Why should we assess climate impacts?

The past decade (2010‑19) was the hottest since records began in 1850 and the year 2019 was the second warmest year on record. The increasing level of heat accelerated the melting of ice sheets in Greenland and Antarctica, and resulted in the highest sea levels in 2019 since the introduction of the high-precision altimetry records in 1993. More erratic patterns of rainfall across the world and extreme weather events such as floods, droughts, heatwaves and tropical cyclones became more frequent or intensified in many countries (WMO, 2020).

These actual consequences of the changing climate, are called climate impacts. The increasing anomalies in climate patterns directly affect all stages of the entire energy value chain of electricity systems, including fuel supply, generation, transmission and distribution, and demand. They can change resource availability, reduce generation efficiency, increase physical risks to grids and assets and alter demand patterns.

The recent trends of increasing renewable energy penetration as an effort to mitigate climate change, may also have unintended impacts on electricity systems, intensifying the level of climate-related stress. An electricity system with a high share of renewable sources could become more susceptible to climate change since renewables such as solar, wind and hydro tend to be sensitive to climate impacts (Ligtvoet et al., 2015). These changing conditions will require governments and utilities to better understand climate impacts on power systems, and to take appropriate actions to enhance their resilience to the adverse effects of a changing climate.

Why should we look at African hydropower?

The continent of Africa is one of the most susceptible regions to climate change. It is projected to experience increasing climate hazards during the remainder of the century. The majority of African countries are likely to see an increase in temperatures above the global average and more variations in precipitation patterns. Some countries in southern Africa have already experienced a notable level of warmth (more than 1°C above the average temperature of 1981‑2010) and abnormally low precipitation in 2019 (WMO, 2020).

The projected changes in temperatures and precipitation patterns in Africa are likely to affect hydropower generation. For instance, the increasing variations in streamflows and evaporations are likely to result in stronger fluctuations in the generation output. In some African countries, hydropower operations could be even further restrained due to water scarcity. The limited adaptive capacity of local operators may aggravate the situation.

Despite the projected climate impacts, hydropower is likely to play an increasingly important role in Africa to support sustainable development and transitions to clean energy. Currently, 17% of electricity is generated from hydropower. This share is expected to increase to more than 23% by 2040 as a result of ongoing efforts to meet both climate goals and universal access to electricity (IEA, 2019). Indeed, Africa still has enormous remaining hydropower potential which is technically and economically feasible. Therefore, many countries have initiated new projects to tap into the continent’s enormous hydropower potential.

However, due to limited information and capacity, most planned hydropower projects in Africa rarely take into account potential climate impacts (CDKN, 2015). In some countries, there is a considerable level of uncertainty in assessing potential climate impacts on hydropower due to a lack of historical observation data and low agreement among climate scientists. Moreover, even when the data is available, public officials and utilities, particularly those in rural areas, have a low capacity to assess climate risks and impacts, and integrate the results into the planning and implementation of hydropower projects. Projects that are not attentive to climate impacts are likely to have difficulties in managing the stress created by a changing climate.

To minimise the adverse impacts of climate change, hydropower needs to enhance its resilience to climate change by incorporating systematic assessments of climate impacts. A resilient hydropower can play a key role in achievement of SDGs, clean energy transitions and climate change adaptation.

This report aims to contribute to increasing the resilience of African hydropower by providing qualitative and quantitative analyses of climate risks and impacts, and introducing potential resilience measures. First, it qualitatively assesses the climate risks on African hydropower based on three dimensions: hazard, exposure and vulnerability. Second, it examines the potential climate impacts on African hydropower quantitatively, comparing two climate scenarios. Finally, the last part presents examples of measures to enhance climate resilience and suggests policy options.