Some 150 million people in the world’s biggest cities could be at risk of flooding by 2070, and at-risk coastal property could have a value of $35 trillion, says a report from the Organization for Economic Cooperation and Development. About 40 million people and $3 trillion worth of property are now at risk, but population growth and urban development will make those numbers skyrocket by 2070, the report said. In a list of the 136 port cities most likely to be at risk from catastrophic flooding in 2070, India took the top two, with Calcutta and Mumbai. The rest of the top 10 were cities in Bangladesh, China, Vietnam, Thailand, Myanmar, and — with Miami coming in at No. 9 — the U.S. Says the report, “Given the large and growing concentration of people and assets in port city locations, and the importance of global trade, failure to develop effective adaptation strategies would inevitably have not just local but also large national and even wider economic consequences.”

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