Cities are vulnerable to climate change and central to its solutions

Over half of the world’s population lives in towns and cities. 1.1 billion of those people live in informal settlements without access to adequate housing, infrastructure and basic services, making them especially vulnerable to climate change. At the same time, up to two-thirds of global greenhouse gas emissions come from urban areas.

Heard it all before? 

That’s because these statistics are typically used to draw the straightforward conclusion: cities are where the climate battle will be won or lost, as UN Secretary General Antonio Guterres puts it.

These facts have helped to build much-needed global momentum. For example, a thematic ‘Urbanisation Day’ is currently under way at COP29 in Baku, with ministerial-level roundtables and a declaration on pathways for resilient and healthy cities. And after years of advocacy by scientists and urban experts, the IPCC is preparing a Special Report on Cities and Climate Change, expected in 2027.

But for the 1.1 billion people in informal settlements who are already facing the dire impacts of climate change – at hugely disproportionate levels compared to their tiny carbon footprints – this momentum is slow and is failing to produce material change. It’s time for decision makers, from global arenas to local government, to take urban informality seriously – especially when you consider some additional, less well-known facts:

• By 2050, the population of people living in ‘slum like’ conditions will triple to over 3 billion people (PDF)
• A mere 1.2% of climate finance for cities is spent on adaptation, and
• Only 3.5% of the money from the major global climate funds is intended to benefit urban residents living in poverty.

This leads us to another straightforward conclusion: integrated approaches that provide low carbon, climate-resilient housing and infrastructure for all must be prioritised, to forge sustainable pathways for growth while boosting resilience and decreasing inequalities. 

Solutions that draw on expert innovation, local knowledge and traditional practices already exist. We know it is possible to use widely available technology and know-how to dramatically reduce urban emissions and protect people and infrastructure in cities. Decades of participatory upgrading of informal settlements (where residents are engaged throughout) can provide knowledge and experience highly relevant to the twin crises of inequality and climate change. 

Climate impacts: testing resilience limits

Unplanned and informal urban settlements are often located in parts of cities that are vulnerable to climate impacts, such as low-lying coastal areas and floodplains, or steep hillsides. Homes and infrastructure are easily damaged by hazards such as flooding, strong winds, landslides and rising sea levels. More action-oriented data and research is needed to understand hazards, such as extreme heat and how they affect health and wellbeing. 

Residents in informal urban settlements lack the resources and capacity to significantly reduce risk on their own, and struggle to access support and subsidies that governments may offer to middle class and wealthier residents. Low levels of public investment in urban infrastructure and basic services, reliance on insecure work with little or no social protections, and a lack of financial and material assets to fully recover from adverse climate events all reinforce vulnerability. 

The intersection of inequality and climate risks can create traps of poverty and vulnerability, and threatens to undo hard-won gains in poverty reduction. Left unchecked, these factors will have an increasingly corrosive impact as vulnerable settlements increase in size, number and density, and as ecosystems that provide some natural protection from climate change are further degraded. 

Prioritising sustainable housing for all

UN Habitat’s new director, Anacláudia Rossbach, has said that creating affordable, sustainable housing for all must be a global priority and we must put people at the centre of policies. The IPCC’s recent scientific assessment (PDF) backs this up. It affirms with high confidence that “the greatest gains in wellbeing in urban areas can be achieved by prioritising investment to reduce climate risk for low-income and marginalised residents and targeting informal settlements”.

Any upgrading of settlements needs to include climate proofing in order to deliver housing and infrastructure that is resilient to climate shocks. Greater recognition of this is needed, along with robust evidence that illustrates linked-up policy and funding for scalable, inclusive solutions.

IIED is working with partners to co-produce evidence that stakeholders and decision makers can use to transform informal settlements and develop scalable interventions that promote equitable climate action.

For instance, forthcoming research with the Centre for Community Initiatives in Dar es Salaam, Tanzania demonstrates how extreme heat, high winds and excessive rainfall leading to flooding have cumulative impacts on the health, incomes and wellbeing of informal settlement residents. This methodology is now being developed so that it can be used by members of the Slum Dwellers International (SDI) network.