ABSTRACT
Climate change is perceived to be the greatest threat to the food security and mankind in twenty-first century. Over the past few decades, increase in average air temperature on earth and its associated effects on climate and crops have became a concern worldwide, particularly after the 4th Assessment Report of Intergovernmental Panel on Climate Change (IPCC, 2007). Since preindustrial era to the year 2009, the carbon dioxide (CO2) concentration in the atmosphere has increased from 280 ppm to 384 ppm coupled with an increase in mean temperature of 0.76ºC. Further, according to the studies carried out by IPCC, it is predicted that by the end of this century increase in average air temperature in Asian countries could range between 1.8 to 6.0ºC and CO2 concentration may reach up to 700 ppm or more (IPCC, 2007). South Asian countries are predicted to have least increase in temperature, in the range of 1.8 to 5.0ºC except for the Himalayas (IPCC, 2007). On the other hand, changes in rainfall pattern have also been predicted in the range of 5 to 20% during the winter season and 40 to 15% during the summer season (IPCC, 2007). As a consequence of rising atmospheric temperature, there will be frequent occurrence of drought, flood and heat waves.
