Donald Trump’s leases of public lands and waters for oil and gas drilling could lead to the production of more climate-warming pollution than the entire European Union contributes in a year, according to a new report.

The Wilderness Society estimates heat-trapping emissions from extracting and burning those fossil fuels could range between 854m and 4.7bn metric tons of carbon dioxide equivalent, depending on how much development companies pursue.

The 28 nations in the European Union produced about 4bn metric tons of CO 2 equivalent in 2014, the last year reported.

“These leasing decisions have significant and long-term ramifications for our climate and our ability to stave off the worst impacts of global warming,” the group said.

“Emissions from public lands are expected to fall well short of the reductions target suggested by leading climate science, and this administration’s leasing decisions are making that problem much worse.”

The US government has offered close to 378m acres (153m hectares) of public lands and waters for oil and gas leasing since Trump became president through April 2019, according to the group. That’s more than any previous administration, according to the Wilderness Society.

The government does not regularly track emissions from fossil fuel development on public lands, and courts have rebuked the interior department for failing to consider the climate crisis in granting leases. The Trump administration has also been trying to overturn an Obama-era moratorium on federal coal leasing.

Multiple candidates vying for the White House in 2020 have said they would ban new drilling on public lands. They include Elizabeth Warren, Bernie Sanders, Joe Biden, Kirsten Gillibrand, Cory Booker, Jay Inslee, Pete Buttigieg and Tim Ryan.

David Hayes, who was interior’s deputy secretary under the Obama administration, testified before US lawmakers at a hearing on Tuesday that some oil and gas activity can and should continue on public lands “but it should be counterbalanced with the aggressive deployment of our public lands to tackle the climate crisis”.

Republicans on the subcommittee holding the House hearing called a witness from the conservative Heritage Foundation to argue that “negligible climate benefits” would come from banning oil and gas production on federal lands.