Informality and Climate Change in Cities of the Global South

More than half of the world’s population now lives in cities. Today, urbanisation is dominated by Asian cities, with 19 of the world’s 33 megacities located in Asia. By 2050, urban areas are projected to host 37 megacities, including Addis Ababa and Dar es Salaam, shifting the geography of rapid urbanisation to Africa (United Nations, 2025). Many of these cities in the global South are marked by informality (Banks et al., 2020; Chen et al., 2026; Satterthwaite et al., 2020), which is understood as economic activities, housing and social practices that exist outside legal frameworks and state planning, both crucial to a city’s functioning. A significant proportion of the global South’s urban population is within these informal systems, typically population dense, lacking infrastructure and characterised by poor living, environmental and health conditions (Oteng-Ababio et al., 2019; UN Economic and Social Commission for Asia and the Pacific, 2022; Weimann & Oni, 2019).

Climate change is shaping the megatrend of urbanisation in the global South (Dodman et al., 2022; Revi, 2023). Climate change and urban informality are closely interconnected through processes of unequal hazard exposure and vulnerability, including adaptive capacities, as well as issues of climate injustice and governance exclusion. Informal settlements are frequently located on hazard-prone land such as floodplains, steep slopes, coastal zones and polluted wetlands because low-income residents are excluded from formal land and housing markets (Hussainzad & Gou, 2024; Kephart et al., 2025; Núñez Collado & Wang, 2020; Satterthwaite et al., 2020). Climate change also deepens existing urban inequalities by disproportionately affecting populations dependent on informal livelihoods and insecure tenure arrangements. Studies show that residents of informal settlements generally possess lower adaptive capacity due to limited assets, weak political representation and restricted access to public services and climate finance (Jamshed et al., 2024; Sharma et al., 2021). Informal settlements are often characterised by relatively low per capita emission footprints, yet they present substantial climate mitigation opportunities when infrastructure, housing and basic service needs are addressed through sustainable and inclusive urban development approaches, including nature-based solutions, ecosystem-based adaptation and community-led upgrading initiatives.

Importantly, informality is not only a condition of vulnerability but also a site of adaptive innovation, where community networks and locally developed coping practices play a critical role in climate resilience (Dodman et al., 2022). The informal economy, informal settlements and informal governance, when reinforced by strengthened links between informal and formal governance systems, present significant opportunities for building resilience against and adapting to climate change impacts in the global South’s rapidly urbanising cities. However, there are gaps in our understanding of the dynamism of informality in these cities (Dodman et al., 2022; Prieur-Richard et al., 2018; Walsh & Greenwalt, 2021). Such informal governance systems often lack formal recognition and a voice at the policymakers’ table, limiting the impact and scalability that informal solutions have the potential for (Satterthwaite et al., 2020).

This collection of articles, covering Latin America, Africa and Asia, provides the latest evidence on some of these aspects. Contributions to the collection include both high-level overviews of climate change and its impacts on informality through systematic reviews, and on-the-ground experiences from case studies and the examination of varied frameworks and lenses for reimagining vulnerability, resilience, adaptation and governance. The special issue addresses several themes, including the impacts of climate change on the informal economy and informal settlements, adaptation strategies and resilience building, the interactions between informal and formal governance structures in climate change response, with a focus on innovation in governance, urban planning and urban service provision in informal settlements across global South cities.

The first set of contributions to the collection focuses on climate change impacts and risks including an evidence mapping of climate change impact, vulnerability and adaptation in informal settlements in South Africa (Andrew Okem, Charity Osei-Amponsah, Dorcas Ettang and Debra Roberts), case studies from Rio de Janeiro, Brazil, examining the risk to informal settlements from flooding, landslides and sea-level rise (Claudio Egler and Thereza Carvalho) and emerging patterns of climate-related mobility in peri-urban areas in Southern Africa (Fidelis Udo). Two contributions focused on heat stress in informal settlements. This includes a systematic evidence mapping of heat stress adaptation strategies across Asia and Africa (Mukesh Gupta, Andrew Okem, Xin Rong Chua, Sherine El-Wattar and Winston Chow), a systematic review of the impacts of heatwaves on health and livelihoods in India (Shreya Borah, Shivani Das and Chandan Kumar), and heat stress adaptation strategies of home-based women handicraft artisans in Ahmedabad, India (Sophiya Islam, Neha Abraham, Sonakshi Yadav and Kajal Rai).

