 Big emerging economies including China looked set on Wednesday to clash with G8 rich countries over how to fight global warming. Papering over deep differences, the G8 said on Tuesday they would work toward a target of at least halving global greenhouse gas emissions by 2050 but emphasized they would not be able to do it alone. The Group of Eight industrial nations want the leaders of eight fast-growing countries to adopt a "shared vision" of tackling global warming in U.N. negotiations due to conclude in Copenhagen in December 2009. The U.N.-led talks aim to create a new framework for when the Kyoto Protocol expires in 2012. "It's the stalemate we've had for a while," said Kim Carstensen, director of environmental group WWF's global climate initiative. "Given the lack of willingness to move forward, particularly by the U.S., it hasn't been possible to break that. Critics said the G8 agreement was a timid advance on last year's summit commitment in Heiligendamm, Germany, to seriously consider the 2050 goal of halving emissions by mid-century. "This is a complete failure of responsibility. They haven't moved forward at all. They've ducked the responsibility of adopting clear mid-term targets and even the 2050 target is not a single thing more than what we got in Heiligendamm," said Daniel Mittler, Greenpeace International's political adviser. WWF called the G8's stance "pathetic". The G8 summit on the northern Japanese island of Hokkaido brings together the leaders of Japan, Britain, Canada, Germany, France, Italy, Russia and the United States. China, India, South Africa, Mexico and Brazil called on rich nations on Tuesday to slash their carbon emissions by 80-95 percent below 1990 levels by 2050, and make cuts of 25-40 percent by 2020. Leaders of these large emerging nations joined the G8 on the last day of its three-day summit in a so-called Major Economies Meeting that Australia, Indonesia and South Korea also attended. The stance of emerging nations is important. The G8 nations emit about 40 percent of mankind's greenhouse gas emissions. But China and India together emit about 25 percent of the total, a proportion that is rising as their coal-fueled economies boom. Washington in particular has said a global climate deal is impossible unless China and India make sacrifices. The big emerging nations said on Tuesday that it was up to the rich nations to do more. "It's not we who are not on board. We've got a more ambitious package. Now we need the U.S. to get on board. It's going to be two years of tough negotiations," said one diplomat from the emerging nations group, who declined to be identified. Negotiators from the Major Economies Meeting group who met in Seoul last month failed to agree on numerical targets for either a long-term global target to cut emissions, or specific mid-term goals for developed countries. The leaders were not expected to go beyond that agreement -- which said major developed economies would set mid-term goals -- in a statement to be issued on Wednesday. "We do not expect our final statement to touch on numerical targets that include the emerging economies," a Japanese official said late on Tuesday. Climate change is not the only bone of contention at Wednesday's talks. Emerging nations are suffering more than rich countries from soaring fuel and food prices and have bristled at the suggestion that their rising demand is to blame. "The emphasis was that rising food prices was hurting the poor and that it was important to increase food production to deal with this," a Japanese official said after a meeting of the big five emerging nations with G8 leaders. "There was concern about rising oil prices and many emerging countries stressed the factor of speculative trade." The 13 leaders also discussed the usefulness of their expanded dialogue amid calls that the G8 should expand to a larger group to better deal with problems that are increasingly global and complex. "The five countries said they expected the dialogue to evolve and progress going forward," the Japanese official said.