Leaders of the world's advanced economies have committed to a long-term goal of slashing their emissions of carbon blamed for global warming.  Officials say the plan is a first step toward building consensus but activist groups and at least one African leader say the declaration is empty.  VOA's Kurt Achin has more from northern Japan, where the leaders are gathering.

Japanese Prime Minister Yasuo Fukuda (l) shakes hands with U.S. President George W. Bush (r) during the working session of the G8 summit, in Toyako on the Japanese island of Hokkaido, 08 Jul 2008

After a working lunch of the so-called "G8" leaders in Toyako, Japanese Prime Minister Yasuo Fukuda announced a new long-term goal on the issue of global climate change.

He says the G8 countries have agreed to cut their carbon emissions in half by the year 2050.

The goal is the highlight of an 18-point declaration the leaders released during the second day of their three-day summit.

Within hours, South Africa's environment minister criticized the statement as an "empty slogan" for its lack of specifics.  The statement is also getting a chilly reception from environmental activists like Ben Wikler, of the group Avaaz.org.

"The G8 countries blew it," said Wikler. "The language the G8 countries used to describe their vision could not have been murkier."

Several key elements of the G8 climate goals have been left open to interpretation by member countries.  The 50-percent reduction is not indexed to any specific base year.  Members can choose to halve their emissions based on  this year's levels, or based on a more ambitious 1990 pollution level.

G8 leaders pose for official group photo at summit, in Toyako, Hokkaido, 08 Jul 2008

The agreement also leaves out any specific mention of targets for medium or short-term carbon-emission reductions, instead urging members to formulate such goals on a nation-by-nation basis.

The director-general for Global Issues with Japan's Foreign Ministry, Ambassador Koji Tsuruoka, briefed reporters on Tuesday's discussion among the leaders.  He says the agreement is designed to be broad, and legally non-binding.

"This is more of a political vision," said Tsuruoka.  "The G8 as a whole is trying to engage the rest of the world."

Specifically, the leaders hope to engage major emerging economies like China and India.  Experts fear their booming growth will be accompanied by sharp rises in carbon emissions.  Several G8 leaders, including President Bush, have said any climate agreement without emerging economies on board is destined to fail.

G8 leaders say they will discuss the climate goals with leaders of emerging powers in meetings scheduled for Wednesday.  Their talks are expected to set a framework for a U.N.-led gathering next year that aims for a global agreement on climate change.