Ice core records from the Dasuopu Glacier indicate that the last decade and last 50 years have been the warmest in 1,000 years. Meteorological records for the Tibetan Plateau show that annual temperatures increased 0.4°F (0.16°C) per decade and winter temperatures increased 0.6°F (0.32°C) per decade from 1955 to 1996.
Reference: Thompson, L.G., T. Yao, E. Mosley-Thompson, M.E. Davis, K. Henderson, K., and P.-N. Lin, 2000. A high-resolution millennial record of the South Asian Monsoon from Himalayan Ice Cores. Science, 289: 1916-1919.
Liu, X. and B. Chen, 2000. Climatic warming in the Tibetan Plateau during recent decades. International Journal of Climatology, 20: 1729-1742.