Page 268 - James Rodger Fleming - Fixing the sky

dioxide, and they return oxygen to the atmosphere. Unlike Lackner forests, trees
also provide shade, habitat, and food for squirrels, birds, and other living things.
Although Lackner says he is not a geoengineer, but merely interested in compen-
sating for current emissions, he envisions his devices being enlisted in the “fight
70
against climate change.” others hope someday to attain negative global carbon
dioxide emissions, but this would entail immense storage problems, similar to
nuclear waste disposal. 71
Lackner has built a demonstration unit in which a filter filled with caustic and
energy-intensive sodium hydroxide can absorb the carbon dioxide output of a
single car. He admits, however, that this system is not safe or practical, so he is cur-
rently looking into proprietary “ion-exchange resins” with undisclosed energetic
and environmental properties. of course, the capture, cooling, liquefaction, and
pumping of 30 billion tons of atmospheric carbon dioxide would require an astro-
nomical amount of energy and infrastructure, and it is not at all certain that the
Earth has the capacity for safe long-term storage of such a large amount of carbon.
Let us look briefly at the chemical energetics that make air capture of carbon
and its sequestration (CCS) such a non-starter (with the possible exception of
selected local sites, such as North Sea oil rigs, where pumping carbon dioxide
back into the wells makes more sense than venting it). First there is the mass
problem. Combustion of coal (mainly carbon-12) results in carbon dioxide waste
products of molecular weight 44. Thus a mole of carbon burned yields energy,
plus a mole of carbon dioxide waste, a mass gain of 267 percent. Lackner did not
acknowledge this mass problem when he wrote, “Ultimately carbon extraction
must be matched by carbon dioxide capture and storage. For every ton of carbon
pulled from the ground, another ton of carbon must be taken out of the mobile
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carbon pool” (emphasis added). In actuality, for every ton of carbon used, 3.67
tons of carbon dioxide have to be captured and stored. There are other problems
as well. Liquefying such a huge amount of Co requires immense pressures, on
2
the order of 80 to 100 atmospheres. We are still not done, since the liquid Co
2
must be piped to injection sites. Imagine all the pipelines needed for the pipe
dream of erecting 3 million large Lackner towers worldwide, or up to 100 million
smaller, container-size units.
The image of a Lackner tower, resembling a huge flyswatter, was superimposed
over New York’s Central Park in a photomontage created by a Canadian film
company. Left unmentioned was the fact that Manhattan alone would require
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hundreds of these scrubbers for its resident population of 1.5 million people (not
counting visitors), so about one in every ten large structures in the city would
resemble a giant flyswatter. The cost of the land to build them, energy to run
them, piping to drain them, and makeup and maintenance of their “idealized”

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