Suck it up: an unorthodox climate solution

A machine to capture CO2 from the air

Nothing anyone is doing has accomplished anything meaningful to prevent climate change.

Sorry to be so blunt about it, but it’s true. Greenhouse gas emissions keep rising, hitting record levels despite the CFL bulb, the Prius, EcoMagination, solar and wind power,  the EU’s carbon-trading scheme, etc.  Nice tries don’t matter to the atmosphere.

The only thing that’s curbed carbon dioxide pollution on a scale that’s meaningful is the global recession.

This is why—unless and until scientists discover a breakthrough in clean energy or political leaders impose a global fossil-fuel tax or carbon emissions cap—we need to thing seriously about geoengineering.

A good place to start is with a recent report from the GAO, Congress’s research arm, called Climate Engineering: Technical Status, Future Directors and Potential Responses. It offers solid information and glimmers of optimism for those of us looking for a way out of the climate crisis.

Regular readers of this blog know that I’m fascinated with geoengineering, a term used to describe a variety of large-scale interventions in the earth’s climate. In particularly, I’m intrigued by efforts to directly capture carbon dioxide from the air. I’ve written about several startup companies that are working on carbon dioxide removal technology, aka CDR. [See Kilimanjaro Energy: towering ambitions, A global thermostat?, Is geoengineering ready for prime time?]

The 121-page GAO report says no geoengineering technology is even close to being ready to deploy:

Climate engineering technologies are not now an option for addressing global climate change, given our assessment of their maturity, potential effectiveness, cost factors, and potential consequences.

No surprise there. Except for some small-scale studies in Europe, there’s been almost no government research into climate engineering.

The GAO report, which was requested by Congress, rated a half dozen or so technologies on a scale of 1 to 9, measuring Technological Readiness Levels, and rated none higher than 3. A technology with a TRL score lower than 6 is considered immature.

But, the report says,  the technology that’s furthest along is one of the least known: direct air capture, which would chemically scrub CO2 out of the atmosphere:

The highest-scoring CDR technology (at TRL 3) was direct air capture of CO2, which has had laboratory demonstrations using a prototype and field demonstrations of underground sequestration of CO2.

The technology itself works, according to the GAO:

Its fundamental chemistry and processes are well understood and laboratory-scale direct air-capture demonstrations are supported at two universities.

What’s more, once CO2 is pulled out of the air, vast amounts of liquified carbon dioxide can be stored underground, according to the report:

Our interviews with National Energy Technology Laboratory (NETL) engineers revealed that the capacity for sequestering CO2 in deep underground saline formations is vast enough to store essentially all CO2 emissions from coal-fired power plants within the United States.

That’s all encouraging for those who favor more research into direct air capture.

But the report goes on to say, unsurprisingly, that the scientists, engineers and companies working on CDR are a long, long way from being able to suck CO2 out of the air on a scale that matters:

Direct air capture is believed to be decades away from large-scale commercialization. Additionally, for each of the currently proposed CDR technologies, we found that implementation on a scale that could affect global climate change may be impractical, either because vast areas of land would be required or because of inefficient processes, high cost, or unrealistically challenging logistics.

To put it plainly: Carbon capture works in a laboratory, but it may never become a real business.

The challenge facing the carbon-capture industry, such as it is, is figuring out how to drive down costs to a point where makes business sense to pull CO2 from the air and sell it to customers to for a useful purpose. Think of it as recycling CO2, the world’s biggest and most dangerous waste product. Liquid CO2, for example, can be injected into oil fields to pump out hard-to-get oil, a proven technology known as Enhanced Oil Recovery.

The GAO report notes:

Carbon dioxide injection in subsurface geologic formations has been used for decades in enhanced oil recovery (EOR) to extract additional oil from depleted oil reservoirs. EOR’s history has made the overall challenges of the permanent sequestration of fluids well understood.

Yes, the oil would eventually be burned, emitting CO2, but some people calculate that it would be a carbon-neutral or even carbon-negative fossil fuel, depending on how much CO2 was stored in the process.

