It could be the biggest climate showdown of the entire Trump administration. On one side: dozens of America’s leading scientists. On the other: EPA administrator Scott Pruitt and other top Trump officials promoting dangerous denial of climate science.

Recently, scientists working on a legally mandated federal assessment of global warming’s threats to America expressed grave concerns that Trump officials may try to alter or suppress the report, which is currently awaiting “final clearance” by the EPA and other agencies.

The scientists’ fears are entirely well-founded, based on my experience successfully suing the George W. Bush administration a decade ago for just such an attempt to censor climate science.

Indeed, Pruitt recently told a Texas radio show host that his agency would take unspecified measures to review the report, even as he dismissed discussions about carbon emissions and climate change as “political.”

That’s ominous but not surprising. The report’s grim findings directly contradict public statements by Pruitt and others on Trump’s team of climate-deniers. America, the report finds, is staring down the barrel of catastrophic changes, including a growing extreme weather risk.

A normal administration would be pushed to constructive action by these alarming findings, which underscore the need for a full-scale mobilization to keep fossil fuels in the ground, ban fracking and fully use the Clean Air Act to cut planet-warming pollution.

But this president isn’t normal, and neither is his EPA chief, who has even denied that carbon dioxide is the primary driver of climate change. I believe they are poised to censor, undermine or delay this critical federal report.

That must not happen.

To fully understand what’s at stake, you have to know this report’s history. In 1990, Congress passed a law called the Global Change Research Act establishing a coordinated national research program on global climate change.

The act requires the federal government to maintain a national climate research plan and produce a scientific assessment of climate change effects in the United States. That report must be updated at least every four years to guide Congress, federal agencies and the public in all climate decisions.

John McCain, Mitch McConnell and every other Senate Republican voted for the law in its unanimous passage through that chamber. President George H.W. Bush signed it into law.

Back then, politicians acknowledged just how badly ignorance about climate change would hurt Americans. Supporting the finest scientific research in the world was a point of pride.

The Clinton administration produced the first scientific assessment of climate change in 2000. But the next assessment, due in 2004, never came. Unlike his father, George W. Bush didn’t stop at opposing climate action but also denied and attacked the science itself.

The younger Bush, like Trump, recognized that the scientific assessment was the single-most powerful document demonstrating the need urgently to reduce greenhouse pollution to avoid catastrophic damages in the United States. As a result, his administration attempted to halt the scientific work and suppress the report.

In 2006, my organization took Bush to court, arguing that continuing the research and releasing the assessment were legally required. We won, and in the spring of 2008, under court supervision and close public scrutiny, the Bush administration released the second assessment report, accurately summarizing the science.

In 2009 and 2014, the Obama administration produced updated assessments that set the gold standard for synthesizing climate science most relevant to our nation.

Today, Trump also recognizes the power of the scientific assessment. That’s why his administration is likely to try to alter or suppress the report, which is scheduled for release this fall.

My organization will be watching the administration carefully, assessing all legal options and returning to court at the earliest possible time to ensure that this essential report is released as required.

The attacks by Trump and Republicans on climate science and our country’s role as the worldwide leader on science are profoundly shocking and unpatriotic. They must be resisted at every turn.