Robert Redford, shown here at an event for the movie "Lincoln." argues in a new ad that Obama could do more to address climate change. (Credit: Robert Redford, shown here at an event for the movie "Lincoln." argues in a new ad that Obama could do more to address climate change. (Alex Brandon/AP)

A major national environmental group has enlisted legendary movie star Robert Redford in its effort to pressure President Obama to move quickly to curb greenhouse gas emissions from power plants.

The Natural Resources Defense Council will air ads on television, online and in social media outlets in which Redford, an NRDC trustee and longtime environmental activist, urges Obama to have "the courage of his convictions."

“Climate change is happening fast," Redford says in the ad, which will run on both broadcast and cable stations in Washington. "We’ve got to stop making the problem worse, and that means reducing carbon pollution from its biggest source, coal-fired power plants. The good news is that President Obama has pledged to act. I just hope the President has the courage of his convictions."

The ad, which includes a snippet of the president's pledge during his second inaugural address to curb climate change, concludes with Redford saying, "Please, urge the President to make dirty power plants clean up their carbon pollution."

The unusual advertising campaign highlights environmentalists' growing frustration with Obama's current climate strategy. Last week billionaire Tom Steyer issued a public challenge to the president, suggesting he either needs to block the Keystone XL pipeline that would ship crude oil from Canada to the Gulf Coast or face a backlash from grass-roots supporters.

Last month, 150 major Obama donors and clean-tech entrepreneurs urged the president to reject Keystone, comparing the decision to Abraham Lincoln's move to abolish slavery.

On Monday, the Energy Information Agency reported that carbon emissions from energy rose 1.4 percent in 2012, setting a new record.

In an interview, NRDC President Frances Beinecke said she appreciated efforts by the White House to tackle climate change through international talks, such as the announcement Saturday that China and U.S. would work together to phase out the production and consumption of a class of chemicals commonly used in refrigerators and air conditioners that are potent greenhouse gases.

"That is a huge breakthrough with the largest carbon emitter," Beinecke said, but she added that her group has decided "to raise a ruckus" to let the president know they expect him to address carbon pollution from power plants.

The administration has not said whether it will impose carbon limits on existing power plants, the nation's single biggest source of greenhouse gas emissions. In April the Environmental Protection Agency delayed a rule that would have imposed the first-ever greenhouse gas limits on new utilities, saying it needed more time to respond to comments.