Sucking CO2 from the Air: A Climate Solution Crazy Enough to Work?

Sucking CO2 from the Air: A Climate Solution Crazy Enough to Work?

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 think 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. [One such device is pictured above.] 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.