Weather report. GHG litigation update.

1. The US


Held v Montana is an action by sixteen young people in Montana challenging the constitutionality of the State’s fossil-fuel based energy system, alleging that this breached their rights, including the right to a ‘clean and healthful environment’ as set out in the Montana Constitution. The action specifically targeted a provision in The Montana Environmental Policy Act (“MEPA”) which contains a limitation (the “MEPA Limitation”) that prevents the State from considering the impacts of greenhouse gas (“GHG”) emissions or climate change in environmental reviews of its energy economy. Since the claim was commenced, clarifications to the MEPA Limitation were signed into law in April 2023, further explicitly prohibiting “an evaluation of greenhouse gas emissions and corresponding impacts to the climate in the state or beyond the state’s borders” for MEPA reviews of new energy projects.

On 14 August 2023 District Court Judge Seeley held that the plaintiffs had standing to bring the action, as they have a “fundamental constitutional right to a clean and healthful environment, which includes climate as a part of the environmental life-support system.” Montana’s GHG emissions and climate change were found to be proven factors in causing climate impacts to Montana’s environment and harm and injury to the Plaintiffs. Montana’s GHG emissions could be fairly traceable to the MEPA Limitation. The MEPA limitation was held to have violated the plaintiff’s right to a clean and healthy environment by prohibiting analysis of GHG emissions and corresponding impacts to the climate of energy projects, as well as how additional emissions will contribute to climate change or be consistent with the Montana Constitution, and was unconstitutional. An injunction was granted prohibiting the state government and public bodies in accordance with the unconstitutional statutes. Montana has sixty days within which to appeal.


On 17 September 2023 a suit was filed by the State of California in the San Francisco which alleges that various oil and gas misled the public for decades about climate change and the dangers of fossil fuels and seeks compensation from those companies to help fund recovery efforts related to California’s extreme weather events, from rising sea levels to drought and wildfires, that have been exacerbated by human-caused climate change.

2. Europe

Two cases are currently before the European Court of Human Rights, brought by claimants from different ends of the age spectrum.

First, Verein Klima Seniorinnen v Switzerland, involving the effect of climate change on elderly women in Switzerland, amounting to violation of their rights under Articles 2 (right to life) and 8 (right to respect for private and family life) of the Convention., and was heard on 29 March 2023. Second, 27 September 2023 the hearing began in Duarte Agostinho and others v Portugal and 32, involving claims brought by young people in Portugal, aged 11-24, alleging that signatories to the Paris Agreement have failed to comply with their commitments, amounting to a violation of their rights under Article 2 and 8 of the Convention.

3. The Oceans

The law of unintended consequences may be applying to the IMO’s 2020 Sulphur Cap. This change was made to preserve human health, due to the toxic nature of sulphur aerosols, but may also have contributed to global warming. Sulphur aerosols also reflect sunlight, and as a result have a cooling effect, and are believed to have masked some of the effects of global warming, especially in the regions of heavy maritime traffic such as the North Pacific and North Atlantic regions. An analysis in July 2023 by Carbon Brief states,

“Carbon Brief’s analysis suggests that the additional warming due to the IMO regulations on marine fuel is approximately equivalent to two additional years of global greenhouse gas emissions from human activity at their current rate. While this does not fundamentally change where the world is headed in terms of warming by 2050, it does make it more difficult to limit warming to 1.5C over the next few decades. However, the change in radiative forcing due to a drop in SO2 emissions remains highly uncertain, especially over the oceans… Taking the high end of the range of estimates of radiative forcing could result in up to 0.18C additional warming by 2030 and 0.25C additional warming by 2050, though most studies have found lower forcing estimates than this.”