The Sendai Framework for DRR 2015–2030 identifies an urgent need for a global effort by researchers, practitioners, and governments to integrate science with action to support risk-sensitive decision making . Tomorrow’s Cities aims to co-produce methodologies and guidelines for this action-oriented, pro-poor, multi-hazard risk-based decision-making agenda.

Understanding and acting on risk is complex. Risk assessments are necessarily based on significant simplifications of the underlying physical and social processes, they are difficult to validate, and the reporting process often obscures caveats implicit in underlying assumptions. Technical outputs may have an inappropriate impact due to inaccurate expectations and limited comprehension).

Experience also shows that state-of-the-art risk modelling on its own is not sufficient to build risk reduction into development planning and to support a movement to pro-poor, resilient actions. Institutional inertia, exclusive decision-making structures, and competing interests can mean even the best new knowledge is used only to enhance existing policy and practice.

This means that risk science has to be built on the best current methods and must also understand the development context within which risk and resilience are positioned by competing actors in a city. It must then be used to convene policy and practical spaces for new coalitions of interest to cohere and bring pro-poor resilience into policy and action.

This editorial outlines Tomorrow’s Cities new approach to risk.