The Justice Department headquarters in Washington. (J. David Ake/AP)

This story has been updated.

All three industry groups involved in a landmark climate-change lawsuit being brought against the federal government have filed motions to withdraw from the litigation.

On Thursday evening, the American Petroleum Institute and American Fuel and Petrochemical Manufacturers — trade associations representing members of the fossil-fuel industry — moved to withdraw from the lawsuit being brought by 21 youth plaintiffs arguing that the federal government has violated their right to a healthy climate system. A third industry group, the National Association of Manufacturers, filed a motion to withdraw earlier this week.

The organizations had joined the litigation last year as “intervenor-defendants.” This means that, while none of them were originally involved in the lawsuit, they were permitted to join as defendants alongside the federal government on the basis that their interests were likely to be significantly affected by the outcome of the case. Because the three industry groups were not original parties in the lawsuit, they say they have the right to request a withdrawal from the case, which the court may or may not decide to grant.

The lawsuit, Juliana v. United States, has garnered international attention, with some experts characterizing it as the “biggest trial of the century.” The 21 plaintiffs, who range in age from 9 to 21, allege that the government has violated their constitutional rights to life, liberty and property by promoting the production of fossil fuels and greenhouse-gas emissions and contributing to the progression of climate change. This, they charge, is a violation of the public-trust doctrine, which dictates that the government must preserve certain common resources for public use, including the climate system, the plaintiffs argue.

The case, originally brought against the Obama administration, has been inherited by the Trump administration, which is the major reason the industry groups say they now wish to withdraw. Earlier this week, National Association of Manufacturers Senior Vice President Linda Kelly told The Washington Post that the group evaluates the cases it wishes to be involved with after each election and had decided that “as the dynamics have changed over the last several months, we no longer feel that our participation in this case is needed to safeguard industry and our workers.”

The American Fuel and Petrochemical Manufacturers issued a similar statement to The Post on Friday. “AFPM has decided to withdraw from this case, as we are confident that the U.S. Department of Justice will rigorously defend its position and that the court will conclude that setting national environmental policy is the role of Congress and the president,” spokeswoman Diana Cronan wrote.

A statement emailed to The Post by API media director Eric Wohlschlegel said, “We continue to focus on the progress the U.S. is making leading the world in reducing carbon and other emissions, and we have full confidence that the courts will recognize that Congress and the Executive branch have the constitutional authority to write and execute the laws of the U.S.”

In moving to withdraw from the litigation this week, the industry groups may be able to avoid having to respond to a request for admission from the plaintiffs. This is a series of allegations or complaints presented by the plaintiffs, mainly surrounding the issue of climate change and its effects in this case, that the defendants are required by the court to address.

They include questions about the industry’s position on the effects of climate change on water supplies, agriculture and other natural systems, as well as the ability of human societies and natural ecosystems to adapt. The questions are used as a discovery tool in the lawsuit, a means of accumulating evidence for a trial. The deadline for this response had been set for Thursday; the industry defendants had requested an extension until June 7.

“After these youths sued the government, the trade associations pleaded their members’ interests would be destroyed if they weren’t allowed to be in the case, but now they are running for the hills,” Julia Olson, co-lead counsel for the plaintiffs and executive director of the advocacy group Our Children’s Trust, said in a statement Thursday evening. “Now, they’ve decided they’re better off being on the sidelines than subjecting themselves to discovery.”  

The industry groups did not refer to the response deadline as a factor in their decision to withdraw.

The lawsuit has already faced a number of hurdles. The Obama administration filed to have the case dismissed — a motion that Judge Ann Aiken, a U.S. District Court judge in Oregon, denied in November in a landmark ruling that cleared the case to continue to trial.

More recently, the Trump administration filed an appeal with the U.S. Court of Appeals for the 9th Circuit requesting that Aiken’s ruling be overturned. On May 1, U.S. Magistrate Judge Thomas M. Coffin recommended a denial of the appeal. Judge Aiken has yet to make a final decision on whether to allow the appeal.

The court also has the power to decide whether to grant the trade associations’ requests to withdraw from the case. Each group has argued that joining the case is not an irreversible decision and that permitting withdrawal would help simplify the judicial process by reducing the number of parties participating in the proceedings.

But Philip Gregory, another co-lead counsel with the plaintiffs, has argued that the motions fail to present a concrete reason for withdrawal.

They plead with the court to let them out, yet fail to give Judge Coffin any reason behind their change of heart,” he said in a statement Thursday.