Overall summary:
There are many ideas for sequestering carbon, these include
storing it in geological formations, pumping it into the ocean (liquid CO2 is
denser than water), injecting it into the seabed, transforming it into
thermodynamically stable minerals, or doing an ‘active earth intervention’ such
as iron fertilization. Dr. Watson talked
us through the pros and cons of these methods, their viability, and his
opinion. Dr. Watson’s message was similar to Dr. Katz’s
– the earth will survive a very high amount of atmospheric carbon, but it’s
doubtful that the current number of
humans can.
Terms
- Iron Fertilization- Spreading iron into the ocean
to increase the population of phytoplankton Phytoplankton blooms remove
CO2 through photosynthesis. This has been tried on the small scale, but
like any ‘active earth intervention’ or ‘geoengineering attempt’, people
are reluctant to try to actively change the environment dramatically to
correct for how we already dramatically changed the environment.
Prevention seems like a safer approach. Nonetheless we may eventually need
this type of interaction. Other ideas such as using space mirrors to reflect
sunlight or putting an anti-greenhouse gas in the atmosphere have also
been proposed
- Acidification- Increased CO2 levels in the
ocean will increase the level of acidity, possibly harming wildlife. Much aquatic life relies on CaCO3
(mollusks, coral, etc.) and higher acidity dissolves this.
- GeologicalCO2 injection- Injecting CO2 into areas
below the earth, sequestering the CO2 into the pockets vacated by oil
drilling. (Long Term Storage)
- Sub-Oceanic Sequestering- Pumping liquid CO2 to the
bottom of the ocean, where it will settle to the bottom and stay in
relative storage, like a giant lake. There are concerns about this because
of ocean acidification, and stability of these giant lakes of CO2
- Sub-sediment storage – pump CO2 below seafloor making
CO2 hydrate. This seems likely to
have the least environmental impact, but issues come up such as who owns
the ocean, who funds this, can we really know the long term environmental
impact?
- Geothermal gradient
- the temperature of the earth increases dramatically as we go down
through the crust. The center of the earth is as hot as the surface of the
sun. At high pressure CO2 is liquid
Eco and Gov
- There are economic costs to all of these solutions, but
almost no short term return.
- This is an international problem, so it’s not easy to assign
or accept responsibility – fiscally or otherwise
- To be successful, there needs to be huge government
initiative and funding.
- Reusing spent oil wells to pump the liquid CO2 into
deep cavities
Connections
- Mimi Katz-Environmental
- Dr. Borton-solar
- Dr. Borton-Environmental
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