For years, the Pacific nation has attempted to seek a mandate from the United Nations court to widen the responsibility of biggest nations to act.
After winning that diplomatic battle, on Monday night (AEDT), Vanuatu climate envoy Ralph Regenvanu will deliver the opening address for his trailblazing Pacific nation.
"We're very excited that finally we're getting to the oral submission stage, our day in court," he told AAP.
Vanuatu climate envoy Ralph Regenvanu will address the UN court in The Hague. (Dan Himbrechts/AAP PHOTOS)
"There's been a lot of diplomatic work and a lot of legal work, and so this is really the culmination of all of that."
In the hearings, the UN's top court will be asked to consider the scale of the responsibility developed countries must carry for the greenhouse gas emissions which have warmed the planet.
Vanuatu - as well as other Pacific nations and developing states - will argue there is a legal responsibility beyond the UN frameworks like the Paris Agreement.
"The argument at The Hague in front of the ICJ, will be that ... all the conventions we've been signing - customary international law - all create obligations for states to act on climate change to prevent harm to future generations into the environment," Mr Regenvanu said.
"The opposing argument, put by high-emitting states, will be basically that only the UNFCCC and the Paris Agreement is the only legal agreement that matters when it comes to climate change and there are no other obligations."
The Paris Agreement is an attempt to keep human-induced climate change to under two degrees in order to stave off the worst effects of global warming.
The world has warmed 1.3C since pre-industrial times, and there are doubts as to whether the biggest nations will meet their Paris Agreement commitments.
A record number of countries and organisations will submit before the ICJ.
The International Court of Justice will consider the scale of responsibility for developed countries (EPA PHOTO)
It is not clear how Australia will argue when it submits at approximately 2am on Tuesday (AEDT).
Australia was one of more than 100 countries to join with Vanuatu last year to petition for the ICJ to issue an advisory opinion, but Mr Regenvanu said those signatures of support for a hearing should not be confused with support for their position.
"I wouldn't say they're behind us," he said.
"There'll be countries for and against ... states will be arguing for less responsibility, less obligations, less consequences, and there will be states pushing the other angle."
The dynamic is similar to annual COP climate talks - such as last month's meeting in Azerbaijan - which feature negotiations on how to progress climate policy.
However, a key difference at the ICJ hearing is that unlike the backroom negotiations at COP talks, in The Hague, arguments will be made in public.
"That's a key difference," Mr Regenvanu says, "and of course we, Vanuatu, have equal standing before the court."
"Regardless of our actual diplomatic power, which manifests at places like COP, when you appear before the court, you are all equal in the eyes of the court
"That gives us greater possibility to some real change that we want to see."
Hearings are scheduled to last a fortnight, featuring dozens of countries from across the globe.
Given the magnitude of the possible ramifications, climate activists from across the globe have gathered in The Hague for the landmark case.
"For civil society ... it's quite a celebratory mood, but we'll see what happens in the in the course of the two weeks of presentations," Mr Regenvanu said.
32°C