Spatiotemporal analysis of projected impacts of climate change on the major C3 and C4 crop yield under representative concentration pathway 4.5: Insight from the coasts of Tamil Nadu, South India

RESEARCH ARTICLE Spatiotemporal analysis of projected impacts of climate change on the major C3 and C4 crop yield under representative concentration pathway 4.5: Insight from the coasts of Tamil Nadu, South India Ramachandran A1, Dhanya Praveen1*, Jaganathan R2, RajaLakshmi D2, Palanivelu K1 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 1 Centre for Climate Change and Adaptation Research, Anna University, Guindy, Chennai, Tamil Nadu, India, 2 Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India * Abstract OPEN ACCESS Citation: A R, Praveen D, R J, D R, K P (2017) Spatiotemporal analysis of projected impacts of climate change on the major C3 and C4 crop yield under representative concentration pathway 4.5: Insight from the coasts of Tamil Nadu, South India. PLoS ONE 12(7): e0180706. https://doi.org/ 10.1371/journal.pone.0180706 Editor: Prasanta K. Subudhi, Louisiana State University College of Agriculture, UNITED STATES Received: March 7, 2016 Accepted: June 20, 2017 Published: July 28, 2017 Copyright: © 2017 A et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. India’s dependence on a climate sensitive sector like agriculture makes it highly vulnerable to its impacts. However, agriculture is highly heterogeneous across the country owing to regional disparities in exposure, sensitivity, and adaptive capacity. It is essential to know and quantify the possible impacts of changes in climate on crop yield for successful agricultural management and planning at a local scale. The Hadley Centre Global Environment Model version 2-Earth System (HadGEM-ES) was employed to generate regional climate projections for the study area using the Regional Climate Model (RCM) RegCM4.4. The dynamics in potential impacts at the sub-district level were evaluated using the Representative Concentration Pathway 4.5 (RCPs). The aim of this study was to simulate the crop yield under a plausible change in climate for the coastal areas of South India through the end of this century. The crop simulation model, the Decision Support System for Agrotechnology Transfer (DSSAT) 4.5, was used to understand the plausible impacts on the major crop yields of rice, groundnuts, and sugarcane under the RCP 4.5 trajectory. The findings reveal that under the RCP 4.5 scenario there will be decreases in the major C3 and C4 crop yields in the study area. This would affect not only the local food security, but the livelihood security as well. This necessitates timely planning to achieve sustainable crop productivity and livelihood security. On the other hand, this situation warrants appropriate adaptations and policy intervention at the sub-district level for achieving sustainable crop productivity in the future. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: The authors received no specific funding for this work. First author would like to mention and acknowledge the Anna Centenary Fellowship. Competing interests: The authors have declared that no competing interests exist. Introduction The majority of the world’s undernourished people live in developing countries. Two-thirds live in just seven countries (Bangladesh, China, the Democratic Republic of the Congo, Ethiopia, India, Indonesia, and Pakistan), with 40 percent living in China and India [1]. The PLOS ONE | https://doi.org/10.1371/journal.pone.0180706 July 28, 2017 1 / 19 Climate change and C3 and C4 crop yield under RCP4.5-South India increasing challenge of food and livelihood insecurity largely depend on the rate of yield gain of the major cereal crops in a country like India [2]. Global warming due to a rise in greenhouse gases may exacerbate the negative consequences on crop productivity and food security [3, 4]. According to the 5th Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), the global (land and ocean) average temperature has risen 0.85˚C (0.65–1.06˚C) over the period of 1800– 2012 [3]. This trend in global warming is predicted to increase during the 21st century under all the Representative Concentration Pathways (RCPs). The projected ranges of temperature increase are 0.3–1.7˚C (RCP 2.6), 1.1–2.6˚C (RCP 4.5), 1.4–3.1˚C (RCP 6.0), and 2.6–4.8˚C (RCP 8.5) for the years 2081–2100, relative to 1986–2005 [3]. Such changes in global mean temperature can radically disturb human society and the natural environment [5]; however, the changes in extreme temperature events, such as heat waves, severe winters, summer storms, hot and cold days, and hot and cold nights, may severely impact the agricultural ecosystems [6]. Despite all technological and cultivar advancements, the weather and the climate are continuing to be the uncontrollable factors affecting crop yield. The yield of crops, particularly in rainfed conditions, depends on the climate to an even larger extent [7]. Research on agriculture in the developing nations has focused on the need to have increased cereal production [8, 9]. Though agriculture in India has undergone major structural changes, it is still the mainstay of the economy with about 49% of the labor force depending on agriculture and the allied sectors for their livelihoods. Agriculture supports the vast majority of the low income, the poor, and the vulnerable people in the country; and climate plays a crucial role, as about 55–60% of the area sown is still rainfed. The share of agriculture and allied activities in the Indian gross domestic product (GDP) was 13.7% during 2012–13 [10]. There are numerous direct and indirect impacts reported on crop production due to the overall impacts of climatic attenuations. The yield of crops, particularly in rainfed conditions, depends on the climate to a larger extent. Global warming may adversely affect the biodiversity and exacerbate the desertification due to an increase in evapotranspiration and a likely decrease in rainfall in dry lands (although it may increase globally) [11]. The direct impacts will have implications for the morphology, the physiology, and the phenology of a plant. Increased temperatures will have profound effects on crop development. Higher temperature exposure beyond the threshold level will eventually affect the quality and the quantity of yields of desirable crops, while weeds infest the areas and pests proliferate [12]. The impacts depend on the relative warming at different growth stages: seed germination, seedling emergence, leaf production, leaf expansion, leaf area duration, flower initiation, flower development, pollination, ripening, maturity, vernalization, and dormancy. Varying precipitation patterns augment the likelihood of short-run crop failures and long-run production declines [13]. The strong negative impacts of warming that lim (...truncated)