A Court Debates Whether a Climate Lawsuit Threatens National Security

Two teams of high-powered lawyers clashed this week in Charleston, S.C., over a global-warming question with major implications: Do climate lawsuits against oil companies threaten national security, as President Trump has claimed?

In the lawsuit, the City of Charleston is arguing that oil companies including ExxonMobil, Chevron and about a dozen others carried out a sophisticated, decades-long misinformation campaign to cover up what they knew about the dangers of climate change.

There are some three dozen similar cases around the country, and recently Mr. Trump issued an executive order calling the lawsuits a threat to national security, saying they could lead to crippling damages. The hearings in Charleston were the first time lawyers had to grapple in a courtroom with the president’s assertions.

Mr. Trump’s executive order was the opening salvo in a broad new attack by his administration against climate lawsuits targeting oil companies. Citing the executive order, the Justice Department this month filed unusual lawsuits against Hawaii and Michigan seeking to prevent them from filing their own climate-change suits. (Hawaii filed its suit anyway, and Michigan’s attorney general has signaled that she will also be proceeding.)

In court hearings in Charleston on Thursday and Friday, Judge Roger M. Young Sr. asked each side to weigh in on the order as they sparred over the companies’ motions to dismiss the case, which was filed in 2020.