Record coal exports in recent years are helping the U.S. appear to be making more progress on global warming than it is. But they may not be helping the planet.
As America gets greener, and produces more energy, it has sent more dirty fuels abroad, saddling other countries with cleaning up the exported pollution.
This fossil fuel trade threatens to undermine President Barack Obama's plans to curb global warming. But the administration doesn't want to figure out how much coal exports are contributing to global warming. It says the impact is small.
U.S. coal consumption declined by 195 million tons from 2008 to 2013. About 20 percent of that coal was exported.
Exports are expected to grow as global demand grows and the U.S. further cleans up its power sector.