Early Carbon Dioxide
Country: United States
Date: September 2006
The early atmosphere of the Earth was rich in
carbon dioxide. Where did the carbon dioxide go?
The early Earth environment was very good for plants that relied on carbon
dioxide to do photosynthesis. Over time the carbon dioxide was converted to
plant matter and caused the fluorishing of plant life.
Since we learn that atoms are neither created nor destroyed in the
normal course of history, this is an excellent question. The "extra"
atmospheric carbon dioxide has for the most part, been broken down into
carbon and oxygen and incorporated into other things.
The carbon is found in carbonate rocks (limestone, marble, etc.);
organic fossils such as coal, lignite, etc. as well as in living and
recently dead animal and plant tissue.
The oxygen is also found in carbonate rocks and organic matter as well
as oxide minerals such as hematite and, of course in the atmosphere.
This is a short list of where it has "gone". But, since carbon dioxide
is a "greenhouse gas" and contributes to "human induced" global warming,
where it is kept (or sequestered) is currently a very significant
Two mechanisms were probably at work.
1) One can probably assume that CO2 was removed by the same
mechanisms that remove it today, by plants, the oceans,
ice, etc. However, if there weren't as many plants
then as there are now, the increase in plants with time
(including the plants in the ocean) would have provided
an increasing sink for CO2, thereby reducing the
concentration in the air.
2) Volcanic activity, which is a very important source of
CO2, might have decreased with time. Therefore the amount
of CO2 added to the atmosphere may have decreased with time.
David R. Cook
Climate Research Section
Environmental Science Division
Argonne National Laboratory
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Update: June 2012