The informal debate, which will bring together prominent scientists, business leaders and UN officials, is "to consider how to translate the growing scientific consensus on climate change into a broad political consensus for action," a UN statement said.

The debate aims to prepare the ground for a high-level meeting to be held next month, on the sidelines of the General Assembly, at UN chief Ban Ki-moon's behest, and a major climate change conference scheduled for December in Bali, Indonesia.

Participants will include Food and Agriculture Organization Director General Jacques Diouf and two leading international personalities -- Chile's former president Ricardo Lagos and South Korean former foreign minister Han Seung-soo -- named last May as Ban's special envoys for climate change to help him negotiate on global warming.

"This debate is a testimony to the political importance of addressing climate change," General Assembly President Sheikha Haya Rashed Al Khalifa said.

"We will need political action if we are to protect our environment, secure our planet and safeguard our future, for our children and generations to come," she added.

"This is one of the greatest challenges of our time."

The meeting is being touted as "carbon neutral," since emissions from air travel to bring experts to New York and the entire carbon-dioxide emissions of the UN headquarters will be offset by investment in a biomass fuel project in Kenya, the top UN official added.

The fuel switch project in Kenya supports the use of agricultural waste instead of traditional fossil fuels to power a crude palm oil refinery, thereby reducing greenhouse gas emissions and creating new economic opportunities for local farmers.

Western industrial countries have hitherto been blamed for most emissions, but Ban said during a visit to Geneva early this month that emerging economies in Asia and elsewhere now had to face up to their own responsibilities.

He then urged China, whose rapid industrial growth has turned it into one of the biggest emitters of greenhouse gases, to do more to tackle climate change.

UN negotiations are trying to tie in emerging countries such as China, as well as the United States, into a new accord on greenhouse gas emission targets to cover the period after 2012.

Ban has made action to roll back global warming a priority since taking office in January.

The UN Intergovernmental Panel on Climate Change (IPCC) reported this year that the world's temperature rose by 0.74 degrees C during the last century and that it is likely to rise 3.0 degrees C in this century unless measures are taken to reduce the rate of warming.

The IPCC found that the evidence that warming was occurring is unequivocal and that it is due to human activities.