Published: February 6, 2018

By Jeff Young

If you think fracking shakes things up, wait until you see Carbon Capture and Storage.

The National Research Council of the National Academy of Sciences just released a study under the mundane title, “Induced Seismicity Potential in Energy Technologies.” The wonky language masks the study’s literally earth-shaking relevance. More simply put, it’s about how our pursuit of energy can trigger earthquakes.

The NRC report confirms what many people living on top of shale gas deposits in Ohio, Arkansas and other places already knew: the wastewater disposal associated with hydro-fracking natural gas can, in rare instances, trigger earthquakes. The report also documents how people living near geothermal energy projects deal with quakes that come along with that form of clean energy.

But the energy technology with the greatest potential to trigger earthquakes is one that many fossil fuel interests see as their best bet to address greenhouse gases: Carbon Capture and Sequestration, or CCS.

In CCS, chemical scrubbers would strip CO2 from the emissions of a power plant. Then the captured CO2 would be pressurized into a liquid state and pumped deep into the earth where it would stay (we hope) instead of adding to climate change in the atmosphere.

I say CCS “would be” doing these things because so far CCS only happens on a demonstration scale. The handful of pilot projects handle only a tiny fraction of the CO2 that would need to be stored if CCS is to have any real mitigating impact on greenhouse gas emissions. And it’s that matter of scale that sets CCS apart in terms of its potential to trigger quakes.

“The difference between Carbon Capture and Sequestration and some of the other technologies we looked at is with CCS we are pushing a fluid down—and potentially very large volumes to get rid of large volumes of CO2,” Colorado School of Mines geology professor Murray Hitzman said. “And we are increasing pressure over very large areas for a very long time.”

Prof. Hitzman chaired the NRC panel that wrote the report, which finds that CCS may have the potential to cause “significant induced seismicity.” Just how much is hard to say. But the report drives home the massive volume we’d need to pump into the earth to make CCS work. As much as 306 million cubic meters of liquefied CO2 could be captured and stored from the world’s coal and natural gas power plants each year. That’s like pumping 120,000 Olympic size swimming pools under the ground.

Hitzman said that even the small-scale CCS demo projects already inject about three times as much liquid as does the average wastewater injection from hydro-fracking. And while the number of noticeable seismic events linked to injection wells is quite low compared to the overall number of wells drilled, the more wells we drill, whether for liquid CO2, wastewater or whatever, the greater the chance of earthquakes.

“It’s a numbers game,” Hitzman said. “The more wastewater wells we have, we undoubtedly will cause more seismic events.”

Prof. Hitzman says it’s a serious concern with CCS and warrants additional research into selecting the proper sites for CO2 storage. And it’s yet another complicating factor for CCS, which is already looking like a monumental task in terms of infrastructure and cost.

Prof. Hitzman will be among the witnesses as the Senate’s Energy committee holds a hearing on the NRC report Tuesday. Here’s hoping the Senators take a good look at the earth-shaking implications of CCS and other energy technologies.

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