A landmark case that began in a Pacific classroom and could change the course of future climate talks is about to be heard in the International Court of Justice (ICJ).
The court will begin hearings involving a record number of countries in The Hague, in the Netherlands, on Monday
Its fifteen judges have been asked, for the first time, to give an opinion about the obligations of nations to prevent climate change — and the consequences for them if they fail.
The court's findings could bolster the cases of nations taking legal action against big polluters failing to reduce emissions, experts say.
They could also strengthen the hand of Pacific Island nations in future climate change negotiations like COP.
Vanuatu, one of the world's most natural disaster-prone nations, is leading the charge in the international court.
The road to the ICJ — nicknamed the "World Court" — started five years ago when a group of law students studying in Vanuatu began discussing how they could help bring about climate action.
"This case is really another example of Pacific Island countries being global leaders on the climate crisis," Wesley Morgan, a research associate with UNSW's Institute for Climate Risk and Response, said.
"It's an amazing David and Goliath moment."
Meanwhile, experts say the Pacific will be watching Australia's testimony on Monday closely.
So what is the court case about exactly, and how did it get to this point?
From classroom to World Court
Cynthia Houniuhi, from Solomon Islands, remembers clearly the class discussion where it all began.
Students at the University of the South Pacific's campus in Vanuatu's capital, Port Vila, turned their minds to the biggest issue faced by their home countries.
While their communities were dealing with sea level rise and intense cyclones, there was an apparent international "deadlock" on climate change action, Ms Houniuhi said.
And each new report from the Intergovernmental Panel on Climate Change painted a bleak picture of their futures.
"These things are real to us," Ms Hounhiuhi said. "And we cannot accept that … fate in the IPCC report.
"[We're] not accepting that there's nothing we can do."
Their lecturer tasked them with finding a legal avenue for action. He challenged them to be ambitious. And he told them to take it out of their classroom, to their national leaders.
So the students settled on an idea: Ask the World Court to issue an advisory opinion on the obligations of states to protect the climate against greenhouse gas emissions.
"That's what resonated to us," Ms Houniuhi, now president of Pacific Islands Students Fighting Climate Change, said.
They sent out letters to Pacific Island governments asking for support and Vanuatu's then-foreign minister, Ralph Regenvanu, agreed to meet with the students.
Vanuatu took up the cause and built a coalition of countries pushing the United Nations General Assembly to send the matter to its main judicial body, the International Court of Justice, for an advisory opinion.
In March last year, they succeeded when the UN nations unanimously adopted the resolution to refer the case — a historic first for the UN General Assembly.
It was a decision celebrated with a parade on the streets of Port Vila.
Australian National University professor in international law Donald Rothwell said Pacific nations had already overcome their biggest challenge in building enough support for the case to be heard.
"From the perspective of Vanuatu and the small island and other states who brought these proceedings, this is quite a momentous occasion, if only because these states rarely have appeared before the International Court of Justice," he said.
"This is the first occasion where they've really had the ability to raise these issues in the World Court, and that in itself will attract an enormous amount of global attention and raise awareness."
Sue Farran, a professor of comparative law at Newcastle University in the United Kingdom, said getting the case before the ICJ was also part of achieving climate justice.
"It's recognition that certain peoples have suffered more than others as a result of climate change," she said.
"And justice means addressing wrongs where people have been harmed."
A game changer on climate?
Nearly 100 countries will speak over two weeks of hearings — an unprecedented number, Professor Rothwell said.
Each has only a short, 30-minute slot to make their argument.
The court will decide on two questions: What are the obligations of states under international law to protect the climate and environment from greenhouse gas emissions?
And, what are the legal consequences for states that have caused significant harm to the climate and environment?
Vanuatu will open the hearings with its testimony.
Mr Regenvanu, now Vanuatu's special envoy on climate change, said the case was timely in light of the last COP meeting, where financial commitments from rich, polluting nations fell short of the mark for Pacific Islands that needed funding to deal with climate change.
For a nation hit with three cyclones last year — and where natural disaster-struck schools have spent months teaching primary students in hot UNICEF tents — the stakes are high in climate negotiations.
"We just graduated from being a least-developed country a few years ago," Mr Regenvanu said.
"We don't have the financial capacity to build back better, build back quicker, respond and recover quicker.
"We need the resources that other countries were able to attain and become rich through fossil fuel development that caused this crisis we are now facing.
"That's why we're appearing before the ICJ. We want justice in terms of allowing us to have the same capacity to respond quickly after catastrophic events."
He said the advisory opinion will stop unnecessary debates that bog down climate negotiations, by offering legal clarity on the obligations of states on climate change.
It will also help define controversial terms, such as "climate finance" — which developing nations argue should not include loans.
And while the court's advisory opinion will be non-binding, it also has the potential to influence climate change litigation around the world.
Professor Rothwell said much would depend on how the court answered the case's second question — on the consequences for states that failed to take climate action.
He said an opinion that favoured small island nations, like in the Pacific Islands, would let them pursue legal action with more certainty.
"That could possibly open up a battleground for major international litigation into the future, subject to how the [International Court of Justice] answers that question," he said.
Mr Regenvanu said Vanuatu was already looking at options it could take once the court issues its advisory opinion.
"Basically all options are on the table from litigation on one extreme, to much clearer negotiation tactics, based on what the advisory opinion says, at the forthcoming couple of COPs."
'This is hope'
Vanuatu brought the case to the ICJ with the support of a core group of 18 countries, including New Zealand, Germany, Bangladesh and Singapore.
Australia, which co-sponsored the UN resolution sending the case to the ICJ, will also speak at Monday's hearings.
"Many will be watching closely, but Vanuatu will be watching more closely than anyone, having led this process," Dr Morgan said.
[YouTube]A Department of Foreign Affairs and Trade spokesperson said Australia had engaged consistently with the court proceedings, reflecting its support for the Pacific's commitment to strengthening global climate action.
Some countries have expressed misgivings about taking the case to the ICJ.
The United States' representative at the General Assembly last year argued diplomacy was a better way to address climate change.
And over the two weeks of court hearings this month, it's expected nations contributing most to greenhouse gases will argue for a narrow reading of their responsibilities to address climate change under international law — one that minimises their obligations.
Other nations will argue that human rights laws and other international agreements — like the Universal Declaration of Human Rights and the International Covenant on Civil and Political Rights — give these nations larger obligations to prevent climate change.
Professor Rothwell said it was hard to predict what conclusion the World Court would reach — and he expected the advisory opinion would not arrive until as late as October next year.
"When we're looking at 15 judges, when we're looking at a wide range of legal treaties and conventions upon which the court is being asked to address these questions, it's really difficult to speculate at this point," he said.
"We'll very much just have to wait and see what the outcome is."
There's the chance the judges will be split, or they will not issue a strong advisory opinion.
But Mr Regenvanu is drawing hope from a recent finding in a similar case at the International Tribunal of the Law of the Sea, which found countries are obliged to protect the oceans from climate change impacts.
"It's given us a great deal of validation that what we will get out of the ICJ will be favourable," he said.
For Ms Houniuhi, the long journey from the Port Vila classroom five years ago is about to lead finally to the Peace Palace in The Hague, where the ICJ will have its hearings.
Ms Houniuhi said the case would let her and her fellow students have their experiences of climate change reflected at the highest level.
But for her, the court case has another important role.
"This is hope for our people."
