Last week's global climate talks in Doha, Qatar ended without any further deal to curb greenhouse gas emissions. That leaves the 1997 Kyoto Protocol in place, which it extended. The only trouble is the United States never ratified the accords, which call for reducing national emissions of CO2 and related gases to 1990 levels by 2020. To make matters worse, in the intervening years, Canada and Japan opted out of the accords. With Doha a failure, and Kyoto in tatters, the environmental community was in a funk.

But before the Doha meeting even began, a bright spot emerged that no one saw coming. According to the U.S. Energy Information Agency (EIA), America's greenhouse gas emissions are now at 1992 levels, down from their peak in 2008. Despite refusing to ratify Kyoto, the United States could be the first developed nation to reach the target.

Who would have thought?

The United States has become one of the cleanest, greenest countries on earth, relative to the size of its gross domestic product. In 2008, CO2 emissions were about 1,600 million metric tons a year, according to the EIA. Today, they are 1,300 metric tons, a drop of nearly 20 percent.

Price Wins

The reason for the change is price, not politics or treaties. Natural gas, which emits 43 percent less CO2 than coal, and releases no particulate matter into the atmosphere, is now the cheapest fuel available for producing electricity since the technology of hydraulic fracturing, or fracking, was perfected. As a consequence, the electricity industry has made a lightening fast changeover in the fuels it uses. In 2008, about half of America's electricity was produced by burning coal, with 20 percent produced from natural gas, according to the EIA. Today, 40 percent of our electricity comes from natural gas with coal's share just 32 percent.