posted on 17 September 2016
-- this post authored by Krishna Rao
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.
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. Why six feet? Some estimatessuggest 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.
The numbers are even more alarming when looking at individual cities. Given the risk that Florida and Hawaii face, it should come as no surprise that Miami and Honolulu top the list of large cities with a significant number of properties at risk from global warming and subsequent rises in sea levels. But they're not alone. More than 1 in 6 Boston homes are at risk, and New Yorkers may find almost 3 percent of homes in the city underwater if sea levels rise in line with climatologists' predictions.
It's important to note that 2100 is a long way off, and it's certainly possible that communities take steps to mitigate these risks. Then again, given the enduring popularity of living near the sea despite its many dangers and drawbacks, it may be that even more homes will be located closer to the water in a century's time, and these estimates could turn out to be very conservative. Either way, left unchecked, it is clear the threats posed by climate change and rising sea levels have the potential to destroy housing values on an enormous scale.
Click on the thumbnail images below for more details on the number, location and value of homes at risk of being underwater by the year 2100 in 10 large U.S. cities:
 In early 2012, when negative equity was at its highest in the U.S, the total dollar amount of negative equity was $1.2 trillion. The total combined current value of all homes at risk of being underwater with a 6 feet rise in sea levels is $882 billion.
 NOAA provides data on which parts of coastal states will be flooded if sea levels rise by varying amounts. We combined this data with the location and value of homes in each state and city to determine the current value of housing at risk if sea levels rise to six feet.
About the Author
Krishna Rao is the Director of Economic Product & Research at Zillow.
>>>>> Scroll down to view and make comments <<<<<<
This Web Page by Steven Hansen ---- Copyright 2010 - 2016 Econintersect LLC - all rights reserved