Climate Change Effects are Cropping Up
9 November 2017
Climate Change Effects are Cropping Up and it's only going to get worse: Transformational Changes in Sub-Saharan Africa
Amanda Fuller, Former Crop Trust Partnerships Fellow
Since 2015, drought-induced crop failures and livestock deaths have left more than 10 million people in Ethiopia dependent on food assistance, while the drought remains relentless even today. In southern Africa, an outbreak of armyworms damages maize harvests and threatens the livelihoods of over 70 percent of the region that rely on agriculture.
These are just two of the many visible signs warning that now fertile farmland may be under considerable threat of becoming unviable. No one understands this better than the farmers in sub-Saharan Africa and the scientists at CIAT and its partners who study the changing climate patterns expected on the continent by the end of this century.
These climate scientists mapped out where and when changes will occur in agricultural viability, in research that’s the first of its kind, and the results are nothing short of alarming. Their findings indicate that, unless adaptation is pursued, the agricultural landscape of sub-Saharan Africa is expected look drastically different than the one these farmers, and our global food supply, currently rely on.
I had the opportunity to interview one of the scientists behind this groundbreaking research, Dr. Julian Ramirez-Villegas, a Climate Impacts Scientist at CIAT. Julian led the paper “Timescales of transformational climate change adaptation in sub-Saharan African agriculture.” You can read the full paper here.
Julian and his team looked at nine of the most important crops for agriculture in Sub-Saharan Africa—banana, cassava, bean, finger millet, groundnut, pearl millet, sorghum, yam, and maize—and the transformations each are projected to undergo in the 21st century. These nine crops account for half of African agricultural production quantity and the majority of the region’s produced protein supply.
The researchers used modelling to map transformational changes –a situation in which, due to climate change, farmers can no longer grow the crop(s) they usually grow, and are thus forced to seek alternatives. Farmers may relocate to produce the same crops, switch to other crops or livestock farming, or abandon farming altogether. Julian’s research focuses on how the viable locations for growing a specific crop are most likely to shift across large geographical areas in the 21st century.
I have always had a passion for the untamable yet fertile sub-Saharan Africa, so when Julian visited the Crop Trust, I jumped at the chance to learn more about the farmers that sow the land and the conflicts that loom on their horizon. We started the interview with the story behind Julian’s research. Why does your research focus on sub-Saharan Africa?
Julian: Sub-Saharan Africa is one of the most vulnerable regions, not only because of the levels of poverty and malnutrition, but also because climate change has been projected to hit this region the hardest. If you add the limited farmer adaptive capacity with very significant impacts on farming systems, you are left with high vulnerability. Sub-Saharan Africa is a region where we expect to see a lot of adaptation investment, and diagnosing where transformational change is projected to occur helps direct those investments.
Julian’s research shows that, most importantly, transformational change will happen in this century if we do nothing. Julian elaborated on the question his research set out to answer and what his team found:
Julian: Our research answered a very simple question: when does transformational change in agriculture in sub-Saharan Africa happen during the 21st century? Our study was based on models grounded in observations of where crops currently grow and where they do not. Through model simulations, our analysis maps where specific crops currently grow, and then determines whether and when they will no longer grow at those same geographic locations. This lead to two major findings. First, transformational change is projected to occur for all nine crops we modelled, which account for 50% of the total crop production in sub-Saharan Africa. Second, these transformations are restricted to specific geographic areas for most crops, and only for certain crops they are more widespread. Common beans, maize and bananas are the three crops most negatively impacted, with the most unstable geographic areas.
The results that Julian’s team found show us all just how important it is to pay attention to transformational changes. “Everything else—crops, locations, adaptations—is in the details, but first attention must be paid to transformational change in the long-term.”
The model simulations produced maps that show where—and when—transformational changes are expected to occur within each of the nine crops analyzed. As you can see, the red areas indicate the most urgent areas that require adaptation. For example, this map of transformational adaptation in yam shows us that most of the area used for yam production in northern Mozambique, in the absence of adaptation, may very well become unviable within the next 20 years.
Out of all nine crops, common bean is likely to suffer the most change. Julian’s research shows that up to 60% of the geographic area in sub-Saharan Africa where common bean grows could undergo transformational changes by the end of the century, most notably across Angola and the Democratic Republic of the Congo.
The models assumed transformational change to occur when farmers can expect 10 out of 20 years of harvests to result in crop failures. How was this 50% crop failure rate determined, and is there any measurement of these rates occurring now?
Julian: We made this assumption as a compromise between a sufficiently high and sufficiently low number of crop failures. Initially, I thought that this measurement of 50% failure is quite site-specific (or at least region-specific). In dry areas, farmers have considerably adapted to unstable rain and low precipitation years, thus they may be better equipped to cope well with high failure conditions. In contrast, in other areas with more optimal precipitation and temperature patterns, even one or two years of failure out of ten may put farmers out of business. It would be important to analyze field data on where these transitions are currently happening and what is triggering them to compare real results against our assumptions, and to see what levels of crop failures are occurring and are tolerable by farmers under present climate conditions.
