Environmental advocates want to know why a U.S. government agency hasn't yet released a crucial climate report.

On Tuesday, the Center for Biological Diversity filed a Freedom of Information Act request with the National Oceanic and Atmospheric Administration. The agency oversees government research on the threats posed by climate change.

The environmental nonprofit asked why NOAA has not yet released the Fifth National Climate Assessment, a cross-government report on climate change that spans 13 government agencies.

Congress mandates that the agency must publish its sweeping climate report every four years, with the next report due to be released in 2022. However, the government website in charge of releasing the report said it's still in "the early stages of development," and indicated a 2023 release.

The environmental group called the agency's delay "dangerous" and stressed the time-sensitive nature of the report.

"Refusing to take the basic steps to prepare the next Climate Assessment is outrageous and dangerous," said Howard Crystal, a senior attorney at the Center for Biological Diversity. "We can't prepare for the droughts, floods, fires and hurricanes to come unless we understand how climate change is affecting our country. Congress set a strict four-year timetable for these reports precisely because timely information related to climate change is so important, and the agency must move forward to comply."

In 2018, the Trump administration attempted to bury the Fourth National Climate Assessment by releasing it the day after Thanksgiving, also known as Black Friday. "Earth's climate is now changing faster than at any point in the history of modern civilization, primarily as a result of human activities," the 2018 report found.

The center slammed the report's release date, calling it "an apparent effort to downplay its grave assessment of accelerating climate change and its perils."

Donald Wuebbles, a climate scientist at the University of Illinois, oversaw the first volume of the 2018 report. He said the Trump administration is slow-walking the 2022 report by delaying putting out an official call in the Federal Register for climate researchers to work on the new report. NOAA put out an official request for comment on the report in July.

"It's not being approved to go out, so therefore they're just sitting on it. And I don't know if it's NOAA or the White House, but somebody's sitting on it, so that's just holding up getting up the NCA 5 going," Wuebbles told E&E News.

In 2017, the climate nonprofit sued the Trump administration for its refusal to release public records on the sudden disbandment of the Advisory Committee for the Sustained National Climate Assessment. Created by the NOAA in 2015, the 15-person panel of climate experts was tasked with supporting the national climate report.

The center called the committee's termination a "dangerous decision."

"Kicking these experts to the curb is a ridiculous rejection of scientific reality that will leave us even less prepared for monster hurricanes and other climate change devastation," Crystal said at the time.

Earlier this month, the Trump administration released a study that found climate change threatens polar bears — after stalling on its release for months. That news came as the Trump administration planned to open up part of the Arctic National Wildlife Refuge in Alaska — which is home to roughly 900 polar bears — to oil and gas companies. The Department of the Interior's environmental impact statement did not give an estimate of how many polar bears could be killed or harmed by the decision.

"To add hundreds of miles of seismic vehicle trails and drilling sites to the stresses these bears are already experiencing would be unimaginable as we fight to ensure their long-term survival," Adam Kolton, executive director of the advocacy group Alaska Wilderness League, told the Washington Post. "Unfortunately, the Trump administration treats science like a meal it can send back to the chef when it doesn't like it instead of as a basis for sound decision-making."

Last month, Donald Trump appointed David Legates, a climate science skeptic, to lead NOAA. The move "blindsided staffers," according to Politico.

"Legates arguably could directly or indirectly influence the direction the [fifth] assessment takes," Rick Spinrad, NOAA's chief scientist under President Barack Obama, toldPolitico. "There's an opportunity to manipulate."

In early September, as record-setting wildfires ravaged the state of California, state Natural Resources Agency Secretary Wade Crowfoot urged Trump to recognize the threat climate change poses to the United States.

"I don't think science knows, actually," Trump responded.