The Breakthrough Institute

By Joanna Calabrese, Breakthrough Generation Fellow

Why can't we just suck all of the C02 out of the atmosphere and get it over with? This is a question that people- from elementary school children to top energy researchers-have asked in the pursuit of new climate-solving technologies. Researchers at Columbia University responded with a resounding YES! last year in their unveiling of the world's first successful demonstration of air capture technology.

A new "air extractor" technology presented by Klaus Lackner, a professor of Geophysics at Columbia's Earth Institute, offers something no other carbon capture technology on the drawing board has.

Unlike conventional carbon capture and storage (also known as geosequestration), which absorbs C02 on-site ( ie. the affluent stream of emissions from power plants), air extractors absorb carbon dioxide from any location on the planet. This means that CO2 emissions can be captured from nearly all large-emitting sources-from stationary factories and power plants to cars and planes in motion. Airplane emissions can be captured next to the runway, or China's emissions can be captured on the coasts of Los Angeles! These synthetic trees can "thrive" in any location.

Synthetic trees don't exactly look like your average tree with green leaves and roots. Although the design is not finalized, Lackner predicts that the device would look more like a post with venetian blinds strung across it; a box-shaped extractor raised about 1,000 feet tall, adorned with scaffolding lined with liquid sodium hydroxide (commonly known as lye). When exposed, sodium hydroxide (lye) is an absorbent of CO2. So, as air flows through the venetian blind "leaves of the tree", the sodium hydroxide will bind the CO2, sifting out cleaner, about 70-90% less CO2 concentrated air on the other side. Lackner estimates that an area of sodium hydroxide about the size of a large TV screen (not your massive plasma media center, but a 20 inch diagonal) and a meter in depth, could absorb 20 tons of CO2 a year- the annual emissions of one average American or 15,000 cars. Paired with a windmill, a carbon-capture tree could generate about 3 megawatts of power.

But is it feasible?

The chemical process of using calcium or sodium hydroxide to absorb CO2 has been known for years but the question of whether it can be done in an affordable energy efficient manner has not yet been fully answered. Constructing and erecting the collector device is only 20% of the cost; the remainder of the cost involves prying the CO2 loose from the absorbent and storing it- an energy intensive process. The back of the envelope calculation of total cost supposes $80 to $100 per ton of carbon captured, which is large as compared to the $25-$75 per ton cost that proponents of a carbon tax or cap-and-trade scheme believe will stabilize atmospheric emissions of CO2. It may seem like too steep a cost to closely consider, but Lackner believes "it's worth looking at things that start out even five times too expensive."

Developing Carbon Capture and Storage (CCS)

When the Breakthrough Institute interviewed Lackner earlier this year about his research, he emphasized the importance of developing carbon capture and storage, despite the common concern that CCS, and thus air capture too, will discourage our society from moving to clean energy alternatives.

"Fossil fuels are not running out anytime soon, and if we were to turn all of them into carbon dioxide, we'll have a climate catastrophe. We may run out of oil and gas; you can be skeptical of that. But we won't run out of coal. We either abandon fossil fuels immediately -- within the next 50 years -- or figure out a way to do CCS.

Some people believe that to fix global warming, we have to completely change our lifestyles. But tying lifestyle changes to the carbon dioxide debate will make you fail in both. We can have a long discussion about whether people should change their lifestyles, but if you try to solve the problem this way, people will say, "Go fly a kite, we're not interested." But if I say, "You don't have to change your lifestyle, just give me 25 cents per gallon," I think I can get away with that.

Energy is really a place where more technology is absolutely necessary. The challenge here is about how to have the right public policies to make it happen.

There aren't that many large scale sources of energy could be tapped at the scale the world needs them. Hydro will never be enough, and neither will wind. Solar, nuclear, and fossil could be enough, but they all have flaws. If we don't place big bets on all three, we could find ourselves with none of them working, and we'll have energy crisis of unprecedented proportions".

An article last month in Newsweek thoroughly assessed air capture and carbon capture and storage, concluding that "Curbing Emissions Won't Be Enough".

"As we head toward 450, 550, even 750ppm this century, environmental leaders are getting serious about carbon capture and storage. A 2005 IPCC report concluded that carbon capture and storage "has the potential to reduce overall mitigation costs and increase flexibility" in reducing greenhouse gases. The U.S. Department of Energy is spending $100 million this year for R&D on carbon storage, up from $1 million in 1997.

Existing carbon capture technology can reduce CO2 emissions from coal-fired or natural-gas power plants by 80 to 90 percent, estimates the IPCC. That translates to an extra penny to a nickel per kilowatt hour of electricity (now 3 to 6 cents). But scientists at the National Energy Technology Laboratory in Pittsburgh, the lead DOE center for carbon capture and storage, think they can slash that to an added cost of no more than 10 percent, says Sean Plasynski, who manages the lab's carbon program. Energy efficiency and some renewables are cheaper now, but if the climate begins to tip out of control, then carbon capture and storage can provide a planet-saving insurance policy."

As we've noted several times here at Breakthrough, high tech solutions still early in the developmental phase often have the potential to play a significant role in transforming our national energy system. With continued support for RD&D, Carbon Capture and Storage, in all of its developing varieties - including synthetic air capture - will likely become a new, viable American energy technology.