Climatic Warming in the Himalaya During Recent Decades

Abstract

Analyses of daily average, maximum and minimum temperatures from 19 stations of 4 countries in the Himalayan region reveal warming trend in the Himalaya after 1973. The linear rate of average temperature increase over the Himalaya during the period 1973 to 2009 is 0.0570C/ year, which exceeds IPCC and NASA’s calculated global and the Northern Hemisphere trend over the same period. Rate of temperature increase was also pronounced with the elevation ranges, geographical regions and the elevation in the Himalaya: high elevation region, Central Himalaya and winter season exhibited higher rate of temperature increase in their categories. Diurnal temperature range (DTR) was calculated from the daily maximum and minimum temperature. The rate of change of DTR in the region was found to be 0.0250C/ year however it was marginal when studied separately for Eastern, Central and Western Himalayas. Winter month exhibited higher DTR than the summer month. Elevation range 1000-3000m with high urbanization rate in the region showed high DTR. Since this study covers temperature study over a period of 3 decades and only deals with some causes of climate warming in Himalaya, a detailed study on the region covering long-term data is necessary to conclude on the climate change in the region.