President Barack Obama is embarking on three days of multinational talks about climate change, the global economy and world hunger in the second and most policy-laden stop of his three-nation, weeklong trip.
The meetings to begin Wednesday in Italy may lack the intrigue of Obama's sit-downs with Russia's top leaders earlier this week or the emotion of the reception that the first black American president is likely to receive in Ghana on Saturday. But they won't lack for ambition, on the surface at least, as the world's most powerful officials address problems that threaten the planet.
Obama and first lady Michelle Obama and their daughters arrived in Rome Wednesday morning. He and the leaders of seven other industrialized nations will meet at L'Aquila near Rome before they widen their circle to include fast-growing countries like China and India, and struggling nations from Africa. In large and small groups, the talks will involve trade, Iran's nuclear ambitions, food security and other issues.
Topping the list are discussions of possible ways to slow the release of greenhouse gases linked to global warming.
Many foreign leaders want the United States to embrace a target of limiting the rise in average planetary temperatures to the 3.6 degree (2 degrees Celsius) level that characterized the preindustrial era in 1900. Scientists say an increase beyond that could trigger dangerous rises in sea level and other dire problems.
White House press secretary Robert Gibbs declined Wednesday to say whether the administration would endorse the goal. But he suggested that the administration is putting its political emphasis on what it can accomplish back home with Congress, not with the Group of Eight (or G-8) at an international summit.
"I would say that I think our biggest contribution to this is the steps that were taken by the House," Gibbs said, referring to legislation requiring reductions in greenhouse gases.
Asked how Obama would define success at this summit on the issue of climate change, Gibbs said: "I think in many ways success for us is going to be getting something through Congress and to his desk that puts in place a system, market-based system, that lessens the amount of greenhouse gases in the air."
Setting goals and achieving them, of course, are different things, and G-8 meetings often are known more for high-minded roundtables and photo opportunities than for concrete results. Even before Obama left Washington, his aides tamped down expectations of breakthroughs at L'Aquila.
On the economy, "This will be more about exchanging views at this midpoint between the two G-20 summits than an opportunity to produce a series of specific deliverables, as you would call them," presidential adviser Mike Froman told reporters, referring to an expanded group of world leaders that generally meets in April.
Obama made a major speech in Moscow and planned another for Ghana, but not one in Italy. Barring a breakthrough on climate change, or perhaps new sanctions against Iran, the emotional highlight of Obama's Italy trip may be his audience Friday with Pope Benedict XVI at the Vatican.
Before that, Obama will meet individually with Italy's President Giorgio Napolitano and Prime Minister Silvio Berlusconi.
The three-day summit will involve ever-growing numbers of nations beyond the G-8, whose members are the United States, Canada, Britain, France, Germany, Italy, Russia and Japan. Various meetings will include representatives of Egypt, Turkey, Mexico and several other nations.
Steven Schrage, a business scholar at the Washington-based Center for Strategic and International Studies, said the G-8 sometimes struggles for a clear-cut identity and purpose. The best title for this week's meeting, he said, might be "G-question mark."
"It's going to start with the traditional G-8," Schrage said, "but then rapidly accelerate into a kind of crescendo of different nations, going up to 39 nations that will span much of the globe."
The most intensive discussions of climate change may occur Friday, when Obama hosts a discussion on the topic. He also will hold a news conference Friday before flying to Ghana in the evening.
Security will be heavy in L'Aquila, which was ravaged by an earthquake on April 6. Officials have prepared emergency airlifts of the world leaders in case another strong tremor hits.
The April earthquake leveled entire blocks in L'Aquila and the surrounding Abruzzo region, driving some 54,000 from their homes and killing 296 people. Berlusconi decided to move the summit from a posh Sardinian island to L'Aquila in a show of support for the stricken population.
Italy is deploying thousands of police officers as it seeks to avoid the violence that marred the last G-8 summit held in this country, when one protester was killed and more than 200 were injured in Genoa in 2001.