations show that historical warming during the late Holocene has committed Khumbu Glacier to future volume loss of 10–23% during this century. Under moderate future warming (RCP4.5) from the present day, Khumbu Glacier could lose 70% volume by 2100 CE due to increasing air temperatures. However, the projected increase in precipitation in tandem with climate warming could offset half of this loss, such that the total decrease in glacier volume by 2100 CE compared to the present day is only 34%. Extreme future warming (RCP8.5) will not be compensated by  changes in precipitation but will instead result in substantial ablation above 6,000 m, causing the highest glacier on Earth to vanish between 2160–2260 CE.