Winds of Change: Climate Change and Sub-Saharan African Agriculture

As most of sub-Saharan Africa lies squarely within tropical and subtropical latitudes, it is becoming apparent that farmers must be made aware of potential climatic impacts and adaptation strategies. And to make things more complicated, these strategies will differ widely throughout the continent. Climate change will impact different regions within sub-Saharan Africa in different ways. For example, current estimates for annual precipitation in 2050 show increases in rainfall across parts of Sahelian and eastern Africa, a nil to minor increase across western and central Africa, and a decrease in southern Africa.

Not only will stakeholders have to continue to grapple with well-documented, existing obstacles including low access to inputs and underdeveloped distribution channels, they will also be forced to start considering the challenges posed by a changing climate. Although daunting, it is undoubtedly possible—through cooperation between public, private, conglomerate, and farmer—for African agriculture to proactively overcome these challenges, so that the region can thrive in the new environment.

Background

Sub-Saharan Africa’s population is growing at one of the fastest rates in the world: by 2050, it is expected that the number of people in the region will nearly double, from the current 1 billion to 1.8 billion. This staggering increase will place a substantial burden on a region that is still struggling towards self-sufficiency under the present conditions. Already, it is home to about 223 million people classified as “undernourished” by the FAO. By 2050, this figure is likely to grow to 350 million.

And data demonstrates that climate change is not some abstract, intangible thing of the future: significant events with considerable impact are already occurring. Accelerating changes in the climate will force an evolution away from “incremental adaptation,” in which farmers change crop planting and harvest dates. Farmers will move through “systems adaptation,” which is based on altering the selection of certain crops or selecting between cultivating crops or livestock, and ultimately to “transformational adaptation,” in which alternative lifestyles would be needed in the event that agriculture would become unfeasible. Because 95 percent of African agriculture is rainfed, the industry is exceptionally susceptible to any potential deviations in annual rainfall.

Pronounced floods and droughts

Over the past decade, a number of historic meteorological events have caused thematic shifts in the fundamentals of several staple commodities.

In 2007, flooding rains, which resulted from an abnormal pattern in the monsoon winds that drive seasonal rainfall, plagued parts of West, Central, and East Africa. Local media began to catch wind of the developing situation in June, but failed to comprehend and gauge its true severity until the damage had already been done a few months later, in September. One country hit particularly hard was Ethiopia, which has had a lot of experience in coping with the effects of drought, but relatively little in understanding the effects of floods. The southwestern region, specifically the lowlands along the Baro River, were hit hardest. That area had historically been sparsely inhabited, but in an attempt to mitigate the impact of frequent droughts, the Ethiopian Government had encouraged its habitation. A household survey conducted in 19 villages and covering 431 households found that nearly 90 percent of respondents said that the flood severely damaged or entirely destroyed their crops, while almost 75 percent stated that the flood severely harmed their cattle.

Two years after the events of 2007, there was another serious flooding situation, this time concentrated in West Africa. Similar to the 2007 event, this flood occurred in June during monsoon season, and resulted in Burkina Faso’s worst flooding in nearly a century. At one point, Ouagadougou, the country’s capital, recorded over 25 percent of its average annual rainfall within just 24 hours.

Viewing a compilation of Landsat 5 data from a NASA and USGS co-managed satellite, water channels across Burkina Faso including the Nakambe, Ouale, and Pendjari Rivers are only faintly recognizable on August 28, 2009 (Figure 1). By September 8, 2009, torrential rains carved out distinguishable lakes and creeks throughout the region, and the aforementioned rivers surged to the point that they killed crops, cattle, and tragically, people (Figure 2). At least 193 deaths have been attributed to these floods, and total damage is estimated to have exceeded $152 million, equivalent to a 1.8 percent decrease in GDP (in current US dollars).

On the other side of the precipitation spectrum, droughts continue to pose significant threats to agricultural productivity throughout the continent. Kenya, along with several other East Africa Community countries, suffered unprecedented droughts in both 2009 and 2011, the latter being the worst in over 60 years. For a region where virtually no farmland is irrigated, droughts are among the most lethal weapons in Mother Nature’s arsenal. This occurred just months after Russia—a major supplier of grains to the rest of the world—suffered through its worst drought in nearly 40 years, sparking food supply concerns in Russia and parts of the Middle East. As a result of these droughts and wildfires, which halved wheat supply, the Russian Government imposed export restrictions on Russian grains. In Kenya, therefore, the effects of its own drought were compounded by the effects of Russia’s. As a result, the region was desperate for grains in a trade environment marred by drought, trade restrictions, and inflated prices. And this was not the first time in recent history that Kenya and its neighbors were socially and economically devastated from the effects of destructive weather. Abnormally strong El Niño floods and La Niña drought events in 1997 and 2000 reduced Kenyan GDP by 11 percent and 16 percent, respectively.

