The failure to agree on swift, concrete steps to reduce greenhouse gas emissions at the summit meeting of the world's most advanced economies points to a continuing logjam and hard bargaining ahead on global warming - especially on the politically sensitive issue of who goes first.
President Barack Obama and his counterparts in the Group of Eight, who are holding two days of meetings in the central Italian mountain town L'Aquila, announced broad agreements to reduce greenhouse gas emissions and combat rising global temperatures over the next four decades.
They also prepared to offer new financial incentives for other nations - including China, the world's leading source of heat-trapping gas - to join in the effort.
But the G8 stopped well short of pledging to take the kinds of steps that could curb emissions more quickly - but also impose higher prices for electricity and other energy, while potentially aggravating the woes of the global economy.
And neither the broad promises of future action nor the relatively modest financial incentives were likely to break the stand-off between the most advanced economies and China, India, Brazil and other emerging powerhouses that have insisted wealthier nations should take the lead.
"China's not going to do anything until the developed countries send a signal that they're going to do something," said Michael Oppenheimer, a geoscientist at Princeton University and a longtime participant in the Intergovernmental Panel on Climate Change.
The stalemate on the international stage mirrors Obama's problem at home. Though the House approved a major climate bill last month, Republicans and other critics have unleashed a hailstorm of criticism.
Unless China and other developing nations make firm commitments to cut back emissions, the Republicans say, emissions limits by the United States would have relatively little impact on global warming but could hamstring the already recessionary domestic economy.
Obama's climate bill, which narrowly passed the House, could send a strong signal if it becomes law, said Dirk Forrister, chairman of the White House climate change task force under President Clinton and now managing director of the financial firm NATSOURCE LLC.
But, he said, "The U.S. Senate will not go along with anything unless it sees some pretty serious action from developing countries." That, analysts say, sums up Obama's conundrum as he tries to push for a meaningful a climate agreement during formal treaty negotiations in Copenhagen this winter.
"It looks like it's going to be a pretty tough fight [in Copenhagen] based on what happened in these meetings in Italy," Forrister said.
U.S. leaders hinted that a broad coalition of developing and developed nations could announce agreements today to team up on research into renewable energy and technology to scrub and store greenhouse emissions from coal.
Michael Froman, Obama's point man at the summit and lead staff negotiator, argued that the major industrial nations' joint statement favoring an 80 percent reduction in their emissions by 2050 represents "significant cooperation" - even though it comes up short of the draft language the White House supported.
The G8 targets roughly followed those in Obama's domestic climate bill.
The G-8 countries also set a global goal of 50 percent emissions reductions by mid-century, and declared that they recognize "the broad scientific view that the increase in global average temperature above pre-industrial levels ought not to exceed 2 degrees Celsius.
They did not announce any specific plans to cut emissions or adopt any short- or mid-term reduction targets. The United States pushed, and failed, to get developing nations to join in the reduction pledge.
"In any negotiation, you put in a number of points," Froman said. "Sometimes they make it in and sometimes they don't." The statement that did not come - the one that would have included China, Brazil and other developing countries - is the one that matters, he acknowledged.
But both he and chief Obama climate negotiator Todd Stern argued that there is plenty of room to work out an agreement before the Copenhagen summit.