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12.8 CO 2 Storage 387

Fig. 12.11 CO 2 density
versus ocean depth

the capping sea water due to ocean turbulence. This vertical mixing results in
certain amount of CO 2 dissolution. Undisturbed CO 2 lake is expected to have a
lifetime of about 10,000 years.

12.8.5 Ecosystem Storage

Like extraterrestrial oceans, terrestrial ecosystems have been an important and long-
lasting natural CO 2 sink by photosynthetic reactions in biomass and complex
interactions with soils. Unfortunately, recent human activities have reduced its CO 2
storage capacity resulting in increased atmospheric CO 2 concentration. Before the
availability of other cost-effective options, ecosystem CO 2 storage is deemed to
have a potential to buy human more time and slow down the negative impact of
increasing anthropogenic CO 2 emissions.
While the CO 2 storage capacity of terrestrial ecosystems is much less than that of
the ocean, it is easy to operate and cost-effective. Ecosystem carbon storage can be
achieved by

• Agricultural carbon storage
• Change in land use
• Energy crops production.

12.8.5.1 Agricultural Carbon Storage

Agricultural carbon storage is an approach to additional CO 2 storage in biomass by
improved management of vegetation and soil in the ecosystem. Specifically, it can