The world's leaders are meeting at the United Nations General Assembly in New York this week.
Sprent Dabwido told the assembly the failure of multilateral institutions could not be more evident than in the ongoing climate change negotiations.
"Small islands may be the canary in the coal mines, but we are all staring a global catastrophe right in the face," Mr Dabwido said.
"Arctic sea ice dropped to its lowest extent in recorded history, shattering the previous record by a jaw-dropping 18 per cent."
Mr Dabwido told the assembly there is a good chance half of all coral reefs will be lost with just a small rise in temperature in the coming years.
"There is little doubt coral reefs will no longer be prominent in coastal ecosystems if global average temperatures exceed two degrees celsius."
His message comes as a new report predicts more than a 100 million people will die by 2030 if there is no action on climate change.
The report was commissioned by a partnership of 20 developing countries currently threatened by rapid climate change.
It says more than 90 per cent of those deaths will occur in developing countries, and are a direct result of human and economic impacts.
The director general of humanitarian organisation DARA, Ross Mountain, says the world's poorest nations are the most vulnerable.
He told Radio Australia's Pacific Beat that Nauru's message to the UN General Assembly is a "very timely" warning that world leaders must take urgent action.
"What we have been able to do with this report is unmask this fiction that addressing climate change now is an economic luxury," Mr Mountain said.
The report says the effects of climate change has lowered global output by 1.6 per cent of world GDP, or by about $US1.2 trillion a year.
It says that while poorer countries face the steepest economic damage in terms of GDP losses, big countries will not be spared.
"In less than 20 years China will incur the greatest share of all losses at over $1.2 trillion. The US economy will be held back by more two per cent of GDP; India, over five per cent of its GDP," says the report conducted by DARA.