A U.S. judge has blocked oil drilling planned in Wyoming because the government failed to adequately consider its impact on global warming—a decision that could complicate President Donald Trump’s broader efforts to expand oil, gas and coal output on America’s public lands.

The ruling, by Judge Rudolph Contreras of the U.S. District Court for the District of Columbia, was issued late on March 19, according to court documents.

It blocked drilling on more than 300,000 acres in Wyoming until the Interior Department’s Bureau of Land Management conducts further analysis about how the development would impact climate change.

“Having reviewed the record and the relevant law, the Court concludes that— withholding judgment on whether BLM’s leasing decisions were correct—BLM did not sufficiently consider climate change when making those decisions,” Judge Contreras wrote in the order.

A spokesperson for the Department of Interior would not comment on ongoing litigation.

Conservation groups—including WildEarth Guardians which jointly launched the lawsuit in 2016—said the decision marked an important precedent that could force the Trump administration to put the brakes on its pro-fossil fuels agenda.

“While the judge’s ruling relates to lands that were leased for fracking in Wyoming, the judge made clear the Interior Department and its Bureau of Land Management have to start accounting for the impacts of oil and gas development on a regional and national scale,” Jeremy Nichols, climate and energy program director for WildEarth, said in an email.

Under Trump’s direction, Interior has already vastly expanded onshore oil and gas leasing activity, and is also preparing to release a proposal that could open up new waters in the Atlantic, Pacific and Arctic to offshore drilling over the objections of most coastal states.

Trump and senior members of his cabinet have repeatedly cast doubt on the science of climate change, and Trump has directed government agencies to reduce the amount of consideration given to global warming in policy and permitting decisions.

The lawsuit by WildEarth and Physicians for Social Responsibility alleged that the government, under former President Barack Obama, failed to comply with the National Environmental Policy Act by failing to account for emissions generated by oil and gas development when it leased parcels in the Western states of Utah, Wyoming and Colorado.

NEPA is a Nixon-era statute that requires officials to weigh the environmental effects of proposed projects and is widely regarded as a bedrock federal environmental policy.

The March 19 ruling only pertains to 282 leases issued in Wyoming after five sales held in 2015 and 2016.

Since then, the Trump administration has pushed aggressively to open more federal lands and waters to fossil fuel extraction even though low oil prices have tempered demand among drillers. On March 20 it held its fourth Gulf of Mexico-wide lease sale, yielding a moderate uptick in revenue and leases won, but a decline in average price per acre.

BLM is also wrapping up a lease sale in Wyoming this week and will hold four more sales in Western states this month.

Onshore