In a high sea level rise scenario, as many as 311,000 homes worth an estimated $117.5 billion are at risk of chronic coastal flooding by 2050, a report from the Union of Concerned Scientists finds.
Funded in part by the Boston-based Barr Foundation, the report, Underwater: Rising Seas, Chronic Floods, and the Implications for US Coastal Real Estate (2018) (28 pages, PDF), defines “chronic flooding” as high tide flooding that occurs twenty-six or more times a year. According to the report, by the end of the century roughly 2.5 million homes and businesses, collectively worth more than $1 trillion, could be at risk, resulting in the displacement of some 4.7 million people — equivalent to the population of Louisiana today.
Based on UCS data from coastal regions, data on existing properties provided by Zillow, the online real estate company, and an extensive series of interviews with market experts, the report notes that every coastal state will be affected by chronic flooding due to sea level rise in the coming decades, with Florida and New Jersey especially vulnerable; that such flooding will exacerbate existing challenges for many low-income and blue-collar communities; that the financial impacts of chronic flooding will reverberate throughout the economy and for the most part are not reflected in current market prices; and that it is necessary to act today to help communities adapt and limit the magnitude of the changes ahead.
"The prospect of these future losses necessitates action today," said UCS senior climate scientist Kristina Dahl. "We must reorient policy and market forces toward solutions that work for people, ecosystems, coastal heritage, and the economy: by employing the best available science and information; by aligning existing policy and market incentives with the realities of sea level rise; and by investing in bold, transformative change that limits harm and fosters new frontiers of opportunity on safer ground."