Global Warming and the Pattern of Overall Climate Changes in Sub-Himalayan Assam Region of North-East India

Abstract

This study examines the changing pattern of climatic factors in the Sub-Himalayan region in the Northeast during last four decades. Sub-regional variation in climatic indicators and their relation with the anthropogenic human activities like deforestation, mining and industrial developments are analysed. In addition, inter-relation among the variations in major climatic components (precipitation, temperature and humidity) are analysed through various time series methods. The analysis reveals a growing uncertainty and erratic nature of yearly and seasonal rainfall, accompanied by significant interregional variations.The monsoon rainfall has been declining significantly over the years, while the proportion of pre and post monsoon months' rainfall has been rising. Both maximum and minimum temperature has been increasing and trend rate of minimum temperature has been higher than that of maximum temperature and the rate is more during winter. There is uncertain variation in maximum-minimum difference of temperature over the years. Finally, significant cointegrated relation exists among all the climate variables.