Summary:
On 18 December 2025 and 4 April 2026, two lawsuits were filed in Japan against the Japanese government’s inaction on climate change. The first suit was filed with the Tokyo District Court on behalf of 452 plaintiffs from all over Japan, including victims of heatstroke, individuals who work in primary industries such as agriculture and fisheries, and children. The second suit, again with the Tokyo District Court, was filed on behalf of 454 additional plaintiffs.
The (in total) 906 plaintiffs in these twin cases summarize their claims as follows:
First, they challenge the legality of the government’s emissions reductions targets, given their inconsistency with the 1.5-degree warming target set out by the Paris Agreement. They challenge the reduction targets set out in the most recent Japanese NDC and the country’s 7th Global Warming Countermeasures Plan, both dated February 2025. Under these instruments, the government’s current targets aim for a 39% emissions reduction by 2030, a 52% reduction by 2035, and a 67% reduction by 2040 compared to 2019 levels, which the plaintiffs argue is incompatible with IPCC science, the 1.5-degree target, and Japan’s obligations as a highly developed nation.
Second, the plaintiffs argue that the government’s failure to enact effective legislation to achieve the 1.5-degree target is unconstitutional. They submit that “currently in Japan, there are no laws that set greenhouse gas reduction targets for 2030 or 2035, nor are there any legally binding emission standards.” They argue that “[t]he right to live peacefully in a stable climate without fear of harm to one’s life, health, or property is a human right that should be guaranteed by the Constitution”, as well as invoking the constitutionally guaranteed right to live peacefully.
In doing so, the plaintiffs draw on IPCC reports and explicitly refer to climate litigation in domestic and international jurisdictions, including the ICJ’s climate advisory opinion.
More information:
More information on the case, as well as case documents, are available here.
The applicants’ submissions in both cases (in Japanese) are available for download below.
Suggested citation:
Tokyo District Court, Call4 et al. v. Japan, filings of 18 December 2025 and 4 April 2026 (pending).