TOKYO: Hundreds of people across Japan sued the central government on Thursday, seeking damages for “unconstitutional” inaction on climate change in the country’s first such litigation.

The landmark lawsuit criticises Japan’s “grossly inadequate” response to the climate crisis, stating it jeopardises the health and livelihoods of the approximately 450 plaintiffs.

“We just submitted our complaint and evidence to the court, and our lawsuit has been officially accepted,” lead lawyer Akihiro Shima said.

Plaintiff Kiichi Akiyama, a construction worker, stated that the relentless heat forced his team to work more slowly, resulting in “huge losses” to his business.

There have also been cases where “people collapse out in the field, or have dropped dead after they return home”, the 57-year-old said.

In the past, five climate-related lawsuits have been filed with Japanese courts, including against coal-fired power plants, said Kyoto University assistant professor Masako Ichihara.

But Ichihara — as well as lawyers working on the suit — say this is the first compensation claim against the state over climate change.

“The defendant’s climate change measures are grossly inadequate, and as a result, the plaintiffs’ rights to a peaceful life and to the enjoyment of a stable climate are being violated,” said the complaint summary, which was obtained ahead of the filing.

This year, Japan sweltered through its hottest summer since records began in 1898, and the plaintiffs argue such heatwaves cause economic losses, ruin crops, and put many at risk of crippling heatstroke.

Akiyama, who frequently works outside in the searing heat, said it now takes his team triple the estimated time to finish their projects.

“I can barely dig with a shovel for 10 minutes without sitting down to rest,” he added.

“We wouldn’t be in this terrible situation if the government had taken more initiative in implementing policies.”

Burning hot playgrounds

Similar legal moves are underway globally, including in South Korea, where young environmental activists won the first such case in Asia.

Last year, a South Korean court ruled that much of the country’s climate goals were unconstitutional. In Germany, climate targets were also ruled insufficient and unconstitutional in 2021.

The suit in Japan is seeking damages of 1,000 yen ($6.5) per plaintiff.

Lead lawyer Shima said plaintiffs wanted to focus on “the issue of the country’s responsibility” rather than on money.

Japan’s case is bolder than previous lawsuits in the country in that it seeks to directly hold the state accountable for climate inaction, academic Ichihara said.

Chances of a legal win are slim, she explained, but “if the purpose … is to raise public awareness, then it may succeed” because of its “very relatable” messaging.

Another plaintiff, who only gave her surname, Saito, was spurred into action by concerns over her six-year-old son.

Published in Dawn, December 19th, 2025