“Planetary Health Litigation” as an Emerging Trend

Climate litigation is expanding worldwide. However, its key issues are undergoing significant transformation. In recent years, growing concern over health-related harms arising from extreme heat, air pollution, and related factors has led to an increasing number of cases seeking to hold states and corporations liable for the link between climate change and human health. Similarly, litigation connecting biodiversity loss to harm to human health and livelihoods has begun to emerge.
This evolving trend can be characterized as “planetary health litigation,” which frames the health-related harms caused by the triple planetary crisis of climate change, environmental pollution, and biodiversity loss as violations of human rights.

This emerging trend has been significantly accelerated by the advisory opinion issued by the International Court of Justice (ICJ) on July 23, 2025. The advisory opinion clarifies for the first time that states have obligations under international law to address climate change. The ICJ’s articulation of legal grounds and standards for assessing state inaction may further accelerate the expansion of climate litigation. In fact, on December 18, 2025, Japan saw the filing of its first seeking state redress related to climate change, following the advisory opinion.

Despite these global shifts, governments and corporations often still tend to treat environmental issues, human rights, and health issues as separate domains, and it cannot be said that they are proactively responding to these changes. In light of this, this report provides an overview of trends and key issues in climate litigation focusing on health-related harms, examines their characteristics, and identifies key actions and considerations required of governments and corporations in response to these developments.

KPMG AZSA LLC

Michikazu Koshiba
Director - Healthcare & Well-being (HC&WB)

Ritsuko Yamagata
Senior Manager

Koya Hatakeyama
Manager - Healthcare & Well-being (HC&WB) 

Ayano Fujiyoshi
Associate - Healthcare & Well-being (HC&WB)