National Geographic News
Coal docks in Norfolk, Virginia.

The port of Norfolk, Virginia, seen here in 1970, is the largest U.S. facility for exporting coal. It saw a surge of activity last year as U.S. coal exports increased 17 percent to set a new record.

Photograph by Charles Rotkin, Corbis

Thomas K. Grose

For National Geographic News

Published March 15, 2013

Ready for some good news about the environment? Emissions of carbon dioxide in the United States are declining. But don't celebrate just yet. A major side effect of that cleaner air in the U.S. has been the further darkening of skies over Europe and Asia.

The United States essentially is exporting a share of its greenhouse gas emissions in the form of coal, data show. If the trend continues, the dramatic changes in energy use in the United States—in particular, the switch from coal to newly abundant natural gas for generating electricity—will have only a modest impact on global warming, observers warn. The Earth's atmosphere will continue to absorb heat-trapping CO2, with a similar contribution from U.S. coal. It will simply be burned overseas instead of at home.

"Switching from coal to gas only saves carbon if the coal stays in the ground," said John Broderick, lead author of a study on the issue by the Tyndall Center for Climate Change Research at England's Manchester University. (Related Quiz: "What You Don't Know About Electricity")

The U.S. Energy Information Administration (EIA) released data this week showing that United States coal exports hit a record 126 million short tons in 2012, a 17 percent increase over the previous year. Overseas shipments surpassed the previous high mark set in 1981 by 12 percent. The United States clearly is using less coal: Domestic consumption fell by about 114 million tons, or 11 percent, largely due to a decline in the use of coal for electricity. But U.S. coal production fell just 7 percent. The United States, with the world's largest coal reserves, continued to churn out the most carbon-intensive fuel, producing 1 billion tons of coal from its mines in 2012.

Emissions Sink

The EIA estimates that due largely to the drop in coal-fired electricity, U.S. carbon emissions from burning fossil fuel declined 3.4 percent in 2012. If the numbers hold up, it will extend the downward trend that the U.S. Environmental Protection Agency (EPA) outlined last month in its annual greenhouse gas inventory, which found greenhouse gas emissions in 2011 had fallen 8 percent from their 2007 peak to 6,703 million metric tons of CO2 equivalent (a number that includes sources other than energy, like methane emissions from agriculture). In fact, if you don't count the recession year of 2009, U.S. emissions in 2011 dropped to their lowest level since 1995.

President Barack Obama counted the trend among his environmental accomplishments in his State of the Union address last month: "Over the last four years, our emissions of the dangerous carbon pollution that threatens our planet have actually fallen."

The reason is clear: Coal, which in 2005 generated 50 percent of U.S. electricity, saw its share erode to 37.4 percent in 2012, according to EIA's new short-term energy outlook. An increase in U.S. renewable energy certainly played a role; renewables climbed in those seven years from 8.7 percent to 13 percent of the energy mix, about half of it hydropower. But the big gain came from natural gas, which climbed from 19 percent to 30.4 percent of U.S. electricity during that time frame, primarily because of abundant supply and low prices made possible by hydraulic fracturing, or fracking. (Related: "Natural Gas Stirs Hope and Fear in Pennsylvania" and interactive, "Breaking Fuel From the Rock")

The trend appears on track to continue, with U.S. coal-fired plants being retired at a record pace.

But U.S. coal producers haven't been standing still as their domestic market has evaporated. They've been shipping their fuel to energy-hungry markets overseas, from the ports of Norfolk, Baltimore, and New Orleans. Although demand is growing rapidly in Asia—U.S. coal exports to China were on track to double last year—Europe was the biggest customer, importing more U.S. coal last year than all other countries combined. The Netherlands, with Europe's largest port, Rotterdam, accepted the most shipments, on pace for a 24 jump in U.S. coal imports in 2012. The United Kingdom, the second largest customer, saw its U.S. coal imports jump more than 70 percent. (Related: "Natural Gas A Weak Weapon Against Climate Change, Study Says")

The hike in European coal consumption would appear to run counter to big government initiatives across the Continent to cut CO2 emissions. But in the European Union, where fracking has made only its initial forays and natural gas is still expensive, American coal is, well, dirt cheap. (Related: "U.K. Dash for Gas a Test for Global Fracking")

European utilities are now finding that generating power from coal is a profitable gambit. In the power industry, the profit margin for generating electricity from coal is called the "clean dark spread"; at the end of December in Great Britain, it was going for about $39 per megawatt-hour, according to Argus. By contrast, the profit margin for gas-fired plants—the "clean spark spread"—was about $3. Tomas Wyns, director of the Center for Clean Air Policy-Europe, a nonprofit organization in Brussels, Belgium, said those kinds of spreads are typical across Europe right now.

