President Barack Obama is trumpeting major progress by his administration toward reducing greenhouse gas emissions, even though some of the most ambitious steps Obama has pledged remain in limbo.

One year ago, Obama unveiled sweeping plans to tackle climate change and cut U.S. emissions of heat-trapping gases 17 percent by 2020. The idea was that U.S. leadership would spur other countries to act as well.

Over the past 12 months, Obama's administration has started putting much of that plan into place. Those steps include the first carbon dioxide limits on existing power plants, new permits for renewable energy projects and energy efficiency standards.

Other steps are still in the early stages. And on the international front, there are signs of resistance to Obama's call for other countries to cut emissions.