The global sanitation crisis: A systems approach to resilient citywide inclusive sanitation

This background paper highlights the urgent need for climate‑resilient sanitation systems as cities face increasing climate‑related pressures. The growing impacts of extreme weather events expose the deep interconnections between sanitation and other essential urban systems, including water supply, energy, transportation, stormwater, and solid waste management. Because these systems are tightly linked, the failure of one component can trigger cascading disruptions across multiple services, amplifying risks to public and environmental health. Sanitation failures can affect non‑sanitation sectors, just as breakdowns in other systems can compromise sanitation service delivery. These interdependencies underscore the importance of integrated resilience planning, where urban sanitation is recognized as a foundational element of overall city resilience. The paper also highlights the vital connection between sanitation and food systems through the safe reuse of wastewater and sludge, emphasizing the increasing relevance of circular economy approaches in fostering sustainable, climate‑adaptive transformations in the sector. With a primary focus on adaptation, the paper articulates why a systems‑based approach is essential for strengthening urban sanitation resilience and ensuring service continuity under climate variability and extreme events.