THE Dalai Lama issued a stern warning when he arrived in Australia yesterday: Tibet faces an environmental catastrophe with the potential to devastate billions of lives across Asia.

On the mountainous Tibetan plateau - the source of the Ganges, Indus, Yangtze and Mekong Rivers - temperatures are rising at twice the global rate.

Melting Himalayan glaciers would affect all countries through which these rivers flow, including India, Pakistan, China, Burma and Thailand, Laos and Cambodia.

''These major rivers, which actually almost cover all Asia, these rivers ultimately come from Tibet,'' he said. ''So I think many human beings depend on these. From that viewpoint we need special care about Tibetan ecology … once something [is] damaged it takes a longer period to recover.''

Tibet's exiled political and spiritual leader urged political leaders to put global interests ahead of national interests to tackle climate change.

''Global issues should be number one [priority],'' he said. ''In some cases in order to protect global issues, some sacrifice of national interest [is required].''

He urged young people to care for the planet because the 21st century belonged to them not his generation.

''Now we are ready to say bye bye,'' said the Nobel Peace Prize winner, 74. He was speaking at the start of his 10-day Australian tour, entitled Our Future, during which he will debate with scientists, deliver public talks and take part in the Parliament of the World's Religions.

His comments follow his warning earlier this month that Tibet's environmental crisis was more urgent than a political solution to his country's future.

It comes as scientists have found that most of the 36,000 Himalayan glaciers are in retreat. Many could vanish within three decades resulting in extensive flooding downstream followed by droughts, the Intergovernmental Panel on Climate Change warned this year.

The Dalai Lama also called on China to review its policy towards its minorities in light of recent violence in Xinjiang province and Tibet. He welcomed the Chinese leadership's emphasis on harmony and believed the Communist Party had the ability to adapt to change.

The world's best-known refugee, who fled Tibet 50 years ago, said he believed Australia could accept more refugees.

''This country still has the possibility to take more people whose lives are difficult, or facing problems,'' he said.

He would not be disappointed if he was unable to meet Prime Minister Kevin Rudd because this visit to Australia was to meet the public.