Carbon flux in the United
States
Biogeochemistry
September 26, 2005
Group A
Dr. Myron Mitchell
Discussion of Research
History and Relevance of subject
Major points of literature
Unanswered questions
Research topics for future
History of Carbon importance
Importance of carbon for atomospheric
systems
Svante Arrhenius figured industrial inputs could lead to a warming
trend
"On the Influence of Carbonic Acid in the Air upon the
Temperature of the Ground“
Philosophical Magazine 41, 237 (1896)

Hogbom & Arrhenius discovered anthropengic additions equal to
that of natural processes
Was not worried based on current industrial inputs of CO2
 Statements were refuted by colleagues
The 1930’s &40’s
Many theories emerging in relation to CO2
additions
 Hilburt(1931)
 Simpson (1937)
 Hutchinson (1948)

“"The self-regulating mechanisms of the carbon cycle can cope with the
present influx of carbon of fossil origin."
1950’s and 60’s
Began to have wider recognition of CO2
importance
Books published increasing public
awareness



Silent Spring by Rachel Carson
The Genesis Strategy: Climate and Global Survival by Stephen Schneider
The Cooling by Bryson
Seminal work of Keeling (1960)
Mauna Loa CO2 Measurements from 1958 to
2002
Congress increasingly aware



NEPA (1969)
RCRA(1976)
Clean Water Act (1977)
1980’s to today
Ice cores and Ecosystem studies
 demonstrate rise in CO2 levels
 Genthon et al. (1985)
Schimel (2000)
Relevance
CO2 issue actively researched in
multiple fields
Necessary for understanding and
prediction of global trends
Major Points
Authors address global and regional changes
Specific numbers for carbon pools by authors
Authors generate numbers using numbers of
harvestable forest land and models
Major points
Need for Standard Metric for obtaining and
analyzing data
Some sinks could become sources
Various biogeochem cycles affect eachother
 Nitrogen deposition is not a cause of
increased carbon assimilation
Unanswered Questions and
Weaknesses
Issues of measuring carbon: all authors
have different numbers and criteria
Very little discussion of how to address
problem
Exactly where is the sink, and does its
location matter
Unanswered Questions and
Weaknesses
Pacala et al. give carbon sink as
0.30 – 0.58 Pg C/year
Field and Fung estimate carbon sink of
2 Pg C/year
Unanswered Questions and
Weaknesses
12.7 Pg C Live Vegetation in Forested
Land for Coterminous US, Goodale et al.
600 – 1000 Gt (544 – 907 Pg) Living
biomass in Terrestrial biosphere for the
major reservoirs on Earth, Falkoski et al.
Unanswered Questions and
Weaknesses
Unanswered Questions and
Weaknesses
Little consideration of Oceans
No consideration of grass lands
Data used was incomplete
Accuracy of models
Unanswered Questions and
Weaknesses
Carbon flux in Southern Hemisphere
Need more current data
Need to form a global model to see net
fluxes
Research Topics
To what degree are other
biogeochemical cycles interrelated?
The role of nitrogen deposition needs to
be further elucidated in grasslands and
estuarine communities.
Relation to fire ecology?
How do the slash and burn policy in
tropics effect this cycle?
Research Topics
Break regions down and get a more accurate
budget of carbon for specific areas.
Southern hemisphere – South America,
Africa, India, South Pacific, Australia
More research on plant physiology over time stomatal decreases?
Aquatic species could be indicators of how
much CO2 the oceans are absorbing
Will land use trends continue?
Works cited
Hulburt, E.O. (1931). "The Temperature of the Lower Atmosphere of the
Earth." Physical Review 38: 1876-90.
Hutchinson, G.N. (1948). "Circular Causal Systems in Ecology." Annals of the
New York Academy of Sciences 50: 221-46.
Keeling, Charles D. (1960). "The Concentration and Isotopic Abundances of
Carbon Dioxide in the Atmosphere." Tellus 12: 200-203.
Simpson, George C. (1937). "Ice Ages." Proceedings of the Royal Institution of
Great Britain 30: 125-142
Genthon et al, Vostok ice core: climatic response to CO2 and orbital
forcing changes over the last climatic cycle. Nature 329, 414 - 418 (01
October 1987
http://chimie.scola.acparis.fr/sitedechimie/hist_chi/text_origin/arrhenius/Arrhenius2.htm