Memorandum 166
Submission from Professor Klaus S Lackner,
Columbia University
Stabilizing the concentration of carbon dioxide
in the atmosphere requires dramatic reductions in worldwide emissions.
At the same time, a growing world population striving for a higher
standard of living will demand more energy, which today is the
major source of carbon dioxide emissions. Stabilization under
a scenario of economic growth can only be achieved through a transition
to a carbon neutral energy infrastructure. Worldwide emission
reductions by roughly a factor of three, which is required to
even approach a stabilization regime, simply cannot be achieved
by efficiency improvement and lowered consumption.
Thus, much effort must focus on replacing fossil
fuels, and on developing means of capturing carbon dioxide and
storing it safely and permanently. The demand for storage could
reach between ten and a hundred billion tons of carbon dioxide
annually. This should be compared to the present fossil fuel related
carbon dioxide emissions of twenty five billion tons of carbon
dioxide per year, or several thousand billion tons over the course
of a century. Surely the storage of such vast quantities, comparable
in size to the amount of water in Lake Michigan, represents a
form of geo-engineering.
About half of all carbon dioxide emissions are
from small and distributed sources where collection at the point
of emission would be difficult. We argue that the easiest way
of compensating for these emissions is to capture an equal amount
of carbon dioxide directly from the air. In the press, this approach
has also been called geo-engineering because it actively manages
the global anthropogenic carbon cycle. However, it should also
be seen as the logical extension of capture at the point of combustion.
Here we want to contrast such carbon cycle management with albedo
engineering efforts that try to counter greenhouse warming with
active efforts of cooling the planet.
The problem of fossil fuels is the mobilization
of carbon. Climate change is only one of several consequences.
At present the public focus may be exclusively on global warming,
but as the global mobile carbon pool increases other impacts like
ocean acidification will become more pressing. Any effort that
allows the unfettered rise in atmospheric carbon dioxide concentrations
in the end is doomed to fail. The simple and direct solution to
climate change and other consequences of carbon dioxide release
is to prevent the run-away buildup of mobile carbon, ie, the buildup
of carbon dioxide in the atmosphere. Carbon dioxide capture and
storage, at the power plant and directly from the air, either
avoid emissions or compensate for emissions that have already
happened, or are about to happen in the near future. By contrast,
albedo engineering, through sulfates, through cloud generation,
through space based solar reflectors only cure a symptom. While
they can slow down warming, they do not address the root cause,
which is a continuously growing mobile carbon pool that threatens
to destabilize the world's ecosystems through warming, through
changes in the hydrological cycle, through eutrophication of eco-systems
and through acidification of natural water bodies. Albedo engineering
will not stop us from breaching 1000 ppm of carbon dioxide in
the atmosphere within the next hundred years; carbon dioxide capture
and storage will.
Carbon dioxide capture and storage requires
three important technologies: the capture of carbon dioxide at
large sources like power plants, steel plants and cement plants;
the capture of carbon dioxide from the air; and the safe and permanent
disposal of carbon dioxide in geological formations or other permanent
sinks. Capture at central sources is certainly feasible. It has
been demonstrated and once it has been made mandatory, its cost
will come down through practice and learning.
Storage of carbon dioxide in geological formations
is already feasible. In addition to this well understood technology,
there are a number of options with more permanence, larger capacity,
and easier accounting. Usually these methods suffer from a higher
price. As an example I point to the formation of mineral carbonates,
which I have championed for nearly 15 years. Taken together all
these methods leave no doubt in my mind that the world can store
all the carbon dioxide mankind could ever produce, as long as
there is the political will to do so. Cost will come down and
capacity for storage is virtually unlimited.
Finally, I have been involved for the last nine
years in an effort to develop the means of capturing carbon dioxide
directly from the air. Some refer to this effort as the creation
of synthetic trees. Just like a tractor is more powerful than
a horse when it comes to plowing a field, these synthetic trees
are about a thousand times faster in collecting carbon dioxide
from the wind passing over them than their natural counterparts.
Thanks to work I have been involved in with a small company, this
technology is now ready to move toward the first air capture parks.
As Altamont Pass in California provided a first demonstration
of serious wind energy, I believe an air capture park for carbon
dioxide could demonstrate to the world that this technology offers
real promise. Air capture would become the carbon dioxide collector
of last resort, in that it would collect all carbon dioxide which
is not amenable to capture at the point of emission. This includes
but is not limited to the carbon dioxide from air plane engines,
from the tail pipes of cars, and potentially the carbon dioxide
from old power plants unsuitable for cost effective retrofits.
We believe that air capture could compete with power plant retrofits
and could collect the carbon dioxide from a litre of gasoline
at a price that is dwarfed by gasoline taxes. We expect to move
rapidly from an initial price of 20 pence a litre to ultimately
less than three pence a litre.
Ultimately, carbon dioxide capture and storage
makes it possible to put a price on carbon at the source. What
needs to be controlled is the mobilization of carbon, which happens
the moment carbon is extracted from the ground. For national or
regional implementation one should also charge for imports of
raw carbon. A cap and trade system, or a carbon tax that acts
on the extraction of carbon and on imports of carbon fuels is
far simpler than current cap and trade devices, as the number
of companies that need to be controlled is greatly reduced, and
their carbon production is already carefully monitored. Moreover,
such a carbon trading scheme would affect all industries equally
and not distinguish between large and small emitters, between
mobile or stationary sources. 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 carbon pool. A coal, gas or oil company
would have to create or purchase certificates of sequestration
that cancel out the mobilization of fresh carbon. Obviously there
is a transition time in which mobilization and sequestration cannot
be fully matched, but at the end of this transition the economy
becomes carbon neutral.
It is thus possible to achieve a worldwide transition
from a fossil fuel economy that smothers the world in excess mobile
carbon to one that is carbon stabilized. Air capture could play
a crucial role as it can compensate for emissions from the transportation
sector. Air capture can also remove excess carbon that has already
accumulated in the environment. It separates sources and sinks
in time and space. Very importantly, air capture makes it possible
for the transportation sector to keep relying on efficient liquid
hydrocarbon fuels. These fuels could be produced from fossil energy
resources like oil, gas or coal, but even if these fuels were
made synthetically with input of renewable energy, the carbon
dioxide emissions from a vehicle would still have to be recaptured
as otherwise they would still accumulate in the atmosphere. In
all cases, air capture technology can truly close to the anthropogenic
carbon cycle. It is an enabling technology that, if successfully
demonstrated, removes the largest obstacle on the path toward
sustainable energy supplies.
November 2008
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