But critics say they are contributing to the very problem they aim to solve.
"Nobody denies this is an important event, but huge numbers of people are going, and their emissions are probably going to be greater than a small African country," said Chris Goodall, author of the book "How to Live a Low-Carbon Life."
Interest in climate change is at an all-time high after former vice president Al Gore and a team of U.N. scientists won the Nobel Peace Prize for highlighting the dangers of rising temperatures, melting polar ice, worsening droughts and floods, and lengthening heat waves.
Two big climate conferences have been held in less than a month, both in idyllic, far-flung, holiday destinations -- first Valencia, Spain, and now Bali. They were preceded by dozens of smaller gatherings.
The pace is only expected to pick up, prompting some to ask if the issue is creating a "cure" industry as various groups claim a stake in efforts to curb global warming.
No, says Yvo de Boer, executive secretary of the U.N. Climate Change Conference.
"Wherever you held it, people would still have to travel to get there," he said. "The question is, perhaps: Do you need to do it at all? My answer to that is yes."
"If you don't put the U.S., the big developing countries, the European Union around the table to craft a solution together, nothing will happen and then the prophecy of scientists in terms of rising emissions and its consequences will become a reality," de Boer said.
The U.N. estimates 47,000 tons of carbon dioxide and other pollutants will be pumped into the atmosphere during the 12-day conference in Bali, mostly from plane flights but also from waste and electricity used by air conditioners at five-star hotels lining palm-fringed beaches.
If correct, Goodall said, that is equivalent to what a Western city of 1.5 million people, like Marseilles, France, would emit in a day.
But he believes the real figure will be twice that, more like 100,000 tons, close to what the African country of Chad churns out in a year.
Organizers said they are doing everything possible to offset the effects.
Host Indonesia, which has one of the fastest rates of deforestation in the world, averaging 300 football fields an hour, said it had planted 79 million trees across the archipelago nation in the last few weeks.
"Our aim is not just to make this a carbon-neutral event, but a positive one," Environment Minister Rachmat Witoelar said.
In largely symbolic gestures, 200 bright yellow mountain bikes are being offered to participants so they can pedal around the heavily guarded conference site, and recycled paper is being used for the reams of documents being handed out. Bins separating plastic and paper dot hallways -- a rare sight in a country where formal recycling is virtually nonexistent.
Yet sport utility vehicles, taxis and other cars sit in long lines at the gates to the site, spewing out exhaust as they wait to get through security checkpoints.
Side trips, from scuba diving to shopping, are being offered at hotels. Indonesia's tourism ministry hopes to showcase its remaining forests, island jewels and bustling metropolises by providing expense-paid junkets.
Optimists hope the meeting will inaugurate a two-year process of intensified negotiations on a deal to replace the Kyoto Protocol, which expires in 2012 and required signatories to reduce greenhouse gas emissions by an average 5 percent below 1990 levels.
But no one expects concrete results here, with closed-door talks expected to be a battle over language and nuance, including whether emission reductions should be voluntary or mandatory and whether developing nations should have the same restrictions as industrial countries.
"We don't need talk, talk, talk," said Ursula Rakova, 43, of Papua New Guinea's Carteret islands, describing how the rising sea has destroyed once-fertile farmland on her island of Huene and split the land mass in two.
"For us to move, we need money to purchase land, build schools, build medical clinics," said Rakova, who along with other farmers and fishermen were ferried by boat, bus and plane to the Bali gathering. "Our situation is before us. We need something tangible."
In all, 190 countries are represented.
The United States is sending more than 100 delegates and all 27 countries of the European Union are flying in national teams, with Germany bringing 70 people and France 50. Many of them are just observers with no formal role.
Non-governmental organizations also are attending, from groups advocating the rights of indigenous people to those seeking to protect rapidly dwindling forests. Groups like Oxfam and CARE, which provide food and other humanitarian aid for the hungry, also are here.
And there are those with something to sell, including technology to produce pure drinking water and businesses ready to capitalize on future carbon trading markets.
Some say the size of the gathering doesn't matter.
"I look at it from a very simple point of view," said Achim Steiner, executive director of the U.N. Environmental Program.
"It may sound like a lot of people, but you have to look at the issues, the number of countries involved, the number of people affected. Global warming is literally everyone's business."