Wednesday, December 06, 2006

Where HAS all the CO2 gone.......

Just when you think it can't get more stupic (combining stupid and stupification in a neat package), the denial crowd grubs down into the ditch and finds more. The latest is a couple of papers by two characters from USC civil engineering, L.F. Khilyuk and G. V. Chilingar (K-C), who, in Environmental Geology inquire: "On global forces of nature driving the Earth’s climate. Are humans involved?" Friend Lubos provides a copy for your amusement. This little gem has been taken apart in the same journal by Werner Aeschbach-Hertig (WAH), also available in Lubos land until the copyright police break down the door.

Nexus has a whack at the K-C Pinata, and handed the bat off to Tim Lambert (handy for destroying English bowling too, something the Aussies seem to enjoy lately). Among other things, K-H claim that the amount of CO2 emitted from outgassing during the very early days, is huge, compared to the amount emitted every year by people. Unfortunately, as WAH point out, they forgot to divide the geological emissions by the number of years that it took. When you
do so, the amount emitted by us per year looks large. Aeschbach-Hertig notes in passing that

It appears that the authors assume that the 4.63 × 1023 g of CO2 degassed from the mantle all remained in the atmosphere. Yet, the present day atmosphere contains less than 3 × 1018 g of CO2, and compared to this number the total anthropogenic CO2 emission of 1 × 1018 g certainly is significant.
This is not quite the case, at least if you read the Figures but here at the Rabettorium we also noticed that there ain't so much CO2 in the air, the mixing ratio is ~ 380 ppm, so where did it all go. Some of it went to us, that's where the carbon comes from, some to the stuff we eat, and the O2 went to well, O2, but mostly to various oxides. There is a nice illustration of the history of the atmosphere from a lecture by Don Wuebbles.
Early on who knows, but soon thereafter (4.3 billion years ago), the water vapor fell out of the sky and made oceans, with an atmosphere about 30% CO2, 10% methane and a bunch of nitrogen. The CO2 concentration then rapidly declined leaving a nitrogen methane atmosphere (where did it go besides the oceans? well be patient little bunnies). If you wonder why people get excited about Titan, the composition of that giant moon's atmosphere is not far off the atmosphere of the earth between 3.5 and 2.5 billion years ago when life arose, and, as its first parlor trick, started to generate O2.

So where did the 4.5 bil year ago CO2 go? As we said, a lot went and hid in the deep oceans, dissolving into the water and forming carbonic acid, and hydrogen carbonate and carbonate ions. Roger Revelle was one of the first to study how CO2 is absorbed into the oceans. A nice discussion of the carbon cycle can be found at the Hadley Center the bottom line being that there is a lot of CO2 at the bottom of the ocean but this is not a perfect guide as life has reared its ugly head and is a major part of the cycle. The carbonates produced by dissolving of CO2 into the ocean, can be incorporated into the earth's crust at the bottom of the seas in subduction zones and then be transported to the continents, hence limestone mountains. The carbonates weather over time returning CO2 to the atmosphere. When you have a couple of billion years, anything is possible.

Since there was no free oxygen back then, to form ozone and absorb light below 300 nm, water vapor and CO2 were photolysed by light whose wavelength was shorter than 200nm to form oxygen atoms. The oxygen atoms recombined to form oxygen molecules, but this oxygen was rapidly consumed by oxydizing iron (to iron oxide) and other metals to oxides and sulfides to sulfates (ok, suphides to suphates or S(2-) compounds to SO4(2-) compounds, sulphur being quiet common in volcanic eruptions and denialist fulminations.

This went on until about 2 billion years ago life arose (at the 2.o billion years ago START in the diagram above and also seen in the rise of atmospheric O2 in the figure at the top) and learned how to convert CO2 to O2 and carbon based stuff. Some of this carbon based stuff decided to turn into oil and coal and gas, which we are now burning.

Khilyuk and Chilingar, of course, only looked at the production of CO2 from outgassing, they somehow neglected to consider that a lot of it got reburied, much of it was recycled and a bunch was transformed by biogeochemical processes. They apparently don't realize the implications of their Figure 7 for example, which, btw has life arising much too late at less than 1 billion years ago. To paraphrase Ev Dirksen a billion years here, a billion years there, and sooner or later you are talking about real time.

UPDATE: The Pete Singer song contest is now open for new entries.

IMPORTANT UPDATE FROM THE COMMENTS:
Eli may have had the thought, but Anonymous had the rhyme (and the guts):
Where has all the carbon dioxide gone?
Long time outgassing.

Where has all the carbon dioxide gone?
Long time ago.

Where has all the carbon dioxide gone?
To rocks and plants and everyone,

When will the denialists ever learn?
When will they ever learn?

19 comments:

Steve Bloom said...

Very nice, thank you. The code for the first graphic needs a fix, BTW.

OT: Note the fifth author here. Coincidence? I think not.

CapitalistImperialistPig said...

Life arising two billion years ago is also pretty late. 3.5 to 3.9 gya looks more credible. Of course an oxygen atmosphere wasn't built in a day.

