A closely-watched international climate case that could yield guidance for governments around the world wrapped its first week of arguments before the top court of the United Nations in The Hague Friday. The case, though not binding, is expected to spell out what countries are legally required to do to combat climate change and help vulnerable nations fight its devastating impact.

The push for the International Court of Justice to hear this case comes — like much of the call to address climate change — from island nations who are losing territory and fear they could disappear under rising seas. The U.N. General Assembly asked the court last year for an opinion on “the obligations of States in respect of climate change.”

“The stakes could not be higher. The survival of my people and so many others is on the line,” Arnold Kiel Loughman, attorney general of the Pacific island nation of Vanuatu, told The Hague-based court.

For years his country has spearheaded calls for reductions of the greenhouse gases that are causing sea ice to melt and oceans to expand, making the seas rise. Vanuatu led this push for international legal intervention as well.

Fifteen judges from around the world must now answer two questions: What are countries obliged to do under international law to protect the climate and environment from human-caused greenhouse gas emissions? And what are the legal consequences for governments when their acts, or lack of action, have significantly harmed the climate and environment?

With 99 participating countries, it is the largest case in the court’s history.

Countries including Vanuatu, Chile and the Philippines want countries like the United States, China and Russia to reduce their emissions and provide financial help to alleviate the devastating impact of climate change that they feel endangers their very existence.

“This is a crisis of survival. It is also a crisis of equity. Fiji contributes 0.004 percent of global emissions but our people bear the brunt of climate impacts. In climate-vulnerable nations, marginalized groups ⎯ women, children and the poor ⎯ are disproportionately affected,” Luke Daunivalu, Fiji’s ambassador to the United Nations, said.

The South Pacific island nation spoke directly after the United States and Russia, both of whom are major petroleum-producing states and staunchly opposed to the court mandating emissions reductions.

Instead, what the United States and other major greenhouse gas emitters want the court to do is defer to the landmark Paris Agreement, in which countries agreed to keep global warming to a 1.5 degree C (2.7 F) limit.

The world has already warmed 1.3 degrees C (2.3 F) since pre-industrial times because of the burning of fossil fuels. Between 1990 and 2020, sea levels rose by a global average of 10 centimeters (3.9 inches) and parts of the South Pacific have seen significantly more.

“States designed this international legal framework to address the uniquely complex collective action problem posed by anthropogenic global warming, and it embodies the clearest, most specific and the most current expression of states’ consent to be bound by international law in respect of climate change,” Margaret Taylor said on behalf of the United States, referring to the Paris Agreement.

The U.S. also pushed back on an idea proposed by several countries that developed countries have a great obligation to reduce emissions and pay reparations because they have been contributing to the problem for a much longer time. “A state cannot have international responsibility for acts that take place prior to the date on which its international legal obligation came into existence,” Taylor said.

What small states like Vanuatu are hoping for does push the norms of international law. Historically, all countries are held to the same standard. Every country that is a party to the 1948 Genocide Convention, for example, has the exact same obligation to “punish and prevent” genocide.

“What I have heard is a concerted effort by major polluters seeking to avoid their responsibilities,” Joie Chowdhury, senior attorney at the Center for International Environmental Law, told The Associated Press. She said the conduct of major polluters responsible for the climate crisis and its catastrophic consequences is unlawful under multiple international laws.

Alongside the hearings, environmental groups held a series of events to promote climate justice. On Sunday, ahead of the hearing, Pacific Islands Students Fighting Climate Change — who first developed the idea of requesting an advisory opinion — together with World Youth for Climate Justice held an afternoon of speeches, music and discussions.

Kjelld Kroon, a climate activist who is involved in a lawsuit against the Dutch state for failing to protect his Caribbean island homeland of Bonaire, watched several days of the proceedings and said he wasn’t surprised that rich countries were opposed to more legal obligations. “This is how a lot of powerful countries in the Global North extract from the Global South,” he told the AP.

But Kroon said he found the presentations by many developing states powerful and said they gave him hope.

Any decision by the court would be unable to directly force wealthy nations into action to help struggling countries. Yet it would be more than just a symbol since it could serve as the basis for other legal actions, including domestic lawsuits.

“If I look at history, I am skeptical,” Kroon said. “But if I look towards the future, I am a little bit positive.”