Scientists must confront climate change deniers and speak up if U.S. President-elect Donald Trump tries to sideline climate research, Interior Secretary Sally Jewell is due to say on Wednesday.
"If you see science being ignored or compromised, speak up," Jewell will tell a meeting of earth and space scientists in San Francisco, according to a draft of the speech seen by Reuters.
Trump has called climate change a hoax and sought to fill his cabinet with oil industry allies like Texas Governor Rick Perry, the Energy Department nominee.
Last week, the Trump team asked the U.S. Department of Energy to supply names of officials who took part in international climate talks - a request that the agency has rejected.
The scientific fact of climate change cannot be ignored no matter who is in the White House, Jewell will say. And she will urge climate experts to publicly defend their work.
"Think about where to raise your voice and then do it," Jewell will tell a meeting of the American Geophysical Union (AGU) - a global association of researchers. "The American people must be able to trust science."
As President Barack Obama's top steward for public lands, Jewell has helped manage terrain that holds vast reserves of oil, gas and coal.
But over nearly four years in office, Jewell has also warned that burning fossil fuels will irreparably harm the planet.
Jewell will say that national historic sites that she now manages - like the 17th century colonial outpost, Jamestown - could eventually be swallowed by rising seas.
Policymakers must confront climate change realities, Jewell said.
Christine McEntee, head of the AGU, said her members were concerned that the Trump administration might not value scientific discovery and rigor. Developments at the Energy Department were particularly alarming, she said, but climate researchers were prepared to defend their methods and discoveries.
"We listen to what science is telling us," she said. "And we'll fight to work without fear of intimidation or retribution."
(Reporting by Patrick Rucker; Editing by Richard Valdmanis and Lisa Shumaker)