The United States has become the world’s largest exporter of liquefied natural gas (LNG). Yet, the local air quality impacts of LNG export terminals remain unexplored. We estimate the effects of the three largest U.S. export terminals on local ambient ozone pollution. Using daily wind direction to determine downwind treatment versus control observations and difference-in-difference (DiD) methods, we document statistically significant 5% to 7% increases in downwind ozone pollution due to export terminals. The estimated effects are robust across multiple specifications. Even with these increases, average daily ozone concentrations remain well below EPA’s National Ambient Air Quality Standards. Nevertheless, the results document measurable, localized externalities from LNG export operations, which emphasizes the need for continued monitoring as export capacity expands.
