In Sub-Saharan Africa, nature-based solutions take root

For the 21 million residents of Lagos, Nigeria, climate change is not a distant concept — it is a current reality. Over the past decade, the city has experienced devastating floods, exacerbated by the loss of over half of its wetlands that previously captured and slowed floodwaters. By 2050, the risk of climate-induced flooding could be twice as high as it is today, affecting an estimated 40 million people.

Communities in the Horn of Africa face their own threats — not from flooding but from a lack of water. The region is experiencing its longest drought on record. Millions of people are facing hunger as a result, many of whom are now displaced as climate refugees.

These scenarios are becoming more common across sub-Saharan Africa. The region is disproportionately impacted by climate change, despite contributing the least to global greenhouse gas emissions causing the crisis.

Yet at the same time, communities are increasingly adopting a powerful tool to build resilience to climate threats: nature-based solutions.

Nature-based solutions gain prominence in Sub-Saharan Africa

According to a new report from WRI and the World Bank, developed in collaboration with the African Development Bank, projects rooted in nature-based solutions are gaining momentum in sub-Saharan Africa. Between 2012 and 2023, the region saw nearly 300 new nature-based resilience projects that collectively secured over $21 billion in funding. And between 2012 and 2021, the number of new projects steadily grew by an average of 15% per year.

While the name may sound technical, nature-based solutions refer to a well-known and intuitive set of approaches that aim to protect, manage and restore natural systems — such as forests or wetlands — to benefit people, nature and the climate simultaneously.

These natural systems can build resilience against hazards like flooding, heat or drought. Critically, they often also produce additional benefits for communities — such as creating jobs, boosting farm yields, increasing incomes, protecting biodiversity and more. For example, planting trees on hillsides can stabilize soils, reduce erosion and enhance water quality for downstream communities by controlling sediment and filtering pollutants, helping to protect crop yields and safeguard rural livelihoods.

Nature-based solutions can also be integrated with traditional built infrastructure, such as roads or dams, to enhance resilience and cost-effectiveness. Using mangroves alongside sea walls to improve coastal protection is one example of this hybrid approach, sometimes referred to as "green-gray infrastructure."

Nature-based projects are diverse

In Tanzania, the Msimbazi Basin Development Project showcases how impactful large-scale green-gray infrastructure projects can be for local residents.

Dar es Salaam, the largest city in East Africa and home to over 5 million people, faces severe flooding every year, threatening lives and the local economy. In 2024, a two-day flood killed at least 155 people. It destroyed low-lying neighborhoods along the rivers that lead into the Indian Ocean. And it disrupted work, school and other activities for hundreds of thousands across the city.

The $260 million Msimbazi Basin initiative, funded by the World Bank and other multilateral donors, aims to protect Dar es Salaam from such extreme flooding in the future by combining river restoration, wetland rehabilitation and engineered solutions, such as dams. It exemplifies the "green-gray" approach that integrates natural systems — such as wetlands that absorb excess water and improve water quality — with traditional engineered infrastructure — such as terracing and drainage channels — to enhance urban resilience.

Such large-scale projects are emerging across sub-Saharan Africa. Of the 297 projects we analyzed, over 75% were large-scale initiatives that secured between $1 million and $500 million in funding. 

However, nature-based solutions can have a significant impact regardless of project size. Indeed, relatively small-scale, locally led projects that secured between $50,000 and $1 million in funding account for the remaining 25% of projects observed in the report.

Coastal communities in Kwale County, Kenya, for example, are taking a grassroots approach to restoring the area's coastlines and developing sustainable livelihoods through mangrove forest restoration and seaweed farming. In response to worsening climate impacts — including rising sea levels, storm surges and declining fish stocks — four community groups have replanted and managed more than 243,000 mangrove seedlings over 17 hectares of coastal land. This restoration effort aims to enhance biodiversity and protect against coastal erosion. As they have restored the mangroves, the communities have also established 91 seaweed farms to help provide an economic buffer against declining fish stocks and climate-induced shocks.

This wide range of project sizes and types highlights the fact that there's no single solution to climate resilience: Diverse approaches will be needed to effectively address climate challenges across sub-Saharan Africa. It also shows that a variety of actors, from grassroots leaders to infrastructure developers, can successfully lead nature-based solutions.

Collaboration is central to nature-based initiatives

Sudan faces many climate challenges, including desertification, erratic rainfall and land degradation. As a key agricultural producer for Africa and the Middle East, these impacts have been particularly devastating and could have ramifications far beyond its borders.

To address these climate challenges, a collaborative initiative between local communities, government agencies and international donors is working to identify vulnerabilities and develop adaptation strategies tailored to Sudan's White Nile region. These include efforts such as forest and wetland restoration, improved land management and community-led conservation. Sudan's national government serves as the project lead, while the Global Environment Facility provided key funding. Communities helped develop strategies to ensure they were tailored to local needs. National and state officials then helped incorporate these strategies into policies, plans and budgets to ensure broader alignment.

Coordinated efforts like these are key to succesfully designing and implementing nature-based solutions — and ensuring they make a lasting impact.

Across sub-Saharan Africa, national governments play an important role in anchoring collaborations that support nature-based projects, leading 61% of the initiatives identified. They also back nature-based solutions financially: Funding for over 80% of projects came from a combination of national governments, multilateral development banks and multilateral donors or funds.

