Plenary Session II: Dr. Timothy Thomas: The Impact of Climate Change on African Agriculture

Dr. Timothy Thomas, Senior Research Fellow, International Food Policy Research Institute (IFPRI)

Transcript

1. Senior Research Fellow, International Food Policy Research Institute (IFPRI) The Impact of Climate Change on Agriculture in Africa Dr. Timothy S. Thomas
2. #2024ReSAKSS #2024ATOR Outline • Current climate of Africa • How the climate has been changing in Africa • Climate models: Projected future climate changes • Crop models: Direct impact of climate change on agriculture • Bioeconomic model: African agriculture in a global food system • Final thoughts and reflections
3. #2024ReSAKSS #2024ATOR African climate is diverse • Physical large: can contain the U.S., China, and India combined • Large north-south gradient, temperate to tropic to temperate • Influence of oceans and seas • Mountains influence climate • Combinations of dry/wet with hot/cool • Leads to diverse agricultural systems Annual precipitation (millimeters) Mean daily maximum temperature (0C) Climate averages for 1985-2015 Source: AgERA5 (Boogaard et al. 2022).
4. #2024ReSAKSS #2024ATOR African climate is changing already • Regression results for each location, showing only those with a trend that is statistically significant at 10%. White areas are not statistically significant. • Maps show changes in the average temperature and precipitation in most place • Also changes in variability, intensity, and frequency of climate shocks Annual precipitation (millimeters) Mean daily maximum temperature (0C) Rate of change per decade, 1979-2021 Source: Author, based on AgERA5 (Boogaard et al. 2022).
5. #2024ReSAKSS #2024ATOR Climate models differ greatly • GFDL is the driest and IPSL the wettest. • All seem to project wetter in a band from Ethiopia westward to Burkina Faso. • Southern Africa is drier in 4 out of 5 models. • UK model is the hottest and MPI model is the coolest. • Southern Africa has the largest (or almost largest) temperature rise in all the models. Annual precipitation (millimeters) Mean daily maximum temperature (0C) Projected changes in climate, 2020-2050, RCP8.5 Source: Author’s calculations based on ISIMIP3b climate model data. GFDL IPSL MPI GFDL UK MRI MPI IPSL MRI UK
6. #2024ReSAKSS #2024ATOR Crop models project losses for rainfed maize • Changes are relative to current climate and exclude future productivity gains • Some places with increased yields. • There are hotspots – places for which maize is important and losses are large. • African losses are less than rest of the world. • Northern Africa has largest losses (though almost no area), followed by Western Africa and Middle Africa. • Chapter also has results for sorghum, wheat, rice, groundnuts, potatoes, and soybeans. Percent change in yield, 2005-2050, RCP8.5 Source: DSSAT crop model results based on five RCP8.5 climate models from ISIMIP3b. GFDL IPSL MPI UK MRI Percent change in yield Region Median Min Max CO2 included World -12.5 -36.2 -8.1 3.8 Africa -11.0 -14.8 -5.6 -0.1 Eastern Africa -3.0 -17.1 2.2 -0.2 Middle Africa -11.3 -18.9 -7.6 -0.2 Northern Africa -26.4 -38.5 -7.8 0.0 Southern Africa -9.4 -18.0 -1.4 -0.1 Western Africa -17.7 -18.8 -13.0 -0.2
7. #2024ReSAKSS #2024ATOR Cultivated area, 2020 (000s hectares) Percent change in yield, 2020– 2050 Percent change in harvested area, 2020–2050 Percent change in production, 2020–2050 Range Includes Range Includes Range Includes Crop Median Min Max Clim CO2 Median Min Max Clim CO2 Median Min Max Clim CO2 Maize 39,721 23.4 21.9 26.6 -3.4 0.5 18.6 15.5 22.0 5.8 2.1 49.1 40.7 52.4 4.7 2.1 Sorghum 28,009 45.6 44.3 46.6 -0.5 0.0 44.3 44.0 45.6 0.6 1.3 110.8 108.1 111.9 0.7 1.1 Cassava 21,272 22.8 22.0 25.5 0.4 -0.5 24.1 23.1 24.7 -0.7 1.1 52.5 51.1 54.5 -0.3 0.7 Millet 20,429 60.6 53.1 68.5 5.3 0.0 33.3 31.4 33.8 -2.3 0.5 113.9 101.1 121.6 2.9 0.5 Rice 17,124 40.6 38.0 46.4 -6.9 5.9 8.2 6.9 10.8 -0.8 -5.0 52.2 47.6 62.3 -7.5 0.7 Groundnuts 17,039 17.5 13.5 21.4 -9.1 8.7 33.8 31.6 39.4 5.5 -7.1 59.0 56.9 60.1 -3.2 2.3 Cowpeas 14,238 69.2 60.9 71.1 1.0 2.2 33.4 33.1 36.8 -0.7 -0.7 125.7 120.3 127.7 0.3 1.4 Wheat 9,912 37.7 36.3 41.8 -11.0 5.2 1.2 0.1 3.4 -5.7 0.2 39.6 36.5 46.5 -16.0 5.2 Beans 9,736 44.5 39.3 46.3 1.5 4.3 40.7 40.3 43.7 1.2 -3.3 104.2 95.4 109.7 3.1 1.0 Vegetables 9,474 43.8 39.9 50.6 -10.1 5.6 31.4 29.4 32.7 -3.7 -1.2 87.7 81.3 99.2 -13.9 4.1 Bioeconomic model projections for top 10 crops in Africa, percent change, 2020-2050 Source: Rosegrant et al. (2024).
8. #2024ReSAKSS #2024ATOR Final thoughts and reflections • Don’t give up on maize. Climate change will have less adverse impact on maize in Africa than in the rest of the world. • Wheat and potatoes on average will suffer large losses from climate change compared to the rest of the world. • Nonetheless, Africa is very diverse, and some parts will still be able to successfully grow wheat and potatoes. • There are “hotspots” in which climate impact will be negative and large. Focus interventions on the hotspots. • Need more research on increases in climate variability and institute policies that increase resilience to climate shocks. • Pay close attention to ongoing research on CO2 fertilization of yields. It makes a 10 to 20 percent difference in crop yields.
9. #2024ReSAKSS #2024ATOR Acknowledgments In addition to the sponsors of this conference, I want to acknowledge the support of the CGIAR Foresight Initiative which funded my time to work on this presentation and the chapter. Contact information Tim.Thomas@cgiar.org
10. THANK YOU