These results project that in the long-term, too many farmers will no longer be able to rely on the farming practices that have provided for their families for centuries. It was easy for me, and for Julian, to recognize the important link between these transformational changes and the need to conserve crop diversity: helping farmers adapt their crops and save their harvests.
How might your research influence which types of crops we should focus our research and conservation efforts on?
Julian: Plant genetic resources definitely have a lot to contribute to agricultural adaptation in the context of transformations, which we can look at in two ways. One way is that we need to boost investment into conservation and use of plant genetic resources for the crops which are predicted to be hit the hardest. Why? Because for some of those crops, we may be able to prolong their suitability or to even avoid transformation altogether. One way of doing this is through crop improvement. This link is quite clear—we need crop improvement in order to find more heat-tolerant, drought-tolerant, or disease-resistant varieties.
In some cases, those genetic resources might not already be collected or conserved in genebanks. They may still need to be found, collected, stored, and then used. Conservation definitely has a great deal to contribute to the adaptation in some of these areas.
Another way to look at this, for those crops that are predicted to remain stable, is that we may want to increase productivity to increase nutritional content and perhaps even expand their suitable areas. Their physiology makes them tolerant to, or only slightly affected by, some particular stress causing transformational changes in other crops. To achieve this, plant genetic resources again have a great deal to contribute—for example to increase yields, nutritional properties, etc.
This study gives us tangible results; concise images depicting very plausible scenarios of how we can expect climate change to impact a valuable resource for our food security. Now, research like this can guide policy makers, global influencers, and more researchers to prioritize where and how we invest in a food secure future. Given what your results tell us, where should we focus future investment?
Julian: There is no quick solution. For starters, we need to diversify our agricultural output. If we diversify, we reduce risk, so we have more options. If some crops fail, we still have others to rely on. This though does not change the fact that we need investment in adapting those crops that will be hit the hardest. We also need to invest in trying to improve, or push forward, some of the other, more resilient crops.
We need to diversify both across crops and within crops. For example, instead of just planting one variety of maize, genebanks such as the Zambian Agricultural Research Institute are developing and supplying farmers with more varieties. This includes the ‘orange maize,’ a drought ready, consistently yielding maize variety, which farmers hope will keep their harvests thriving even as drought becomes more frequent.
Julian is well aware of the benefits of diversifying our plant genetic resources. In fact, he was one of the brains behind the Crop Wild Relatives gap analysis, a project that attempts to inventory the gaps in ex situ conservation of those distant cousins of the domesticated crops that feed us. The genetic resources in these plants may be extremely useful for finding and incorporating adaptation characteristics into future generations of crop varieties.
How does your research emphasize the importance of identifying, collecting, conserving, and then using these crop wild relatives in breeding for adapting agriculture to challenges we will face in the future?
Julian: Crop wild relatives possess characteristics that are inherent to ‘wild stuffs.’ This means that their agronomic, or sometimes nutritional, characteristics are not very suitable to modern agricultural and food systems. However, this also means that they are harsher than modern crops with respect to their response to the environment. They may be more drought or heat tolerant, like the heat tolerant beans bred by CIAT, or disease resistant. At the same time, land use and climatic changes threaten natural ecosystems to the extent that entire populations or species of crop wild relatives may be lost within the next few decades. Better-adapted crops will be key in responding to these changes. If we want those useful crop wild relative characteristics to make our crops more adaptable to climate change, we need to collect, conserve, and study them.
To Julian, and to many others that research and work with crops on a daily basis, plant genetic resources are “important assets of humanity.”
“We want to preserve this diversity; we want to use it, because we think it is important for adaptation.”
The Crop Trust works closely with our partners like CIAT to both conserve, and make available, these plant genetic resources. Research like Julian’s shows the urgency to fund a global system of crop diversity conservation—a goal that the Crop Trust and its partners are diligently working towards.
What is the next step for you and your research? Will you be delving deeper into these transformational changes?
Julian: It would be ideal to continue investigating the nature and impact of transformational change. A key future avenue is to find empirical, field-based evidence of what triggers these changes in different regions and contexts; this would give us a clear idea of the role of climate change and variability in triggering change, and would allow us to develop better models for projecting transformational change. Research on this issue at CIAT, and across the CGIAR, is scarce. My paper has raised attention from several CIAT researchers, but so far the greater focus has been on incremental or systemic adaptations.
Which brings us back to Julian’s big takeaway: attention must be paid to transformational change in the long-term. Julian’s research is a reminder to us all that climate change effects are already cropping up—but the bigger concern is what is yet to come. The only way we will adapt our food system is to first thoroughly understand how and when we can expect our agricultural systems to change.
Otherwise, farmers will be left without fertile land, harvests, or income, and the world without a food secure future. Every colored dot on those nine maps could very well represent thousands of farmers in dire need of adapted crops. Their harvests—and their livelihoods—depend on a delicate balance of the natural environment, despite facing a disastrously changing climate.
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