Last month I joined the magnificent crew of the Rainbow Warrior, a team of experts, and Greenpeace colleagues from around the world. For two days we sailed along Fukushima’s beautiful, rugged coast working under rough conditions as the ship swayed along one-meter swells, and doing our best not to succumb to seasickness.

Greenpeace ship Rainbow Warrior sailing past the destroyed Fukushima Daiichi nuclear plant, five years after the accident.

For 14 years I’ve been with the environmental organisation and throughout my career have experienced the stereotypical life of a “Greenpeace-er” – I’ve been arrested for revealing corruption in the whale meat market, helped stop toxic plastics in infant toys, worked to stop ocean dumping of industrial waste, and of course have had many unique opportunities on the Rainbow Warrior. Now, as I prepare to leave my position as Executive Director of Greenpeace Japan, I realise that this could be my last time on this gorgeous ship.

Junichi Sato, Executive Director of Greenpeace Japan

But this journey has specific significance.

I’ve joined the Rainbow Warrior crew and a research team to investigate the marine impacts of radioactive contamination from the 2011 Fukushima Daiichi nuclear disaster.

It was on this day, five years ago when a tsunami, triggered by a 9.0 magnitude earthquake rocked Japan. 15,894 people died and 2,561 still remain unaccounted for - a tragedy that we commemorate and will continue to mourn. Sadly, the disaster didn’t end there. More than 146,000 people living in nearby towns were forced to evacuate due to the nuclear disaster, of which 100,000 remain and have been unable to return. We know that levels of nuclear radiation are still high in some of the areas– figures that the Japanese government have not been telling us – and this is why we’re here. For the people, for the country, and to remind the world that a nuclear disaster is on-going and never-ending.

Greenpeace divers hold up banners reading “Never again” during sampling operations off the coast of Fukushima Daiichi nuclear plant, Japan (March 2016)

Former Japanese Prime Minister Mr Naoto Kan was also on board and it’s been a privilege to be sailing with him. During our few days on the ship Mr Kan shared some personal stories: the stresses and strains of having to deal with a crisis of this magnitude; dealing with Tokyo Electric Power Company (TEPCO), the owner of the Fukushima Daiichi nuclear plant; and how he went through the very real decision of whether or not to evacuate Tokyo. The agony and the experience of witnessing the event up close has turned him from being a supporter of nuclear power, to a staunch opponent.

Former Prime Minister of Japan, Mr Naoto Kan, onboard the Rainbow Warrior. He has restated his opposition to nuclear power, and called for Japan’s energy policy to be based on renewable energy.

Not much has changed in five years. As we sailed within 2km of the Fukushima Nuclear Daiichi Plant, it looks in almost the same disastrous state that it was five years ago; and in abandoned towns like Iitate and Namie hundreds of thousands of bags of decontaminated waste pile up along the street and the roadside.

But with more awareness in the community and people power rising, the honest truth about what happened five years ago is beginning to emerge. Three former TEPCO bosses have been charged for allegedly failing to take proper safety measures on Fukushima Daiichi, despite being aware of the risk from a tsunami. And despite claims that TEPCO has been footing the cleanup costs, it has since been revealed that Japanese taxpayers have been footing the almost US$100bn bill.

Greenpeace nuclear expert takes radiation measurements with a Geiger counter around and inside the house of Hiroshi Kanno, a vegetable farmer evacuated from Iitate village after Fukushima Daiichi nuclear disaster.

But it’s not just Fukushima where this has happened. It’s been 30 years since Chernobyl and the nuclear costs are still ongoing.

The Fukushima and Chernobyl disasters remind us we need to bury nuclear energy in the past and transition to clean, safe renewables. Even today - five years after Fukushima and 30 years after Chernobyl - these disasters continue to cause immense human suffering. Hundreds of thousands of people have been forced to abandon their homes. Millions more live in contaminated areas.

For the thousands of lives lost – not just from the Fukushima disaster but also from the earthquake – we need to shift to a renewable future. Together we can stop nuclear accidents like Fukushima or Chernobyl from ever happening again.

Junichi Sato is the Executive Director at Greenpeace Japan.