It is interesting to note that the 2009 Burkina Faso floods occurred during a moderate El Niño cycle. El Niño refers to the warm phase of an oceanic oscillation in the Eastern equatorial Pacific Ocean. An oceanic oscillation is a cycle defined by changes in air pressure, sea temperature and wind direction over oceans. La Niña is the cool phase, with colder sea surface temperatures.

Each oscillation changes weather patterns in the tropics in different ways for different regions: it is generally accepted that the most direct relationship between El Niño (also frequently referred to as ENSO, or El Niño Southern Oscillation) and Africa is in Southern Africa, specifically South Africa. During a moderate to strong El Niño phase, Southern Africa typically sees below-average rainfall. The opposite is true during the cooler La Niña phase, during which the region can expect above-average rainfall. One other interesting item to note is the fact that Eastern Africa maintains an inverse relationship to Southern Africa. During El Niño cycles, Eastern Africa typically sees above-average precipitation, while it experiences below-average precipitation during La Niña seasons. At this time, the correlations behind ENSO and Africa are not as well documented as those of other regions. An improved understanding of these inherent macro-atmospheric relationships would be extremely valuable to members of both the private and public sectors operating in the region.

Predicting the 2050 sub-Saharan climate: a true long-range forecast

Historians and political scientists often pay homage to the proverb, “history repeats itself.” For those forecasting climate change, including the dozens of leading scientists who author the IPCC reports, the proverb does not exist. The exhaustive task of working with a limited time series of data—one that dates back merely a century amidst an atmosphere that has existed for hundreds of millions years—relies on a blend of sophisticated modeling and human observation.

Scientists have only in recent decades begun to understand the clear threat that greenhouse gases pose to the climate. In the IPCC Special Report on Emission Scenarios, the panel highlights agriculture’s 24 percent contribution to global greenhouse gas emissions. Africa accounts for 15 percent of global agricultural, forestry and other land use related emissions, and these emissions are expected to grow by 30 percent between 2010. This growth alone is expected to result in a loss of over 3 percent in the amount of land area that is suitable for agriculture in sub-Saharan Africa.

Unsurprisingly, high-emission base cases have higher estimates regarding the rate at which the climate will change. Assuming world temperatures climb 4°C by 2100, annual precipitation across Southern Africa would fall by as much as 30 percent, and parts of Southern and Western Africa would experience deteriorations of groundwater recharge rates by as much as 70 percent. The IPCC also upgraded the likelihood of human activity being the primary cause of overall warming from “very likely” to “extremely likely”—which means that there is at least 95 percent confidence that this will be the case. The panel further believes that it is “likely” that mean temperatures will increase by 2°C by 2050 (minimum 66 percent confidence-level).

In addition to the above projections, several intra-continental forecasts have been shared and reiterated in the IPCC AR5 report. The panel is highly confident near-term temperature increases in sub-Saharan Africa will outperform mid-latitude regions, and that there is a “very likely” chance that extreme precipitation events in sub-Saharan Africa will become more intense and more frequent by 2100 (minimum of 90 percent confidence). Monsoon patterns are also slated to change—it is “likely” that monsoon winds in West Africa will weaken, however, precipitation from monsoons is “likely” to intensify due to an overall increase in moisture availability throughout the Inter Tropical Convergence Zone (equatorial latitudes).

The IPCC believes with high confidence that the El Niño Southern Oscillation (ENSO) will continue to be a dominant driver in inter-annual precipitation variability, and that ENSO-related precipitation impacts in sub-Saharan Africa are “likely” to increase. The intra-continental magnitude of impacts will also vary: Sahelian Africa is projected to become disproportionately wetter—consensus estimates of a 7.5 percent increase in median annual rainfall by 2050; a 6.3 percent median increase in East Africa, and a 2.8 percent and 2.1 percent increase in West Africa and Central Africa, respectively. Southern Africa is the only region forecasted to see a decrease in median annual rainfall values by 1.6 percent.

