Michael Economides and Christine Ehlig-Economides recently published a paper, which according to them contained a revelation. The world's scientists had got geological storage of carbon dioxide (GS) all wrong. The paper asserts that its implications "are profound" and concludes that GS is "a profoundly non-feasible option for the management of CO2 emissions". What is even more profound is the unanimity in which scientists, research bodies and stakeholders around the world have refuted the claims made by the paper.
Michael Economides, a compatriot of mine, is no stranger to limelight. An active blogger on energy matters, he also admits to being something of a climate change skeptic. He is featured in Sen. James Inhofe's (a radical Oklahoma senator who famously called climate change "the greatest hoax ever perpetrated on the American people") list of 400 scientists who question climate change. He has questioned green jobs, while claiming that drilling will transform the economy, "positioning our nation for a cleaner, more secure energy future". His wife, Christine Ehlig-Economides is a respected petroleum engineer and professor in Texas.
It is obvious that neither of them are strangers to the oil industry and storing fluids in the subsurface. However, this time they simply got it wrong. Quick to rebut their claims were the European Technology Platform for Zero Emission Fossil Fuel Power Plants (ZEP), Pacific Northwest National Laboratory, Lawrence Berkeley National Laboratory, Edinburgh University, Imperial College and the American Petroleum Institute (links to rebuttal documents included).
Here are some excerpts from these documents:
"We consider this to be a serious misrepresentation of the scientific, engineering and operational facts surrounding CCS" [ZEP]
"From this narrow analysis, the authors make sweeping conclusions that are not relevant to the general feasibility of CCS." [LBNL]
"The conclusions asserted by the Ehlig-Economides and Economides paper are flawed and stand in stark contrast to the enormous body of literature and field experience on CO2 injection and storage in the subsurface." [PNNL]
"This paper includes a number of mis-statements and erroneous base assumptions which could lead readers to arrive at inappropriate conclusions regarding the role that CCS can play in addressing CO2 emissions" [API]
The rebuttal documents are united in pointing out the basic flaws of the Economides' analysis (WRI has also posted a response here):
- The availability of storage reservoirs is far greater than assumed (the authors, for example, rule out outcropping aquifers and "open" reservoirs, when both types are capable of secure storage);
- Many reservoirs are thicker that the authors assume;
- The assumed storage efficiency (or the % of pore space that the injected CO2 will occupy) is very low;
- Dissolution of CO2 is not as slow as is assumed.
It also turns out that when more realistic assumptions are plugged into the Economides' calculations, the conclusions are very different, indicating that, for example, the Mt. Simon formation in the Illinois basin alone could store around 16 billion tons of CO2 - roughly double the amount of U.S. annual emissions today, and representative of some estimates for how much mitigation would come from CCS alone by 2050.
The couple also go so far as to call into question the success of established CCS projects like Sleipner, with scant justification. Even though it is not the first time this happens, these claims are unjustified as I explain here.
One has to wonder how they expected a paper as flawed as this this to withstand scientific scrutiny, or what the motivation behind its publication is. Once again, and as was the case for climate change, the IPCC's conclusions stand intact: the world is likely to have sufficient storage capacity for decades to centuries worth of emissions.
Let's hope that the transition to a truly sustainable energy system will not take that long, obviating the need for CCS. But for now a pressing climate problem calls for its deployment alongside other solutions.