Comment on egusphere-2022-604

Abstract

Sub-Saharan Africa (SSA) is the region most vulnerable to climate change and related hydro-meteorological risks. These risks are exacerbated in rapidly expanding urban areas due to the loss and degradation of green and blue spaces with their regulating ecosystem services. The potential of nature-based solutions (NBS) to mitigate hydro-meteorological risks such as floods is increasingly recognized in Europe. However, its application in urban areas of SSA still needs to be systematically explored to inform and promote its uptake in this region. We conducted a multidisciplinary systematic review following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocol to establish the general patterns in the literature on NBS and hydro-meteorological risk mitigation in SSA. We searched scientific journal databases, websites of 12 key institutions and 11 NBS databases and identified 45 papers for analysis. We found at least one reported NBS in 71 % of urban areas of SSA across 83 locations. 62 % of the papers were clustered in South Africa, Kenya, Tanzania and Nigeria only, while the most studied cities were Dar es Salaam and Kampala. Moreover, 66 NBS practices were identified, most of which (n=44) were for flood mitigation. With only Mozambique (n=2) reporting NBS among the most at-risk countries, we found that NBS are implemented where risks occur but not where they are most severe. Mangrove restoration and wetland restoration, reforestation and urban forests, and agroforestry and conservation agriculture were the most common NBS practices identified for floods, extreme heat and drought mitigation, respectively. Traditional practices that fit the definition of NBS, such as grass strips and stone bunds, and practices more popular in the Global North, such as green roofs and green façades, were also identified. These NBS also provided ecosystem services, including 15 regulatory, 5 provisioning and 4 cultural ecosystem services, while 4 out of every 5 NBS created livelihood opportunities. We conclude that reported uptake of NBS for hydro-meteorological risks in SSA is low. However, there could be more NBS, especially at the local level, that are unreported. Furthermore, NBS can help SSA address major development challenges such as water and food insecurity and unemployment and help the sub-region develop climate-resiliently. We, therefore, recommend that NBS be mainstreamed into urban planning and for knowledge exchange opportunities between SSA and Europe and other regions to be explored to promote uptake.