Homes in danger of inundation by rising sea level in Miami, Florida, in the year 2100. 32,986 homes (30 percent of the Miami housing stock), worth $16 billion, will be underwater if sea level rises by six feet. Graphic: Zillow

By Krishna Rao
2 August 2016 (Zillow) – If sea levels rise as much as climate scientists predict by the year 2100, almost 300 U.S. cities would lose at least half their homes, and 36 U.S. cities would be completely lost. One in eight Florida homes would be underwater, accounting for nearly half of the lost housing value nationwide. The median value of a home at risk of being underwater is $296,296. The value of the average U.S. home is $187,000. Typically, when we talk about “underwater” homes, we are generally referring to negative equity. But there is, of course, a more literal way a home can be underwater: Rising sea levels, and the flooding likely to come with them, could inundate millions of U.S. homes worth hundreds of billions of dollars. In fact, based on our calculations, it may turn out that actual water poses almost as much of a problem for the housing market in the future as negative equity has in the past.[1]

Number of potentially underwater properties in U.S. coastal states due to rising sea level. Nationwide, almost 1.9 million homes (roughly 2 percent of all U.S.homes) worth a combined $882 billion, are at risk of being underwater by 2100, if sea levels rise by six feet. Graphic: Zillow

To quantify the impact of rising sea levels, we used maps released by the National Oceanic and Atmospheric Administration (NOAA) showing which parts of costal states will be underwater if sea levels rise by six feet.[2] Why six feet? Some estimates suggest sea levels will rise that much by the year 2100 if climate change continues unchecked. Using that data in conjunction with our database of information on more than 100 million homes nationwide, we determined which properties were at risk of being submerged (at least their ground floors) in the next century or so and what they’re currently worth. Nationwide, almost 1.9 million homes (or roughly 2 percent of all U.S. homes) – worth a combined $882 billion – are at risk of being underwater by 2100. And in some states, the fraction of properties at risk of being underwater is alarmingly high. More than 1 in 8 properties in Florida are in an area expected to be underwater if sea levels rise by six feet, representing more than $400 billion dollars in current housing value. In Hawaii, almost 1 in 10 homes are at risk. [more]

Climate Change and Housing: Will a Rising Tide Sink all Homes?