Then, in a 2005 report - its most detailed examination of CCS - the IPCC concluded carbon capture at coal plants could provide somewhere between 15 and 54 percent of the emissions reductions needed by 2100.
But most of those reductions aren't expected to happen until the second half of the century. And in its 2007 assessment, the IPCC warned that CCS might not make "important contributions" to climate change mitigation until after 2030, a decade later than previously thought.
Meanwhile, scientific findings have shown things are getting worse.
This March, for example, a collection of scientists reported that many indicators of climate change - surface temperature, sea-level rise, ocean and ice sheet dynamics, ocean acidification, and extreme climatic events - were at or beyond the IPCC's worst-case projections.
"There is a significant risk that many of the trends will accelerate, leading to an increasing risk of abrupt of irreversible climatic shifts," said the report from the Copenhagen Climate Science Congress.
And in May, scientists at the Massachusetts Institute of Technology reported that their most comprehensive modeling shows global temperatures are likely to increase twice as much as they projected just six years before.
"This increases the urgency for significant policy action," said Ronald Primm, director of MIT's Center for Global Change Science.
'Blessed with real estate'
From the roof of the Mountaineer Plant, you can see for miles. And you get a bird's eye view of the huge vacant lot, where AEP had originally planned to build a second generating unit.
Today, it's a good thing that unit was scrapped. If Mountaineer is going to add more CCS units, perhaps enough to scrub all of its CO2 emissions, it needs the space.
"We're blessed with real estate," Spitznogle said during a plant tour in mid-August.
Lack of space could turn out to be one of the most basic problems utilities face. The rule of thumb is that CCS requires a footprint equal to the existing power plant.
"In other words, it is likely that the installation of a system to treat the entire plant flue gas output would double the land space occupied," Spitznogle said. "Some plants can accommodate this requirement, but many plants cannot."
Space is just one of the problems, though, and may not be the most serious.
For example, removing carbon dioxide from the plant's other emissions takes a lot of energy. And that means a lot of cost.
In an October 2008 report, the Union of Concerned Scientists said the current "state-of-the-art" CO2 capture system - using chemical amines to scrub out the gases - takes so much energy that it reduces plant output by one-quarter.
"Stated in other terms, it is like having to build one new coal process for every three to four conventional plants," the report said.
At Mountaineer, AEP is taking another process. It uses chilled ammonia, rather than amines, to strip the carbon dioxide from other plant emissions.
Amine-scrubbing is estimated to increase power costs by 60 to 70 percent. AEP hopes its ammonia process will cost less, but concedes it will still "require significant amounts of energy and therefore result in higher costs for coal-fueled electricity."
In July, Harvard University experts reported that CCS could cost even more than feared - enough to double electricity costs from first-generation plants. Costs would drop as the technology matures, but still amount to an increase of 22 to 55 percent, according to the Harvard report.
In the environmental community, some remain very skeptical of carbon capture and storage. Greenpeace labels the technology a "false hope." Author Richard Heinberg of the Post-Carbon Institute warns that coal supplies might run out before CCS is ready for wide deployment.
Some in the coal industry, led by Massey Energy President Don Blankenship, still argue that global warming is a hoax or a Ponzi scheme.
Last week, 18 of the nation's top scientific organizations wrote to Congress, to repeat previous warnings about global warming.
"Observations throughout the world make it clear that climate change is occurring, and rigorous scientific research demonstrates that the greenhouse gases emitted by human activities are the primary driver," the groups said. "If we are to avoid the most severe impacts of climate change, emissions of greenhouse gases must be dramatically reduced."
For at least two decades, legislative efforts to deal with climate change have failed. Sen. Robert C. Byrd, D-W.Va., led efforts in 1997 to block the Clinton administration from ratifying an international treaty to curb emissions. Shortly after taking office in 2001, President George W. Bush reneged on a campaign pledge to require emissions cuts.
But President Obama supports massive cuts in greenhouse pollution. This summer, the House passed a bill that many scientists and environmental groups support. All three of West Virginia's House members voted against the measure. They said emissions reductions should be delayed, and more CCS funding provided, to help the coal industry.
The United Mine Workers union said the House bill provided a "remarkable" amount of money for CCS, and that, under the bill "the future of coal will be intact."
But the UMW is still pushing for further delays in emissions cuts and more money for CCS.
Political observers list Byrd and Sen. Jay Rockefeller as being on the fence. Both have said they want more done to give coal time to perfect and deploy CCS.
Physicist Joseph Romm, who edits the Climate Progress blog, is skeptical that CCS will be a major part of the solution to climate change.
"But, Romm wrote recently, "I could be wrong, and it's well worth finding out if CCS works."
And, Romm added, "If more money for CCS gets Byrd's vote, at least to block a filibuster ... it's well worth it."