CNN Money: U.S. cuts greenhouse gases despite do-nothing Congress

A curious thing is happening to the air in the United States. It's getting cleaner.

Despite there being no real effort by Congress to address global warming and America's longstanding reputation as an energy hog, U.S. carbon dioxide emissions are falling.  

The lackluster economy has something to do with it. But it doesn't fully explain what's happening. Consider that even factoring in a stronger economy, forecasters see greenhouse gas emissions continuing to fall.

It's possible the country may meet its pledge to reduce emissions 17% by 2020.

So what's going on?

Some of the reductions can be attributed to executive decisions taken by the Obama administration to curb pollution from power plants and other sources.

Investments in energy efficiency have also helped, along with state rules requiring utilities to purchase power from renewable sources.

But the main and most surprising reason: cheap natural gas.  MORE