June 10, 2015 6:00 PM, EDT

Trucks a Key Part of Obama Administration’s Climate-Change Goals

The Obama administration is adding crucial elements to its campaign against climate change this month with proposals to limit carbon emissions from trucks and aircraft, two of the heaviest fuel users.

Following earlier rules to boost the mileage of cars and reduce coal use in electricity, the initiatives on tractor-trailers and airplanes are key to reaching President Obama’s pledge to cut emissions by 26% by 2025, researchers say.

The rules also lay the groundwork for United Nations climate negotiations set to conclude in Paris in December.

With the final rule scheduled to come out this summer, the changes for trucks and aircraft are meaningful, too, and do not come with the organized industry resistance that the Environmental Protection Agency is facing on its power-plant standard.

Truck and aircraft makers have been working with the administration on how it can structure its plans. For trucks, environmental groups are pushing the president to set fuel-economy improvements of 40% from 2010, a goal they say is both technologically feasible and long overdue because tractor-trailers average 6 miles for every gallon of diesel.

That change alone could cut U.S. oil use by 1.4 million barrels a day and eliminate more than twice the greenhouse gases emitted by New Jersey each year, according to the Sierra Club.

In contrast to his first term, when he sidelined climate concerns in favor of an “all-of-the-above” energy strategy, Obama now says combating climate change is a top priority.

The United States promised to cut greenhouse-gas emissions 26% to 28% below 2005 levels by 2025. U.S. emissions are already down more than 10% from 2005, although the independent Energy Information Administration predicts emissions will increase, not fall, in the next decade.

“They appear to be moving on all fronts,” said Karl Hausker, who wrote a report for the World Resources Institute on how the United States could achieve its goals. “We’re confident they can meet it. It’s not easy, but it’s doable.”

Setting efficiency rules for automobiles and small trucks to boost average mileage to 54.5 miles per gallon by 2025 was a major effort early in Obama’s tenure, and EPA’s plan to curb power-plant emissions is the centerpiece of the second-term agenda.

EPA said U.S. planes account for 11% of greenhouse gases from U.S. transportation activity and 29% from all aircraft globally, although the agency said a final rule on aircraft isn’t likely until 2018.

The EPA also is preparing rules to cut methane leaks from oil and gas drilling, and switch out the use of climate-harming refrigerants.

Rules on methane and refrigerants could be issued this summer, said David Doniger, director of the climate program at the Natural Resources Defense Council.

“It’s the summer of climate action,” he said.