According to recent research, extreme weather could cause four times as much economic loss in the U.S. by 2050 as it does today. And that’s without any increase in the frequency or intensity of storms.

The main reason for greater risk is that the population in areas prone to rough weather—including the east, west and Gulf coasts—is rising more rapidly than in many other parts of the country, according to Benjamin L. Preston, a senior research scientist at Oak Ridge National Laboratory. Greater wealth per person—more valuable homes and possessions in harm’s way—is the second leading factor.

Population from 1960 to 2009 went up fast in areas along the oceans, notably Florida and California (see map). The increase is a combination of general population growth and people moving to those regions from elsewhere in the country.

Population Growth (ratio of population in 2009 versus 1960)

For more read "Cost of Storm Damage Will Rise Sharply, Even Without Climate Change" in the August issue of Scientific American.