Adam said...

Good article. Two typos:

"They apparently don't realize the implications of their Figure 7 for example, which, btw has life arising much too at less than 1 billion years ago." - "too late"?

Paragraph and tag around second figure seems broken - a spurious space between the "<" and "onblur"?

EliRabett said...

Thanks for the corrections.

Steve, Roger I is I think much more subtle than Roger II.

CapitalistImperialistPig said...

I think that oxygen producing cyanobacteria go back more than a couple of billion years, but for a long time any spare oxidizing capacity went into converting most of the crustal iron from ferrous to ferric. Once that dirty job was done - 2 gyr or so - the atmosphere could be made for safe for oxygen.

Or maybe I really don't remember any geochemistry.

Anonymous said...

Interesting link, Steve.


Building fences to keep out the rabits (sp?) does seem to be one of RP's forte's.

Anonymous said...

(With apologies to Bob Dylan)

Where has all the carbon dioxide gone?
Long time outgassing.

Where has all the carbon dioxide gone?
Long time ago.

Where has all the carbon dioxide gone?
To rocks and plants and everyone,


When will the denialists ever learn?
When will they ever learn?

Anonymous said...

There are more (endless?) verses where that one came from:

Where have all the denialists gone?
Talk about outgassing.

Where have all the Inhofes gone?
Long time ago.


Where have all the Virgina State Climatologists gone?

Gone to greener ($) pastures everyone.

When will they ever learn?
When will they ever learn?

Anonymous said...

Where has all the Exxon-Mobil money gone?
For Michael-Mann-harassing.

Where has all the Exxon-Mobil money gone?
We'll probably never know.

Where has all the Exxon-Mobil money gone?
Gone to denialist think tanks everyone.

When will we ever learn?
When will we ever learn?

Gareth said...

The apologies are due to Pete Seegar, not his Bobness... You get minus points for Peter, Paul & Mary.

Dano said...

I think the carbon went into all those bunnies counted in BuFEx.

Just a thought.

Best,

D

Anonymous said...

"The apologies are due to Pete Seegar, not his Bobness"

Sorry Pete.

I musta been thinkin' of blowin in the wind, which is a Dylan tune.

Lab Lemming said...

Why do they use g instead of kg?..

OMFG I just read the rest of the paper. What total fruitcakes! Is the best way to beat peer review to be so totally off the wall about everything that reviewers just throw up their hands in disgust? I mean, wow. Just, wow. The sad thing is that all the issues addressed here have actually been done-correctly (to the best of current knowledge, of course) by very clever, hard-working researchers whose papers will never get the type of attention that this one has.

Why can't I get reviewers this pliant?

John A said...

Unfortunately the reconstruction of past carbon dioxide from the cartoon you provided does not show the variation over the last 600 million years (probably because of the scale used.

Otherwise you'd find that the modern CO2 concentration is two or three magnitudes lower than it has been for most of the time since the Cambrian explosion.

But why spoil the article with an explanation like that? People might think you were a skeptic, and that would never do.

EliRabett said...

Hi John, how about telling us how much fossil fuel was in the ground 600 million years ago, how much carbon was stored in soils, and oh yes, how well the biological pump in the ocean was moving CO2 into carbonate shells in at the surface to the deep ocean where they could be incorporated into the lithosphere.

And now compare how much carbon is in all of those reservoirs today compared to the amount of carbon in the atmosphere 600 M years ago.

Lab Lemming said...

Yes, but eli, you are forgetting-
A lot of the carbon balance is based on the observation that Earth and venus have similar bulk compositions, and the CO2 in venuses atmosphere is about equal to the CO2 in carbonate rocks.

But there's a catch.

The bulk compositional equivalence is based on XRF basalt analyses from the venus landers- landers ownd and operated by the USSR. So in fact, the entire carbon budget for the inner solar system is a communist conspiracy. Do you hink it is a coincidence that CO2 is supposed to absorb infra-RED?

Oscarphone said...

The very latest is that ocean floor subducts into the mantle and the CO2 contained in it flips a molecule in the process and turns into methane. Methane then comes to the surface as methane, natural gas or oil. In other words, "fossil" fuels are renewable and continuous. That explains why oil abandoned wells are filling up again, from the bottom.

Eco-fascists ain't gonna like that.

Anonymous said...

"The very latest is that ocean floor subducts into the mantle and the CO2 contained in it flips a molecule [sic] in the process and turns into methane."

Hmmm... sounds like alchemy to me.

"That explains why oil abandoned wells are filling up again, from the bottom."

Really? Evidence?

"Eco-fascists ain't gonna like that."

Well, even assuming that it was true, letting the subterranean carbon genie out of the bottle to reconstruct an atmosphere from hundreds of millions of years ago isn't exactly a good idea.


Bernard J.

guthrie said...

Oh dear, not the abiogenic oil crap again.

Even if it was possible, fields which do appear to be filling up are doing so at a rate far lower than the extraction rate, thus, it won't be possible to keep pumping it forever.
Not to mention the lack of actual evidence for the theory in the first place.