Climate is critical in southern Africa’s water-energy-food nexus

There has been a recent upsurge in research and policy interest in natural resource scarcity, particularly in relation to the water-energy-food nexus. In a recent paper, we show how the nexus can be used to recognise the complex interdependencies between sectors and to highlight the need to minimise potential trade-offs. For example, a nexus approach shows how the actions in one sector can produce damaging effects in other sectors.

Biofuels provide a good example of nexus linkages, whereby production and supporting policies can generate increased competition for land and water. Linkages are also strong in river basins, where competing demands for water can sharpen the trade-offs and opportunity costs associated with water use in agriculture and electricity generation, as well as for urban and environmental needs.

In an article published in Nature Climate Change last week, we reviewed the nexus in southern Africa – a region emblematic of the connections between water, energy and food.

How climate affects the nexus

Physical and socioeconomic exposure to climate is high in vulnerable areas and sectors. And climate plays an important role in determining medium-term (i.e. in the period between 5 and 40 years from now) water availability, potential agricultural production, and some components of energy production and demand.

At the national level, for example, water and energy are closely coupled through significant hydropower production in many of the region’s countries.

Water and food linkages are also strong. This is most evident when looking at rainfed and irrigated agriculture, which together account for most freshwater consumption in southern Africa.

Meanwhile, food and energy linkages are growing due to increasing irrigation, mechanisation, and fertilization of agriculture.

Climate change will generate additional pressures on the nexus. The region’s population is projected to double by 2050 and is concentrated in areas exposed to high levels of climate variability. Rapidly increasing demand for energy by industry and mining, fast expansion of urban areas, and agricultural intensification are likely to place further strain on the water-energy-food nexus. Annual precipitation in the southernmost countries is expected typically to decrease by as much as 20% by the 2080s. These changes would propagate into reduced water availability and crop yields.

El Niño forecasting to smooth fluctuations

Indeed, there is strong evidence that floods and droughts significantly impact the nexus. Moreover, southern Africa’s climate is influenced by the El Niño-Southern Oscillation, which tends to bring drier conditions to the region. For example, South Africa experienced a dip in GDP in the 1983 El Niño year. Whilst forecasting of El Niño events has improved, no two events are the same and their impacts differ considerably.

Seasonal forecasting of El Niño events has the potential to help smooth fluctuations in the nexus. However, there remain significant barriers – such as forecast reliability and the ability and incentives of users to act on such information. If these barriers can be overcome, seasonal forecasting can make a significant difference to lives of people in southern Africa. It can inform guidance on the targeting and access to agricultural inputs and credit, the design of interventions during food crises and improvements to trade and agricultural insurance.

Three regional initiatives for southern Africa

Recognition of spatial and sectoral interdependencies in the nexus should inform policies, institutions and investments for enhancing water, energy and food security in the climate-sensitive environments of southern Africa. We therefore recommend that three regional initiatives could be strengthened to better manage the challenges associated with the water-energy-food nexus.

Firstly, the Southern African Development Community (SADC) has already established protocols on shared water, energy, and food security. It has also initiated a regional seasonal climate forecasting forum and has initiatives on trade and the green economy. However, there are barriers to cross-sectoral integration. Entrenched vertically structured government departments and sector-based structures of agencies and policies complicate coordination among those responsible for water, energy and food. The political economy of governance and operation is also challenged by institutional capacity and power imbalances in the region.

There is a need to map nexus governance structures at finer scales, and to identify measures that can enhance successful cross-sectoral approaches. Some efforts are underway in regional strategy and policy formulation to better achieve cross-sectoral coordination. However, the modalities for achieving such coordination are still under debate.

Secondly, the Southern African Power Pool, an alliance of 12 energy-generating bodies from 12 countries, which help smooth spatial and temporal shortfalls in electrical capacity through an inter-connected grid. The network is intended to function as a competitive market in which surpluses and deficits are resolved via trades and negotiations. It therefore has the potential to serve as a buffering mechanism for climate-induced electricity insecurity at the river basin scale. This could be achieved through enhanced coordination with other agencies such as SADC.

Thirdly, the international trade of agricultural products results in significant transfers of embedded water between countries. One of SADC’s main goals for regional integration is to promote trade among member countries. Efforts are ongoing to reduce existing barriers, such as trade regulations and the lack of reliable transportation infrastructure. Although strong open trade can be an important tool to alleviate climate-induced food deficits, southern African countries have varying levels of trade connectivity and trade link strengths. The potential benefits of food trade to alleviate production shocks are therefore likely to be uneven across southern Africa and further investigation is required.

In the highly climate-sensitive environment of southern Africa, emerging strategies to cope with challenges to the nexus – such as those already developed under SADC – will only bear fruit if the co-dependencies and inter-relationships between sectors are recognised.