Conversations about climate change often focus on future effects, but according to the latest Assessment Report from the Intergovernmental Panel on Climate Change, changes to the global climate have already had a significant impact on food production. Global agricultural productivity has declined over the past 30 years by 1-5 percent per decade, and this deterioration is expected to continue, even if we only experience low levels of warming (+2 ºC).
This likely means particularly bad news for African agriculture, as tropical crops such as maize and rice seem to be especially vulnerable to climate changes. Identifying which crops are most and least resilient to weather shocks, as well as ways to mitigate such shocks, will continue to be an important research priority in the region. In Climate Change Impacts on African Crop Production, a recent working paper released by the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), Julien Ramirez-Villegas and Philip K. Thornton examine projected trends until the 2050s for nine important staple crops (maize, common bean, cassava, sorghum, yam, finger millet, pearl millet, groundnut, and banana) and one major cash crop (coffee) across Africa.
Their results are sobering. Approximately 90 percent of Africa’s current cropped maize area will experience negative impacts; the authors estimate maize production will drop by 12-40 percent by 2050. Countries across West Africa, especially the Sahel, will experience the worst effects due to their shortened cropping seasons and inherent risks of heat stress. According to the authors’ projections, if countries do not make efforts to adapt to climate change, such as developing and adopting heat- and drought-resistant crop breeds, the best-case scenario is that by the end of the 21st century, total maize production in Africa will have fallen from around 42 million tons per year to around 37 million tons per year, a decline of 12 percent. The worst case scenario, on the other hand, will see maize production plummet by as much as 40 percent, to only 25 million tons per year. Since maize is one of the largest contributors to caloric intake in the region, these statistics highlight the urgent need for adaptation measures.
Common bean, another major staple crop across the continent, will also be hard hit. Production and yield decreases of at least 40 percent are expected throughout the Sahel, east and central Africa, and southern Africa. However, common bean yields may actually increase in other regions (namely, parts of the East Africa highlands, western regions of southern Africa, and coastal North Africa), pointing to the fact that this crop is highly sensitive to climate.
Agriculture in Mali, Senegal, Burkina Faso, and Niger, all Sahelian countries, stands to lose the most. As temperatures rise past the level at which crops can grow and as precipitation decreases, suitable planting areas in these countries, already limited, are expected to decrease for 70 percent or more of the study crops; in other words, many of these nine crops will no longer be able to be grown at all. Producers in this region will need to adapt by diversifying their livelihoods to include livestock breeding or agroforestry, by improving crop management practices, or by adopting more heat-resistant crops like cassava and yams.
While the area suitable for planting maize, common bean, banana, and finger millet is expected to decline, several of the other study crops are not projected to lose area, and may even gain suitable area in some regions. These variations suggest that regional adaptation measures could include expanding cropping into new countries and agro-ecological regions. East Africa and more temperate regions of southern Africa could provide new opportunities for cassava production, and bananas, groundnuts, and millet could also successfully expand to East Africa.
In order for these geographical shifts to take place, however, there will need to be accompanying shifts in regional trade policies, diets, and farming systems. Successful adaptation to climate change will require continued investment in research, development of heat- and drought-resistant crops, and incentives for farmers to adopt new, potentially more costly, techniques.
By: Sara Gustafson