Nature-based solutions for climate change adaptation and resilience in urban informal settlements: Insights from Kenya and Argentina

This article is an abridged version of the original text, which can be downloaded from the right-hand column. It highlights some of the publication’s key messages below, but please access the downloadable resource for more comprehensive detail, full references, or to quote text. 

Introduction

Nature-based Solutions (NbS) are increasingly recognised for their contribution to addressing climate change impacts and overall environmental challenges in urban areas. In cities, NbS offer a range of benefits and ecosystem services including flood management, cooling effects and recreational opportunities. However, their implementation and effectiveness are often influenced by factors such as space availability. Despite their proven benefits, NbS implementation in urban informal settlements with limited space and high exposure to climate risks is particularly challenging. These settlements are frequently excluded from formal urban planning processes and typically lack basic services and infrastructure.

This article examines the role, implementation, and transformative potential of NbS in two of the largest informal settlements in the Global South: Kibera in Nairobi, Kenya, and Villa 20 in Buenos Aires, Argentina. Drawing on community perceptions and participatory upgrading processes, this study offers comparative insights into locally driven NbS across diverse socio-ecological contexts.

Methodology

This research uses a qualitative, theory-informed case study approach focused on community perceptions, practices, and the transformative potential of NbS. It is structured around a four-dimensional analytical framework covering: NbS-society relations, design, implementation, and effectiveness.

• In Kibera, data were collected through a survey of 137 households using both open- and closed-ended questions to explore residents’ lived experiences with climate risk, environmental change, and adaptation measures.
• In Villa 20, two rounds of semi-structured interviews were conducted with nine community leaders from an Urban Lab over 2022–2023, enabling longitudinal insights into perception shifts and engagement dynamics.

Data were analysed using content, thematic and narrative analysis to identify dominant patterns and assess the transformative potential of NbS across both sites.

Kibera, Nairobi (Kenya)

Context and challenges

Kibera is one of Africa’s largest informal settlements, covering about 2.1 km², with a population density of approximately 55,994 persons per square kilometre. Its location along Ngong and Nairobi Rivers makes it highly susceptible to flooding. The settlement also faces challenges such as poor sanitation, inadequate waste management, and urban heat island effects. Most residents lack secure land tenure, formal infrastructure, and access to basic services.

NbS are one of the measures introduced and adopted in the Kibera settlement to reduce climate and disaster-associated impacts, particularly flooding.

Implemented NbS and community perception

• River restoration and flood mitigation: Community-led efforts include regular clean-ups of the Ngong River, tree and grass planting along riverbanks, and construction of small footbridges. The NbS are credited with reducing flooding, improving water quality, and curbing the spread of disease vectors such as mosquitoes.
• Urban greening: Residents have created green roofs, green walls, and informal public green spaces, often using repurposed materials such as sacks and plastic containers. These grassroots initiatives improve air quality, provide shade and cooling, and enhance food security through small-scale kitchen gardens.
• Social cohesion and livelihoods: NbS have fostered community mobilisation, particularly among youth groups, and generated employment opportunities through urban gardening and site maintenance. They are also perceived as strengthening community trust and environmental awareness.

Challenges and limitations

• Limited technical knowledge, inadequate funding, insecure land tenure, and high population density were identified as major barriers to the effective implementation and scale-up of NbS.
• While many initiatives are grassroots-driven, broader institutional and policy support remains limited. Respondents expressed concern that without scaled-up action, vegetation cover may decline due to continued development pressures.

Villa 20, Buenos Aires (Argentina)

Context and challenges

Villa 20 is one of the largest informal settlements in Buenos Aires, located in the city’s southern zone, which is prone to flooding and marked by significant social and environmental inequality. It spans 37 hectares and is home to 13,750 families living in approximately 12,500 houses. As of 2022, Villa 20 and other informal settlements in Commune 8 had, on average, just one tree per 282 residents, contrasting with the citywide average of one tree per 6.7 inhabitants.

Efforts to address local challenges include Buenos Aires City’s Law 5705/2016, which initiated the participatory upgrading process in Villa 20. The law aims to construct new housing units, improve existing houses, enhance and consolidate public spaces, and provide adequate infrastructure and services, among other objectives. In recent years, the upgrading process has increasingly incorporated NbS into its goals and activities.

Implemented NbS and community perception

• Pilot NbS projects: Introduced vertical gardens, permeable pavements, native vegetation planting, pergolas with creepers, and hydroponic systems. These interventions were co-designed with community input and implemented through collaboration among local government, NGOs, and international donors.
• Evolving perceptions: Initially, residents viewed NbS as limited to superficial greening (e.g. tree planting). Over time, exposure to workshops and participatory design processes expanded understanding of NbS to include broader ecosystem services and links to health, safety, and climate resilience.
• Education and capacity-building: Environmental awareness campaigns, field visits, and training with landscape architects helped residents develop the skills and motivation to maintain and expand NbS initiatives. Community leaders emphasised the need to integrate NbS with the provision of basic services such as sewage systems, waste management, and clean water access.

Outcome and impact

• NbS have improved air quality, reduced local temperatures, increased social cohesion, and created communal spaces for recreation. The greening of Villa 20 has instilled a sense of pride and ownership among residents.
• Some initiatives, such as rain gardens and vertical vegetation, are now being integrated into broader city-led upgrading plans, signalling growing institutional support and paving the way to long-term sustainability.

Challenges and limitations

• Policy and regulatory barriers, funding constraints, and scepticism regarding government commitment persists. Maintenance responsibilities often fall disproportionately on women, while residents stressed the urgent need for legal frameworks that uphold environmental justice in informal settlements.

Key messages and implications

• Transformative potential: NbS can deliver not just environmental improvements but also enhance livelihoods, food security, and social inclusion when locally adapted and community-led.
• Community ownership is key: Both case studies show that effectiveness and sustainability are highest when residents are engaged in the design, implementation, and monitoring of NbS.
• Education and awareness raising are crucial: Residents often implement NbS without knowing the term or its full potential. Targeted outreach and participatory learning can bridge this gap.
• Challenges must be addressed holistically: Insecure tenure, limited space, and inadequate infrastructure are systemic issues that need to be addressed alongside NbS implementation for durable outcomes.
• Policy integration is essential: Embedding NbS into broader urban planning and upgrading processes, as seen in Villa 20, is a promising model for scale and institutional mainstreaming.

Suggested citation

Kibii, C., Guerra, F., Bananayo, P. B., & Sandholz, S. (2025). Nature-based solutions for climate change adaptation and resilience in urban informal settlements: Insights from Kibera, Kenya and Villa 20, Argentina. Nature-Based Solutions, 7, 100216. https://doi.org/10.1016/j.nbsj.2025.100216