Nature-based solutions do more than enhance climate resilience

The coastal city of Beira, Mozambique, sits at the mouth of a major river system and is particularly vulnerable to climate-driven flooding. At the same time, its half-million residents struggle with high levels of poverty and unemployment. The Cities and Climate Change Project (3CP), launched in 2012, was designed to address the core challenge of flooding. But it also sought to maximize other benefits, such as improving public health and job creation. This large-scale urban flood resilience initiative integrated wetland restoration with engineered drainage systems along Beira's Chiveve River, enhancing biodiversity, improving erosion control and providing a 17-hectare multi-use urban green park for residents.

Today, the completed project helps protect over 50,000 people from recurrent flooding. At the same time, it has created over 1,200 jobs, increased economic stability for local businesses, and supported community health by making green space more accessible and improving air quality.

These multifaceted benefits show how nature-based solutions can serve as a holistic approach to urban development and climate adaptation. In fact, 83% of nature-based interventions we identified were designed to deliver multiple climate resilience goals, including improved water quality, increased water quantity, flood mitigation, erosion and landslide mitigation, fire risk mitigation and urban heat reduction. But beyond climate resilience, they also aimed to drive economic benefits; more than 50% of projects in the region are expected to create jobs and improve livelihoods through greater economic opportunities. In addition, projects often strove to address biodiversity conservation and improve health and food security.

Nature-based projects can also support equity

Climate challenges do not exist in a vacuum; their impacts are often felt most acutely by those who are vulnerable or marginalized in a society. For example, devastating floods last year in Nairobi, Kenya, affected poor urban communities living in informal settlements the most, amplifying existing inequalities. And droughts often result in disproportionately higher burdens on, and risks to, women who are responsible for securing water and food. In South Africa, government agencies issue permits and licenses to access or use water from certain sources. Women hold only 10.5% of these licenses, resulting in unequal access to water resources based on gender disparities.

The city of Johannesburg is using gender-responsive nature-based solutions to both address the city's water insecurity and to advance equity. One ongoing project, part of the SUNCASA initiative, ensures participation from women and other marginalized groups in project planning, preparation, long-term management and local decision-making. It supports the development of women-led tree nurseries, the saplings from which will help revitalize the upper Jukskei River catchment. In addition to creating new jobs for women and youths, the initiative could benefit over a million people through improved water security, decreased flood risk and better urban heat management.

Johannesburg is not alone in the shift toward equitable nature-based solutions. References to gender equity were frequent among the nearly 300 nature-based projects we evaluated, and they become more common over time: 68% of projects implemented between 2012 and 2021 referenced gender equity in project design documents, while 98% of those implemented between 2022 and 2023 did the same.

This upward trend highlights a growing recognition that inclusivity is critical to climate resilience efforts. However, further research is needed to evaluate how deeply these commitments are embedded in project design, implementation and outcomes, with the goal of ensuring that gender considerations translate into meaningful, on-the-ground impact.

Cities are an emerging priority for nature-based solutions

Like many places across sub-Saharan Africa, the city of Brazzaville, Republic of Congo, faces increasing climate risks like flooding and extreme weather. In response, the city is formally incorporating nature-based solutions into its urban planning and climate resilience strategy. Specifically, Brazzaville is expanding its 2023 Urban Forest Strategy to not only enhance urban greening, but also to deliver targeted interventions like strengthening flood protections in high-risk areas. Its approach prioritizes planning that is community-led and responsive to gender equality and social inclusion; planting guidelines that safeguard ecosystem integrity; and financial commitments that are robust and long-lasting. This comprehensive approach creates a model for other cities looking to integrate nature-based solutions into their climate resilience strategies.

Historically, developers have sited most nature-based solutions projects in rural areas. But urban projects like Brazzaville's have gained traction in recent years. In 2023, they accounted for nearly half of the World Bank and African Development Bank's climate resilience investment projects utilizing nature-based solutions, up from just 16% between 2012 and 2021. This shift is critical as urban areas increasingly face threats such as extreme heat, flooding and green space loss, all of which are exacerbated by rapid, unplanned development.

The Green-Gray Infrastructure (GGI) Accelerator, led by WRI Africa, is building on this momentum by providing technical assistance in areas like policy support, cost-benefit analysis, and improvements to monitoring and evaluation. The GGI Accelerator is working with an initial cohort of 11 cities (including Brazzaville) across seven countries to help increase the use of nature-based solutions and green-gray infrastructure in city plans, budgets and infrastructure projects. Ultimately, this could not only improve cities' climate resilience but also reduce biodiversity loss and generate jobs.

The work continues

As these leaders show, nature-based solutions offer major potential to bring climate resilience and other benefits to sub-Saharan Africa. But scaling them to meet the region's urgent climate adaptation needs remains challenging, particularly in cities. Policies still favor traditional gray infrastructure over nature-based solutions or green-gray approaches. In addition, current approaches that funders and financiers use to evaluate economic benefits often fail to account for the types of benefits nature-based solutions may provide.

To unlock the full potential of nature-based solutions, key stakeholders — including national and local governments, multilateral development banks and local communities — must continue to collaborate to expand diverse funding mechanisms, further integrate gender and social equity considerations, and enhance monitoring and evaluation to assess long-term impact.

With concerted efforts, cities and national governments across Africa can grow nature's power to build a resilient, sustainable future, reducing climate risks while fostering economic growth and social well-being.

This article is also published on World Research Institute. illuminem Voices is a democratic space presenting the thoughts and opinions of leading Sustainability & Energy writers, their opinions do not necessarily represent those of illuminem.