The EU has a cap-and-trade carbon market, the $148 billion, eight-year-old Emissions Trading System (ETS). But it's in the doldrums because of a huge oversupply of permits. That's caused the price of carbon to fall to about 4 euros ($5.23). A plan called "backloading" that would temporarily extract allowances from the market to shore up the price has faltered so far in the European Parliament. "A better carbon price could make a difference" and even out the coal and gas spreads, Wyns said. He estimates a price of between 20 and 40 euros would do the trick. "But a structural change to the Emissions Trading System is not something that will happen very quickly. A solution is years off."

The Tyndall Center study estimates that the burning of all that exported coal could erase fully half the gains the United States has made in reducing carbon emissions. For huge reserves of shale gas to help cut CO2 emissions, "displaced fuels must be reduced globally and remain suppressed indefinitely," the report said. (Related Quiz: "What You Don't Know About Natural Gas")

Future Emissions

It is not clear that the surge in U.S. coal exports will continue. One reason for the uptick in coal-fired generation in Europe has been the looming deadline for the EU's Large Combustion Plant Directive, which will require older coal plants to meet lower emission levels by the end of 2015 or be mothballed. Before that phaseout begins, Wyns says, "there is a bit of a binge going on."

Also, economic factors are at work. Tyndall's Broderick said American coal companies have been essentially selling surplus fuel overseas at low profit margins, so there is a likelihood that U.S. coal production will decrease further. The U.S. government forecasters at EIA expect that U.S. coal exports will fall back to about 110 million tons per year over the next two years, due to economic weakness in Europe, falling international prices, and competition from other coal-exporting countries. The Paris-based International Energy Agency (IEA) calls Europe's "coal renaissance" a temporary phenomenon; it forecasts an increasing use of renewables, shuttering of coal plants, and a better balance between gas and coal prices in the coming years.

But IEA does not expect that the global appetite for coal will slacken appreciably. The agency projects that, by 2017, coal will rival oil as the world's primary energy source, mainly because of skyrocketing demand in Asia. (Related: "Pictures: A Rare Look Inside China's Energy Machine")

U.S. coal producers have made clear that they aim to tap into that growing market.

Currently, U.S. exports to Asia are somewhat constrained because there is little port capacity for big coal ships on the U.S. West Coast, and because metallurgical coal, the high-heat content rock that is used for steelmaking, is mined exclusively on the U.S. East Coast. Nevertheless, demand for U.S. "met" coal is so great in Asia that the shipments make a round-the-world journey from Appalachia. They are sent by train to the port of Baltimore, where they steam to sea through the Chesapeake Bay, then south across the Atlantic Ocean and around Africa's Cape of Good Hope to reach Asian ports.

Whether U.S. exports to Asia expand will depend largely on the fate of controversial proposals to expand port capacity in Bellingham and Longview, Washington, and Corpus Christi, Texas. (Related: "Seeking a Pacific Northwest Gateway for U.S. Coal" ) Those new ports would allow easier transport of the abundant coal of the Powder River Basin of Wyoming and Montana, which is especially well suited for generating electricity. Powder River Basin coal is prized because it is low in sulfur and can cut acid rain emissions, but as with all coal, carbon dioxide emissions remain a major problem.

John Eaves, chief executive officer of St. Louis, Missouri-based Arch Coal, which saw the bulk of its exports last year go to South Korea, told investors last month that the company would be proactive in working to gain greater port capacity. Despite the low price currently fetched for coal overseas, Eaves said the company expects the international market to improve even as domestic demand for coal recedes. "As we look to the U.S. over the next three to five years, let's face it, demand's going to be pretty flat," he said. "We see exports as a long-term development opportunity." (Related Interactive: "World Electricity Mix")

This story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge.

jim prescott
jim prescott

We should be sharing our tech with other countries so they can cut their emissions as well. It would not hurt our exports because of the amount of natural gas that we have in this country. If anything it would be a great boost for our economy as well as cleaner air in the world

Bowie Bob
Bowie Bob

If one were to follow the logic of this headline, the US doesn't have an emissions problem, only the oil exporting countries.   The article isn't all that bad.  Of course, some won't understand this, but if the Chinese didn't get their Met coal from the US, they would get it from somewhere else.

