Paul D. Bates Niall Quinn Christopher Sampson Andrew Smith Oliver Wing Jeison Sosa James Savage Gaia Olcese Jeff Neal Guy Schumann Laura Giustarini Gemma Coxon Jeremy R. Porter Mike F. Amodeo Ziyan Chu Sharai Lewis‐Gruss Neil B. Freeman Trevor Houser Michael Delgado Ali Hamidi Ian Bolliger Kelly E. McCusker Kerry Emanuel Celso M. Ferreira Arslaan Khalid Ivan D. Haigh Anaïs Couasnon Robert E. Kopp Solomon Hsiang Witold F. Krajewski
Published February 12, 2021
We develop a method to estimate past, present, and future flood risk for all properties in the conterminous United States whether affected by river, coastal or rainfall flooding. The analysis accounts for variability within environmental factors including changes in sea level rise, hurricane intensity and landfall locations, precipitation patterns, and river discharge. We show that even for a conservative climate change trajectory we can expect locally significant changes in the land area at risk from floods by 2050, and by this time defenses protecting 2,200 km2 of land may be compromised. The complete dataset has been made available via a website (https://floodfactor.com/) created by the First Street Foundation in order to increase public awareness of the threat posed by flooding to safety and livelihoods.
The data, based on decades of peer-reviewed research, provides the cumulative risk of flooding for more than 142 million homes and properties over a 30-year mortgage.
Across much of the United States, the flood risk is far greater than government estimates show, new calculations suggest, exposing millions of people to a hidden threat — and one that will only grow as climate change worsens.