The ruling by the U.N. Human Rights Committee was given in the case of Ioane Teitiota, from the Pacific nation of Kiribati, who brought a case against New Zealand in 2016 after authorities denied his claim of asylum as a climate refugee.

Teitiota migrated to New Zealand in 2007 and applied for refugee status after his visa expired in 2010. He claimed the effects of climate change and a rising sea level had forced him to migrate. He was deported to Kiribati in September 2015.

The committee upheld New Zealand’s decision to deport Teitiota, saying he did not face an immediate risk if returned, but it agreed that environmental degradation and climate change are some of the most pressing threats to the right to life.

“Without robust national and international efforts, the effects of climate change in receiving states may expose individuals to a violation of their rights,” the committee said in a statement released earlier this month.

This would trigger non-refoulement obligations which forbid a country form returning asylum seekers to a country in which they would likely be in danger.

The committee added that the risk of an entire country becoming submerged under water was so extreme that a life with dignity may not be possible even before this happened.

Teitiota’s lawyer did not immediately respond to a request for comment.

The low-lying South Pacific island nation of Kiribati has a population of more than 110,000, but its average height of 2 metres (6-1/2 ft) above sea level makes it one of the countries most vulnerable to rising seawater and other climate change effects.

New Zealand and Australia, the two most developed countries in the South Pacific, have resisted calls to change immigration rules in favour of Pacific people displaced by climate change.

The U.N. ruling is not binding but could open the door for future climate change asylum seekers, asylum advocates said.

“The decision sets a global precedent,” said Kate Schuetze, Pacific Researcher at Amnesty International.

“It says a state will be in breach of its human rights obligations if it returns someone to a country where – due to the climate crisis – their life is at risk, or in danger of cruel, inhuman or degrading treatment,” she said in a statement. (Reporting by Praveen Menon, editing by Richard Pullin)