This paper considers the very large differences in adaptive capacity among the world’s urban centres. It then discusses how risk levels may change for a range of climatic drivers of impacts in the near term (2030–2040) and the long term (2080–2100) with a 2°C and a 4°C warming for Dar es Salaam, Durban, London and New York City. The paper is drawn directly from Chapter 8 of Climate Change 2014: Impacts, Adaptation and Vulnerability, the IPCC Working Group II contribution to the Fifth Assessment Report. It includes the complete text of this chapter’s Executive Summary. The paper highlights the limits to what adaptation can do to protect urban areas and their economies and populations without the needed global agreement and action on mitigation; this is the case even for cities with high adaptive capacities. It ends with a discussion of transformative adaptation and where learning on how to achieve this needs to come from.

This paper reviews the literature on health in the informal settlements (and “slums”) that now house a substantial proportion of the urban population in Africa, Asia and Latin America. Although this highlights some important gaps in research, available studies do suggest that urban health inequalities usually begin at birth, are reproduced over a lifetime (often reinforced by undernutrition), and may be recreated through vulnerabilities to climate change and a “double burden” of communicable and non-communicable diseases. The review begins with a discussion of papers with a life-course perspective on health, poverty and housing, before considering recent literature on chronic poverty and ill-health over time. It then discusses the literature on the cost, quality and access to care among low-income groups, and the under-recognized threat of unintentional injuries. This includes recent literature that discusses where low-income residents may suffer an “urban penalty” rather than benefiting from urban bias — although there are also studies that show the effectiveness of accessible, pro-poor health care. The concluding section examines emerging risks such as non-communicable diseases and those associated with climate change. It notes how more gender- and age-sensitive strategies can help address the large inequalities in health between those in informal settlements and other urban residents. With greater attention to the multi-faceted needs of low-income communities, governments can create interventions to ensure that urban centres fulfil their enormous potential for health.

Informal settlement upgrading is widely recognized for enhancing shelter and promoting economic development, yet its potential to improve health equity is usually overlooked. Almost one in seven people on the planet are expected to reside in urban informal settlements, or slums, by 2030. Slum upgrading is the process of delivering place-based environmental and social improvements to the urban poor, including land tenure, housing, infrastructure, employment, health services and political and social inclusion. The processes and products of slum upgrading can address multiple environmental determinants of health. This paper reviewed urban slum upgrading evaluations from cities across Asia, Africa and Latin America and found that few captured the multiple health benefits of upgrading. With the Sustainable Development Goals (SDGs) focused on improving well-being for billions of city-dwellers, slum upgrading should be viewed as a key strategy to promote health, equitable development and reduce climate change vulnerabilities. We conclude with suggestions for how slum upgrading might more explicitly capture its health benefits, such as through the use of health impact assessment (HIA) and adopting an urban health in all policies (HiAP) framework. Urban slum upgrading must be more explicitly designed, implemented and evaluated to capture its multiple global environmental health benefits.

Globally, there are 2 billion 'informal' workers, who lack access to social protection while facing profound health risks and socioeconomic exclusions. The informal economy has generated most jobs in Low and Middle -Income Countries (LMICs), but few studies have explored informal workers' complex health vulnerabilities, including in the face of climate change. This paper will discuss recent action -research in Indore (India), Harare, and Masvingo (Zimbabwe) with informal workers like vendors, waste -pickers, and urban farmers. We conducted qualitative interviews (N = 110 in India), focus group discussions (N = 207 in Zimbabwe), and a quantitative survey (N = 418 in Zimbabwe). Many informal workers live in informal settlements ('slums'), and we highlight the interrelated health risks at their homes and workplaces. We explore how climate -related threats-including heatwaves, drought, and floods-negatively affect informal workers' health and livelihoods. These challenges often have genderinequitable impacts. We also analyse workers' individual and collective responses. We propose a comprehensive framework to reveal the drivers of health in the informal economy, and we complement this holistic approach with a new research agenda. Our framework highlights the socioeconomic, environmental, and political determinants of informal workers' health. We argue that informal workers may face difficult trade-offs, due to competing priorities in the face of climate change and other risks. Future interventions will need to recognise informal workers' array of risks and co -develop multifaceted solutions, thereby helping to avoid such impossible choices. We recommend holistic initiatives to foster health and climate resilience, as well as participatory action -research partnerships and qualitative, intersectional data -collection with informal workers.

Informal rental housing remains a hidden – yet central – pillar of low-cost shelter markets across the global South. The large informal settlement of Mathare Valley illustrates Nairobi’s rapidly changing informal rental housing markets, with the ongoing rise of tenements alongside metal shacks. Informal single-room rental units (shacks and tenements) already house most Nairobi residents in low-quality but highly profitable shelter. This case study describes how multiple exclusions can shape access to rental housing and examines the politics of shelter delivery. We underscore the importance of private rental markets and offer recommendations for inclusive, multi-pronged interventions combining support for rental housing, land governance and infrastructure delivery. Through a better understanding of the myriad actors and dynamics of informal rental housing, it may be possible to develop strategies that serve low-income tenants for whom renting is often the only viable option.