Four days after President Donald Trump took the oath of office, an official at the Department of Agriculture sent an email, the first in a string of messages signaling to staff that the term "climate change" could soon be erased from the agency's vocabulary.

"It has become clear one of the previous administration's priorities is not consistent with that of the incoming administration," wrote Jimmy Bramblett, a deputy chief in the agency's Natural Resources Conservation Service (NRCS). "Namely, that priority is climate change. Please visit with your staff and make them aware of this shift in perspective within the Executive Branch."

Over the course of the next six months, Bramblett and other officials sent emails to staff, coaching them to avoid using the term "climate change" and instead use the term "weather extremes." In one email, a department head suggested that the agency "remove or significantly alter" an internal survey and report in which staff discussed whether climate change is "human induced."

"It's clear that Trump's political agenda is blocking out any science that NRCS is responsible for," said Meg Townsend, an attorney with the Center for Biological Diversity, which obtained the emails. "That can affect not just the day-to-day jobs of the agency staff, but the food we eat and the air we breathe."

The emails, released to the center last week in response to a Freedom of Information Act request, come as farmers are increasingly coping with the effects of climate change. Farmers, whether doubtful of climate change or not, often use the terms "weather volatility" or "extremes," taking their cues from industry groups. The agency now appears to be following along—a move that worries agricultural scientists who say the fuzzy terminology not only could make communicating climate-related risks more difficult, but also could have a chilling effect on research.

"It remains to be seen. Will that language stymie research efforts to help—and I'm going to use the language I'm not supposed to—adapt to climate change?" said Charles Rice, a professor of agronomy at Kansas State University and chair of the National Academy of Sciences Board on Agriculture and Natural Resources.

"Whether you like it or not, weather is changing, and it has had and will have an impact on our ability to produce food. If you shut off that funding, it will take several years to rebuild that effort, because you've lost a generation of research," Rice said.

The emails were released in response to one of many requests that Townsend's group filed with government agencies seeking climate-related internal communications. The USDA initially refused to comply with the request, claiming there were "no responsive records," but eventually released the documents. Other agencies, including, the Environmental Protection Agency and departments of Interior and State, have refused to comply, prompting the center to file a lawsuit, Townsend said.

NRCS runs a number of programs, including those that set aside farmland for conservation and promote farming practices that improve the carbon-capturing abilities of soil. The service also runs a soil carbon inventory and gives out grants for projects that cut greenhouse gases.

In an emailed statement Monday, NRCS said it "has not received direction from USDA or the administration to modify its communications on climate change or any other topic. The agency continuously evaluates its messaging to America's farmers, ranchers and foresters as they work to implement voluntary conservation on their operations to improve the health of our soil, air, water and habitat."

USDA Has Recognized Climate Change for Years

Starting in the George W. Bush administration—which launched the department's Climate Change Program Office—the USDA has increasingly focused resources and research on climate change-related problems facing agriculture.

Under the Obama administration, the USDA set up regional "climate hubs," a network of centers where farmers can get information and data on climate-driven changes in weather. The agency also launched a "climate smart agriculture" initiative, setting a goal of cutting greenhouse gas emissions from U.S. agriculture by 120 million metric tons by 2025—or 2 percent of economy-wide emissions.

"Farmers, ranchers and other producers in the U.S. and around the world are feeling the impact of climate change now," former Agriculture Secretary Tom Vilsack said in 2014. "They are experiencing production challenges from extended droughts, more severe flooding, stronger storms and new pests and diseases."

But, while Vilsack prioritized programs that help farmers cope with these challenges, he also acknowledged that the term "climate change" was a political hot potato, especially in farm country.

Lobbyists' Terminology Creeps in Under Trump

The American Farm Bureau Federation, the industry's powerful lobbying group, has cast doubt on the scientific consensus behind human-induced climate change, even as it has acknowledged that its members are battling its impacts.

Those preferred terms—"variability" and "extremes"—have now migrated to the USDA, an agency run by Sonny Perdue, a former Georgia governor who has expressed doubts about the human impact on the climate.

In one email, sent in February—before Perdue's confirmation—NRCS's director of soil health, Bianca Moebius-Clune, instructed employees to use "weather extremes" as a stand-in for climate change. She also suggested the term "resilience to weather extremes" in favor of "climate change adaptation," and "build soil organic matter" or "increase nutrient use efficiency" in favor of "reduce greenhouse gases."

These favored terms are widely used in agriculture to describe conservation practices that happen to have a climate benefit. But the emails suggest they're being suggested as a form of disguise.

"The key question is, are these euphemisms and alternative wordings merely cosmetic but not substantive, or are they a first step away from advancing mitigation solutions to climate change that agriculture can contribute?" said Ferd Hoefner, director of the National Sustainable Agriculture Coalition. "The jury is still out on that."