Glasgow, Scotland ? Leaders of the world’s most prosperous nations convened a three-day summit Wednesday to address endemic poverty, environmental neglect and other global challenges, even as President Bush declared his continued opposition to mandatory limits on greenhouse gas emissions.

Outside the tightly guarded conference site, activists intent on disrupting the annual conclave of the Group of 8 nations scuffled with police, tied up traffic and caused some merchants to shutter their shops in the Scottish capital of Edinburgh.

G8 leaders – representing Britain, France, Germany, Italy, Russia, Japan, Canada and the United States – launched the conference with a private dinner for which Queen Elizabeth and Prince Phillip served as hosts.

Some leaders, including British Prime Minister Tony Blair, the G8 chairman, have expressed hope the group’s efforts would lead to meaningful progress on difficult and divisive issues such as Africa’s plight, climate change and energy consumption.

Yet even before the summit could get started, Bush said he would resist any efforts to impose the kind of greenhouse gas limits contained in the previously negotiated Kyoto accord, which the United States declined to ratify.

The Kyoto agreement requires its signatories to make significant reductions in emissions of carbon dioxide and other pollutants widely believed to contribute to the gradual warming of the planet, a phenomenon that could have grave long-term environmental consequences.

Although new limits were not on the summit agenda, Blair has been pushing the Bush administration to show more flexibility on the issue.

“I think there’s a better way forward,” Bush told reporters during a stop in Denmark on his way to Gleneagles. “I would call it the post-Kyoto era, where we can work together to share technologies, to control greenhouse gases as best as possible.”

Shortly before the summit’s opening dinner, Blair acknowledged that a consensus might not be reached on fighting global warming, but he said he opposed efforts to try to isolate the United States over the issue.