The World Bank is warning cities around the world are unprepared for fast-increasing risks from extreme weather and other hazards, which is compounded by population growth and surging migration.
By 2050, 1.3 billion people and US$158 trillion ($232 trillion) in assets will be affected by worsening river and coastal floods alone, warns a new report prepared by the Global Facility for Disaster Reduction and Recovery (GFDRR), managed by the World Bank.
But as cities expand and revamp, there's the opportunity to reduce risk with more resilient infrastructure and preventive policies.
Many city officials have no clear idea of the range of disaster risks they face and how serious they could be.
Argentina, for instance, has no volcanoes but is affected by ash from eruptions in Chile, while Malawi's 2009 earthquake came as a surprise.