In an ad produced by the American Coalition for Clean Coal Electricity, a coal industry group, then-candidate Barack Obama tells a cheering crowd that he wants to create new clean energy jobs with clean coal technology. "Yes we can," the crowd chants.
Rival organization the Reality Coalition, made up of environmental groups such as the Sierra Club and the National Wildlife Foundation, produced a spot with a mock salesman touting clean coal technology as he sprays an aerosol can of soot inside a family's home.
The public relations battle is the face of an ongoing debate among environmentalists, the government and the coal industry about how to contend with the massive amounts of carbon dioxide emitted into the atmosphere by coal-burning power plants.
According to the Department of Energy, coal-fired power plants produce 49 percent of U.S. electricity -- the largest of any source - and that trend is expected to continue into 2030.
On April 17, the Obama administration's Environmental Protection Agency took a major step toward regulating carbon dioxide -- the gas produced from burning fossil fuels and a primary contributor to global warming. It ruled that the gas was a pollutant, which under the Clean Air Act, means the agency has a responsibility to take action.
Companies running coal plants face a significant challenge: with more regulation likely on the way, what will they do with the tons of carbon dioxide created during the coal-burning process?
That's where the disputed term "clean coal" comes in. The coal industry tends to consider anything that reduces pollutants from burning coal as a clean coal technology. In 1990, the federal Clean Air Act forced coal plants to reduce emissions of sulfur and other pollutants, so they installed "scrubbers" to remove them before they reach the atmosphere.
The current debate over clean coal technology centers on carbon capture and storage technology, or CCS, which is sometimes interchanged with the term "clean coal," as a way to comply with carbon regulation.
Critics, such as the Reality Coalition, argue that clean coal technology doesn't actually exist and criticize the environmental costs of continued reliance on coal energy when the government can focus on renewable energy sources such as wind and solar.
"When coal is mined, it destroys the land and surrounding communities. When coal is washed it produces millions of tons a year of toxic, water-polluting slurry," David Roberts, a senior writer for the environmental news blog Grist, recently told the PBS program NOW.
"Not a single commercial coal power plant in America captures or otherwise prevents CO2 emissions. 'Clean coal' is a PR gimmick," he said.
President Obama supported clean coal funding while he was a U.S. senator and touted its usefulness during his presidential campaign. "We could invest in renewable sources of energy and in clean coal technology and create up to 5 million new green jobs in the bargain, including new clean coal jobs," Obama told a campaign crowd in Charleston, W.Va., in April 2008, according to the AP.
The president's $787 billion economic stimulus bill also includes $3.4 billion to help improve the technology.
The process starts with integrated gasification combined cycle, or IGCG, as coal is turned into a gas before it is burned to create energy. From this gas, carbon dioxide and mercury can be removed. If the carbon dioxide is stored deep underground, it won't escape into the atmosphere and trap heat -- otherwise known as global warming.
While this technology exists in individual parts, a complete carbon capture and sequestration process has never been implemented in a commercial power plant, according to Kelly Gallagher, director of the Energy Technology Innovation Policy research group at Harvard University's Belfer Center for Science and International Affairs.
"It is fair to say there is quite a lot of experience in both capture and storage. What we haven't done very much of, and that is, in the world, is integrating the whole thing: an intergraded plant that captures carbon and permanently stores CO2," she said.
American Coalition for Clean Coal Electricity vice president Joe Lucas praised the Obama administration's financial commitment to developing CCS technology and said that government assistance is necessary to make carbon capture and storage a viable commercial technology.
Lucas said that politicians and other groups agree that carbon capture and storage technology is necessary to reduce global carbon emissions.
"The number of organizations - the International Panel on Climate Change, the International Energy Agency, MIT, you could even say Vice President Al Gore himself in an 'Inconvenient Truth,' have clearly said you cannot ... you will not be able to succeed in having a successful program to reduce greenhouse gas emissions without these technologies," Lucas said.
The closest the United States has come to a full-scale carbon sequestration and storage plant is the FutureGen project under the Bush administration, which was canceled last year due to its expense. FutureGen was a $1 billion Department of Energy project aimed at demonstrating a full-scale model of the integrated technology. It could be revived, Gallagher says.
Lucas points out that coal power plants in Wisconsin and West Virginia are planning demonstrations soon to prove their ability to capture -- but not store -- at least some carbon dioxide output.
There are several hurdles for carbon capture and storage implementation. Without a carbon tax or cap-and-trade regulatory structure, power companies have no reason to store tons of CO2 under the earth. And, if they were forced to implement these new technologies, CCS could significantly increase the cost of electricity.
Gallagher said it isn't clear whether carbon capture and storage technology would significantly increase energy costs in the long run because the technology hasn't been implemented, although the first few plants would probably produce more expensive electricity.
For example, Gallagher said the carbon capture process increases the amount of energy used in a coal power plant by as much as 25 percent.
Aside from the technological hurdles, the Obama administration and Congress will need to decide how to regulate carbon, which would create a market for carbon capture, as coal power plants would find it in their interest to trap carbon dioxide in the ground.
Gallagher said that what is needed is either a tax on carbon or a carbon cap and trade system, where carbon emissions are capped and companies can trade credits to allow them to exceed the limit.
"I think (people in the Obama administration) get it. They get how important the carbon capture and storage technologies will be to climate mitigation and that we need to see if they work at large scale, given how heavily reliant the United States is on coal," Gallagher said. "I think we will have a much more clear picture of their intentions when the (federal) budget comes out."