Environmental advocates say they've poked a hole in the popularized belief that capturing and burying CO2 underground is an effective response to the threat of global climate change. Called carbon capture and sequestration (CCS), the CO2 burial process is also known as "clean coal" in industry advertising campaigns.

A new research paper by Friends of the Earth (FOE) Denmark says that governments and institutions have greatly overstated the potential of CCS to curb greenhouse gases and asserts that even if widely deployed, it would only avoid a "small fraction" of global warming emissions from coal-fired power plants by mid-century.

Frequently cited studies by the Paris-based International Energy Agency (IEA) and other organizations declare that a coal facility fitted with CCS would be able to grab 85 to 90 percent of carbon exhaust and store it safely underground by 2020. These reports have bolstered grand claims about the technology's potential to shrink emissions.

But those studies use a faulty approach that offer a limited snapshot of a single coal plant operating during a single year far in the future, argues Palle Bendsen, the main author of the new FOE study.

"When CCS technology is observed over time and across the sectors where it is planned to be applied, it is obvious that CCS cannot deliver," he said.

The FOE research uses IEA scenarios, but in contrast to the agency, it employs a "sectoral as well as a long term approach" to crunch the numbers, Bendsen said.

"The captured emissions are interesting," he wrote in the study, "but it is the emissions to the atmosphere that matters."

His research found that about 11 percent of total coal plant emissions would be avoided over the next 50 years – assuming 40 percent of coal plants have CCS by 2050. That means 90 percent of the emissions expected from the world’s coal plants would still reach the atmosphere.

"I couldn't believe it," Bendsen told SolveClimate of his "very, very surprising" result.

The method he used considers emissions from all coal plants and from "outside the capture process" through 2049. The "outside" factors include greenhouse gases associated with "an energy penalty" – defined as the extra energy that will be used up in the capture process – as well as emissions expelled to build the CCS plants, transport the coal, inject the gases underground and monitor leakages. 

Bendsen, who claims he has been researching CCS for eight years, says the paper is the first of his knowledge to look at the technology's "aggregate effect on the climate system."

A Battle Brews Over CCS Mitigation

According to growing scientific warnings, climate change emissions must peak by 2015 and then decline rapidly to prevent a 2 degree Celsius temperature rise, the level identified as the maximum allowable before catastrophic damage kicks in.

The paper concludes that "CCS cannot deliver significant reductions in time to play a role in the effort of keeping the global temperature increase below 2 degrees Celsius."

In contrast, IEA, in its 2009 "Technology Roadmap for CCS," said that CCS is "essential" to achieve the agency's goal of a 50 percent reduction in global warming emissions by 2050 from 2005 levels.

"CCS is the only technology available to mitigate greenhouse gas (GHG) emissions from large-scale fossil fuel usage in fuel transformation ... If CCS technologies are not available, the overall cost to achieve a 50% reduction in CO2 emissions by 2050 will increase by 70% industry and power generation," the report said.

Jeff Chapman, the chief executive of the Carbon Capture and Storage Association (CCSA), a London-based CCS lobby group, wholeheartedly agrees with IEA.

"We will continue to burn fossil fuels all over the world for many decades to come," Chapman told SolveClimate. The only "practical alternative" to spewing out carbon gases, he added, is to "store the CO2 so deeply underground that it never actually appears in the atmosphere."

Chapman, who said he did not look at the FOE report in detail but was aware of its general conclusions, said "there is no option" but to pursue CCS.

"Anyone who resists the development of carbon capture and storage would be resisting the mitigation of climate change," he said.

But for environmental groups like FOE, the world is in a race against time to prevent severe climate change, and CCS is too immature a technology for that task. In a statement on the study, the organization said "it is impossible to deploy [CCS] early enough."

Still, under an aggressive scenario — where 90 percent of all coal plants get fitted with CCS — FOE admits that 23 percent of global emissions would be avoided by mid-century. The study authors called that possibility highly "unrealistic," though.

Currently, there are four major commercial demonstration CCS plants up and running — two offshore in the North Sea, one onshore in Algeria and another in Canada.

In recent years, several planned projects have been abandoned by governments and industry because of wildly soaring costs. The highly touted FutureGen CCS project in Illinois, for instance, was canceled by the Bush administration in 2008 after costs ballooned from around $950 million to $1.8 billion.

IEA says that 100 CCS plants would have to be operating by 2020, and 3,400 in 2050, to keep warming under 2 degrees. IEA declined comment on the FOE report.

A Hybrid of Science and Politics

Bendsen, who admittedly is not a scientist, said the project started on "intuition."

"We never did any calculations," he said. "I'm not a scientist. I'm just sitting here in Denmark in this very small organization, and I had this observation, and I didn't know what to do about it." FOE Denmark employees work on a volunteer basis.

Bendsen called his paper, which was six months in the making, a "sort of a hybrid" of science and politics. No scientist has "signed up" to the results, he said, but those who have seen it have "all said, 'Yeah, it's probably correct.'"

In particular, Palle pointed out Sivan Katha, a senior scientist at the Stockholm Environment Institute's U.S. Center, and Philip Vergragt, a senior associate at the Tellus Institute, a research and advocacy group based in Boston, as having given their tacit acceptance of the paper. Neither Katha nor Vergragt returned comment requests to verify that claim.

Still, while not peer reviewed, Bendsen said he is certain the basic science underpinning his paper his sound.

"What we want is to challenge the CCS lobby and all these institutions and organizations that support CCS to come up and prove we're wrong," Bendsen said.  "And I'm quite sure it will be very difficult for them."

See also:

Coal Barons Urge Capitol Hill: No Carbon Regulation Until CCS Is in Place

Obama: The Making of a Clean Coal President

CCS: A Piece of the Puzzle

Will West Virgina's CCS Demo Make a Dent in 'Clean Coal's Problems?

Coal Mine Where 25 Died Had Been Fined Repeatedly for Safety Violations

British Progress Toward Carbon Capture and Storage Drags

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