Coal exports from the United States are leading to an increase in greenhouse gas emissions globally even as the country attempts to clean up the air within its borders, Associated Press, or AP, reported Monday.

U.S. energy companies have exported more coal in the last six years than ever before, the report said, analyzing preliminary data released by the Energy Information Administration, or EIA. In the same time period, the U.S. reduced domestic coal consumption by 195 million tons. However, more than 20 percent -- about 118 million tons -- of that coal was reportedly shipped overseas, accounting for about 10 percent of worldwide coal exports in 2013, the year for which latest data are available.

As a result, the reduction in domestic coal consumption made the U.S. appear to be making more progress than it really is on curbing greenhouse gas emissions.

“This is the single biggest flaw in U.S. climate policy,” Roger Martella, former general counsel at the Environmental Protection Agency, told AP. “Although the administration is moving forward with climate change regulations at home, we don't consider how policy decisions in the United States impact greenhouse gas emissions in other parts of the world.”

In the current system to track the emissions of carbon dioxide and other greenhouse gases, only fossil fuels consumed inside a nation’s borders are taken into account.

“Energy exports bit by bit are chipping away at gains we are making on carbon dioxide domestically,” Shakeb Afsah, a Maryland-based economist told AP.

U.S. coal exports to Germany, which is the fifth-largest consumer of U.S. coal, for instance, have more than doubled in five years, to 5.4 million tons in 2013 from 2.5 million tons in 2008. As a result of Germany’s increased reliance on coal for energy production, carbon dioxide emissions in the country went up by 1.2 percent in 2013, according to World Bank data.

Dirk Jansen, a spokesman for BUND, a German environmental group, termed it a case of “political greenwashing” and blamed the U.S. for a worldwide increase in carbon dioxide emissions.

"Obama pretties up his own climate balance, but it doesn't help the global climate at all if Obama's carbon dioxide is coming out of chimneys in Germany," he said.

Meanwhile, energy companies in the U.S. are reportedly looking to double coal exports in the next few years, fuelling further demand for coal worldwide, AP reported.