Atmospheric CO2 data by mass and math... Is this right?

Sorry don't have numbers handy, but I think they should be easy to find, and yours seem about correct. The only hitch might be that growing plants take in CO2 and give "back" O2, essentially absorbing only the carbon (somewhat opposite to animals and human industry which put organic carbon into the air by combining it with O2), whereas oceans absorb both the carbon and oxygen of CO2.

The "aside" is ambiguosly worded.

Edit to David B: Interesting points, but you seem to be talking about flows, whereas the question is really about the changes in stocks, e.g. the net increases in carbon from say 1910 to 2010, in air, in oceans, and in plants (corresponding to the consumption of fossil fuels and other human activities releasing CO2).

Just to get overly specific and build off of what Dook stated, my belief is that biosphere/atmosphere exchange overestimates biosphere carbon uptake.

Most large scale carbon flux estimates come from eddy covariance. These towers are relatively accurate during the day time, however the rely on atmospheric turbulence (eddies) to properly sample gas concentrations. Because wind tends to be low at night, most PM eddy covariance data is discarded as unreliable.

As Dook pointed out plants take-up CO2 and emit O2. However at night, mitochondrial respiration continues in leaves, stems and roots (as well as in soil micro flora) and can put a significant portion of the daytime CO2 uptake, back into the atmosphere.

Anyways, I don't have specific numbers but would venture to guess that roughly 10% of daytime CO2 uptake is replaced throughout the night and thus plant carbon uptake estimates should most likely be scaled back somewhat.

Pat says "Wikipedia gave me an answer on how much 1 tonne of CO2 occupies - 171.88 cubic feet."

That comes out to 5.81 kilos/cubic foot. Air at atmospheric pressure is about .075 lbs/ft3 or .034kg/ft3 according to Wikipedia.

Pat should be more careful in checking math results.

Edit:

http://en.wikipedia.org/wiki/Carbon_dioxide_in_Ear...

"Most sources of CO2 emissions are natural, and are balanced to various degrees by natural CO2 sinks. For example, the natural decay of organic material in forests and grasslands and the action of forest fires results in the release of about 439 gigatonnes of carbon dioxide every year, while new growth entirely counteracts this effect, absorbing 450 gigatonnes per year.[11] Although the initial carbon dioxide in the atmosphere of the young Earth was produced by volcanic activity, modern volcanic activity releases only 130 to 230 megatonnes of carbon dioxide each year,[12] which is less than 1% of the amount released by human activities (at approximately 29,000 megatonnes).[13] These natural sources are nearly balanced by natural sinks, physical and biological processes which remove carbon dioxide from the atmosphere. For example, some is directly removed from the atmosphere by land plants for photosynthesis and it is soluble in water forming carbonic acid. There is a large natural flux of CO2 into and out of the biosphere and oceans.[14] In the pre-industrial era these fluxes were largely in balance. Currently about 57% of human-emitted CO2 is removed by the biosphere and oceans.[15] The ratio of the increase in atmospheric CO2 to emitted CO2 is known as the airborne fraction (Keeling et al., 1995); this varies for short-term averages but is typically about 45% over longer (5 year) periods. Estimated carbon in global terrestrial vegetation increased from approximately 740 billion tons in 1910 to 780 billion tons in 1990.[16]"

It's interesting that the earth naturally releases 439 gigatonnes and takes in 450 gigatonnes yearly. That's 11 billion tons difference and a negative feedback to warmists.

edit:

It's a mathematical fact that a tonne of CO2 takes up 19,643 cubic feet and that it takes 7,493,659.421 tonnes of CO2 to fill a cubic mile. I've had to rework my math. I apologize for the mistake earlier. Sorry!

http://www.icbe.com/carbondatabase/CO2volumecalcul...

Volume of one ton CO2 = 22730moles × 24.47L/mole = 556200L = 556.2m³

556.2 cubic meters converts to 19,643 (rounded up) cubic feet

I'm pretty close to giving you a figure on what 1 trillion tonnes would be if it were still in the atmosphere. I know I screwed up on my math earlier. My bad!

http://answers.yahoo.com/question/index?qid=200608...

I know the available troposphere volume in cubic miles - 7.6 billion cubic kilometers converts to 1,823,336,965.2 cubic miles of troposphere