Geoscience Reference
In-Depth Information
CO
2
would enter the atmosphere) but could pose problems for health
and safety. My favorite option would use gravitational storage in the
deep oceans. If CO
2
is deposited in the deep ocean, the CO
2
would be
heavier than water and would remain there for many centuries.
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At present, CCS faces many hurdles. It is expensive, untested, and
would need to be scaled up to handle tens of billions of tons of CO
2
each
year. We have inadequate data on the performance of underground
storage, and extensive experience is necessary to ensure scientifi c and
public acceptability. People are frightened of the prospect of a huge burp
of CO
2
causing unforeseen damage.
Like many other large-scale and capital-intensive technologies, CCS
is caught in a vicious cycle. Firms will not invest in CCS on a large scale
because it is fi nancially risky; it is fi nancially risky because public accep-
tance is low and there are big hurdles to large-scale deployment; and
public acceptance is low because there is so little experience with CCS at
a large scale. Breaking out of this vicious cycle is a major dilemma for
public policy in this as in other new, large-scale energy systems.
SOME FUTURISTIC TECHNOLOGIES
Other proposals for removal of CO
2
from the atmosphere sound
more like science fi ction than hard-headed engineering. One cute ex-
ample is to grow billions of trees, cut them down, and store them along
with their carbon in some remote location to prevent decomposition.
One variant of this was suggested by the distinguished physicist Free-
man Dyson:
After we have mastered biotechnology, the rules of the climate
game will be radically changed. In a world economy based on bio-
technology, some low-cost and environmentally benign backstop to
carbon emissions is likely to become a reality. . . . [For example,] it
is likely that we shall have “genetically engineered carbon-eating
trees” within twenty years, and almost certainly within fi fty years.
Carbon-eating trees could convert most of the carbon that they ab-
sorb from the atmosphere into some chemically stable form and
bury it underground.
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