Scientists Model Potential Global Impacts of a Yellowstone Supereruption
Researchers outline how a large eruption at Yellowstone could trigger widespread ashfall, disrupt infrastructure and agriculture, and cause long-term climate and health effects.
A team of volcanologists and disaster experts has modeled the consequences of a worst-case Yellowstone supereruption. Using data from past eruptions and recent disaster responses, they describe a scenario in which magma intrusion triggers phreatomagmatic explosions, generating a plume that could reach 30–50 km altitude and spread ash across North America.
The model predicts immediate hazards such as pyroclastic density currents that would devastate areas within a few kilometres of the vent, and ashfall up to several metres thick in cities like Billings, Montana. Ash would disrupt power grids, water treatment, transportation and communications, leading to shortages of food, fuel and medical supplies.
In the weeks following the eruption, the authors anticipate prolonged ash deposition, damage to crops and livestock, and a global rise in food prices. Sulfur dioxide injected into the stratosphere could form sulfate aerosols, producing a modest cooling effect of up to 1.5 °C in some regions.
Health impacts may include increased respiratory illnesses, silicosis and cardiovascular problems from ash inhalation, especially as health systems struggle to recover. The study estimates that hundreds of thousands could die directly, while indirect mortality could reach hundreds of millions over subsequent years.
The researchers emphasize that while the probability of an eruption in the near term remains low, monitoring of seismic swarms, ground uplift and gas emissions continues under the Yellowstone Volcano Observatory’s alert system.