A pipeline company’s lawsuit against the environmental group could chill free speech, experts said. First Amendment issues are likely to figure prominently in an appeal.

© Jack Dura/Associated Press

In his first few weeks, President Trump has frozen climate spending, shaken up staffing at agencies like the E.P.A. and set off a wave of legal challenges.

The early days of the transition have been marked by dismissals and dread.

New York and Vermont recently passed laws like these, which require energy companies to pay climate damages and will likely face fierce challenges.

The high court declined to hear a challenge to a major case in which Honolulu is suing energy companies over climate change.

The lawsuit, an unusual strategy for the oil giant, comes after California’s attorney general sued Exxon last year alleging it misled the public about plastics recycling.