The White House removed the official in charge of the federal program that produces the U.S. government’s definitive reports on climate change, three people familiar with the situation said.

The official, Michael Kuperberg, a climate scientist who had been executive director of the U.S. Global Change Research Program (USGCRP) since July 2015, was told Friday evening to return to his previous position as a scientist at the Energy Department. He had been expected to stay on through the production of the fifth edition of the congressionally mandated National Climate Assessment.

The climate assessment examines the present-day harms that climate change is having on the United States and makes projections about future damage down to the local level from greenhouse-gas emissions from burning fossil fuels.

The USGCRP is a program Congress created to help coordinate the climate science programs of 13 federal agencies. The program works to “advance understanding of the changing Earth system” and facilitates the production of the National Climate Assessment and other reports.

Kuperberg directed that office through the release of the fourth edition of the climate assessment, which detailed the potentially dire consequences for Americans should the country take little action to cut emissions and prepare for climate change’s effects, such as sea-level rise, droughts and hotter, longer-lasting heat waves.

The report, produced by federal and outside scientists, angered the White House, since President Trump has consistently downplayed the seriousness of the climate threat and the scientific consensus that human activities are playing the dominant role in warming the planet.

Kuperberg’s removal was confirmed by a current federal official and a former White House official, both of whom spoke on the condition of anonymity because they were not authorized to comment on the matter. It was also confirmed by Don Wuebbles, a climate scientist at the University of Illinois who led the development of the Climate Science Special Report for the Fourth National Climate Assessment and is a friend of Kuperberg’s.

“Mike called me on Saturday and said he was just notified that he was let go, that his detail was over and that he should go back to the Department of Energy,” Wuebbles said.

The former White House official described Kuperberg as “shocked” by his removal. “He was extremely dedicated,” the official said. “He did a very good job of figuring out how to walk that political line. He had no idea it was coming.”

Kuperberg did not reply to requests for comment.

His dismissal comes just as Betsy Weatherhead, a mainstream climate scientist, takes over as the federal coordinator of the next assessment which is just getting underway. Weatherhead will work with the USGCRP but be formally located within the U.S. Geological Survey. While the bulk of the work on the report will take place under Joe Biden’s administration, government officials are starting to select which scientists will participate in writing it now, with the first deadline for author nominations coming up on Saturday.

Removing Kuperberg could allow the White House to insert someone whose climate science views more closely align with Trump’s. That may be exactly what’s about to happen, according to Myron Ebell, a climate change contrarian at the Competitive Enterprise Institute who is close to the administration.

Ebell said in an interview that the job will most likely go to David Legates, a meteorologist from the University of Delaware who was recently appointed to be the deputy assistant secretary of Commerce for environmental observation and prediction at the National Oceanic and Atmospheric Administration (NOAA). While that is a senior position at NOAA reporting directly to the acting administrator, Legates does not have a role in the climate assessment process while serving in that capacity.

“It makes sense if they want to take the national assessment in a direction that relies on science rather than junk science, science fiction and speculation,” Ebell, who has long been critical of the scientific consensus on human-caused global warming, said of a potential Legates move to the climate research program. Legates has argued that carbon dioxide is not a pollutant, and promoted the benefits of burning fossil fuels for energy.

Even if he were to hold the climate research job for just the remaining few months of Trump’s term, Ebell said he could help select the authors of the next assessment and influence its final content that way.

Once the assessment’s authors are selected, it can be difficult to change them as the process moves along, Ebell said, regardless of the administration in office at the time.

However, he cautioned that he heard that the personnel change would be announced Monday, and said the delay could indicate there’s a ‘glitch’ in the appointment.

The USGCRP has traditionally stayed insulated from political influences, instead serving as a coordinating office and funding agency for carrying out the major report and providing other climate science information useful to the public and policymakers.

Kuperberg’s removal “seems quite consistent with decisions at NOAA and elsewhere,” said Kathy Jacobs, who is director of the Center for Climate Adaptation Science and Solutions at the University of Arizona and ran the Third National Climate Assessment. “[It’s] a last-minute attempt to remove people who may not be perceived as supporting the president’s agenda.”

It also occurs against the backdrop of the removal of several government officials at the White House’s request, including a senior official at the U.S. Agency for International Development, the director of the National Nuclear Security Administration and Monday’s firing of Defense Secretary Mark T. Esper.

Wuebbles and Jacobs said they did not understand why the administration would dismiss Kuperberg now.

“I can only speculate they want to see if they can manipulate the Fifth National Climate Assessment before the next administration comes in,” Wuebbles said. “Why they want to do that, I don’t understand.”

Jacobs said any damage done by removing Kuperberg could be reversed by the Biden administration.

“I would be more concerned if Trump had won the election,” she said. “If USGCRP is rudderless for a few months, I don’t consider that a devastating situation. The question is: What are they going to do in the interim?”

Brenda Ekwurzel, director of climate science for the Union of Concerned Scientists, said Kuperberg’s removal at this time is “troubling.”

“I think people underestimate how important USGCRP is,” she said, emphasizing that it plays a role in coordinating reports for the international community, as well. “It does not send a good signal internationally,” she said, especially considering the United States is set to rejoin the Paris climate accords under Biden.