It’s not from more frequent or fiercer hurricanes—the rate and sternness of them actually is down over the last several years—but the increasing density of population and supporting building on hurricane-prone shores and the increasing costs of the buildings that’s driving the cost of hurricane damage.
Counties along the US shoreline that endured hurricane-strength winds from Florence in September experienced a surge in population from 1980 to 2017, with an increase of 95 people per square mile—more than double the density. Overall, Gulf and East Coast shoreline counties, those vulnerable to hurricane strikes, increased by 160 people per square mile, compared with 26 people per square mile in the rest of the mainland, over the same period.
The devastating effect of Florence, like Harvey in 2017, was primarily related to flooding.
For storms like Harvey, changes in land use that come with urbanization, such as replacing permeable surfaces like grass with impermeable surfaces like concrete, can cause big changes in water runoff.
Sandy had downgraded from being a hurricane to what’s known as an “extratropical” storm by the time it made landfall in 2012, but it hit major population centers causing “extensive damage across several northeastern states,” making it the 4th most expensive storm to hit the U.S. since 1980 with $72.19 billion in damages according to NOAA’s analysis.
Yet insurance—for flooding, wind damage, and so on—isn’t seeing rising premiums. That’s especially the case for flood insurance. That’s also where Government has crowded out private insurers with Government flood insurance sold at artificially low premiums, wholly independent of the risks actually being covered.
And that means that no one has any incentive to think about where they build, whether commercially or residentially: the damage will be repaid with OPM.