The US Department of Agriculture (USDA) has directed its officials to avoid using the term "climate change" in their work, and refer to "weather extremes" instead.

According to the Guardian, a series of emails between officials of the Natural Resources Conservation Service (NRCS), a USDA unit that oversees farmers' land conservation, show the Trump administration had in February listed "climate change" in the "avoid" category. The term was replaced by "weather extremes".

An official statement from Bianca Moebius-Clune, director of soil health, instructed employees to use "resilience to weather extremes", instead of "climate change adaption".

The term "sequester carbon" is also ruled out and replaced by "build soil organic matter", the daily reported on Tuesday.

In an email to staff, Moebius-Clune said: "We won't change the modelling, just how we talk about it — there are a lot of benefits to putting carbon back in the sail [sic], climate mitigation is just one of them."

In a separate email to senior employees, just days after Trump's inauguration, Jimmy Bramblett, deputy chief for programmes at the NRCS, said: "It has become clear one of the previous administration's priority is not consistent with that of the incoming administration. Namely, that priority is climate change. Please visit with your staff and make them aware of this shift in perspective within the executive branch."

Other emails show the often agonised discussions between staff unsure of what is forbidden.

Tim Hafner, a staff, wrote to Bramblett: "I would like to know correct terms I should use instead of climate changes and anything to do with carbon … I want to ensure to incorporate correct terminology that the agency has approved to use."

Suzanne Baker, a New York-based NRCS employee, On April 5 emailed a query as to whether officials were "allowed to publish work from outside the USDA that use 'climate change'."

Some staff said they would "prefer to keep the language as is" and stressed the need to maintain the "scientific integrity of the work".

A USDA statement on January 23 said it had issued "interim operating procedures outlining procedures to ensure the new policy team has an opportunity to review policy-related statements, legislation, budgets and regulations prior to issuance".

US President Donald Trump has repeatedly questioned the veracity of climate change research, infamously suggesting that it is part of an elaborate Chinese hoax.

The President has started the process of withdrawing the US from the Paris Climate Agreement, has instructed the Environmental Protection Agency (EPA) to scrap regulations aimed at cutting greenhouse gases, and has moved to open up more public land and waters to fossil fuel activity.

The mentions of the dangers of climate change have been removed from the websites of the White House and the Department of the Interior, while the EPA scrapped its entire online climate section in April.

"These records reveal Trump's active censorship of science in the name of his political agenda," said Meg Townsend, open government attorney at the Center for Biological Diversity.

"To think that federal agency staff who report about the air, water and soil that sustains the health of our nation must conform their reporting with the Trump administration's anti-science rhetoric is appalling and dangerous for America and the greater global community."

The Center for Biological Diversity is currently suing several government agencies, including the EPA and the State Department, to force them to release information on the "censoring" of climate change verbiage.

The emails within the USDA indicate that staff have been instructed to steer clear of acknowledging climate change or its myriad consequences.

US agriculture is a major source of heat-trapping gases, with 15 per cent of the country's emissions deriving from farming practices. A USDA plan to address the "far reaching" impacts of climate change is still online.

However, Sam Clovis, Trump's nomination to be the USDA's chief scientist, has labelled climate research "junk science".