"Climate change is both a national and a global problem and an issue that transcends political affiliations," Joan Ruddock, British parliamentarian and co-chair of the new Climate Change Dialogue initiative, told a news conference.

Canadian lawmaker Bryon Wilfert, saying his country now had the toughest global warming policies of any G8 nation, said governments had been lazy in tackling the crisis that threatened millions of lives across the world through droughts and floods.

"There is an urgency that not all players grasp or share," he said in a thinly veiled reference to the United States' refusal to ratify the Kyoto Protocol on cutting emissions of greenhouse gasses from burning fossil fuels.

In a written message of support to the inaugural meeting, British Prime Minister Tony Blair who put climate change at the top of the agenda for his 2005 presidency of the G8, said it was the biggest threat facing the planet.

"The predictions of the scale of the changes ahead and their impact are frightening," he wrote. "We must take urgent action to reduce the damage we are doing."

Apart from the G8 nations, parliamentarians from developing countries India, China, Brazil, Mexico and South Africa are also taking part as are institutions such as the World Bank, International Energy Agency and oil giant BP.

Carbon dioxide emissions from these five developing nations are predicted to outstrip those from the G8 -- which includes the world's biggest polluter the United States -- within three decades at current rates of growth.