Environmental Engineering Reference
In-Depth Information
to the shore as possible. Potential sites are as follows:
Americas
•
Hudson Canyon, Delaware Canyon, and Hatteras Canyon
•
Mississippi Canyon
•
Baja California Trench, Monterey Canyon, and Columbia River Canyon
•
Several canyons along the coast of Mexico toward the Gulf of Mexico and the Pacific
•
Along the west and east coasts of South America
Europe
•
Outflow of the Mediterranean Sea at Gibraltar
•
Canyons along the coast of Portugal and the Bay of Biscayne
•
Coast of Norway
•
From western Scotland and Ireland over the Hebridian Shelf into several canyons
Asia, Australia, and Oceania
•
Several canyons from the coast of India into the Arabian Sea and Bay of Bengal
•
Several canyons from the coast of China into the South China Sea
•
Japan is surrounded with the deepest trenches in the world
•
Canyons leading to the Japan Abyssal Plain from Korea and eastern Siberia
•
Canyons along the southeastern coast of Australia
•
Trenches along the Philippine and Indonesian islands
Altogether the access to the deeper layers of the ocean from industrial-urbanized continents is
quite limited. For example, the industrial countries of central and eastern Europe are too far from
the deep ocean. Because overland pipelines would be even more expensive to lay than underwater
pipes, it is unlikely that power plants in those countries would utilize ocean sequestration. The
same is true for power plants in the midwestern United States and central Canada. It is conceivable,
though, that new power plants will be built along the coasts of continents where access is available
to the deep ocean. From these plants,
electricity
can be transmitted deeper into the continents,
because it is cheaper to transmit electricity in cables than to transport
carbon dioxide
in pipes
overland. Nevertheless, the deep ocean will be accessible to only a limited number of power plants;
therefore, ocean sequestration can be only one of several options to be employed in the amelioration
of the greenhouse effect.
Apart from the technical and geographical problems, there is a concern about the environmental
impact of deep sea sequestration of CO
2
. Even though CO
2
is not toxic, large-scale injection of
CO
2
into the deep ocean would create localized regions of high carbonic acid concentrations. It is
estimated that the discharge of CO
2
from ten 500-MW coal-fired power plants will create a volume
of 100 km
3
in which the pH is less than 7. In that volume, fish and other creatures must either
escape or die. However, the impacted regions would be minuscule in comparison to the world's
ocean volume. Nevertheless, there is a general public opposition to disposing of anything in the
ocean, so it is not clear whether an international agreement on ocean sequestration of CO
2
can be
forged.
