Climate Shocks and U.S. Bank Stability

This paper investigates the effects of systemic climate variability on U.S. banking stability using the El Niño-Southern Oscillation (ENSO) as a quasi-natural experiment. In contrast to studies focusing on rare, localized natural disasters, we examine how persistent and spatially heterogeneous ENSO-induced climate anomalies-especially those associated with the often-overlooked La Niña phase-affect banks across the continental United States. ENSO is the most influential source of interannual climate variation on Earth and provides a compelling setting to study the transmission of exogenous physical risks to the financial sector. We construct a 30-year quarterly panel of over 800,000 bank-quarter observations (1994-2023), combining detailed financial data with geolocated branch networks and high-resolution teleconnection estimates of local temperature anomalies. Our empirical strategy combines three key elements: a regime-based climate shock identification grounded in recent climate science, a granular spatial matching of institutions to localized exposure, and a dynamic panel framework based on local projections. Our results show that strong La Niña shocks reduce the distance to default by roughly 20%, with effects peaking between 7 and 11 quarters after the shock. These disruptions operate primarily through rising credit risk, lower profitability, and weaker solvency-particularly in banks with large real estate exposure, broad but climate-sensitive geographic footprints, and sizable balance sheets. These findings underscore the need for prudential regulation to incorporate granular, forward-looking metrics of physical climate risk, especially as ongoing climate change is expected to increase the frequency and intensity of ENSO events.