Climate Change and Indian Agriculture: Impacts, Adaptation and Mitigation Strategies

Abstract

Agriculture is the mainstay of the Indian economy where about 65-70 percent of the population is dependent on it for their livelihood. Therefore, the climate change has direct effect on India. There is a strong evidence to suggest that change in climate has been occurring during the past 100 years. The mean global temperatures increased by 0.6OC during last 100 years and warmest summers were observed in the last decade of the 20th century and first decade of 21st century. This is mainly attributed to the increased concentration levels of GHGs, viz. Co2, CH4, N2O and CFCs. If the emissions of GHGs are continued at the current rate, the average global surface temperature would rise form 0.6 to 2.5OC in the next fifty years and between 1.4 to 5.8OC by the end of the 21st century. A slight warming trend of 0.4OC over the last 100 years has been noticed over the Indian sub-continent and the changes were found to be more significant during winter. The spatial variability of air temperatures over the country indicated warming in peninsular region while north-west India has exhibited cooling trend. On the rainfall variability over the country, the data did not show any significant trend. However, increase in frequency and intensity of extreme weather events such as droughts, floods or unseasonal rainfall are noticed. Sub-divisional rainfall trends during the recent decades indicated decreasing rainfall trends in north-east-region while increasing trends are noticed in north-west and north India. Projected scenarios for the Indian sub-continent indicated a warming to the extent of 3.5 to 5.5OC by 2080s and more warming is expected in winter than in summer season. Similarly, a marginal increase in rainfall of 7 to 10 percent is predicted over the sub-continent by 2080. The climate change can influence crop yields. Higher temperatures are likely to alter the fertility status of soils significantly. Additional application of fertilizers may be needed to counteract the adverse processes. Conditions will be more favourable for the proliferation of weeds, insect -pests and diseases in the warmer climates and crop damages are likely to increase. The expected rise in sea level may range from 10 to 50 cm by 2050 and may pose a serious threat to agriculture in low lying coastal areas. Cultivars with a better use of N can reduce surplus N-fertilizer inputs thus protecting the environment by reducing N2O emissions and thus mitigating climate change. Biological nitrification inhibition or suppressing nitrification by such genes, which are available in some tropical grasses, may pave the way for genetically engineered development of cultivars. Integrated farming systems, intercropping, INM and IPM practices as well as integrated watershed management practices are required to be adopted to manage the adverse effects of climate change in India.