Climate Change and Its Impact on Crop Productivity

The changing patterns in day to day weather situations, rising CO2 concentrations, rising sea level, increasing temperature is an indicative of the fact that climate change being encountered by the life of earth at present. Climate change is caused by natural and anthropogenic factors-the natural being due to the periodic tidal pulls exerted by the astronomical bodies on earth’s atmosphere and the enhanced one’s are due to Changes in the climate through past and present are being evidenced through tephrochronological, dendrochronological, paleonological and archaeological measurements.Climate change has an impact on entire ecosystem, the greatest being on agriculture. Increasing CO2 concentration increases photosynthetic rates in C3 plants, and reduces transpiration due to decreased stomatal aperture, thus increasing water use efficiency Elevated CO2 at 330 ppm raised rice yields by 20% and further increase to 700 ppm increased yield by 26.4%. Increased yield is counteracted by a higher temperature that causes moisture stress, delays the maturity of crops due to increased senescence and reduction in grain filling period. Under warm temperature, 2°C above normal, decline in grain yield was to the tune of 8.4% in rice and 12.2% in wheat. A decline in yield to the tune 12.1% and 8.9% in rice and maize has been reported with the decline in solar radiation by 10% from normal. A yield decline of about 13% has been reported with an increased exposure to UV radiations at 320 nm caused due to ozone depletion. On an average the crop climate models suggest a decline in productivity by 3-17°C with 2°C rise in temperature, suggesting future research to recognize the potential interactions of climatic variables to ameliorate the adverse influence of changing climate on agro ecosystems. Climate change is expected to adversely affect the sustainable development capabilities of most Asian developing countries by aggravating pressures on natural resources and the environment. Development of sustainable cities in Asia with fewer fossil fuel-driven vehicles and with more trees and greenery would have a number of co-benefits, including improved public health. (IPCC 2014). To overcome this we have to Increase crop diversity by inter-cropping and appropriate cropping systems/rotations/land use; Adopt land/water conservation agriculture methods suited to varied agro-climates, balanced use of biocides/chemicals; Increase carbon fixation in the soil by growing deep-rooted crops so as to decrease carbon foot - print; Use water judiciously: more crop/unit of water; Use less fossil fuels; Use more solar/wind sources of energy; Climate smart agriculture needs to be adopted for better tomorrow.