At the time, the agency agreed changes were necessary, “particularly in areas of the country with elevated levels of air pollution.” Obama administration officials said they planned to work with states such as California, the industry and others toward creating an updated national set of standards.

AD

AD

On Tuesday, the EPA appeared to be carrying on that work to scale back emissions of the poisonous gas, which forms when fuel is burned at high temperatures. The agency did not issue a specific proposal — that is unlikely to come until 2020 — but officials said they plan to begin a formal rulemaking process for what they called the Cleaner Trucks Initiative.

“This initiative will help modernize heavy-duty truck engines, improving their efficiency and providing cleaner air for all Americans,” EPA acting administrator Andrew Wheeler said in a call with reporters. “We are under no regulatory or court order requirements to launch this initiative. We are doing it because it’s good for the environment.”

Environmental advocates, who have fiercely opposed the administration’s efforts to roll back dozens of Obama-era regulations, including those aimed at combating climate change, reacted to Tuesday’s news with cautious optimism.

AD

AD

“This is a positive step and may be the first thing this EPA has done that will actually reduce air pollution,” said Paul Billings, senior vice president for public policy at the American Lung Association.

Even California officials, who have clashed with the administration over its proposal to freeze fuel-efficiency standards for the nation’s cars and light trucks, seemed encouraged by Tuesday’s announcement.

“It’s good that they are moving forward, because heavy-duty NOx is a huge problem, both as a precursor to ozone and fine particles,” Stanley Young, spokesman for the California Air Resources Board, said in an email. “CARB petitioned EPA to begin this process, as have many other state and local agencies, so we are pleased that the agency is moving forward to address the next generation of new heavy-duty engines.”

AD

AD

California regulators have begun a public process to set new state emissions limits, with a proposal likely next year.

Industry groups also welcomed the EPA’s announcement.

“This new initiative sets the next chapter for diesel technology,” said Allen Schaeffer, executive director of the Diesel Technology Forum, which represents engine manufacturers and suppliers. He said the effort probably will result in cleaner engines that perform better, last longer and improve air quality. “It’s the beginning of a journey, but I think a good one.”

Tuesday’s push for tighter tailpipe pollution standards for heavy-duty trucks seems at odds with the deregulatory push that has defined the Trump administration. Even as he announced the initiative on a call with reporters, Wheeler boasted about the more than two dozen regulatory rollbacks the agency has set in motion, while noting greenhouse gas emissions from major industrial sources have fallen slightly in recent years.

AD

AD

“The Trump administration has proven that burdensome federal regulations are not necessary to drive environmental progress,” he said.

Since the Trump administration took office, the EPA has sought to undo Obama-era regulations to limit methane emissions, reduce carbon dioxide emissions from power plants, reconsider rules governing the disposal of coal waste and slow requirements to make passenger cars more efficient.

Under then-Administrator Scott Pruitt, the EPA last year also proposed repealing tighter emissions standards for “glider” trucks, which use older engines that emit dozens of times as much soot and contaminants as newer ones. The agency later backed off the proposal, though it has not made a final decision.

AD

Bill Wehrum, head of the EPA’s Office of Air and Radiation, took issue with the notion that Tuesday’s announcement was one of the few actions the Trump EPA had taken to actually combat air pollution.