Integrated Assessment of Climate Change Impacts On Principal Crops and Farm Household Incomes in Southern India.

This study aims to assess the impact of climate change on agricultural production in southern India and its implications for farm household income and food security.  The study team applies standardized approaches known as ‘AgMIP Protocols’ to integrate the climate, crop and economic models and assess.

Farm households in Tamil Nadu, Andhra Pradesh, and other Provinces excluding south-western Kerala of the Deccan Plateau are located in the rain-shadow of the Western Ghats. With meagre annual rainfall averaging 500 to 900 mm, the region is experiencing steadily decreasing soil fertility, growing dependence on groundwater for irrigation, falling ground water tables, and increasing fallow lands - characteristics that may be impacted by changes in long term climate trends. Agriculture sustains over half of the region’s population.  The study is carried out in Tamil Nadu (TN) and Andhra Pradesh (AP) States of South India. Household production systems are characterized based on principal crops and water sources. Irrigated rice based cropping system in TN and  rainfed/irrigated maize based cropping systems in TN and AP are taken up for integrated impact assessment.

Crop models DSSAT and APSIM with climate parameter inputs from select RCP based (RCP 4.5 and 8.5) scenario downscales and management inputs from farm surveys are used to simulate base and climate impacted future yields with/without adaptations. Simulated yields are used for economic analysis to assess impacts on household incomes, employment and poverty. Usually, future yields are simulated by crop models using future climate parameters derived from climate models, whereas management inputs are assumed to remain constant at present levels.To overcome this limitation, we attempt to develop plausible future trends and values for regional level management inputs through a participatory discussion process, following Shared Socio-economic Pathways (SSPs) being developed at global level under varying developmental assumptions. AgMIP labels them Representative Agricultural Pathways (RAPs). Some of these RAPs based management variables are used in crop models along with future climate parameters to simulate future yields. Future farm characterizations derived from RAPs are combined with crop model simulated yields in economic tradeoff analysis using a Multi-Dimensional (TOA-MD) model for overall household impact assessment. The integrated analyses are replicated for a set of adaptation options to assess their efficacy in moderating climate change impacts on the selected crops based production systems and households of the study region.