Dear list=20
I'd like to stress one important point on Carbon sequestration
Earth, neglecting radiocarbon cosmogenic formation, can be considered a
closed system for CThis means that Carbon in the earth is constant, =
was
formed during the nucleosynthesis and entered in the earth during the =
planet
formation... Carbon can be allocated is several environmental =
compartments
which exchange carbon at different timescales creating the C cycle. =
Usually,
according to these timescales, C cycle can be split in biogeochemical
(mainly composed by oceans, atmospheric and terrestrial C reservoirs =
which
cycles on timescales comparable to the man life) and geochemical cycle.
Anthropogenic actions acting on short timescales (CO2 is rising since =
the
industrial era) are altering the biogeochemical cycle fastening the =
release
of CO2 (fossil fuel burning) from a reservoir (fossil reservoir) which =
can
be considered part of the geochemical cycle.=20
Oceans, sequestering CO2 by means of a chemo-physical mechanism (Henry =
law),
and terrestrial ecosystems (sequestering carbon via photosynthesis) are
acting as a buffer (atmospheric increase of CO2 is lower than CO2 =
release
from fossil fuel burning) for anthropogenic emissions, both SEQUESTERING =
CO2
with long release timesWhile Oceans response can be predicted and =
its
timescale quantified terrestrial response, because of the complex =
mechanisms
determining the exchange, is more difficult to be predicted and =
timescale
quantified
-Messaggio originale-
Da: Ecological Society of America: grants, jobs, news
[mailto:[EMAIL PROTECTED] Per conto di Christopher A. Farmer
Inviato: mercoled=EC 7 marzo 2007 22.32
A: ECOLOG-L@LISTSERV.UMD.EDU
Oggetto: Re: carbon sequestration?
Hi All,
I feel that the best way to look at this question is to look at it in =
terms
of the carbon cycle. If we are talking about carbon with respect to =
global
climate change, the exact form of carbon doesn't matter. CO2 in the
atmosphere is what affects radiative forcing, so no matter how that CO2 =
is
taken up, any reduction in CO2 would help lessen the effects of warming.
If you are sequestering carbon in forests and soils, you are talking =
about
the conversion of CO2 into cellulose, lignin and other plant materials =
that
will hopefully remain in that pool for a long time. That is, the forest
needs to remain forest for a long time to actually sequester carbon.
If you are talking about sequestration of carbon in the ocean, you are
looking at two different processes. First, CO2 will be used for cellular
material by algae and other photosynthetic organisms in the water =
column.
When they die, they settle to the ocean bottom and eventually lithify =
(turn
to some kind of sedimentary rock). The other process is a geologic =
process
whereby CO2 is absorbed in clayey materials when silica rich rocks =
(think
granite and sandstone) are weathered. These clays will be transported
downstream and eventually reach the ocean and become sediment.
So I guess the take away point would be that any process which removes =
CO2
from the atmosphere and stores it in a long lived pool/sink could be
considered sequestration.
Hope that helps,
Chris Farmer
--- Christopher Habeck wrote:
Carbon sequestration is the capture and long-term storage of atmospheric =
ca=3D
rbon by terrestrial plants, soils, and the ocean. Christopher =
Habeck=3D20
Zoology Graduate Student=3D20
University of Wisconsin=3D20
> Date: Wed, 7 Mar 2007 10:52:30 -0800> From: [EMAIL PROTECTED]> Subject: =
ca=3D
rbon sequestration?> To: ECOLOG-L@LISTSERV.UMD.EDU> > I'm a bit confused =
ab=3D
out what people mean when they talk about carbon sequestration. In some =
pap=3D
ers it seems to refer to atmoshpheric carbon dioxide uptake, other times =
it=3D
seems to refer to the ability of soils or plants to store carbon. So, =
gene=3D
rally speaking does "carbon sequestration" refer to CO2 or C?> > Sorry =
if t=3D
his is a dumb question, I have no background in this. Thanks in =
advance...>=3D
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--- end of quote ---
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