But, the official said, there were moderate voters who like the president’s economic policies who “just want to know that he’s being responsible” on environmental issues. And that is who the speech will be aimed at convincing.
Mr. Trump is expected to give remarks in the East Room of the White House. He will be joined by Mr. Wheeler, a former coal lobbyist, who has played a lead role in crafting rollbacks of rules on climate change and clean air, and David Bernhardt, the interior secretary and a former oil lobbyist, who has led the way in opening up the nation’s public lands and waters to more drilling.
Last month, in a move that represented the Trump administration’s most direct effort to date to protect the coal industry, the E.P.A. finalized its plan to replace former President Barack Obama’s stringent rule on coal pollution with a new rule that would keep plants open longer and significantly increase the nation’s emissions of planet-warming carbon dioxide pollution.
This summer, the E.P.A. is expected to finalize another plan that would replace Mr. Obama’s strict regulations on planet-warming tailpipe pollution, replacing them with a new rule that experts say is likely to function as a total repeal of the original regulation.
The incongruous message of environmental preservation is so starkly at odds with Mr. Trump’s own record, experts say, that the moment already smacks of the surreal.
“It is an utter farce for the president to talk about America’s environmental leadership, when he has been a champion of the polluters,” Mr. Brinkley said.
Frank Luntz, a Republican consultant and pollster, said he had presented Republican lawmakers with data in recent weeks that showed that the public — and particularly younger people — wanted to see action to safeguard the environment, but that the issue was seen as owned by Democrats.
“It is still not a top-five priority” among Republicans, Mr. Luntz said. “These guys, they really do care, but they don’t know how to get it done in this polarized environment.”