A showdown is brewing in the U.S. courts, one that pits young Americans against President Donald Trump and the fossil fuel industry.

Central to the fight is a lawsuit that accuses the federal government and energy companies of failing to adequately address human-caused global warming. A group of 21 citizens, ages 9 to 20, claim that failure violates their "constitutional rights to life, liberty and property."

Now Trump and fossil fuel defendants want the case to go away.

SEE ALSO: How 21 kids could keep climate websites from going completely dark

Both groups filed separate motions last week to the Ninth Circuit Court of Appeals to scrap an earlier ruling that upheld Juliana v. United States. It's unusual for the government to try to appeal a case to a higher court before a lower court has ruled on it — especially since this case is moving toward a trial later this year.

Kelsey, lead plaintiff suing U.S. to take action on climate, is teaching youth about climate change in her home @fluxoregon @UOsojc @OCTorg pic.twitter.com/IpbB9UKG4U — Miles Trinidad (@miles_trinidad) March 9, 2017

Environmental groups and some climate scientists have praised the children's lawsuit as a groundbreaking strategy to force the government to act on climate change.

The lawsuit initially targeted former President Barack Obama who, for all his efforts to tackle climate change, still couldn't shake the nation's dependence on oil, coal and natural gas. Now Trump has inherited the lawsuit. But unlike Obama, Trump says he doesn't believe climate change is a threat. His EPA administrator, Scott Pruitt, is working to dismantle the climate policies that Obama put in place.

If successful, this first-of-its-kind lawsuit could force even a skeptical government to curb carbon dioxide emissions and help communities adapt to the effects of global warming. Hence all the attempts to stop it.

The Trump administration filed a motion on March 7, disputing the earlier ruling that the children have a viable legal claim.

In November, U.S. District Court Judge Ann Aiken denied the Obama administration's motion to dismiss the lawsuit — setting a landmark precedent for climate issues as legal rights.

"I have no doubt that the right to a climate system capable of sustaining human life is fundamental to a free and ordered society," Judge Aiken said in her decision.

The Trump team also filed a motion to delay trial preparations until after the court considered the appeal. On top of that, lawyers asked for an expedited review of both motions, citing a Jan. 24 letter filed by the young plaintiffs' lawyers.

That letter — a legal preservation notice — requests that federal agencies and fossil fuel industries retain records relating to climate change and any communications between the government and oil, gas and coal companies.

Lawyers filed the letter after it seemed likely the Trump administration would remove global warming-related content from the websites of the Environmental Protection Agency, NASA and other agencies.

'We'll be asking supporters to take bold actions to show support for youth plaintiffs.' -Jess, @OCTorg organizer. #PIELC2017 #youthvgov pic.twitter.com/ETX1yZNNto — Our Children's Trust (@OCTorg) March 4, 2017

The Trump administration called the letter "extraordinarily broad," saying it placed an outsized burden of discovery on the federal government. The United states could be "irreparably harmed" without a stay, the administration claimed in its motion.

On March 10, fossil fuel industry groups filed a similar motion requesting appeal of Judge Aiken's decision. The defendants' attorneys also claimed the companies would be forced to spend "enormous" resources to produce all the documents and witnesses required in the expert discovery phase.

Julia Olson, a counsel for the 21 young plaintiffs and executive director of Our Children's Trust, said the Trump administration's efforts to quash the lawsuit demonstrate the government's "misplaced priorities."

"They're right. It is a big case," she said in a statement. "They prefer to minimize the procedural obligations of not destroying government documents over the urgency of not destroying our climate system for our young plaintiffs and all future generations?"