Climate change: 26% increase in annual flood losses in the United States projected by 2050

Climate change could lead to a 26.4% increase in annual flood losses in the United States by 2050, the cost of which will be borne disproportionately by disadvantaged communities, according to a modelling study in Nature Climate Change.

Flood hazard mapping is essential in risk management to conduct cost–benefit analysis for climate change actions or to estimate the feasibility of new developments. However, typical models used for regulatory or commercial purposes rely on historical data and fail to capture projected climate change. Low-resolution and unrealistic modelling settings also limit their practical applications.

Using advanced modelling techniques, property-level asset data and climate projections, Oliver Wing and colleagues develop a comprehensive, high-resolution and forward-looking estimation of flood risk in the United States. The authors estimate that annual, national flood losses currently average US$32.1 billion and are projected to rise by 26.4% to US$40.6 billion by 2050. At present, the risks are revealed to be borne by poorer communities with a proportionally larger white population. Future increases in flood risk, however, will have a greater impact on African American communities on the Atlantic and Gulf coasts. In addition to climate change, projected population change could also cause a large increase in flood risk.

The authors conclude that these results show the flood risk faced by the United States under climate change, highlighting the need for adaptation to this risk and mitigation efforts to prevent further losses.