How to cut CO2 emissions:

Over the past six years, the United States has reduced its carbon emissions more than any other nation in the world.

Efforts to curb so-called man-made climate change had little or nothing to do with it. Government mandated "green" energy didn't cause the reductions. Neither did environmentalist pressure. And the U.S. did not go along with the Kyoto Protocol to radically cut CO2 emissions. Instead, the drop came about through market forces and technological advances, according to a report from the International Energy Agency.

Breakthroughs in how natural gas is extracted from underground shale formations were the key factors that led to the reductions, the report said. Natural gas has a low carbon footprint and is widely available in the United States.