Nature-Based Solutions in Sub-Saharan Africa for Climate and Water Resilience: A Methodology for Evaluating the Regional Status of Investments in Nature-Based Solutions from a Scan of Multilateral Development Bank Portfolios

Nature-Based Solutions (NBS) are an integral solution to addressing SubSaharan Africa’s (SSA) growing infrastructure service needs, while maximizing the impact of limited resources to enhance resilience to water and climate risks. For example, restoring watersheds can enhance water security, increasing urban green space can reduce urban heat, and protecting mangroves can reduce coastal flood risk. Recent research has estimated that NBS can provide up to 11 percent of total infrastructure investment needs globally and can provide 28 percent better value for money spent than gray infrastructure. As major financiers of infrastructure and climate-adaptation projects in the region, multilateral development banks (MDBs) play a critical role in catalyzing finance for NBS in SSA. While MDBs have a track record of investing in NBS, there is an urgent need to analyze the state of play of NBS projects in MDB portfolios and identify the enabling conditions that lead to successful implementation in order to increase the pace and scale of these investments to address growing climate and water risks. This technical note outlines the methodology used to create a region-wide dataset of 85 direct investment projects from two MDBs—the World Bank and the African Development Bank—that have implemented NBS for climate and water-resilience objectives over a 10-year period (2012‒21). This methodology includes processes for tracking project attributes that can be used to evaluate overall trends of MDB-led NBS projects in the region. For instance, the dataset reveals hat 64 percent of NBS projects were integrated green-gray infrastructure projects, whereas 36 percent were focused primarily on green infrastructure and that NBS interventions primarily yielded benefits for the water and sanitation (60 percent) and agriculture (35 percent) sectors. This methodology provides a foundation to make actionable recommendations for MDBs to scale up NBS adoption in the region.