TOYAKO, Japan (Reuters) - Environmental groups slammed rich nations’ leaders for ducking their leadership responsibilities when they addressed global warming at a summit on Tuesday, with WWF saying the lack of progress was “pathetic”.

Protesters shout slogans at a march against the G8 Hokkaido Toyako Summit in Sapporo, July 8, 2008. Environmental groups slammed rich nations' leaders for ducking their leadership responsibilities when they addressed global warming at a summit on Tuesday, with WWF saying the lack of progress was "pathetic". REUTERS/Kim Kyung-Hoon

“The G8 are responsible for 62 percent 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,” WWF said after the G8 issued a communique on climate change.

“WWF finds it pathetic that they still duck their historic responsibility,” the campaign group said in a statement.

Earlier, Group of Eight G8 leaders meeting in northern Japan said they would work with nearly 200 states in the United Nations climate change talks to adopt a goal of at least halving greenhouse gas emissions by 2050.

They also said midterm goals -- such as the EU’s plan to cut greenhouse gas emissions by at least 20 percent from 1990 levels by 2020 -- would be needed to achieve that target.

Leaders said the statement represented progress by the G8 on addressing climate change.

“At Heiligendamm, only six countries were recommending a 50 percent global greenhouse goal by 2050,” said Carolyn Olsen, chief spokeswoman for Canadian Prime Minister Stephen Harper.

“Now all G8 countries are calling on the world to adopt a 50 percent by 2050 goal, and they have called for ambitious mid-term goals from all G8 countries and meaningful contributions from all major economies. This is major progress since last year.”

But campaigners criticized the lack of a commitment to midterm targets and said the 2050 goal was insufficient because many scientists say emissions cuts bigger than 50 percent are needed to offset potentially devastating climate change.

“This is a complete failure of responsibility. They haven’t moved forward at all. They’ve ducked the responsibility of adopting clear midterm targets and even the 2050 target is not a single thing more than what we got in Heiligendamm,” said Daniel Mittler, political adviser for Greenpeace International, referring to the German town where last year’s G8 was held.

“Now we’re one year after Heiligendamm when they pledged quick and decisive action and all they come up with is ‘yes, we’ll discuss it at the U.N.’, that’s just not good enough,” he told Reuters.

“This is the result of an oil man preventing the world from moving forward one last time, and the only good news is that this will be Bush’s last G8 summit.”

Oxfam said the G8 climate agreement threatened the world’s poor.

“Rather than a breakthrough, the G8’s announcement on 2050 is another stalling tactic that does nothing to lower the risk faced by millions of poor people right now,” said Oxfam spokesman Antonio Hill.

UK-based development agency Tearfund also said the G8 was dithering.

“The G8 are crawling forward on emissions cuts at a time when giant leaps and bounds are needed,” Peter Grant, Tearfund’s international director, said.

“To do little more than restate last year’s G8 commitment to halve emissions by 2050 is a very disappointing outcome, demonstrating a lack of leadership and vision.”