Study of Tree-rings to understand past climate

Information on climate and its variability during the different time scale is important to understand the various internal and external forcing on the climate and thereby make a reliable future prediction. The present knowledge of climate variability, climate change is based upon the observed meteorological data. The information beyond the instrumental period is also very important to understand the long term climate change variability on decadal to century scale. However, such past climate data information is limited and discontinuous. Very little information is available on Indian climate, particularly over the Himalayan region earlier to about a century when the instrumental records commenced. The tree-ring records, though shorter in palaeoclimatic time frame, are accurate and their time resolution is to a specific season or year. Preliminary studies based on tree-ring samples in the region beyond 500 years in age with well marked and environmentally sensitive annual growth rings and can be used to reconstruct past climatic variation over the region.