The issue features three contributions with a focus on infrastructure-related adaptation in informal settlements. This includes a systematic review examining decentralised solar energy interventions drawing on a comparative analysis of Dharavi in India, Rocinha in Brazil and Diepsloot in South Africa (Tsungai Mukwashi, Thulisile Mphambukeli and Innocent Chirisa); case studies from Freetown, Sierra Leone, and Harare, Zimbabwe on the value chain of building materials in informal settlements (Camila Cocina, Marcelle Mardon, Alexandre Frediani, Patience Mudimu-Matsangaise and Francis Reffell); and an examination of residents’ willingness to pay for benefits or willingness to accept compensation for losses of green infrastructure in Lagos, Nigeria (Oluwaseun Oguntuase).

Governance plays a critical role in climate change action in informal settlements. This collection includes a systematic review of the linkages between formal and informal governance frameworks for climate adaptations in African cities (Lilian Kong’ani, Tanya Dayaram, Khadija Ally, Rabia Jacobs, Alice McClure, Christina Mazivila, Matlhatse Mohale, Christopher Jack, Romyne Karan, Casea Dickinson and Vhulenda Netshitanzwani); an examination of the role of climate resilient hubs in two secondary cities in Zimbabwe in fostering locally led informal climate change governance (George Masimba); case studies of Ajmer, India and Durban, South Africa on how Urban Living Labs successfully foster self-organisation in the context of informality and uneven urban governance (Alejandro Barcena, Joanne Douwes, Anshuman Karol, Hayley Leck, Shruti Priya, Rabi Raj, Nina Schoonman and Catherine Sutherland); and an exploration of care-centred governance drawing on experiences from informal settlements in Argentina and Kenya (Pablo Mariani, Christina Schade, Matteo Fabris, Yamila Castro, Byron Dedeis, Gabriel Mukwaa and Kagwe Wastee).

The special issue concludes with an exploration of climate agendas and action plans. One of the contributions on this theme is a multi-sited fieldwork in Ghana, the Philippines and the Dominican Republic that unpacks the challenges and opportunities of localising the global climate agenda in informal settlements. Findings from this study show a misalignment between the assumptions of global agendas, such as the Paris Agreement and the Sustainable Development Goals and their on-the-ground localisation (Jose Núñez Collado, Maxwell Fobi and Andre Brown). Another contribution examines the first generation of climate action plans (CAPs) in Mumbai, Bengaluru and Chennai. Experiences of these early adopters demonstrate the value of city-level climate planning in India and the need for decentralisation towards inclusive climate governance (Aravind Unni, Shalini Sinha, Ashil Ismail, Roshni Nuggehalli and Dulari Parmar). The final contribution is a case study on the development and implementation of Peru’s CAPs in municipalities, highlighting the roles of architects and urban planners within a context of structural informality (Liliana Miranda, Richard Valdivia-Sisniegas and Eduardo Calvo).

This special issue will be of interest to members of the research community looking to deepen their understanding of informality as a critical part of the urbanisation process in the global South, rather than something merely awaiting formalisation. It will also be of use to urban practitioners and policymakers, providing evidence of what works and does not work in different contexts, highlighting the different actors, enabling conditions and barriers that affect the outcomes of local actions in informal contexts. Above all, this collection of local stories is a resource for the people living and working in informal settlements, acting as a testament to the innovation and resilience of people who, when traditional urban development is unresponsive to their needs, build new cities within cities and informal economies that underpin the welfare of millions of vulnerable and marginalised people around the world.