Mortality caused by tropical cyclones in the United States

Natural disasters trigger complex chains of events within human societies. Immediate deaths and damage are directly observed after a disaster and are widely studied, but delayed downstream outcomes, indirectly caused by the disaster, are difficult to trace back to the initial event. Tropical cyclones (TCs)—hurricanes and tropical storms—are widespread globally and have lasting economic impacts, but their full health impact remains unknown. This study conducts a large-scale evaluation of long-term effects of TCs on human mortality in the contiguous United States (CONUS) for all TCs between 1930 and 2015. The authors observe a robust increase in excess mortality that persists for 15 years after each geophysical event. They estimate that the average TC generates 7,000–11,000 excess deaths, far exceeding the average of 24 immediate deaths reported in government statistics. Tracking the effects of 501 historical storms, they compute that the TC climate of CONUS imposes an undocumented mortality burden equal to roughly 3.2–5.1% of all deaths and explains a substantial fraction of higher mortality rates along the Atlantic coast. Excess mortality risk is especially elevated among infants, people aged 1–44, and Black populations. Understanding why TCs induce this excess mortality could yield substantial health benefits.

Rachel Young, Solomon Hsiang