Diesel supplies in the U.S. are at their lowest level since 2008, raising concerns over the impact this could have on the country’s economy.

As of Friday, October 14, the U.S. had 25.4 days of diesel supply left in storage, according to data from the Energy Information Administration (EIA).

For the past two years, amid pandemic closures and climate pledges promising to invest more in renewable, green energies, refineries in the U.S. have significantly reduced their capacity—leading to less diesel produced in the country.

This tight supply of diesel—which has been exacerbated by a ban on Russian imports after the beginning of the country’s invasion of Ukraine and by U.S. refineries undergoing seasonal maintenance—is expected to send prices soaring this winter, when demand is likely to increase.