Robust features of future climate change impacts on sorghum yields in West Africa

Sultan, B., Guan, K., Kouressy, M., Biasutti, M., Piani, C., Hammer, G. L., McLean, G. and Lobell, D. B. (2014) Robust features of future climate change impacts on sorghum yields in West Africa. Environmental Research Letters, 9 10: 1-13. doi:10.1088/1748-9326/9/10/104006


Author Sultan, B.
Guan, K.
Kouressy, M.
Biasutti, M.
Piani, C.
Hammer, G. L.
McLean, G.
Lobell, D. B.
Title Robust features of future climate change impacts on sorghum yields in West Africa
Journal name Environmental Research Letters   Check publisher's open access policy
ISSN 1748-9326
Publication date 2014-10-01
Year available 2014
Sub-type Article (original research)
DOI 10.1088/1748-9326/9/10/104006
Open Access Status DOI
Volume 9
Issue 10
Start page 1
End page 13
Total pages 13
Place of publication Bristol, United Kingdom
Publisher Institute of Physics Publishing
Language eng
Abstract West Africa is highly vulnerable to climate hazards and better quantification and understanding of the impact of climate change on crop yields are urgently needed. Here we provide an assessment of near-term climate change impacts on sorghum yields in West Africa and account for uncertainties both in future climate scenarios and in crop models. Towards this goal, we use simulations of nine bias-corrected CMIP5 climate models and two crop models (SARRA-H and APSIM) to evaluate the robustness of projected crop yield impacts in this area. In broad agreement with the full CMIP5 ensemble, our subset of bias-corrected climate models projects a mean warming of +2.8 °C in the decades of 2031–2060 compared to a baseline of 1961–1990 and a robust change in rainfall in West Africa with less rain in the Western part of the Sahel (Senegal, South-West Mali) and more rain in Central Sahel (Burkina Faso, South-West Niger). Projected rainfall deficits are concentrated in early monsoon season in the Western part of the Sahel while positive rainfall changes are found in late monsoon season all over the Sahel, suggesting a shift in the seasonality of the monsoon. In response to such climate change, but without accounting for direct crop responses to CO2, mean crop yield decreases by about 16–20% and year-to-year variability increases in the Western part of the Sahel, while the eastern domain sees much milder impacts. Such differences in climate and impacts projections between the Western and Eastern parts of the Sahel are highly consistent across the climate and crop models used in this study. We investigate the robustness of impacts for different choices of cultivars, nutrient treatments, and crop responses to CO2. Adverse impacts on mean yield and yield variability are lowest for modern cultivars, as their short and nearly fixed growth cycle appears to be more resilient to the seasonality shift of the monsoon, thus suggesting shorter season varieties could be considered a potential adaptation to ongoing climate changes. Easing nitrogen stress via increasing fertilizer inputs would increase absolute yields, but also make the crops more responsive to climate stresses, thus enhancing the negative impacts of climate change in a relative sense. Finally, CO2 fertilization would significantly offset the negative climate impacts on sorghum yields by about 10%, with drier regions experiencing the largest benefits, though the net impacts of climate change remain negative even after accounting for CO2.
Keyword Climate change
Crop
Africa
Q-Index Code C1
Q-Index Status Confirmed Code
Grant ID ANR-10-CEPL-005
SES-1048946
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Queensland Alliance for Agriculture and Food Innovation
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