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. They argue that emissions limits by the United States and other advanced economies alone would have relatively little effect on global warming, while potentially harming the domestic economy.
Obama's climate bill, which narrowly passed the House, could send a strong signal if it becomes law, said Dirk Forrister, who was chairman of the White House climate change task force under President Clinton and now is 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 climate agreement during formal treaty negotiations in Denmark 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 agreement today to team up on research on 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% reduction in their emissions by 2050 represented "significant cooperation" -- even though it came up short of the draft language that the White House had supported.
The G-8 targets roughly followed those in Obama's domestic climate bill.
The G-8 countries also set a global goal of 50% emissions reductions by mid-century, and declared that they recognized "the broad scientific view that the increase in global average temperature above preindustrial levels ought not to exceed" 2 degrees Celsius (3.6 degrees Fahrenheit).
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.
