A model city in Japan is helping Asian cities go green

Without dissolved oxygen, fish cannot survive. Healthy water normally contains between 7-8 mg/l of the gas. Less than 5 mg/l is dangerous to marine life. And if the level drops to 1-2 mg/l for even a few hours, the result is catastrophic for fish and shellfish living in the ecosystem. Usually, a mass die-off occurs.

In the 1960s, officials measuring the levels of dissolved oxygen in the city of Kitakyushu’s Dokai Bay registered an alarming reading: the dissolved oxygen in the bay was near zero. There was virtually none.

Kitakyushu was one of the centers of heavy industry that was powering Japan’s “economic miracle” at the time. Steel mills, coal factories and chemical plants dotted the city, pumping untreated wastewater directly into Dokai Bay and soot and chemicals into the sky.  

Little could survive in the bay, which explains why the body of water was nicknamed the “Sea of Death”.

People’s health was also beginning to suffer, and residents had had enough. Starting in 1950s, a women’s association began a campaign to bring back blue skies, which prompted an about-face from the government. Local officials began work with businesses, research institutions and citizen groups to find solutions to the pollution plaguing the city.

In the 1990s, a second wave of pollution from automobiles and household waste was headed off through similar cooperation.

In one of the greatest environmental comeback stories of the 20th century, Kitakyushu was transformed from industrial wasteland to the first “Eco Town” in Japan. Hundreds of species of marine life now live in Dokai Bay and the skies are blue again. For its passionate commitment to the environment, the city of just under 1 million people has received global accolades. In 1990, Kitakyushu became the first city in Japan to receive the UN Environment Programme’s Global 500 award. And along with Paris, Chicago and Stockholm, Kitakyushu was named one of four Green Growth Model Cities by the Organisation for Economic Co-operation and Development in 2011. More recently, the organization chose Kitakyushu as one of its nine pilot cities or regions to advance the Sustainable Development Goals.


Kitakyushu city officials aren’t content to collect honours for having cleaned up their own backyard. Through the city’s Asian Center for Low Carbon Society, they have been taking their hard-earned expertise to other cities around Asia and the Pacific. Since 2010, Kitakyushu has implemented more than 192 projects in waste management, water supply, waste treatment and air pollution control in 78 cities across 16 countries.

A new cooperation agreement between the city and UN Environment signed on 2 August 2019 will help bring that expertise to bear on one of the most pressing problems in Southeast Asia: plastic pollution.

Marine litter is a worldwide problem, but with more than 60 per cent of marine plastic generated in Southeast Asia, large strides forward can be taken with a regional focus.  

UN Environment is currently implementing a Sweden-funded project to reduce marine litter in Southeast Asia and an initiative funded by Japan to tackle marine plastic along the Ganges and Mekong rivers. Through the cooperation agreement with Kitakyushu, the city’s expertise will support local governments in Thailand and Cambodia to implement effective waste management plans.

“Kitakyushu’s vast experience and expertise in waste management will be a tremendous asset as we work to beat plastic pollution in cities and regions across Asia,” said Dechen Tsering, UN Environment’s Regional Director for Asia and the Pacific. “It’s hugely important we tackle this problem now and one of the best ways we do that is through this type of international cooperation.”

 “Our city has long been a champion of the environment, and we’ve learned many lessons over the years,” said Kenji Kitahashi, Mayor of Kitakyushu. “We want to share these lessons with cities and regions that are facing the same problems that we faced, and we look forward to working with the UN Environment Programme to do so.”

Learn more about UN Environment’s work on chemicals and waste.


The UN Climate Action Summit will take place in New York City on 23 September 2019, to increase ambition and accelerate action on the global climate emergency and support the rapid implementation of the Paris Climate Change Agreement. The 2019 UN Climate Action Summit is hosted by UN Secretary General António Guterres.