The impacts of climate change are notgoing to be the similar for every developing country or even for each regioninside a country. Some developing countries with temperate climates may wellbenefit from warming. The Ricardian studies in India revealed that agriculturewould be sensitive to even modest warming (Mendelsohn, 2009).
The impact ofclimate change on farm level net revenue was assessed by Ricardian approach usingpanel data over a twenty year period on 271 districts of India. Change in 2oCtemperature and change in 7 per cent precipitation uniformly across India wouldlead to an estimated 9 per cent decline in farm-level net revenue annually(Kavi Kumar, 2009). The probability of crop production loss inIndia would be 10-40 per cent due to climate change during 2080 to 2100(Aggarwal, 2008). Climate change is one of the biggest environmental threatspotentially impacting wheat production and nutritional security. Increase intemperature (maximum and minimum) during the crop growth stage indicates a needto breed wheat genotypes resilient to climate change without compromising yield(Sendhil R. et al., 2017).WWF report in 2010 on impacts of climatechange on growth and yield of rice and wheat in upper Ganga basin stated thatanalysis of future climate scenarios in 11 districts of the Upper Ganga RiverBasin indicated spatial and temporal variation for changes in temperature andrainfall.
Simulation analysis carried out for the quantification of the climatechange impacts on rice-wheat system and for suggesting low-cost adaptationstrategies in these areas, projects varied impacts on growth and yield of riceand wheat during Rabi and Kharif seasons in A2 and B2 2080scenarios of climate. Climate change is projected to increase the temperatures morein the A2 scenario than in the B2 scenario. The projected increase intemperature is relatively higher during the Rabi season than in the Kharifseason. Temperatures are projected to increase more in areas which arecurrently warmer. An increase in temperature is likely to be relatively less inthe hilly areas of Dehradun, Haridwar and Bijnor. Kharif rainfall isprojected to significantly increase in the north and northeast parts of thestudy region whereas Rabi rainfall is projected to increase marginallyin the south and eastern parts of the study area.Due to the impact of climate change,there is a reduction in both area and yield of some major crops (paddy,groundnut and sugarcane) in Tamil Nadu by about 5.
2 to 9.5 per cent. It isanticipated that overall production would decrease in between 9 to 22 per centfor these crops in 2020 (Palanisami et al., 2009). The areas of Tamil Naduwhich produce rice and other food grains are already suffering with lessproduction and may have drought because of global warming.
This has eventuallyaffected the availability of food. The flooding of coastal areas as a result ofsea-level rise would lead to a loss of agricultural land. It would also lead tointrusion of salt water into coastal aquifers which would in turn affectagricultural production in Tamil Nadu (Jayaseelan, 2012). While examining theimpact of climate change on the yield of major food crops (rice, sorghum andmaize) in Tamil Nadu by bring together a unique 39-year period (1971 to 2009)panel dataset, Rainfall and temperature had positive and significant effects onrice and sorghum yields up to a threshold level of rainfall and temperature.Beyond the threshold level, further increases in rainfall and temperatureresulted in negative impacts on yield.
The presence of thresholds in weatherimpacts was an important finding and showed that there was an inverted U-shapedrelationship between crop yields and climate variables (Saravanakumar, 2015).