According to Germany's top negotiator Bernd Pfaffenbach on Thursday, the world's richest nations acknowledged that human activity was a significant contributor to global warming, and that there was a need to reduce the greenhouse gases that trigger it.
But a draft statement made only cursory reference to the binding Kyoto accord on cutting greenhouse gases, signed by seven of the G8 powers and championed in Gleneagles by France and others - but termed economic suicide by US President George Bush.
France made clear that it saw the outcome as only just sufficient.
"Even if it does not go as far as we would have liked, it has one essential virtue in my eyes - that is, to re-establish a dialogue and cooperation between the Kyoto seven and the United States on a subject of the highest importance," French President Jacques Chirac said.
While uncertainties remained in understanding climate science, all eight leaders agreed enough was known to act now to begin to slow down and arrest and reverse the increase in greenhouse gases.
The draft commits all eight countries to "act with determination and urgency" to reach common goals that included reducing greenhouse gases, but without offering any yardstick.
Clouds of pollution are so big they
can be monitored by satellite
The draft also stated that the United Nations provided the appropriate forum to negotiate a future multilateral regime to address climate change.
However, environmentalists were dismissive of a text that made no concrete commitment to any measurable reduction in greenhouse gases.
"President Bush is isolated from the 12 other countries who have all emphasised the need for tough targets to reduce CO2 emissions," Greenpeace director Stephen Tindale said, referring to the participation of South Africa, Mexico, India, China and
Brazil in some of the G8 meetings.
The draft said it was in the interests of all to work with large emerging economies - a reference in particular to China and India, which are expected to produce increasing amounts of greenhouse gases.
The G8 powers pledged to promote work on more efficient and cleaner energy use, and also to promote the transfer of new technology to developing countries, and to "launch a dialogue on climate change, clean energy and sustainable development".
Friends of the Earth director Tony Juniper said the Bush administration had "again done its best to derail international action to tackle climate change".
But he added: "Even if there was no progress here, there has been a big impact on public awareness."