As many of us are paying attention to the climate change negotiations in Doha, Qatar these next two weeks, I think it’s important to keep in context just how many moving pieces there are when it comes to crafting domestic policies that address a global issue. As I wrote awhile back during the presidential campaigns, I view climate change as a global challenge, which requires a global approach from individual nations.

As we watch what unfolds (or doesn’t, if you’re more pessimistic), I expect we’ll hear a fair amount about how the United States’ booming natural gas market is not only helping it achieve more domestic energy production (which is generally a good thing), but also reducing carbon emissions as power generation switches over from carbon-intensive coal generation to natural gas.

But just because we (the United States) are burning more natural gas at the expense of coal, and consequently emitting less carbon per unit energy, that doesn’t mean that coal is staying put on our soil. Instead, coal exports from the United States are up, and not just to Asia, which we hear about most of the time in terms of building coal power plants like crazy. Europe is actually importing most of the coal the United States is exporting for use in power generation.

This chart from the U.S. Energy Information Administration shows the destination for U.S. coal exports for the first eight months of 2012. Europe leads, while Asia is a close second. Also note that roughly half of our coal is used for steam/power generation in Europe, while nearly three quarters is used for manufacturing and metallurgical processes in Asia.

So keep in mind that even coal, which is typically thought of as a domestic energy source, can be shipped around the world, effectively like a leakage of carbon from the United States to other regions of the world. And carbon emissions aren’t solely from generation power; developing economies also require steel. Lots of steel. And that means carbon (in the form of coal).