Geneva - Five young people told how rising waters threatened their countries or how melting ice was undermining traditional ways of life as they told an international conference of their personal experiences with climate change.

These so-called climate change witnesses were addressing more than 200 leaders from all sectors of society gathered in Geneva Tuesday at the first annual meeting of the Global Humanitarian Forum.

"My friend went out hunting but never returned. He never returned because he fell through thin ice, ice that should never have been thin at that time of year," said Jesse Mike, a native Inuk from Baffin Island, Canada.

"This is how my people show their anger," said James Bing, 18, from the Marshall Islands, located between Australia and Hawaii, performing a war dance on stage.

"That is how angry I am right now," he said finishing to loud applause. Scientists have said his islands are threatened by rising sea levels and the land mass was shrinking.

"My ancestors ate food they grew themselves. I am eating American canned food as we have no soil. I want my soil back," he said.

Bing and Mike were the human face of climate change - the theme of the forum conference.

"What is absolutely crucial is that we and people around the world measure and weigh the impact of climate change not just in scientific terms but by its social, economic and humanitarian implications," said Forum founder and President Kofi Annan, the former UN secretary general.

The humanitarian impact of climate change was the chosen theme and "the single most destructive force" confronting humankind, said Annan.

"We must have climate justice. As an international community we must recognize that the polluter must pay," he added.

Former Irish president and ex-UN high commissioner for human rights Mary Robinson told the conference justice had to be at the centre of any debate on climate change.

The debate was ever more urgent said Annan as world leaders are to gather next year in Copenhagen to thrash out a new global climate agreement for beyond the expiration of the Kyoto Protocol in 2012.

The Forum annual meeting is due to end Wednesday. (dpa)