This story is excerpted from the MT Lowdown, a weekly newsletter digest containing original reporting and analysis published every FridayThe state’s approach to disclosing climate impacts in its regulatory decisions has entered Montana’s judicial arena once more. On Sept. 29, Montana Environmental Information Center filed a lawsuit against the Montana Department of Environmental Quality, alleging that the state failed to properly consider and disclose the climate impacts and greenhouse gas emissions associated with Yellowstone County Generating Station, a gas plant NorthWestern Energy opened in Laurel in 2024 that was forecast to emit more than 23 million tons of atmosphere-warming greenhouse gases over a 30-year operational life. In its complaint, MEIC resurfaced a pair of rulings the Montana Supreme Court issued in the past year. “DEQ failed to take a ‘hard look’ at the climate-related impacts of YCGS’s greenhouse gas emissions — including direct, secondary and cumulative impacts — and no-action alternatives or potential mitigation measures to avoid those impacts, as [the Montana Environmental Policy Act] requires,” according to the lawsuit. MEIC and Northern Plains Resource Council have asked the district court to toss out the analysis DEQ did and order it to create a new one “that complies with MEPA, the Montana Constitution, and the Montana Supreme Court’s directive” in the January decision regarding the gas plant.