Informal settlements are home to over a billion people and are among the communities most exposed to the impacts of climate change. Yet they are often left out of climate plans and funding decisions. In fact, over the past two decades, only a tiny sliver (3.5 percent) of global climate finance has reached the urban poor. This deepens their vulnerability and misses a major opportunity to support low-carbon, resilient development.

For climate action to be just and effective, informal settlements cannot be left on the sidelines and must instead be part of the solution. This expert note highlights how transforming them is vital to achieving national and global climate goals and how including them in planning can drive more just, resilient, and low-carbon development. It argues that slum transformation must be part of climate and urban development strategies, and that climate finance must reach those living and working in informal settlements. The expert note describes the benefits of prioritizing municipal infrastructure for neglected communities; reducing carbon lock-in; and coordinating government actions, vertically and horizontally, so policies and plans can work together rather than against each other. It also stresses the need to engage meaningfully with residents so they can help shape solutions.

Opportunities for action are highlighted within international climate and development processes under the United Nations Framework Convention on Climate Change, the COP30 Agenda, and the Urban 20, alongside deliberations at the World Urban Forum and over what will succeed the UN 2030 Agenda for Sustainable Development. This expert note draws on existing World Resources Institute research and action, which includes work with partners through initiatives such as REHOUSE and the Coalition for High Ambition Multilevel Partnerships (CHAMP).