Timescales for climate change adaptation in sub-Saharan Africa

CIAT and its partners have long used computer modelling to understand the impact of climate change on staple crops around the world.

But this year, for the first time, they used the models to show when changes in policy and practice need to take place in sub-Saharan Africa (SSA), in order to maintain production levels and avoid placing food security and the livelihoods of smallholder farmers at risk.

The team* examined, region by region, the likely effect of different climate change scenarios on nine crops that constitute 50% of food production in sub-Saharan Africa.

While six of the crops are expected to remain stable, up to 30% of areas growing maize and bananas, and up to 60% of those producing beans are projected to become unviable by the end of the century. In Uganda and Tanzania for example, where more than two-thirds of SSA’s beans come from, the scientists predict that around 1.85 million hectares of bean areas will become unsuitable by 2100.

Other regions are expected to be hit even sooner: for example, banana-growing parts of West Africa (including Ghana, Togo and Benin) and maize-growing regions in Southern Africa (Namibia, Botswana, Zimbabwe and Mozambique) will need “transformational adaptation” within the next ten years.

Transformation could range from changing the type of crop grown, or in extreme circumstances, moving away from agriculture altogether. Given that options such as breeding improved crops can take 15 years or more to complete, the study, published in Nature Climate Change, stressed the need for prompt action by policymakers.

“The study tells us where, and crucially when, interventions need to be made to stop climate change destroying vital food supplies in Africa,” said Julian Ramirez-Villegas, lead author of the study, working with the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS). “We know what needs to be done, and for the first time, we now have deadlines for taking action.”

The good news was that the scientists found that production of millet, sorghum, cassava, groundnut and yams should remain more or less stable for the rest of the century. In the case of cassava, the findings support CIAT’s landmark “Rambo Root” study from 2012 that found that the crop would be a climate change “survivor” in SSA, and a vital failsafe crop for many smallholders.

For at-risk areas, the study outlined three adaptation phases:

1. The incremental adaptation phase requires actions to help prolong the suitability of affected areas. These could include improved on-farm practices and provision of climatic advisory services such as seasonal weather forecasting. The study highlights the development of more suitable crops by scientists – particularly those tolerant to heat or drought – as “critical”.
2. The preparatory phase requires appropriate policies and enabling environments to be established. At the national level, this may entail re-assessment of major agricultural development and food security policies including research, development and extension. It will also be useful to provide incentives for development of new processing and storage facilities for substitute crops and piloting of markets for their by-products.
3. The transformation phase requires farmers and communities to change cropping systems. Where no viable alternatives exist, a move away from crop-based agriculture may be required.

“Timescales of transformational climate change adaptation in sub-Saharan African agriculture” was published in Nature Climate Change on 7 March 2016. Article is available at: http://dx.doi.org/10.1038/nclimate2947

*The team included scientists from CIAT; University of Bonn, Germany; University of Leeds; CCAFS; University of Copenhagen; CSIRO Agriculture; Australian National University.