New research from the World Resources Institute finds that 147 million people will be affected by floods by the end of the decade - "the numbers will be catastrophic." The number of people affected will double worldwide by 2030.
Due to the annual flooding of rivers and coasts at the end of the decade, the number of people affected grew exponentially, compared to 72 million people just 10 years ago.
Damage to urban property will rise from $ 174 billion to $ 712 billion per year.
By 2050, "the numbers will be catastrophic," according to the report. A total of 221 million people will be at risk, and the death toll in cities will cost $ 1.7 billion a year.
When the World Resources Institute (WRI) first developed its flood modeling tool in 2014, the predictions felt "like a fantasy," said Charlie Iceland, director of water initiatives at WRI.
"But now we are seeing this increase in the magnitude of the damage in real time," Iceland said. "We have never seen this type of flood before."
Floods are getting worse due to the climate crisis, decisions to populate high-risk areas, and land subsidence from overuse of groundwater.
The worst floods will come in South and Southeast Asia, including in Bangladesh, Vietnam, India, Indonesia and China, where large populations are vulnerable.
The effects will be less severe but increasingly severe in the US, where the risk is greatest for coastal flooding. The United States ranks third among the countries with the most losses from urban coastal flooding in the next 10 years, after China and Indonesia.
Coastal flood damage in the US was $ 1.8 billion in 2010 and will rise to $ 38 billion in 2050, with half of the country's population exposed in just three states: Louisiana, Massachusetts, and Florida.
According to a separate study, what are now occasional floods could become daily events for most of the US coastline.
This is because hurricanes are stronger, seas are higher, and rainfall patterns are changing, all due to human-caused global warming.
River flooding will get worse in the United States, but that damage will stay more or less the same as large investments will be made in flood protection.