Judges on the 9th Circuit Court of Appeals raised serious doubts Monday about granting the Trump administration's motion to have a climate change lawsuit filed by children against the president thrown out of court.

Deputy Assistant Attorney General Eric Grant, appointed recently by the Trump administration, asked the western appeals court to block the lawsuit because it would require reshaping the entire U.S. energy system away from fossil fuels.

“It is really extraordinary because plaintiff seeks unprecedented standing to pursue unprecedented claims in pursuit of an unprecedented remedy," Grant told the three-judge panel during oral arguments.

"According to plaintiffs' complaint, virtually every single inhabitant has standing to sue virtually the entire executive branch to enforce an enumerated constitutional right to a climate system capable of sustaining human life" by enacting a plan “to phase out fossil fuel emissions.”

The case, Juliana v. United States, is slated to be heard at a lower federal district court in Oregon Feb. 5. But the Trump administration asked the appeals court to have the case thrown out through "mandamus" before the merits of the case are even heard. The "writ of mandamus" would force the lower court to dismiss the case, a move the lower court had rejected.

The child plaintiffs in the case, led by Our Children's Trust, argue that the government, in propping up fossil fuels, has failed to address climate change on behalf of children as a constitutional matter regarding the health and prosperity of future generations.

But the judges at Monday's hearing expressed repeated skepticism over tossing the case. Chief Judge Sidney Thomas and Judge Marsha Berzon both expressed apprehension that dismissing the case through mandamus could unravel hundreds of court cases.

“If that were true we would be absolutely flooded by appeals from people who think their case should have been dismissed by the district court," Thomas said. "If we set the precedent on this kind of case, there’s no logical boundary to it.”

Grant argued that there is precedent under Cheney v. U.S. District Court for the appeals court to dismiss the case through mandamus when the argument is over a constitutional claim.

Thomas and Berzon both reiterated that such a ruling could be too high a hurdle.

Grant said the case in the appeals court, as it was in the district court, was on "a motion to dismiss."

"But it’s not before this court on a motion to dismiss that’s the problem,” Berzon responded.

“It would be if you had prevailed and they appealed, then we would be considering these issues anew," Thomas said, explaining when a motion to dismiss would be germane.

"But now it's a mandamus case, you’re asking us for relief under a sliding scale of factors," the chief judge added. "It seems to me premature.”