Although Africa is a minor contributor to carbon emissions, it is potentially a significant actor in mitigation through avoided deforestation, provided that countries succeed in intensifying production. However, Africa is above all a continent already experiencing the effects of climate change and will continue to do so increasingly.
It is possible to anticipate certain risks through adaptation measures and to moderate yield variability. This is what PARM works toward, through the production of data, analyses, and strategies. Uncertainty about future climate developments makes it difficult to implement economic strategies such as affordable climate risk insurance or agronomic strategies such as developing adapted seeds. However, scenarios from the Intergovernmental Panel on Climate Change (IPCC) help anticipate the most probable changes, such as an increase in average temperatures in West Africa of at least 1.5 °C by 2060, and to formulate hypotheses about unknowns, such as the frequency of heatwaves or droughts within a year, as well as adaptive capacities and their effect on yields.
Effects already visible in Africa
Rising temperatures
Since the mid-1970s, annual and seasonal average temperatures in West Africa have increased by 1 to 3 °C, with sharper rises in the Sahara and Sahel. Unpredictable heatwaves have also become more intense and longer compared to the last two decades of the 20th century. Extremely hot days (above 35 °C) and tropical nights (minimum temperature above 20 °C) are becoming more frequent.
Erratic rainfall
Since the 1990s, West Africa has become wetter overall, but rainfall is less frequent and more intense, causing floods. Between 1981 and 2014, the Gulf of Guinea and the Sahel experienced heavier precipitation, and the frequency of convective storms tripled (storms generated by rising warm air from the surface). Despite this, meteorological, agricultural, and hydrological droughts have increased in frequency since the 1950s, with more frequent multi-year droughts. PARM’s risk assessments confirm these trends: in Tunisia, the risk of multi-year droughts is very high, particularly affecting agriculture and groundwater. In Burkina Faso, PARM noted an increase in agricultural losses linked to droughts as well as floods.
According to the IPCC’s sixth assessment report, maize and wheat yields in Sub-Saharan Africa decreased by 5.8% and 2.3%, respectively, between 1974 and 2008 compared to what they would have been without climate change. The expansion of woody species, shrubs and trees, on large grazing lands has reduced forage availability for livestock, increasing mortality and driving up livestock prices, key factors in local tensions.
Still according to the IPCC, African countries’ per capita GDP was on average 13.6% lower between 1991 and 2010 than it would have been without anthropogenic climate change (over 20% for Burkina Faso, Niger, Mali, and Mauritania).
PARM’s approach: understanding risks for better adaptation
One of PARM’s added values is measuring these changes in countries, studying their impacts on production or value chains, and analyzing them in relation to other existing risks, current climate risk management measures, and gaps for better adaptation. The study of historical series helps track trends and their effects.
In the Sahel and North Africa, long-term annual rainfall totals are generally favourable but erratic, while temperature trends are unfavourable for existing crops such as wheat or olive in Tunisia, as shown by the data below.
Figure 1. Precipitation during the growing season
Figure 2. Maximum temperature during the spring season in Tunisia
Figure 3. Date of grain ripening
These evolving trends and risks result in yields that stagnate and remain highly volatile despite significant public efforts and price regulation policies.
Figure 4. Trends in soft wheat yields in Tunisia (tons/ha)
In Tunisia, the overall risk evolution analysis leads us to recommend refocusing wheat production in the northern regions of the country while intensifying it through practices combining organic matter conservation, precision irrigation, and agricultural insurance coverage for olives, coupled with a quality labelling policy for olive oil to regulate price fluctuations.
Climate risks expected to intensify in Africa
Future trends and risks
Future warming will negatively affect food systems in Africa by shortening growing seasons and increasing water stress. With global warming of 1.5 °C, maize yields could drop by 9% in West Africa (assuming limited adaptation). Sorghum yields are also expected to decline in West Africa. Global warming above 2 °C will cause a decrease in staple crop yields across most of Africa compared to 2005 levels, even if adaptation options are implemented. Beyond 2 °C, losses of more than 40% in pasture productivity are also projected for western Sub-Saharan Africa. Global warming of 3 °C would reduce agricultural labor capacity by 30–50% in Sub-Saharan Africa due to rising temperatures. Climate change threatens livestock production through reduced forage and drinking water availability, direct heat stress on animals, and increased prevalence of livestock diseases.
PARM’s contribution: anticipating losses and targeting vulnerable areas
Combining current agricultural data with weather scenarios has made it possible to simulate the impact of climate change on economic losses linked to reduced agricultural production. For example, agricultural risk assessment in Burkina Faso estimated sector losses under the IPCC’s medium scenario for 2040 (+1 °C). Results show that areas at intermediate latitudes in the country will be most affected because yields there are relatively good but temperatures are already high. Conversely, the North, which is very hot and dry, has low yields, while the South benefits from favourable rainfall and more stable yields.
Figure 5. Geographic distribution of average annual losses in the agricultural sector for the period 2020-2040 (climate change scenario of +1 °C without precipitation change; data expressed in US$ per grid point at 5 arc-minute resolution, approximately 80 km²).
Tools for preparing
Being able to anticipate these changes makes it possible to implement longer-term adaptation strategies. Where expected losses are greatest, and where current production methods will no longer be suitable, it will likely be necessary to consider the most radical adaptation solutions, such as changing the cultivated species in favour of those adapted to warmer or drier conditions, like millet and sorghum, or continuing to grow maize but investing heavily in irrigation where it is possible. Where losses are less significant, such as in the north of the country, consideration could be given to developing tools already underway, such as soil water conservation practices.
Overall, climate risk insurance is often considered one of the most effective tools for managing economic losses due to climate risks, including those linked to future climate change. However, the cost of unsubsidized insurance may be out of reach for many smallholder farmers. Should then climate insurance be subsidized to increase their affordability and for how long ? We will not answer this in this paper because it is a matter of nation al public choice, but let us recall the favourable conditions for insurance to be economically self-viable;
Insurance is well adapted to protect against risks that:
- occur with a low frequency
- generate severe economic losses
- are pooled and idiosyncratic
In the case of smallholder farmers facing droughts, these conditions are generally not fully met (droughts tend to be frequent, generate very harmful for crops and livestock but on non commercial – low added-value crops and livestock, and they hurt a large number of farmers but in a rather systemic way). This is why if a country’s public choice is to develop drought insurance products for small holders, it is likely that the subsidization of insurance will be necessary.
This said, the best strategy for managing agricultural risks is often holistic and addresses the several aspects of climate risks: water conservation practices, seed adaptation, water management and irrigation, better storage, and insurance.
