Environmental groups scored a major victory Thursday when a federal judge invalidated an offshore oil and gas lease sale in the Gulf of Mexico, the largest in American history, which was initiated by the Trump administration.

Judge Rudolph Contreras’ ruled that Trump’s Bureau of Ocean Energy Management, an agency within the Interior Department, conducted a flawed environmental analysis that underestimated the greenhouse gas emissions the drilling would cause.

“The Court believes that [the Bureau of Ocean Energy Management’s] error was indeed a serious failing,” Contreras wrote.

The New York Times reports:

“This is huge,” said Brettny Hardy, a senior attorney for Earthjustice, one of several environmental groups that brought the lawsuit.

“This requires the bureau to go back to the drawing board and actually consider the climate costs before it offers these leases for sale, and that’s really significant,” Ms. Hardy said, adding, “Once these leases are issued, there’s development that’s potentially locked in for decades to come that is going to hurt our global climate.”

Contreras decision impacts 80 million acres in the Gulf of Mexico – although just 1.7 million acres had already been leased by Shell, BP, Chevron and Exxon Mobil for $192 million.

The Biden administration begrudgingly executed the leases late last year. The Washington Post explains:

Shortly after taking office, President Biden suspended new oil and gas drilling on lands and waters owned by the federal government. But after a Louisiana judge struck down the moratorium last summer, administration officials said they were forced to go through with the sale in November.

It’s unclear if the Biden administration will appeal Thursday’s ruling. While Biden has frequently expressed his opposition to offshore drilling, his administration is also sensitive to the political and economic impact of rising gas prices.

The New York Times explains that environmental groups are skeptical of his commitment to end offshore drilling:

In November, for example, [Biden’s] Interior department issued a long-awaited report that was supposed to determine the future of federal oil and gas leasing. It skirted the question of ending the practice and instead recommended the government charge companies higher rates to drill.

The Times continues:

Environmental groups said they want the administration to live up to its campaign promises. “We will continue to hold the Biden administration accountable for making unlawful decisions that contradict its pledge to take swift, urgent action on code red climate and environmental justice priorities,” said Hallie Templeton, legal director at Friends of the Earth, an environmental group that was part of the lawsuit.