“I’m so nervous about today … it’s going to be OK. Let’s pray.”

Those were the quiet but powerful words of Cynthia Houniuhi on Wednesday morning, just before the international court of justice (ICJ) handed down its historic advisory opinion on climate change at the Peace palace in The Hague.

In the packed courtroom, thousands of kilometres from home, tension hung in the air. For Houniuhi – one of the original 27 Pacific law students who sparked the global legal campaign that led to the ruling – the moment was overwhelming.

As the judges began to speak, she became teary. Years of hard work and late nights had come down to this.

“I was literally hanging on to each and every word the judge was saying. I was anticipating, waiting for the things I hoped to hear. The more I listened, the more emotional I became,” Houniuhi said.

“When the judges stated that states’ obligations are not limited to the Paris agreement or the climate regime but also extend to environmental law, human rights law and international customary law, I cried right there in the courtroom.”

The ICJ’s advisory opinion for the first time gives the Pacific and all vulnerable communities a legal mechanism to hold states accountable and to demand the climate action long overdue.

In the landmark opinion published on Wednesday, the court said countries must prevent harm to the climate system and that failing to do so could result in their having to pay compensation and make other forms of restitution. It says states are liable for all kinds of activities that harm the climate, but it takes explicit aim at fossil fuels.

For a young Pacific woman at the forefront of this global fight, this win wasn’t just political, it was personal. And it was history.

“We were there. And we were heard,” she said.

The group of students all hailed from Pacific island countries that are among the most vulnerable in the world to the climate crisis. They came up with the idea of changing international law by getting the world’s highest court to issue an advisory opinion on the climate crisis.

The campaign was led by the nation of Vanuatu, a Pacific state of about 300,000 people that sits at the forefront of the climate crisis and has been ranked by the United Nations as the country most prone to natural disasters.

Sitting beside Houniuhi was Vishal Prasad, executive director of the Pacific Islands Students Fighting Climate Change (PISFCC), quietly taking it all in.

“I’m still trying to process everything,” Vishal said on Thursday.

“Cynthia was beside me, and our Pacific team was there. Line by line, paragraph by paragraph, I was amazed. From the obligations of states under the Paris agreement to the recognition of human rights and the right to a clean, healthy environment – and then to hear the court speak so strongly on fossil fuels – it was incredible.”

The Ni-Vanuatu anthropologist and minister for climate change, Ralph Regenvanu, remembered when those same students first approached him for support in 2019.

“Back then I never imagined it would grow this big. It felt like a wild dream – this idea that we could go to the ICJ. But we thought, ‘Why not?’ There was youthful ambition and energy, and surprisingly – with support from across the world – we got here. Especially thanks to the international youth climate justice movement.”

But it wasn’t easy. Over the years, the movement faced resistance from major emitting countries. The Pacific had to go back, gather more evidence, more testimonies – and keep pushing, despite the odds.

Setting a standard for the world

Siosiua Veikune, a youth climate advocate from Tonga and PISFCC member, said the group’s cautious optimism about the case gave way to overwhelming gratefulness when the ruling was handed down.

“At first, we were skeptical. History has shown that courts sometimes speak to some issues but leave others out. But this ruling … it was bold. It was clear.”

“As a young Tongan, I hope we’ve helped set a healthy legal standard – a blueprint that can be replicated globally. This duty of care … it goes beyond legal obligations. It speaks to who we are in the Pacific.”

The opinion didn’t just recognise states’ climate responsibilities – it tied them directly to human rights and the lives of frontline communities.

Many in the Pacific and those who have been following the advisory opinion, including those who contributed to oral submissions, cheered with joy when the advisory opinion came down.

Rufino Varea, director of the Pacific Islands Climate Network, said the court had handed Pacific people “legal backbone for climate justice”.

“No more excuses. Those who fuel this crisis must stop the harm and help repair it,” he said.

“The law now reflects the justice our communities have always demanded – and we will use this opinion everywhere we fight for our people.”

Pacific feminist climate activist Tamani Rarama said the ruling offered new tools in the fight for accountability.

“Now we have clarified, more nuanced international legal advice – a pathway for justice, redress and repatriation for the loss and damage our frontline communities have endured for years.”

From scientific submissions provided by the Pacific Community to testimonies gathered by PISFCC in the Witness Stand for Climate Justice, every part of the case was anchored in the experiences of Pacific people.

Dr Coral Pasisi, the Pacific Community’s director of climate change, reflected on what the ruling means to her personally.

“My children told me before I left: there better be a decent outcome. Especially my 10-year-old son, who said, ‘Mum, you’ve been doing this for 13 years, and the adults still aren’t listening. Maybe you need to bring the kids to the table.’

“What this advisory opinion does is bring that next generation into the heart of climate discourse. It’s a recognition of intergenerational responsibility. And we cannot have that conversation without bringing our children into it in a meaningful way.”

As the Pacific celebrate, PISFCC and Pacific leaders are already discussing how to use the ruling in upcoming negotiations – especially in the lead-up to Cop30 in Brazil and working out what it means to the Pacific.

For Houniuhi and the students who began it all, the work is far from over.

“This is a victory forged by Pacific youth but owned by all,” she said.

“We pushed the world’s highest court to listen – and it did. Now we move from legal words to living change. Young people will make sure this ruling cannot be shelved or spun.”

As for how she’ll celebrate, she plans to wait until she gets home.

“It still feels surreal. Some of the people I want to celebrate with are back home. So, for now, I’m holding back the celebration – just feeling deeply grateful.”