The Earth is experiencing the warmest period in human history. 2024 will likely be the warmest year since homo sapiens happened. 2025 will likely be worse, but not as bad as 2026, and so on. Fresh reports reveal current carbon atmospheric loading at 427 parts per million (ppm), far surpassing the goal of 350 ppm. And, astonishingly, global carbon output continues to increase. Humans are burning more fossil fuels, releasing more methane, and flying, driving, boating, and emitting more carbon than ever.
Does human-caused (anthropogenic) global warming violate human rights? The United Nations (UN) Human Rights Council and the UN General Assembly have recently issued resolutions recognizing the right to a healthy environment. Most regional conventions, such as the African Charter on Peoples and Human Rights, recognize the right to a healthy environment, as do constitutions in at least 84 countries and six states in the United States (Hawai‘i, Illinois, Massachusetts, Montana, New York, and Pennsylvania). The U.S. Constitution, however, is silent about the environment. Nowhere, however, does international, regional, national, or U.S. subnational law expressly confer a human right to a healthy climate.
This hasn’t stopped some from arguing that the lack of climate action violates a recognized human right, such as a right to a healthy environment, well-being, or dignity. According to the Sabin Center at Colombia School of Law, there have been nearly 2,700 “climate litigation cases.” The United States is responsible for nearly two in three of these cases. Most of these cases involve claims that are either statutory-based (e.g., Massachusetts v. EPA) or common-law based (e.g., Connecticut v. American Electric Power). Very few seek to vindicate a human right to a healthy climate or a similar claim.
This stands in contrast to developments elsewhere in which courts have ordered governments and private parties to reduce greenhouse gas emissions based on rights-based claims, for instance, in the Netherlands (e.g., Urgenda Foundation v. Netherlands (2019)), Germany (e.g., Neubauer v. Germany (2021)), and the European Court of Human Rights (e.g., Verein KlimaSeniorinnen Schweiz and Others v. Switzerland (2024)). Yet, high courts in some countries (e.g., Norway and Ireland) have rejected such claims, and at least one government, Switzerland, has announced it will not follow the court’s ruling.
No human rights-based climate action based on U.S. federal law has yet to reach anything close to the merits, however. The most celebrated is Juliana v. U.S., a 2015 case in which plaintiffs alleged that the Due Process Clause of the U.S. Constitution affords a fundamental right to a stable climate. The district court agreed. On appeal, the Ninth Circuit assumed that the government had violated plaintiffs’ constitutionally protected liberty interest to live in a climate system capable of sustaining human life. It found that a “substantial evidentiary record documents that the federal government has long promoted fossil fuel use despite knowing that it can cause catastrophic climate change and that failure to change existing policy may hasten an environmental apocalypse.” It held that plaintiffs met their prima facie burden of proof that climate change is real, “apocalyptic,” and caused in part by actions and inactions of the U.S. government. Two (of three) judges, however, still voted to dismiss the case on the ground that the plaintiffs lacked Article III standing, skeptical that the relief sought would reduce plaintiffs’ injuries and maintaining that separation of powers entrusted action to the elected branches.
The circuit court then remanded the case to the district court for dismissal. Yet, the plaintiffs filed a motion under Rule 15, requesting permission to amend their complaint to add a claim for declaratory relief, which, presumably, the court could redress under Article III. The district court granted the request, denied the government’s motions to dismiss, and set a trial date. Thereafter, however, a three-judge panel of the circuit court ordered the lower court (under writ of mandamus from the federal government) to dismiss the case again, this time with prejudice. In July 2024, the Ninth Circuit rejected the plaintiffs’ petition for the court to review the matter en banc. Thus, federal claims arguing a fundamental right to a healthy climate seem to have reached their Waterloo.
This brings us to similar claims based on state constitutional rights. While no state constitution recognizes a right to a healthy climate, a half dozen recognize a right to a healthful environment or something similar, including Montana. Enacted in 1972, the Montana Constitution provides that “All persons are born free and have certain inalienable rights. They include the right to a clean and healthful environment.” It also requires that “[t]he state and each person shall maintain and improve a clean and healthful environment in Montana for present and future generations.” Further, it requires that the legislature provide “adequate remedies for the protection of the environmental life support system from degradation” and “prevent unreasonable depletion and degradation of natural resources.” The Montana Constitution also recognizes other rights, including that “[t]he dignity of the human being is inviolable. No person shall be denied the equal protection of the laws.”
Accordingly, in March 2020, in Held v. Montana, youth plaintiffs filed a lawsuit against the State of Montana, arguing that the Montana Environmental Policy Act’s (MEPA) exclusion of consideration by state agencies of the causes or effects of greenhouse gases contravenes the “right to a clean and healthful environment,” the right to dignity, and other rights guaranteed by the state’s constitution, among other provisions.
In June 2023, the state trial court presided over the first climate rights trial in U.S. history, hearing from experts on how the MEPA amendment affects the climate in Montana and elsewhere and adversely affects the youth plaintiffs. The court made first-time findings regarding effects and causes. For the former, the court found that annual “extreme heat days” (temperatures of more than 90 degrees) in Montana are expected to increase by 11–30 days by midcentury. Montana is expected to experience 5.6°F to 9.8°F of warming by 2100. This will reduce snowpack, shorten snowpack runoff duration in the spring and summer, and melt the glaciers in the famed Glacier National Park, affecting water sources throughout the state, region, and continent.
For the latter, it found that Montana is connected to about 180 million tons of CO2 emissions through extraction, processing and transportation, and consumption. Extraction accounts for 70 million tons of CO2 being released into the atmosphere, more than many other countries, including Brazil, Japan, Mexico, Spain, and the United Kingdom. Transportation and processing accounts for another 80 million tons of CO2, about the same as Columbia, which has 50 times more people. Consumption accounts for another 32 million tons of CO2, more per capita than all but five states. In all, Montana (with 1.1 million residents) is responsible for about 166 tons of CO2 emissions, roughly the same as Argentina (with 47 million residents), the Netherlands (with 18 million residents), and Pakistan (with 248 million residents). In the court’s words, “Montana is a major emitter of GHG emissions in the world in absolute terms, in per person terms, and historically.”
The court then ruled in favor of the plaintiffs, finding inter alia that they have standing and that the MEPA amendment violates their “right to a clean and healthful environment” and other rights enshrined in the Montana Constitution. Montana’s appeal to the Montana Supreme Court was argued in July 2024 and is pending.
Other cases warrant attention. The plaintiffs in Navahine v. Hawai‘i Department of Transportation argued that the state’s transportation policies favoring fossil fuels violate the state’s constitutional right to a healthy environment. In June 2024, the parties settled, agreeing to develop a plan to zero-out carbon emissions in the transportation sector by 2045. In Honolulu v. Sunoco et al., the City and County of Honolulu allege that defendant oil and gas companies have committed negligence, fraud, trespass, and other violations of state common law. After the Supreme Court of Hawai‘i permitted the case to proceed, the defendants filed a writ of certiorari with the U.S. Supreme Court to intervene to find that the U.S. Constitution and the Clean Air Act preempt all state-based climate claims, conceivably including those that are rights-based. As of this writing, the Court has invited the U.S. Solicitor General’s views but has not yet ruled on the petition.
Thus, for now—and while there are outliers in some global and a few U.S. subnational arenas—courts generally remain reluctant about recognizing a human right to a healthy climate. While climate rights jurisprudence remains a work in progress, these cases suggest that pursuing the rule of law in climate contexts warrants generational persistence. Time will tell.
