Global Warming and Its Possible Impact on Agriculture in India

Progress has been significant in climate science and the direct and indirect influences of climate on agricultural productivity. With the likely growth of the world's population toward 10 billion by 2050, demand for food crops will grow faster than demand for other crops. The prospective climate change is global warming (with associated changes in hydrologic regimes and other climatic variables) induced by the increasing concentration of radiatively active greenhouse gases. Climate models project that global surface air temperatures may increase by 4.0-5.8 degrees C in the next few decades. These increases in temperature will probably offset the likely benefits of increasing atmospheric concentrations of carbon dioxide on crop plants. Climate change would create new environmental conditions over space and time and in the intensity and frequency of weather and climate processes. Therefore, climate change has the potential to influence the productivity of agriculture significantly. Climate variability has also become a reality in India. The increase in mean temperature by 0.3-0.6 degrees C per decade since the 1860s across India indicates significant warming due to climate change. This warming trend is comparable to global mean increases in temperature in the past 100 years. It is projected that rainfall patterns in India would change with the western and central areas witnessing as many as 15 more dry days each year, whereas the northern and northwestern areas could have 5 to 10 more days of rainfall annually. Thus, dry areas are expected to get drier and wet areas wetter. It is projected that India's population could reach 1.4 billion by 2025 and may exceed China's in the 2040s. If agricultural production is adversely affected by climate change, livelihood and food security in India would be at risk. Because the livelihood system in India is based on agriculture, climate change could cause increased crop failure and more frequent incidences of pests. Therefore, future challenges will be more complex and demanding. This chapter focuses on the variability of climate change and its probabilistic effects on agricultural productivity and adaptation and mitigation strategies that can help in managing the adverse effect of climate change on agricultural productivity, in particular for India.