Preliminary estimates show China may have outperformed its annual goal to cut carbon intensity by 3.5 percent in 2012, officials said.

With that target, the country aims to cut its carbon emissions per unit of gross domestic product by 17 percent between 2011 and 2015.

The government is preparing a national plan on climate change through 2020, said Su Wei, director general of the climate change department at the National Development and Reform Commission. China aims to cut intensity by 40 to 45 percent versus 2005 levels by 2020.

President Obama can deliver on his international carbon-reduction commitments without new congressional action by making full use of his authority under the Clean Air Act and other laws, according to the head of a prominent environmental think tank.

Armond Cohen, executive director of the Clean Air Task Force (CATF), said in an open letter to the president released today that Obama's pledge of reducing heat-trapping emissions 17 percent by 2020 and 80 percent by midcentury is already within reach.

A coalition of environmentalists, faith-based groups and poverty advocates is hoping to persuade President Obama to host a national climate change summit at the White House early in his second term as a way of making good on his pledge to initiate a national discussion on the issue. Advocates of the idea sent a petition to the White House after a Nov. 12 news conference at which Obama spoke of his plan to launch "a conversation across the country" on the risks of climate change and ways to address them.