The impact of climate change on agriculture is becoming increasingly evident, especially for smallholder mixed crop-livestock (MCL) systems operating throughout sub-Saharan Africa. A new study using advanced modeling techniques explores how these systems could be affected by future climate scenarios, shedding light on significant challenges—and potential opportunities—within the agricultural sector.
Researchers have enhanced the SIMPLACE modeling framework by incorporating integrated crop-vegetation-livestock models, which are pivotal for developing sustainable agricultural practices. They applied this framework to simulate various scenarios across 786,500 square kilometers of West Africa, focusing on staple crops such as maize, millet, and sorghum, alongside livestock populations and their greenhouse gas emissions.
The results indicate dire consequences for MCL systems as climate change progresses. Particularly alarming is the projected future decline of crop biomass, expected to fall by up to 56%, alongside grass biomass plunging by nearly 57%. Following this trend, researchers anticipate livestock numbers could decrease significantly—by as much as 43%—which will undoubtedly impact total emissions, particularly methane (CH4) emissions, which may diminish by up to 47%.
While the northern regions, particularly the Sahelian zone, are expecting sharp declines, pockets within the Sudanian zone could witness the opposite effect: some areas are projected to see livestock populations increase by about 24%. This discrepancy highlights the variability and complexity of climate impacts, as the same climatic forces can lead to distinct outcomes over relatively short geographical distances.
The study is timely, as smallholder farmers face pressure not just from climate variability, but also from growing populations and changing dietary preferences, which heighten food demand. Many of these farmers rely on sustainable practices like the use of crop residues for livestock feed, which aids both crop fertility and animal health. Yet, these systems must adapt to the increasingly erratic weather patterns driven by climate change.
Using the SIMPLACE framework, the authors conducted modeling simulations to assess crop yields, livestock numbers, and greenhouse gas emissions over historical (1981-2005) and projected future periods (2020-2050). They leveraged Global Circulation Model (GCM) projections to estimate changes and discovered alarming decreases in forecasted outputs.
The ramifications are stark: milk production could drop by 41% and meat production could fall by 47% within the Sahelian region. Such losses signal severe economic and nutritional impacts on communities dependent on these livestock and crop systems for their livelihoods.
Despite these challenges, there are efforts underway to maintain and sustain these mixed farming systems. Until now, many studies treated crop and livestock models separately, which could overlook important interactions between them at the ecosystem level. By enhancing the SIMPLACE framework to analyze MCL systems holistically, researchers hope to discover pathways for improving agricultural sustainability and productivity.
Another significant aspect of the research is its focus on the differing ecological zones. The Sahelian zone, characterized by annual grass types and harsh climate, contrasts sharply with the Sudanian zone, which experiences wetter conditions and more resilient perennial grasses. This variation plays a significant role in determining the agricultural outputs and stresses both systems may face.
The findings from this work have major ramifications, calling for urgent action and adaptation strategies to safeguard food security within the region. The study concludes by emphasizing the importance of integrating crop and livestock management with climate resilience strategies to secure sustainability and productivity for these systems.
Future research will need to continue refining these models and exploring new agricultural techniques to help farmers adapt to rapidly changing environmental conditions. The aim is to not only mitigate the impacts of climate change but also to bolster the resilience of those smallholder farmers who play such a pivotal role in the agricultural fabric of sub-Saharan Africa.