Toyako: The Group of Eight (G8) nations, papering over deep differences, on Tuesday said  they would work toward a target of at least halving global greenhouse gas emissions by 2050 but emphasised they would not be able to do it alone.

In a communique released during a summit in northern Japan, G8 leaders also agreed that they would need to set interim goals on the way to a "shared vision" for 2050 although they gave no numerical targets. Mention of mid-term goals was an advance from last year when the G8 agreed at Heiligendamnn, Germany, only to "seriously consider" a goal of halving emissions by mid-century.

But calling on countries involved in UN negotiations on climate change to also "consider and adopt" the 2050 goal satisfies the US, which has said it cannot agree to binding targets unless big polluters such as China and India rein in their emissions too.

Dan Price, assistant to US President George W. Bush for international economic affairs, said the statement reflected that "the G8 alone cannot effectively address climate change, cannot effectively achieve this goal, but that contributions from all major economies are required".

Critics outside the rich nations' club slammed the deal, although many had already predicted that chances for bold steps were slim until a new US president takes office next January.

Ducking responsibility

"The G8 are responsible for 62 per cent of the carbon dioxide accumulated in the Earth's atmosphere, which makes them the main culprit of climate change and the biggest part of the problem," environmental group WWF said in a statement. "WWF finds it pathetic that they still duck their historic responsibility."

Five big emerging economies including China, India and South Africa also panned the G8 and called on rich nations to slash their greenhouse gas emissions by 80-95 per cent below 1990 levels by 2050, and make cuts of 25-40 per cent by 2020.

South African Environment Minister Marthinus van Schalkwyk said he feared this year's communique was a step backward.