UNITED NATIONS, United States — As the scientific consensus on global warming grows, it's time to look more closely at how to share the economic, social, and humanitarian burdens that climate change will likely bring.

That was the main message of a panel discussion on "The Ethical Dimension of Climate Change," organized by the Baha'i International Community and held here on 30 April 2007 during this year's UN Commission on Sustainable Development.

"If sea levels rise at the rates they are predicting, we may see hundreds of millions of refugees," said Arthur Lyon Dahl, president of the International Environment Forum, a Baha'i-inspired organization.

"Where will they go? Who will take them in? What does it mean about immigration regulations?" asked Dr. Dahl, noting that these were only some of the moral and ethical questions that are being posed by the looming effects of climate change.

Sponsored by the nations of Tuvalu and the Marshall Islands, with assistance from the UN Office of the High Representative for Least Developed Countries, Landlocked Developing Countries and Small Island Developing States (UN-OHRLLS), the event became one of the most talked-about side events at the Commission this year, said Tahirih Naylor, a representative of the Baha'i International Community to the United Nations.

"The timing of the event on the opening day of the Commission really helped to bring attention to the ethical issues surrounding climate change, helping to frame discussions at the Commission, at least among nongovernmental organizations and major groups," said Ms. Naylor.

The panelists included Enele Sopoaga, former Permanent Representative of Tuvalu to the UN; Om Pradhan of the UN-OHRLLS; Don Brown, project coordinator of the Collaborate Program on the Ethical Dimensions of Climate Change; Tony Barnston of the International Research Institute for Climate and Society at Columbia University; Rabbi Lawrence Troster, Fellowship Program Director of GreenFaith; and Dr. Dahl, who is a Baha'i and also the coordinator of the UN Environment Programme environmental diplomacy program at the University of Geneva.

Dr. Brown, who is at the Rock Ethics Institute at Pennsylvania State University, said the moral and ethical issues that accompany rising sea levels or widespread crop failures will be matters of life and death for many people.

"How much warming should we tolerate?" he asked. "What is the atmospheric concentration of greenhouse gases that the world should identify as a target? There is no more obvious moral and ethical issue than this issue. It will literally determine who lives and who dies, whether Tuvalu survives, whether the Marshall Islands survive."

Such issues, Dr. Brown said, will force multilateral institutions like the United Nations to rethink international law and norms.

Ambassador Sopoaga said the issues for nations like Tuvalu are particularly stark.

"The future will be catastrophic for all communities, for all countries, but particularly for those who have already been identified as particularly vulnerable to the impacts of climate change," he said, noting that some forecasts suggest that small island states will disappear entirely under the rising ocean.

"It is a moral obligation, beyond political obligation or economic obligation, to help countries like Tuvalu and small island developing states, and of course the least developed countries," he said. "We have to do something urgently."

Mr. Pradhan of the UN-OHRLLS said that the latest predictions indicate that small island nations would be "simply wiped out."

"This is the time to remind the international community that ethics and morality do play a very important role in any human activity, especially when we have a situation where climate change is affecting such a large number, especially the poor and vulnerable," he said.

All the panelists agreed the release of recent studies by the UN's Intergovernmental Panel on Climate Change and the UK's Stern Review Report on the Economics of Climate Change have established a high level of confidence that climate change is real and that the consequences will be great.

"Some of the people against acceptance of global climate change demand something like at least 98 percent certainty," said Mr. Barnston. "We have somewhere around 90 percent or the low 90s. To me that's pretty high. It's not 75 percent like it was a decade ago."

All of the panelists also agreed that preventing the most drastic consequences of climate change would require that many people change their behavior - such as by driving fuel-efficient cars, shifting to renewable energy, and the like.

The question now, Mr. Barnston said, is how to motivate humans to change their behavior.

"When we discover something inconvenient to our lifestyle, it takes years to adjust to it, years to accept it, to believe it, and then to do something about it," he said, giving as examples the discovery that smoking is harmful or sunburns are not healthy. "We have to shorten the time lag before all levels of society accept that climate change is a danger just like cigarette smoking is a danger."

Dr. Dahl and Rabbi Troster both said that religious belief could be an important factor in providing the motivation for ethical behavior.

"How do we create a willingness to make the sacrifices that are going to be necessary," asked Dr. Dahl. "How do we build a sense of global solidarity when we are all facing the same common challenges?

"Religion is that dimension of society that has traditionally been responsible for morality and ethics," he answered. "We have to look at moderation. And all religions have taught about being content with very little."

Rabbi Troster said religious communities believe that the attitude in which humanity views itself in relation to creation is fundamental in changing behavior.

"This is central to the concept of moral action," he said. "If we change our attitudes, we will change our behavior."