Iaone Teitiota is arguing in the New Zealand courts that he faces persecution and harm due to rising sea levels if he returns to his homeland.
The Immigration and Protection Tribunal rejected his bid to stay in in New Zealand as a refugee on the grounds he doesn't fit the category of a refugee under the Refugee Convention.
Bill Hodge, the Associate Professor of Law at Auckland University, agrees.
"The definition in Article 1A(2) has to do with a well-founded fear of persecution on the grounds of race, ethnic origin, nationality, religion, gender and so on," he said.
"I'm afraid - and I'm trying to be sympathetic and humanitarian here - but the definition in the Convention does not apply to a person who is effectively a climate refugee or an economic refugee because of climactic reasons.
"So I think he's got a big uphill battle here - I don't think he will be successful."
Iaone Teitiota came to New Zealand six years ago on a work visa, and he and his wife have since had six children.
His visa has expired and he's now an illegal immigrant.
He says he doesn't want to return to Kiribati because he fears for his children's health and safety due to food shortages, sickness and inundation caused by rising sea levels.
"Kiribati is sinking - that's why I want to stay here," he said.
"I don't like my kids to die when I go back to Kiribati.
"I'm scared for my kids."
In the High Court in Auckland this week, Mr Teitiota's lawyer, Michael Kidd, argued the deprivation of basic necessities needed to live healthily, such as fresh water and nutritious food, is a form of persecution.
He says this is the case in Kiribati due to rising sea levels and tidal floods which have contaminated water supplies, ruined crops and led to outbreaks of diseases such as gastroenteritis, which can prove fatal.
"I think this is a very important case for the world - with regard to Kiribati, it's probably got a shelf life of, you know, 25 to 35 years and then it's all gone," he said.
"It's the responsibility of the rest of the world to either do something about climate change and stop the seas from rising or allow these people to re-settle.
"The persecution is climate change, pure and simple."
Professor Hodge says Mr Kidd's argument is impressive but is unlikely to clinch the case for Mr Teitiota.
"It doesn't really fit the definition of persecution, which ordinarily requires a direct human agency that is one-on-one or against the person specifically," he said.
"And whatever else you can say - I'm not a denier or a climate sceptic - but you can't say that 'A-ha, China is pouring carbon dioxide into the atmosphere deliberately to swamp Kiribati'."
"Nobody can possibly argue that, so it doesn't fit the Convention from 1951."
Mr Kidd maintains that persecution can be indirect and that by not taking any action to reduce dangerous emissions, countries could be held to account.
"A refusal to implement the Kyoto Protocol or do something about CO2, I think, could be taken as a form of intent," he said.
"And essentially that's the case we're making 'cause Kiribati and these small islands, they haven't caused all these CO2 gasses."