In addition to atmospheric considerations, rising sea levels are a major concern for any coastal country. The IPCC predicts sea levels will rise between 0.17 to 0.38 meters by 2050, and have “very high confidence” that coastal cities and other lowlands will be faced with submergence, flooding, soil erosion, and decreased soil quality from increased salinity.

As of 2005, an estimated 56 million people live in coastal regions within sub-Saharan Africa. A study performed in 1992 indicated that a 1-meter rise in sea level would displace roughly 3.7 million Nigerian coast-dwellers. In Nigeria, nearly 25 percent of the population is now considered coastal. Lagos alone has gone from under 1 million inhabitants in 1965 to nearly 16 million today. This logic implies a conservative displacement of at least 5 million people—and that is only in Nigeria.

Crop suitability: a dynamic discussion

It is essential that all stakeholders grow more knowledgeable about the changing climate and its implications. Beyond obtaining access to seed varietals better equipped to withstand harsher climates, producers will also need to review the suitability of various crops and determine which crops have the ability to grow and thrive under a broader range of climatic conditions.

One example of this logic is to compare cassava growth ranges with those of beans. Cassava can grow anywhere between 15° and 45°C, and must receive roughly 300 to 2,800 mm of rainfall per season. Given the current IPCC outlook, there is no reason to expect that the suitability of planting cassava will be negatively impacted in Africa: in fact, there should be a pronounced increase in suitability across eastern Africa, where annual rainfall amounts are expected to increase.

On the other hand, beans have a growth temperature range of 14° to 26°C and a rainfall range of 200 to 710mm per season. This narrower range means that less land will be deemed suitable for the cultivation of beans, with the most significant declines expected to occur in East Africa (28 percent reduction from current production totals) and central Africa, where a stunning 80 percent loss is forecasted by 2050. Central Africa is currently the heart of sub-Saharan Africa bean production, yet the specific growth ranges will likely turn future growth prospects grim. Thus, investors, policymakers, and farmers can take note of the rising potential opportunity of cassava, and the growing necessity of a hedge for beans.

It will become increasingly important that farmers use natural resources like water effectively and efficiently. As the overwhelming majority of African agriculture is rainfed, there is a need to shift towards irrigation throughout the continent—but this shift will be particularly critical in Southern Africa, where rainfall is anticipated to decrease. Beyond forcing rethinking on crop suitability, climate change is putting immense pressure on livestock rearing. Pastoralists, or nomadic livestock herders, make up a significant proportion of people involved in the raising of livestock in many African countries. Depletion of resources is making their nomadism increasingly difficult to sustain, and these groups are increasingly driven into conflict with one another as they fight over finite resources. Climate change will likely force pastoralists—whose nomadic ways have been relatively unchanged for centuries—to somehow adapt to new realities.

Conclusions

It is essential that all stakeholders grow more knowledgeable about the changing climate and its implications. Beyond obtaining access to seed varietals better equipped to withstand harsher climates, producers will also need to review the suitability of various crops and determine which have the ability to grow under a broader range of conditions.

As knowledge about the potential implications of climate change continues to grow, it is critical that policymakers, investors, businesses and citizens keep abreast with the latest findings from the International Panel on Climate Change. And all of these groups should prioritize working with farmers and anyone involved with agriculture to ensure that all parties are aware of changing realities. In the past decade, the world has witnessed time and again the monumental role that weather can play in commodity markets and in the broader struggle for food security.

Climate change is complex, and its specific outcomes are nearly impossible to be certain of. As a result, adaptation strategies will have to be dynamic and adaptable. The African Risk Capacity, for example, is an African Union-led initiative aiming to better prepare countries on the continent for the effects of climate change. As the potential for unexpected natural disasters is increasing, the organization is aiming to better manage climate risk through data, which allows for the targeted, timely and efficient pooling of resources in the event of a disaster.

Effective climate mitigation strategies will have to be dynamic, data-driven and efficient, while taking into account important regional and country-specific nuances. Everyone has a stake in ensuring that agriculture adapts to the changing climate around the world. As it can lead to increased volatility in production, it can therefore lead to increased volatility in food prices. This will only be compounded by the fact that populations in many parts of the world are growing wealthier, meaning that the rate at which their demand for food grows outstrips the rate at which their population grows. In order to meet this demand, by 2050, global food production will need to increase by 70 percent. It will become essential for Africa, which has the greatest potential to become the newest global breadbasket, to intelligently build the vessel in which it will navigate the uncharted waters of climate change; after all, the winds are changing.