Obama unveils first US national climate action plan

US President Barack Obama has unveiled the country's first national climate action plan, pledging to limit carbon emissions from American power plants.

Delivering a speech at Georgetown University, Obama said the planet is changing in ways that will impact all of humankind, and that the 12 warmest years in recorded history have all come in the last 15 years.

"Americans across the country are already paying the price of inaction. As a president, as a father, and as an American, I'm here to say -- We need to act," Xinhua quoted Obama as saying.

The president noted that power plants, which currently represent one-third of all US carbon emissions, "can still dump unlimited amounts of carbon pollution into the air for free".

"That's not right ... and it needs to stop," he added.

"I'm directing the Environmental Protection Agency (EPA) to put an end to the limitless dumping of carbon pollution from our power plants."

Obama described a low carbon clean energy economy as being an engine of growth for decades to come.

"There's no contradiction between a sound environment and strong economic growth," said Obama.

"Using less dirty energy, transitioning to cleaner sources of energy, wasting less energy ... is where we need to go."

Obama said he was directing the Department of the Interior to greenlight enough private renewable energy capacity on public lands to power more than six million homes by 2020.

He asked the federal government to consume 20 percent of its electricity from renewable sources within the next seven years.

The president also set a goal to reduce carbon pollution by at least three billion metric tonnes cumulatively by 2030, more than half of the annual carbon pollution from the US energy sector.