Farmers can adapt to climate change to some degree by shifting plantin dates, choosing varieties with different growth duration or changing crop rotations. However, many of these coping mechanisms may result in lower yields. In the Indo-Gangetic plain delayed planting is already one of the major causes of reduction in crop yeilds-rice as well as wheat. The Indo-Bangetic plain is one of the most populous and productive agriculture ecosystems in the world wupporting 900 million people or more than 80% of the population on the Indian subcontinent. The rice wheat cropping system is the economic backbone of this region and only a small gradual decrease in productivity in either rice or wheat crop will drastatically imperil food security. Most studies project decreased yields in non-irrigated wheat and in rice, and a loss in farm level net revenue between 9% and 25% for a temperature increase of 2 – 3 degree celcius .Agaarwal and Mall (2002) observed that a 2 degree celcius increase resulted in a 15 – 17 % decrease in grain yield of rice and wheat.
