The needs for advanced studies on impacts of climate change have been realised. In this study, the major focus is on changing climatic pattern and increasing natural hazards and its environmental consequences in Nepal. The climatic records of Nepal extend back to a relatively short period and may not adequately represent the range of natural climatic variability. Long term climatic data is needed to understand ongoing climate change phenomenon. In recent decades, dendrochronological data have been widely used in the world as a long term, high resolution, proxy of climate change. Dendrochronology is a branch of science which deals with the study of tree rings. Dendroclimatology reveals the relationship between past climate events and annual tree growth. The annual rings of trees can be important sources of long-term paleoclimatic data if they are dated accurately. However, the properties of tree rings can vary in response to climate change. Using trees growing in a particular site where climate has been highly limiting to the process of tree growth, the features of dated rings can be averaged year by year to obtain a time series of the growth response to past variations in climate.