Fig 1.
Comparison between simulated crop yield and FAO time series data at the country level for Maize, Millet and Sorghum 5-Year Moving Average.
The yields at pixel level were aggregated over West Africa for the estimated period 1979–2013 with MIRCA2000 landuse data using EWEMBI climate dataset. Pearson correlation coefficient (R) was calculated between FAO and Simplace yields.
Fig 2.
Heatmap of the Pearson correlation coefficient (R) between the simulated and observed FAO country level mean yields for maize, pearl millet and sorghum 5-Year Moving Average.
Yields at pixel level were aggregated over countries with MIRCA2000 land use data and Pearson correlation coefficient R calculated over the period 1979–2013. Grey boxes indicate that correlations are not statistically significant (p-value > 0.05).
Fig 3.
Relative change in mean yields for the varieties of 90 days with and without [CO2] in West Africa under RCP45/SSP2-4.5 scenario for a near term (2035–2064) as compared with the reference period (1975–2004) in CMIP5, CMIP6 and the difference between CMIP6 and CMIP5 models.
Areas with significant changes with 95% confidence level are represented (bootstrap method).
Fig 4.
Projected changes in average yields for the varieties of 90 days (a) with and (b)without [CO2] fertilization effect in the SIMPLACE crop model (b) in West Africa under three scenarios (RCP26/SSP1-2.6, RCP45/SSP2-4.5, RCP85/SSP5-8.5) for the two time periods (2035–2064 and 2065–2094) as compared with the reference period (1975–2004). The different crops were weighted according to their respective areas. The error bars represent the 95% confidence interval. Blue and orange bars represent the change of multi-model mean yields in CMIP5 and CMIP6 models.
Fig 5.
Relative change in the number of years of crop failure for the varieties of 90 days with and without [CO2] in West Africa under RCP45/SSP2-4.5 scenario for a near term (2035–2064) as compared with the reference period (1975–2004) in CMIP5, CMIP6 and the difference between CMIP6 and CMIP5 models.
A crop failure is defined as a year with a simulated yield below the 10% quantile of historical yields. Areas with significant changes with 95% confidence level are represented (bootstrap method).
Fig 6.
Relationship between climate changes (growing degree days, rainfall, maximum and minimum temperature) and relative change in mean yield of sorghum 90-day in CMIP5 and CMIP6 models.
Changes are computed under RCP85/SSP5-8.5 scenario for a long term period (2065–2094) as compared with the reference period (1975–2004). Absolute changes are shown for growing degree days and minimum and maximum temperature, while relative changes were computed for rainfall and crop yields. The orange circles represent future changes projected in CMIP5 and CMIP6 is presented in cyan. This figure has a restricted y axis to zero in relative change in mean yield to enhance the clarity of the results and exclude the most extreme pixels (five pixels over 2250 pixels were excluded).
Fig 7.
Future changes in maximum temperature (°C), growing degree days (°C/days) and precipitation (%) over West Africa under RCP45/SSP2-4.5 scenario for the two time periods (2035–2064 and 2065–2094) as compared with the reference period (1975–2004) in CMIP5, CMIP6 and the difference between CMIP6 and CMIP5 models.
Areas with significant changes with 95% confidence level are represented (bootstrap method).
Fig 8.
Relationship between climate changes (growing degree days, rainfall, maximum and minimum temperature) and yields changes of sorghum 90-days in the difference between CMIP5 and CMIP6 models.
Changes are computed under RCP85/SSP5-8.5 scenario for a long term period (2065–2094) as compared with the reference period (1975–2004). Absolute changes are shown for growing degree days and minimum and maximum temperature, while relative changes were computed for rainfall and crop yields. Positive values indicate higher values of future changes in CMIP6 compared to CMIP5.