Lewis Ziska, one of the United States’ leading climate-change scientists, has quit the USDA’s Agriculture Department and says he’s protesting the Trump administration’s attempts to bury one of his studies. The study, which was published in Science Advances, was about how rice loses nutrients to the increasing amounts of carbon dioxide in our atmosphere—which has implications for the 600 million people who depend on rice for most of their calories. Ziska, who’s worked at the USDA for 20 years, says the Trump administration questioned the findings of his study and attempted to minimize its press coverage. “This was a joint decision by ARS national program leaders—all career scientists—not to send out a press release on this paper,” a statement released by the USDA said in response to Ziska’s complaint.

Several government employees recently reported that they’d lost their jobs over climate-change disagreements and a Politico investigation showed that the USDA regularly buried its own climate-research discoveries. “You get the sense that things have changed, that this is not a place for you to be exploring things that don’t agree with someone's political views,” Ziska said.