By Wallace Mawire
Across African cities and globally, Nature-Based Solutions (NBS) and green-gray infrastructure (GGI) interventions are changing the landscape of climate resilience.
When done right, the projects can protect people from climate shocks, enhance biodiversity, and improve socio-economic and health outcomes. According to a World Resources Institute (WRI 2025) report, new NBS projects in sub-Saharan Africa have increased by an average of 15% annually from 2012-2021.
Now, the question is how to sustain the momentum and ensure that NBS is integrated into long-term climate resilience planning.
Under its Green-Gray Infrastructure Accelerator, WRI is bringing a cross-sectoral approach to NBS integration and fostering peer learning exchanges across African cities.
In Rwanda, WRI has convened cross-sectoral stakeholders to implement ambitious NBS projects for urban resilience at the city scale, restoring or planting 2,407 hectares and over 100,000 trees over two years.
At the same time, building on a national push for climate resilience and green growth, the partnerships have worked to integrate NBS into emerging climate and urbanization plans at city and national scales.
In a coming on March 12, 2026 webinar titled: Scaling Green Infrastructure for a Resilient Rwanda speakers from the Rwandan government, development agencies and community groups will discuss what is needed to move beyond one-off projects to the long-term integration of nature and infrastructure into policy.
This webinar is part of WRI Africa’s Green-Gray Infrastructure Accelerator Webinar Series, which draws on the experience of Cities4Forests, Urban Water Resilience, and partners from across the continent to illuminate best practices for planning, financing, implementing and institutionalizing natured-based solutions for urban climate resilience.
According to the WRI, cities across sub-Saharan Africa face escalating climate risks — droughts, extreme heat, and frequent floods — that threaten public health, livelihoods and economies. By 2050, the share of urban residents in Africa facing at least eight days a year over 35 degrees C will rise from 66% to 85%, worsening heat-related illnesses and reducing worker productivity. Meanwhile, land-use changes are accelerating biodiversity loss, weakening essential ecosystem services.
With sub-Saharan Africa’s urban population expected to double by 2050, cities must address infrastructure gaps to protect vulnerable communities and ensure a climate-resilient future. This will be especially critical for the 60% of the region’s urban population that live in informal settlements, as they are particularly susceptible to climate risks.
The Green-Gray Infrastructure (GGI) Accelerator works with cities in sub-Saharan Africa to address climate resilience challenges by delivering effective, context-tailored climate and infrastructure solutions. It offers cities technical assistance across the arc of project development — from feasibility to financing, and from pilot implementation to scale and replication. Through the effective scaling of nature-based solutions (NBS) and GGI, these cities will become more livable, equitable, inclusive, resilient, and vibrant.
Green-gray infrastructure leverages the benefits of natural “green” infrastructure like forests and mangroves with traditional “gray” infrastructure like seawalls and water treatment plants. Through this approach, cities can strengthen their existing infrastructure systems while building their climate resilience, protecting biodiversity and enhancing natural ecosystems.
The initial cohort is comprised of 11 cities across seven countries in sub-Saharan Africa, Addis Ababa and Dire Dawa, Ethiopia, Kigali and Musanze, Rwanda, Johannesburg and Gqeberha, South Africa, Bukavu and Uvira, the Democratic Republic of Congo, Nairobi, Kenya, Kumasi, Ghana, and Brazzaville, the Republic of Congo.
WRI said communities in sub-Saharan Africa (SSA) are predicted to experience some of the most intense impacts from climate change that will severely impact lives and livelihoods, economic growth, and human and environmental health. Nature-based solutions (NBS) can play a vital role in building community resilience and mitigating the impacts of climate change.
To scale up NBS investments in SSA, WRI said there is an urgent need to track, monitor, and understand the current status of where and how NBS projects are implemented.