If NG membership wasn't a gift, I don't believe I would pay for it anymore.  Instead of Geography, NG today seems to be all about politically correct and progressive environmentalism.  I dare the editors to run a story that shows man improving the human condition.  Or run an article about extreme environmentalism forcing billions of humans into lower standard of living and millions dying as a result.

craig hill
craig hill

Your statistisc about declining co2 in the US is Alice in Wonderland-misleading.  

John C.
John C.

Back to reality;

1) Our world wide industrial economy was created with inexpensive, energy rich fossil fuels. This coincided with an unprecedented rise in human living standards, lifting billions out of subsistence poverty. We will never be able to sustain that economy with windmills and solar cells. It's not politics pr public policy, it's simple physics and chemistry.

2) Government meddling in the energy market to try to make fossil fuels more expensive so that wind and solar are relatively less expensive is idiotic. Whenever government tries to "help" by ham-handedly rigging markets it always ends in disaster, as in the housing crash that was fueled largely by government supported "hot money" creating a market bubble. Also, the Fed pumping billions of QE dollars into Wall Street to create the stock market bubble we now have that will soon explode.

Solar and wind will always remain marginal in the energy sector. Stop wasting taxpayer money and bungling with the markets to prove otherwise. Nuclear and natural gas are the future of energy, that's the reality of the situation.

wjw33 Will
wjw33 Will


If the sun, wind, and water belong to the people then is it un-American to consider nationalizing coal, NG, and oil?  Really, does it belong to one company NOW and not generations in this great nation?  No, I don't have a shovel...and I use lights...and drive a car...and appreciate innovative entrepreneurship but when is the earth ours for generations and not just yours, now?


Citizen USA

Harry Bryant
Harry Bryant

How utterly hypocritical is this.  We're saying coal is too dirty for us (in so many ways) but it's OK for the rest of the world as long as the price is right.  We should be transitioning from fossil fuels as fast as possible... starting with coal.  All exports should be banned or made prohibitively expensive with a tax/tariff  which would be applied to development of clean energy.  The fact is that while our own transition to clean energy continues we will need dirty fossil fuels to facilitate that transition.  We should make sure that during that period the fossil fuels are used here at home.

Corbin Holland
Corbin Holland

Explain the physics and chemistry that you speak of please because the engineers in Germany, India, and around the world will disagree with you. All of these multi-billion dollar firms with some of the smartest engineers in the world have this crazy idea that we can generate electricity without greenhouse emissions.   Nations like Iceland that are 100% renewable are trying to figure out what to do with the excess energy. The United States is not as small as Iceland so the amount of energy the nation needs will be greater so converting to a carbon free way of generation will take us more time than smaller nations like Iceland or Denmark, but it will happen. Natural gas is a great way to get cheap energy with lower emissions and will help the United States in the near future. After what happened in Japan, people will not want nuclear energy and it will lose public support until the technology for it is safer. Wind accounted for more than half of the new generating capacity that came online last year. I am going have to disagree with you and your outdated ideas on generating electricity. Have you ever heard of distributed generation? You will.

John C.
John C.

@wjw33 Will

One reason is that countries that have nationalized their resources in the past drove out the private companies that were able to extract those resources effectively resulting in an economic disaster. Nationalization, meaning letting government beauracrats play businessman, never works.

Nate Whilk
Nate Whilk

No matter what the problem is, it's always the USA's fault. Typical.

@Harry Bryant "All exports should be banned or made prohibitively expensive with a tax/tariff  which would be applied to development of clean energy."

If they're made "prohibitively expensive", not only will there not be any buyers, there won't be any taxes collected. In addition, the money we've spent on "clean energy"-- such as the one-half billion dollars of OUR money Obama threw away to Solyndra, for example--has wound up going only to the guys at the top. The government is a lousy venture capitalist.

I suggest you think more about your comments before you post them.

Corbin Holland
Corbin Holland

I do not like the emissions that coal makes, but I am also not going to deny a higher quality of life for developing nations who are going to buy it. Exporting coal provides the United States with jobs and we are exporting goods. Last time I checked we were in horrible debt and were importing more goods than we were exporting. If you really want to help the world, use dollars to do it. People feeling good about themselves is not going to trump putting food on the table for their family. Why don't we push for a world wide carbon tax instead of trade barriers that will only hurt jobs in the United States.


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