China and U.S. Assume Leading Roles in Fighting Climate Change

ABC's Bill Blakemore reports from New York:

Chinese President Hu Jintao promised world leaders at today's UN Climate Summit that China will increase efforts to cut greenhouse reductions "per unit of GDP" but made no mention of any planned leveling or lowering actual carbon emissions.  (Also called "intensity cuts," percenatge-of-GDP cuts may still let greenhouse emissions rise if GDP is rising).

Hu emphasized in his short speech how developing countries need help from rich countries, who put most of the excess carbon in the atmopshere, in fighting and adapting to global warming's dramatic impacts, and repeated the notion of "common but differentiated responsibilities" among nations.

Hu did take a new stance of assuming a leading role in fighting climate change, in effect joining the US president, who spoke first, in asserting such leadrship.

President Obama's speech listed a number of carbon-cutting measures now underway in the US and declared the extreme importance of curbing global warming, continuing the same aggressive commitment to fighting global warming he promised in his 2008 campaign.

Mr. Obama also referred to the carbon-cutting legislation now being considered by the US Senate, but he did not add any new specifics.

The US president did clearly differentiate his approach from from the inaction of the preceding Bush administraion and in effect apologized for it, saying "in past eight months" a completely different course has been promoted by the White House.

A poignant note was struck between the two speeches by the president of the small island nations of The Maldives, who told the gathered world leaders in the UN's General Assembly that if there is no agreement in the upcoming climate summit in Copenhagen, then, as he said, referring to accelerating sea level rise, "we will die, our country will not exist."