L'AQUILA, Italy -- President Obama joined other world leaders on Wednesday in backing new targets for battling global warming, a move the Bush White House had resisted. White House officials confirmed that Obama agreed to language supporting a goal of keeping the world's average temperature from rising more than 2 degrees Celsius (3.6 degrees Fahrenheit).
The agreement by the Group of Eight industrialized nations, meeting in Italy, marks a significant step in efforts to limit greenhouse gases blamed for the world's rising temperature. The G-8 previously had not been able to agree on that temperature limit as a political goal.
It remains only a target, however, and it is far from clear that it will be met, especially as China, India and other rapidly industrializing nations generate and consume more energy from coal and other sources.
Climate change experts say the 2-degree threshold wouldn't eliminate the risk of runaway climate change but would reduce it. Even a slight increase in average temperatures could wreak havoc on farmers around the globe, as seasons shift, crops fail and storms and droughts ravage fields, scientists say.
The G-8 leaders also agreed to a goal of having industrialized nations reduce their greenhouse gas emissions by 80 percent by 2050. It would be part of a worldwide goal of a 50 percent cut in such gases from all nations, rich and poor.
James Connaughton, the chair of the White House Council on Environmental Quality under President George W. Bush, said the G8 agreement goes a step further than a deal struck at a meeting last year in Japan by assigning a specific goal to industrialized nations. Developing countries back then balked at agreeing to a 50 percent worldwide reduction come 2050.
"This would appear to be a good-faith attempt to assure the developing countries that the developed countries will bear a greater proportion of the task," Connaughton said in an interview with The Associated Press.
White House adviser Mike Froman said the administration supports the new nonbinding goals.
He said the starting point for the targeted reduction could be as early as 1990. The two goals will not be included in a declaration from a broader group that includes poor and developing nations that are wary about the potential impact of such reductions on emerging economies, Froman said.
Opponents say such sharp reductions in carbon emissions would hamper businesses and industries.
The Department of Energy in 2008 completed a study for the Bush White House in 2008 that showed if industrialized countries slashed their emissions by 80 percent, that would require developing countries to cut their future emissions by 65 percent to meet the worldwide target.