Small island states have urged rich nations at UN climate talks in Bali to cut emissions of greenhouse gases far beyond their existing plans.
"The principle must be that no island must be left behind," said Angus Friday of Grenada, chair of the 43-member alliance of small island states at the meeting on the Indonesian island.
Low-lying states, such as the Maldives in the Indian Ocean or Tuvalu in the Pacific, were already suffering from rising seas and storm surges linked to climate change.
And in the long term, many low-lying atolls risked being washed away.
The Bali talks, of more than 10,000 delegates, are seeking to launch negotiations on a new global deal, to be agreed by 2009, to fight climate change.
The UN's climate panel says seas could rise by 18 to 59cms this century, threatening the economies of small island states that often depend on farming, fishing and tourism.
Seas rose 17cms over the past century.
The group said that even the most ambitious goals by industrial nations were insufficient to avoid dangerous change.
The EU has set a target of limiting warming to a temperature rise of 2 Celsius (3.6 F) over pre-industrial levels.
"Emissions must be reduced at a level that ensures that global temperature rise remains well below 2C," the alliance said in a statement.
Small islands also said they would need far more aid as they feel the impact of climate change.
"The infrastructure needs alone of the most vulnerable countries could measure in the billions" of dollars, Friday said.
The government of the Maldives, for instance, needed $175 million to build a barrier around a single coral island to make the atoll "twice the height of this chair" above sea level, he said.
"We are not in this process as beggars," said Clifford Mahlung of Jamaica, adding that small islands were not to blame for climate change.
"In Jamaica we used to repair coastal roads from erosion and storms once every four years," he said.
"With what is happening now we have to repair those roads four times a year."
Friday said Grenada, long considered south of the Caribbean hurricane belt, had been reclassified after two storms within 10 months in 2004-05.
Losses from Hurricane Ivan alone in 2004 were $800 million.
But he also said that small island states had dropped past threats to sue the United States, the top emitter of greenhouse gases, for compensation.