Today, direct air capture of CO2 is too expensive to make recycling carbon practical. Estimates of the costs vary widely, from $27 to $135 per ton of CO2 removed in one study cited by the GAO to $420-$630 in another. A global carbon market, in theory, could help finance direct air capture.

But a small group of scientists and entrepreneurs aren’t waiting around. The photo above? That’s a prototype of an air capture machine being designed by Carbon Engineering, a Calgary, Alberta, startup founded and led by climate scientist David Keith.

Remember, it’s will take decades to bring this technology to scale. So the time to get started is now.



  1. David Lewis says

    Capturing Carbon, by Robin Mills, is the best book currently available on Carbon Capture and Storage. It has a review of air capture technologies and developments.

    To start with however, Mills points out that it is far cheaper to capture carbon when it is still failrly concentrated, for instance as in fossil fuel fired power plant exhaust. He dismisses the idea that renewables and pro nuclear advocates have that even capturing CO2 from concentrated sources like this will never be employed because it is too expensive. He quotes Stephen Chu: “Energy efficiency is the lowest cost solution, but CCS is not far behind”.

    In stark contrast to all those who say CCS is decades away, recent reports indicate we could be capturing coal plant exhaust right now at full scale. CEO of American Electric Power Mike Morris says he cancelled plans to immmediatly start to build a full scale coal fired power plant, the Mountaineer, in Virginia, that captures 90% of its CO2 only because his regulator will not allow his company to pass the modest extra cost on to its customers because of the failure of Congress to put a price on CO2 emissions by passing climate legislation. Morris states in the interview that adding CCS with the technology he has today would tack on 2 cents a kWhr to the cost of electricity.

    Getting back to Mills. He sees air capture as a way to compensate for small and dispersed CO2 sources such as cars, planes and residential heaters in a carbon constrained world. Quoting from page 82, Capturing Carbon:

    “Indirect [AIR] capture is therefore the ultimate backstop for climate policy. Storage capacity permitting, we can, at cost in money and energy, remove any quantity of carbon dioxide from the atmosphere. This may be crucial if we discover that we are on the path to sudden, catastrophic climate change. Even if we were to halt all emissions immediately, it would take millennia for the elevated concentration of atmospheric carbon dioxide to be fully absorbed. By contrast, air capture might be able to take us back to pre-industrial levels within some decades. As a ‘geoengineering solution’, it addresses the problem directly, rather than reducing global warming indirectly.”

    Dr. Richard Alley summed up the present state of knowledge of how CO2 has been the biggest factor controlling the planetary temperature since there has been an atmosphere in a 2009 talk at the largest annual gathering of planetary scientists that takes place in the world, i.e. the AGU at San Francisco. He was asked about air capture in the Q&A after the speech, at minute 51:20: . “The question is really one of economics. Can you make it go fast enough at an energetically low enough cost…. There’s a lot of possibilities…. There are good people working on these questions…. There’s optimism, but none of its looking real easy yet. [ shakes his head, looking very skeptical ] I encourage you to check Klaus’s stuff, [ i.e. Klaus Lackner had a booth at that conference ] because that’s indeed interesting, but its probably still easier to keep it out of the air than to take it out with what we have right now. [applause].”

    The question Dr. Alley is answering came at around 51:20 in the speech. The entire speech is on video here:

    Dr. James Hansen has been saying that current estimates of the cost of removing as little as 50 parts per million of CO2 from the atmosphere are around $20 trillion.

    I encourage people to read Capturing Carbon.


  1. […] Suck it up: an unorthodox climate solution-Marc Gunther Blog: Nothing anyone is doing has accomplished anything meaningful to prevent climate change. Sorry to be so blunt about it, but it’s true. Greenhouse gas emissions keep rising, hitting record levels despite the CFL bulb, the Prius, EcoMagination, solar and wind power,  the EU’s carbon-trading scheme, etc.  Nice tries don’t matter to the atmosphere… (more) […]

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