$35 Billion Worth Real Estate Could Be Underwater by 2050

Millions of acres of coastal land will be in flood zones by mid-century, potentially costing communities huge sums in lost property taxes as developed land becomes uninhabitable, an analysis released Thursday shows.

Research non-profit Climate Central conducted a unique study of sea-level rise, projecting the amount of real estate, buildings, and tax revenue that hundreds of coastal counties will lose as tides encroach on developed areas. It found that an estimated 4.3 million acres — an area nearly the size of Connecticut — will be underwater by 2050, including $35 bn worth of the real estate.

“There are about 30 counties that are going to lose more than 10 percent of their land area by 2050,” Climate Central senior adviser Don Bain said. The losses will magnify by 2100. Climate Central researchers focused on 2050 because global warming patterns are unlikely to change significantly in the next few decades. Such patterns, however, could change by the end of the century, depending on the decrease (or increase) in global emissions.

The analysis, which looked at 328 counties in 25 coastal states including Alaska and Hawaii, aims to alert state and local officials about the threat that climate change poses to tax revenue that pays for public schools, emergency protection, and municipal services. It says that smaller tax bases can lead to lower tax revenues, reduced public services, and a potential downward spiral of disinvestment and population decline.”

The report urges common adaptation strategies, such as steering development away from coastal areas. “Frankly, we’re fiddling around on the margins, but we’re not addressing the core of the issue and we’re not thinking about it on the scale that it needs to be done,” Siders said.

Climate Central researchers combined the latest sea-level rise models released last year by the Intergovernmental Panel on Climate Change with NOAA data showing coastal tide levels. They combined their analysis with property tax records to determine which parcels face a future flood threat and the value of the threatened real estate.