This book on Climate Change discusses the various segments (such as rainfall, temperature, Sun Spot numbers, Q.B.O, El-Nino, La-nina, MJ.O, flood, drought etc.) of climate with focus on the importance of knowledge of Climate Change and its impact with respect to environmental engineering. Decadal and interdecadal variability of climatic parameter was identified. The concerns relates to Climate variability over Central North East region of India.