Is cassava the answer to African climate change adaptation?

1. Is cassava the answer to African climate change adaptation? Julian Ramirez-Villegas Andy Jarvis, Beatriz Herrera and Carlos Navarro

2. Why cassava?: a main staple in Africa • Contributed ~84 kcal/capita/day in 2007 (globally) • In Africa, however, it was 154 kcal/capita/day (387 wheat, 359 for maize, 205 rice) • Africa: ~124.3 million Ton produced in 2010 (52% of total) FAOSTAT (2012)

3. Crop hardiness: reported physiological responses • Adapted to warm and moist areas, but can deal with dryness Pn (umol CO2 per m2/s) El-Sharkawy (2006) El-Sharkawy and Cock (1986)

4. Some limiting factors • Pests and diseases • Low input farming systems, thus large yield gaps Herrera et al. (2011) Licker et al. (2010)

5. Potential for climate change adaptation

6. “In 2002, cassava was considered an ‘orphan crop’, neglected by both investors and practitioners of agricultural research” Fauquet et al. (2012)

7. Potential for climate change adaptation • No systematic approach to quantify the potential of cassava • Lobell et al. (2008) report increases of +1.1 % (average) • Liu et al. (2008) report little impacts on cassava yield (-2 to 1 %)

8. Approach • Use a simple suitability model to quantify the response of the crop by 2030s (SRES-A1B) • Uncertainty in projected climate quantified through the use of multiple (24) GCMs • Compare with other staples in the region (maize, beans, sorghum, banana, millet, potato) • Benefits of further crop improvement • Assess the impacts on pests and diseases

9. The EcoCrop model …uses parameterised thresholdsto determine climaticsuitability of a particular environment… Ramirez-Villegas et al. 2013 Agr. For. Met. 170: 67-78

10. Findings • Positive impacts or very little negative effects Low signal Moderate to high uncertainty

11. Cassava vs. other staples

12. Benefits of crop improvement Breeding drought / waterlogging Breeding heat / cold tolerance

13. In addition to large CO2 stimulation Rosenthal et al. (2012) report ~100 % increases in root yield under elevated CO2 Under optimal management Further evidence of the crop’s potential under climate change

14. But more work is needed on pests and diseases Potentially less pressure

15. In 2012, our article empowered CIAT to play a major role in the Global Cassava Partnership 21st Century, now receiving funds from the Gates Foundation.

16. Conclusions • Cassava consistently outperforming other staples in SSA under climate change • Stress-tolerant cassava for managing risk • And also for transformational adaptation (transition systems) • Crop improvement to further increase biotic stress resistance