U.S. Supreme Court Chief Justice John Roberts brought a temporary halt late Friday to a landmark climate change lawsuit that was set to begin later this month.

President Donald Trump’s Justice Department asked the Supreme Court to stop the lawsuit in a filing on Thursday. Roberts approved the request on Friday even though the US high court in a unanimous ruling in July had said that the case could proceed.

Twenty-one children and young adults sued the federal government in August 2015, alleging the government had failed to protect them from the impacts of climate change.

Here’s what’s at stake for the 21 kids suing the Trump administration over climate change

Arguments before the Ninth Circuit will decide whether the case goes to trial.

ThinkProgress’ Kyla Mandel explained the basis for the case.

The lawsuit uses a legal theory known as atmospheric trust litigation, which argues the government must hold certain common elements such as rivers or shorelines, and in this case, the atmosphere, for public use. By failing to protect and preserve a clean atmosphere for future generations — by promoting fossil fuels, for instance — the lawsuit argues that the government is violating its obligation to the public trust.

Now, Roberts has halted discovery and the trial “pending a response to DOJ’s stay request, which is due by 3p Wednesday,” per BuzzFeed News’ Chris Geidner, who noted the timeline for the lawsuit is now unclear.

Trump, who once bizarrely claimed “global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive,” accused scientists of having a “political agenda” while discussing climate change during an interview on CBS’ 60 Minutes that aired last weekend.