One discipline that has been targeted more specifically is climate science. President Trump has long downplayed the threats from human-caused global warming. At the National Oceanic and Atmospheric Administration, staff members have been ordered to comb their research awards for terms including “climate science,” “climate crisis,” “clean energy” and “pollution.”

Aurora Roth is finishing her doctoral studies at the Scripps Institution of Oceanography at the University of California, San Diego, and preparing to apply for jobs. Instead, she said, “I am wondering what institutions will even exist in a year.”

She and other scientists could figure out how to reword their funding applications to avoid mentioning climate change, Ms. Roth said. But “feeling attacked just on the basis of doing science in the world? That’s a hard thing to sit with,” she said.