Ocean at the door: New homes and the rising sea (2019 edition)

In 2018, Climate Central and Zillow produced the first nationwide analysis of the number of new homes in areas vulnerable to coastal flooding in all 24 coastal states and the District of Columbia. This research projected how many homes will become exposed to on-average annual ocean flooding in the coming decades—depending on what choices the world makes around greenhouse-gas pollution today. This report improves those results by incorporating full home footprint data instead of point location estimates, and also provides results for bigger floods, in addition to annual ones.

The results are clear. If the world makes moderate cuts to greenhouse-gas pollution—roughly in line with the Paris agreement on climate, whose targets the international community is not on track to meet—some 17,800 existing homes built after 2009 will face an at-least 10 percent flood threat each year, on average, by 2050. The figures for 2100 are more than two times higher—and more than three times higher if pollution grows unchecked.