ENSO, U.S. Hurricanes, and Global Disasters

THB Deep Dive Report #2

This is THB Deep Dive Report #2.

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THB Deep Dive Report #1 — The University Problem.

ENSO, U.S. Hurricanes, and Global Disasters — Executive Summary

From the full report.

The El Niño-Southern Oscillation (ENSO) drives the largest year-to-year climate variability on Earth. This deep dive updates my past analyses of the relationship of (a) ENSO and U.S. hurricane damage and (b) ENSO and global disaster losses.

First, more than 25 years ago Chris Landsea and I published a paper showing that that U.S. hurricane damage varies with ENSO: La Niña years in general have larger U.S. hurricane losses than El Niño years. The update shows that the original 1999 finding holds with almost 30 years of additional data. The La Niña-to-El Niño ratio of median normalized CONUS damage was 4.0× in the 1925-1997 period covered by the original paper; in the 1998-2025 period the ratio was 7.5×.

Second, global disaster losses over 1990-2024 show a strong La Niña signal at the aggregate level: median global losses total `$270 billion in La Niña years versus ~$155 billion in El Niño years (2024 dollars). U.S. hurricane losses likely dominate the global aggregate in any year with a major U.S. landfall. Global weather-disaster death rates (annual median) are ~1.3x greater during La Niña than El Niño, dominated by a handful of catastrophic events.

Third, as of 22 June 2026, NOAA carries an El Niño Advisory: El Niño conditions are present and expected to strengthen into Northern Hemisphere winter 2026-27. Forecasters predict a 63% chance of a “very strong” El Niño (SST anomalies exceeding 2.0°C) developing this fall. The base-rate expectation for the 2026 Atlantic hurricane season favors below-average U.S. losses, but tail risk remains.

The policy implications are clear: ENSO information has economic value for decision-makers who can act on probabilistic knowledge. ENSO shifts where and when the risks of extremes occur. This report quantifies some of the better known consequences of this important mode of climate variability.

The full report can be found below, for paid THB subscribers.

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