Geoscience Reference
In-Depth Information
Atlas should probably be considered an evolving assessment of U.S. reservoir
capacity for CO
2
storage.
35
The total lower estimate (sum of the three reservoir types) from the 2010
Carbon Sequestration Atlas shown in
Table 2
indicates the potential to store
the equivalent of 830 years of CO
2
emissions from electricity generation in the
United States at current emission rates (2.2 billion tons per year). The total
upper estimate indicates the potential for over 9,000 years of CO
2
emissions
from electricity generation.
Table 2. Geological Sequestration Potential for the United States and
Parts of Canada (billion metric tons of CO
2
)
Lower
estimate
Lower
estimate
Upper
estimate
Upper
estimate
R
eservoir
t
ype
(2010)
(2008)
% Change
(2010)
(2008)
% Change
Oil and gas
f
ields
143
138
+3.6%
143
138
+3.6%
Deep saline
f
ormations
1,653
3,297
-50%
20,213
12,618
+60%
Unmineable
c
oal seams
60
157
-62%
117
178
-34%
Totals
1,856
3,592
-48%
20,473
12,934
+58%
Source: 2008 and 2010 Carbon Sequestration Atlases.
D
EEP
O
CEAN
S
EQUESTRATION
The world's oceans contain approximately 50 times the amount of carbon
stored in the atmosphere and nearly 10 times the amount stored in plants and
soils.
36
The oceans today take up—act as a net sink for—approximately 1.7
GtCO
2
per year. About 45% of the CO
2
released from fossil fuel combustion
and land use activities during the 1990s has remained in the atmosphere, while
the remainder has been taken up by the oceans, vegetation, or soils on the land
surface.
37
Without the ocean sink, atmospheric CO
2
concentration would be
increasing more rapidly. Ultimately, the oceans could store more than 90% of
all the carbon released to the atmosphere by human activities, but the process
takes thousands of years.
38
The ocean's capacity to absorb atmospheric CO
2
may change, however, and possibly even decrease in the future.
39
Also, studies
indicate that as more CO
2
enters the ocean from the atmosphere, the surface
waters are becoming more acidic.
40
