"We are here to fight for our human right to exist," he said.
Many islanders say their nations will die if the average global temperature rises two degrees Centigrade, a number considered a safe upper limit by many delegates. They say the limit should be reduced to 1.5 degrees above the levels at the beginning of the Industrial Revolution.
A man from Vietnam, which has enormous areas of land near sea level along the Mekong River and its delta, reminded the delegates that his largely-rural country's 86 million people "have not been one of the big greenhouse gas emitters."
In a hall near one of the vast rooms where journalists from all over the world working intensely on their laptops, climatologist Stephen Schneider of Stanford University went largely unnoticed.
With him was his wife, Terry Root, a Stanford ecologist who did some of the first widely accepted work assessing global warming's enormous impacts on ecosystems and species extinction rates.
Steve Schneider had seen the coming dangers in the year 1975 when he readjusted some computer models (using computers that were primitive by today's standards) to determine that the excess greenhouse gas humanity was pouring into the air would not be part of a cooling of the planet, as he had briefly thought, but of a potentially catastrophic rise in global temperature.
Schneider now looked out across a swirling assembly of thousands of people from every country, all still wrestling to figure out how they - and everyone - might agree on unified action to control the planetary changes he had predicted a quarter of a century ago.
We asked him for his thoughts.
He paused and said, "After two decades of special interests blocking planetary sustainability, we are haltingly moving forward at last."
In another part of the complex, Princeton scientist Michael Oppenheimer watched, bemused, as a speaker decried the slow progress of the negotiations.
Today the scientific journal Nature would be publishing the latest of Oppenheimer's articles -- this one written with colleagues at Princeton and Harvard -- describing an even greater vulnerability of earth's polar ice sheets to global warming than scientists had previously suspected.
"There are always these ups and downs in U.N. Climate summits," he told ABC News. "In the end, the world's leaders are going to live up to their responsibilities and set us on a path to solving this."