Review of Climate Change Impacts on the Hydropower Sector
The United Nations has been organizing global climate summits for over 3 decades now. Almost every country on earth participates in these summits – called COPs – which stands for ‘Conference of the Parties' to work towards a solution to climate change. In the most recent summit, COP26, the participating countries agreed on four main goals. The first goal was to “Secure global net-zero by mid-century and keep 1.5 degrees within reach”. This implies that the greenhouse gases emitted in the atmosphere should be decreased drastically. Today, burning fossil fuels for electricity, heat, and transportation remains the biggest source of greenhouse gases emission. As the world is ever-developing, and the energy demand is ever-increasing, the need for a clean energy source is more crucial than ever before. With a detailed study of the energy production and consumption trends, IRENA (2021) predicts that to achieve net-zero, the current contribution of renewables has to increase from 25% (2017) to 86% (2050). As such, many new hydropower projects (an additional 850 GW by 2050) are being planned in the world to help mitigate climate change (IEA, 2021). The hydropower projects themselves also suffer from climate change impacts. The changes in the hydrologic cycle affect the quantity, seasonality, and intensity of flow in the river, making the hydropower generation vulnerable to climate change.
In this project, we reviewed over a hundred case studies of the impact of climate change on individual hydropower projects all around the world. The global review has separate sections for Asia, Africa, North America, Latin America, Europe, and Australia. Each section is further divided into regions of similar hydro-climate or hydro-politics (making a total of 17 regions) were the major climate change impacts have complied. Our review concluded that the impact of climate change on hydropower is not uniform all around the globe. Four primary mechanisms of climate change affecting global hydropower were identified as: permanent glacier depletion; loss in seasonal snow storage; increased variability; and increased evaporation. These mechanisms have the potential to produce a positive, a negative, or no change to the hydropower generation depending on the seasonality of temperature and precipitation, timing of peak electricity demand, type and design of the hydropower project (with or without storage), and the project location (upstream development).
In this review paper, we also presented the current approaches to quantifying the risks and room for improvement. Climate risks assessment of the individual projects is essential to design new resilient hydropower projects and identify adaptation measures to the existing ones. These assessments involve the development of a series of models with uncertainties cascading through them. Oftentimes, these uncertainties are not well quantified or communicated in the assessment result which might lead to miscommunication of the vulnerability of the projects. Moreover, the current approaches are well developed to assess the risks associated with the long-term performance of the hydropower, specific impacts due to changes in floods, and sediment concentration are still difficult to quantity. Competition with the market with other renewable sources of energy, and competition for water with other demands are likely to increase under climate change. Moreover from a socio-economic perspective, issues such as landlessness, joblessness, marginalization, and food insecurity that are typically associated with the poorly planned dam and infrastructure are possibly aggravated under climate change. The quantification for the latter two is barely done in climate risk assessment.
The review paper was published in January 2022 in the journal WIREs Climate Change and can be found here .
References:
- Wasti, A., Ray, P., Wi, S., Folch, C., Ubierna, M., & Karki, P. (2022). Climate change and the hydropower sector: A global review. Wiley Interdisciplinary Reviews: Climate Change, e757. https://doi.org/10.1002/wcc.757