Obama set to unveil plan to tackle greenhouse gas emissions

US President Barack Obama is running out of time to make good on his lofty vow to confront climate change head-on, and Congress is in no mood to help.

Moving ahead on his own, Obama was set to announce a set of actions that will take years to implement. He was scheduled to detail his climate change plan in a speech this morning, Hong Kong time.

The centrepiece of the plan is a push to issue new regulations that would curb greenhouse-gas emissions from new and existing power plants, according to people briefed on the plan by the administration. Other components would include energy efficiency, renewable energy sources and help for communities preparing for the effects of climate change.

"This is a serious challenge, but it's one uniquely suited to America's strengths," Obama said in a White House video announcing the speech at Georgetown University.

Yet environmental activists are frustrated that Obama, despite deeming climate change a priority as far back as his first presidential campaign, waited until his fifth year in office to issue a detailed plan. In his state of the union address in February, Obama gave lawmakers an ultimatum that if Congress wouldn't pass climate legislation, he'd take action himself. Four months later, Obama appears to have lost patience.

"His view reflects reality," said White House spokesman Jay Carney. "We've seen Congress attempt to deal with this issue, and fail to."

Days earlier, as word came of Obama's plans for existing power plants, the leader of the House of Representatives, Speaker John Boehner, called it "absolutely crazy", making it clear the obstacles Obama would face in trying to push anything through Congress.