DOHA, Qatar -- With weary middle-aged delegates in serious suits dominating the scene at U.N. climate talks here, groups of enthusiastic young people are getting noticed.

The groups have converged on the Doha Exhibition Center with props and posters and to express frustration about the inability of world leaders to reach agreement to slash emissions of heat-trapping greenhouse gases.

Adam Greenberg of the U.S.-based youth organization SustainUS greeted participants at the entrance to the conference this morning with others from the loose-knit coalition whose members also hail from Bahrain, Colombia, Canada and Europe. They stood along the electric walkway silently holding signs in black and white, protesting what they saw as the fossil fuel industry's stranglehold on Western governments.

"Youth from around the world come to these climate negotiations because we feel that we really have no other choice," said Greenberg, a recent college graduate who at 23 is one of the oldest of about 200 youth delegates at the conference, which is starting its second week. Many of his compatriots are attending the conference while preparing for final exams or filling out college applications, he said. But they consider this year's climate talks too important to miss.

"This is where the future on climate change essentially gets decided," he said.

International youth dress as Robin Hood's merry men to promote climate aid for poor countries at the Doha, Qatar, talks. Photo by Jean Chemnick.

In fact, this round of negotiations has more to do with housekeeping than decisionmaking. Delegates from 195 countries have come to Doha to put the finishing touches on the second and final commitment period of the Kyoto Protocol; end another negotiating track that was initiated in Bali, Indonesia, in 2007; and start to lay the groundwork for a new agreement that would include a wider range of parties -- including the United States -- as contemplated under last year's Durban Platform.

There's no chance this year's talks will produce the revolutionary agreement that Greenberg and his companions hope will help hold climate change to 2 degrees Celsius or less, a goal recommended by the Intergovernmental Panel on Climate Change. This frustrates young delegates -- one noted on a sign that the U.N. Framework Convention on Climate Change was first negotiated in 1992 and that the talks have been happening for "longer than I've been alive."

"As young people, it's our lives that are at stake," Greenberg said, adding that his choice of whether to have children would depend in part on whether the world had made real progress to avoid a climate change catastrophe.

Greenberg's group was not the only one staging an "action." Volunteers from international hunger group Oxfam and the youth group YouthGo dressed as Robin Hood and his merry men in support of a tax on emitters to help poor countries. A group of high school students from countries like Egypt and Brazil calling themselves Youththinkgreen encouraged passers-by to attach green crepe paper leaves to their "hope tree" expressing their hopes and fears for the conference.

The tree in question was 17-year-old Danielle Corado Rodrigues, a slight high school student from Rio de Janeiro who said she first got interested in environmental issues when she joined a recycling club at school, "and everything got bigger and bigger, and now I'm here."

Asked why climate change in particular was so important to young people, Rodrigues said her generation would have to live with its consequences.

"We only have this one world," she said.

Youth delegates greet conference participants at the start of the second week of negotiations in Doha. Photo by Jean Chemnick.

In the conference halls today, leading negotiators were quick to praise the young people even as they moved to temper their expectations.

"I very much welcome what I call a very healthy impatience on the part of youth and on the part of many constituencies," said Christiana Figueres, executive secretary of the UNFCCC, during a media briefing.

She agreed with them that action to curb emissions had gone too slowly but added that what the world was doing was no less than reshaping its economic structure to reduce carbon output.

"That does not happen overnight," she said.

She added that the past few years have seen considerable progress toward the international community's goals of reducing emissions and predicted that Doha would also represent a "firm step in the right direction."

"I always understand youth, because I was youthful," said Qatar's Abdullah bin Hamad Al-Attiyah, president of the 18th Conference of the Parties.

When he met with youth delegates last week, Al-Attiyah said they reminded him of his activist past. As he grew older, he said, he learned patience.

"You cannot change the whole world in just a few days," said Al-Attiyah, who was once president of the oil cartel OPEC. "This is an accumulated process."