Simulating Potential Impacts of Future Climate Change on Post-Rainy Season Sorghum Yields in India

Keerthi Chadalavada,Sridhar Gummadi,Kumara Charyulu Deevi,Koteswara Rao Kundeti,Kailas Kamaji Dakhore,Senthil Kumar Thiruppathi,Dakshina Murthy Kadiyala,Ranjitha Kumari Bollipo Diana

doi:10.3390/su14010334

Abstract

Given the wide use of the multi-climate model mean (MMM) for impact assessment studies, this work examines the fidelity of Coupled Model Intercomparison Project Phase 5 (CMIP5) in simulating the features of Indian summer monsoons as well as the post-rainy seasons for assessing the possible impacts of climate change on post-rainy season sorghum crop yields across India. The MMM simulations captured the spatial patterns and annual cycles of rainfall and surface air temperatures. However, bias was observed in the precipitation amounts and daily rainfall intensity. The trends in the simulations of MMM for both precipitation and temperatures were less satisfactory than the observed climate means. The Crop Environment Resource Synthesis (CERES)-sorghum model was used to estimate the potential impacts of future climate change on post-rainy season sorghum yield values. On average, post-rainy season sorghum yields are projected to vary between −4% and +40% as well as +10% and +59% in the near future (2040–2069) for RCP 4.5 and RCP 8.5, respectively, and between +20% and +70% (RCP 4.5) as well as +38% and +89% (RCP 8.5) in the far future (2070–2099). Even though surface air temperatures are increasing in future climate change projections, the findings suggest that an increase in the post-rainy season sorghum yields was due to an increase in the rainfall amounts up to 23% and an increase in the atmospheric CO2 levels by the end of the 21st century. The results suggest that the projected climate change during the post-rainy season over India is an opportunity for smallholders to capitalize on the increase in rainfall amounts and further increase sorghum yields with appropriate crop management strategies.

Highlights

Sorghum is an important nutraceutical crop for the small and marginal farmers across the semi-arid tropics (SAT) of the world [1]
The multi-model mean (MMM) rainfall tended to underestimate the rainfall totals in the western ghats, where average SW rainfall totals varied from 2000 mm to 4300 mm
The MMM is often defined as an “ensemble of opportunity” which solves the problem of uncertainties up to some extent that is embodied in the spectrum of future climate change projections

Summary

Introduction

Sorghum is an important nutraceutical crop for the small and marginal farmers across the semi-arid tropics (SAT) of the world [1]. Sorghum is the fifth largest cereal preferred in diverse ecologies. The crop is cultivated in four (Asia, Africa, the Pacific and the Americas) major regions across the globe. In India, sorghum is the fourth largest cereal crop. In the case of Africa, it is the second most important crop after maize [2]. Sorghum is one of the most preferred climate-smart crops for rainfed farmers under severe

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