Will Floods Cost Coastal Cities $1 Trillion a Year by 2050?

A version of this post originally appeared in The Resilience Blog.

Take rising seas, sinking land, and more damaging storms. Combine worldwide with growing populations and economies in coastal cities. Together they add up to an increasing annual bill for flood damages. With climate change intensifying, how much could this cost cities every year by 2050?

Nearly $1 trillion, if too little is done to prepare, according to findings published recently in Nature Climate Change. (If that seems outlandish, consider that Hurricane Katrina alone has cost the United States around $125 billion so far, and arguably the full damages aren’t yet known.) Staving off this massive bill won’t come cheaply, and it can’t be cut to zero. But the research finds that cities could more than cover their potential losses: by steadily maintaining and improving flood defenses*, they could lower global losses to around $52 billion a year.

Here are seven of the most vulnerable coastal cities, and what floods may cost them in 2050: