BigPond News – Heads of Commonwealth nations and the United Nations have opened an unprecedented summit to strengthen the debate on global warming 10 days ahead of Copenhagen talks.

Opening the meeting, Commonwealth Secretary-General Kamalesh Sharma warned of the ‘looming existential catastrophe of climate change’ and said the organisation had to restate its ‘shared responsibilities towards the preservation of our planet’.

The CHOGM summit has begun in Trinidad and Tobago with a speech from the Queen

Queen Elizabeth II, the titular head of the 53-nation Commonwealth composed mainly of former British colonies, also attended the start of the three-day summit in Trinidad and Tobago yesterday.

In a rare move, non-members UN chief Ban Ki-moon, French President Nicolas Sarkozy and Danish Prime Minister Lars Loekke Rasmussen were to address the leaders behind closed doors later yesterday seeking to forge a common stand on tackling climate change.

The three leaders were invited to Trinidad by Prime Minister Patrick Manning, who said there had been ‘some concern about the way negotiations were going ahead of Copenhagen next month’.

Britain’s Prime Minister Gordon Brown (2nd R) laughs next to Queen Elizabeth 11 and other leaders during the opening ceremony of the Commonwealth Heads of Government Meeting in Port-of-Spain, yesterday. REUTERS/Carlos Barria

‘A political statement out of (the Commonwealth) is not a statement that one can take lightly,’ Manning told journalists on Thursday.

‘It comes with the weight of so many countries and so many people, that therefore we feel it can have some effect on influencing the way that the discussions go in Denmark.’

Climate change and rising sea levels, blamed on global warming caused by greenhouse gases emitted mostly by the world’s industrial powerhouses, threaten many developing nations, a number of which are Commonwealth members that have struggled to have their voices heard.

Fears that the Copenhagen conference starting December 7 would fail to reach a deal on replacing the Kyoto Protocol when it expires in 2012 were eased this week with pledges to cut emissions by Beijing and Washington.

The offers by the world’s two biggest greenhouse gas emitters were widely hailed, even amid questions over how effective they would be.

The United States said it was aiming to curb emissions by 17 per cent from 2005 levels by 2020.

It is less than calls by the European Union, Japan and UN scientists – but the first concrete numbers put on the table by the world’s largest economy and second biggest polluter.

Britain’s Queen Elizabeth II, and Prince Philip walk in the grounds of President George Maxwell Richards’ official Home in the Port of Spain, Trinidad before joining guests at a State Dinner Thursday. Queen Elizabeth and Prince Philip traveled to the West Indian nation to open the biennial Commonwealth Heads of Government Meeting, CHOGM, where Prime Minister Gordon Brown will meet with other world leaders.(AP Photo/Chris Radburn/PA Wire)

US President Barack Obama will also present at Copenhagen longer-term pledges of a 30 per cent reduction in emissions by 2025, 42 per cent by 2030 and 83 per cent by 2050, officials said.

China said by 2020 it would cut the amount of carbon dioxide emitted per unit of gross domestic product (GDP) by 40 to 45 per cent compared to 2005 levels.

That is essentially a pledge of greater energy efficiency: with electricity demand soaring, China relies on carbon-belching coal to generate about 70 per cent of its energy needs.

India, a Commonwealth member and home to a billion people, has yet to unveil its emissions targets ahead of Copenhagen.

Indian Environment Minister Jairam Ramesh said China’s decision to unveil a carbon emissions target had put pressure on India to follow suit.

‘China has given a wake-up call to India,’ the minister told the Hindustan Times newspaper in an interview published yesterday.

The Commonwealth, which this year celebrates its 60th anniversary, is also grappling with issues such as whether to admit the former Belgian colony of Rwanda as its newest member.

The move, backed by Australia, Britain and Canada, has triggered controversy amid concerns over Rwanda’s rights record following the 1994 genocide in which 800,000 people died.

Several leaders from Gambia, Namibia and Nauru were absent from the table yesterday, as well as the military leader of Fiji, which was suspended from the Commonwealth in September for refusing to schedule elections by October 2010.