International Crops Research Institute for the Semi-Arid Tropics
Abstract
Climate change predictions point to a wanner world within the next 50 years, a trend that is increasingly being supported by 'on-the-ground' measurements. However, the impact of rising temperatures on rainfall distribution patterns in the semi-arid tropics (SAT) of Africa and Asia remains far less certain. During 2008, ICRISA T's crop modelers, GIS experts, crop physiologists and plant breeders met in Hyderabad, India for one week. Using a range of weather data driven tools, they initiated research to test the hypothesis that "in the medium term (2010-2050). ICRISAT is well placed to help farmers mitigate the challenges and exploit the opportunities that are posed by climate change through: (i) the application of existing knowledge on crop. soil and water management innovations, and (ii) the re-deployment and re-targeting of the existing germ plasm of its mandate crops." Rather than selecting specific climate change scenarios, we chose to undertake a 'sensitivity-based' analysis in which we looked at the impact of a factorial combination of climate change of5 different temperature increases (I, 2, 3, 4 and 5°C) and 3 different percentage changes in seasonal rainfall (0%, + I 0% and -10%) and compared the outputs with a 'control' of the current climate at each location for which the analyses was undertaken. We undertook three types of analyses. Firstly, we looked at the implication of these climate change combinations for changes in the length of growing period (LGP) and how they might effect the global distribution and extent of the SAT. Secondly, we examined in some detail how these scenarios would impact on crop production (millet, sorghum, groundnut and pigeonpea) in eastern, southern and western Africa and in India. We also looked, albeit to a lesser extent, at the potential 'fertilizer effect' of enhanced CO2 levels on crop production. Finally, we examined the potential of improved production practices and better adapted germplasm to mitigate the impact of climate change
