As climate change produces more extreme weather events and more people crowd into cities, we’re likely to see more of the type of flooding that hit northern India and Pakistan last September. On that occasion, rising waters killed about 600 people and displaced up to two million others. Economic losses totaled billions of dollars.
That’s the unhappy prediction of a new online tool from the World Resources Institute (WRI) and several Dutch environmental groups. Called the Aqueduct Global Flood Analyzer, it maps current vulnerability to floods, as well as future vulnerability from climate change and socio-economic forecasts.
“Floods affect more people than other natural disasters, but they’re often overlooked and under-estimated,” says Tianyi Luo, a WRI research analyst. “The lack of access to flood data makes it harder for decision-makers to assess flood risks. This is the first online tool for decision-makers to assess [that].”
The tool combines models of flood risk with data about economic wealth concentration. And the upshot is that floods are set to affect 54 million people and cause $521 billion worth of damages by 2030, up from 21 million people and $96 billion now.
The tool ranks countries by their vulnerability, with India, Bangladesh and China set to see the most people affected. The U.S. comes in 18th from 170 countries, with 262,000 affected, up from 67,000 now. The tool predicts economic losses totaling $15 billion, which actually sounds conservative (we covered some other flood predictions for the U.S. here).
It’s striking how much of the damage will occur in Southeast Asia. Cities like Shanghai, Dhaka, Bangladesh, and Ho Chi Minh City, in Vietnam, are all in for substantially greater flood risk over the next 15 years. That’s because climate change will intensify rainfall events, but also because these cities will be home to more people. Urbanization heightens risks as cities often turn to flood-prone areas as they run out of less vulnerable real estate.
The real value of the maps is you get a sense of the benefits of flood defenses. Normally, it’s hard to fathom the value of, say, a new levee to keep out a river. With these maps, it becomes crystal clear how much an investment may be worth it.