Antarctic Ocean: The Big Kahuna of glacial period carbon sinks

UF research gives clues about carbon dioxide patterns at end of Ice Age

GAINESVILLE, Fla. — New University of Florida research puts to rest the mystery of where old carbon was stored during the last glacial period. It turns out it ended up in the icy waters of the Southern Ocean near Antarctica.

The findings have implications for modern-day global warming, said Ellen Martin, a UF geological sciences professor and an author of the paper, which is published in this week’s journal Nature Geoscience.

“It helps us understand how the carbon cycle works, which is important for understanding future global warming scenarios,” she said. “Ultimately, a lot of the carbon dioxide that we’re pumping into the atmosphere is going to end up in the ocean. By understanding where that carbon was stored in the past and the pathways it took, we develop a better understanding of how much atmospheric carbon dioxide the oceans can absorb in the future.”

Scientists know that during the transition from the last glacial period to the current inter-glacial period about 14,000 years ago, carbon dioxide levels rose very quickly at the same time that the age of the carbon dioxide in the atmosphere fell, as measured by radiocarbon data. That suggests carbon dioxide had been stored in the ocean and suddenly released, she said.

One idea holds that it was building up in the Southern Ocean around Antarctica, where extensive sea ice on the surface of the ocean initially prevented the exchange of gasses into the atmosphere, Martin said. The other possibility is that the same process occurred in the Northern Hemisphere with ice sheets in the North Pacific Ocean, she said.

In her lab, Martin and lead author Chandranath Basak, a UF graduate student in geological sciences; Keiji Horikawa, a UF postdoctoral fellow in geological sciences; and Thomas Marchitto, a University of Colorado geology professor, studied that question by using a technique to measure isotopes of neodymium, a rare earth element not commonly found in marine sediments but preserved in microscopic fossil fish teeth. The isotopic signature of a water mass, which is captured in the fish teeth, reflects the location where the water mass came from, she said.

“It’s essentially what we call a water mass tracer,” Martin said. “You can tell where the water masses have formed and where they have moved to by using this tracer.”

The researchers took samples that had been shown to have old carbon in them and measured the neodymium isotopes on fish teeth from the sediments to see if they could reconstruct whether they had come from the North Pacific or the Southern Ocean, she said.

“When we did this, we got a signal that looks very much like the Southern Ocean,” she said. “It implies that all the carbon was being stored in the Southern Hemisphere and as the ice sheet melted back, it released that carbon dioxide into the atmosphere, causing part of the big increase in carbon dioxide and introducing old carbon back into the atmosphere.”

By giving information about environmental conditions during the last glacial period, the research findings can help scientists to reconstruct what the world was like at that time, she said.

The implications are that while large amounts of carbon could be stored in the ocean when there was a great deal of sea ice, the opposite is the case in a world that is warming, with less ice, which allows more carbon dioxide to be released into the atmosphere, Martin said. Thus, in a warming scenario the oceans may not be able to store as much carbon dioxide as they could under glacial conditions

The oceans are a critical part of the carbon dioxide cycle, Martin said. “The oceans have 60 times more carbon dioxide in them than the atmosphere, so when we worry about what’s happening with carbon dioxide in the atmosphere, we often look to the oceans as a potential source or sink.”

The concentration of carbon dioxide in the atmosphere during the glacial periods was about 200 parts per million, compared with 280 parts per million during a typical interglacial period, Martin said. Today that level has soared to about 380 parts per million, she said.

The time period that encompasses the last glacial period to the current interglacial period when carbon dioxide levels went up very quickly is often referred to as the “mystery interval” because scientists hadn’t known where the carbon was stored, Martin said.

“Now we have a better understanding of how the system worked,” she said.

-30-
=================================

One wonders how the sea life down there tolerated all that extra carbon resulting in “ocean acidification”.

Advertisements

  Subscribe  
newest oldest most voted
Notify of
Michael Jankowski

Translation: A lot of CO2 released to the atmosphere is “natural.”
Spin: Global warming is going to release more sequestered CO2 by melting Antarctic “ice sheets pullling back,” which means “it’s worse than we thought.”

Will Crump

Mr. Watts,
Thank you for posting this article which identifies another potential positive feedback to additional global warming.
“The implications are that while large amounts of carbon could be stored in the ocean when there was a great deal of sea ice, the opposite is the case in a world that is warming, with less ice, which allows more carbon dioxide to be released into the atmosphere, Martin said. Thus, in a warming scenario the oceans may not be able to store as much carbon dioxide as they could under glacial conditions.”
REPLY: You act as if this is news, any kid in high school chemistry class knows about the solubility of CO2 in water, in fact I’ve posted on it many times here on WUWT.
http://wattsupwiththat.files.wordpress.com/2007/11/co2-h2o_solubility.png
What’s news is that this team confirmed the southern ocean was the main sink then. This finding also points to why CO2 lags temperature in paleoclimate temperature and CO2 reconstructions.
– Anthony

DocattheAutopsy

So, effectively warm oceans release CO2, and cold ones store it?
Seems like something chemists have known for about 100 years now.

Nick Luke

As a non-scientist, does this mean that the temperature had to drop before the CO2 could be sequestered in the water? Conversly, did the temperature have to rise before the gas was re-released into the atmosphere? Or have I misunderstood Boyle’s Law all these years?

Mike Davis

Proudly funded by NSF with your money and mine! Science has truly become a contest to see who can write the most preposterous funding proposal.

Jacob

So, does this support the theory that CO2 rises in response to warming (not causing it) ?
That is: warmer temps cause sea ice melt, and this causes co2 release from the oceans that the ice hindered before?
So, a rise of co2 concentrations follows the warming, and is not it’s cause it ?

Stop Global Dumbing Now

Just these:
1) “Thus, in a warming scenario the oceans may not be able to store as much carbon dioxide as they could under glacial conditions”
Didn’t we already know this?
2) “The concentration of carbon dioxide in the atmosphere during the glacial periods was about 200 parts per million, compared with 280 parts per million during a typical interglacial period”
Haven’t we already proven that in past interglacials it was much higher?
3) “introducing old carbon back into the atmosphere.”
Does “old carbon” have a similar chemical signature to fossil fuel carbon? Wouldn’t that confound the measurements of evil AGW carbon vs pristine polar bear carbon? (I guess that would be penguin carbon since it’s in Antarctica.)

Mike Davis

It is good to see that these researchers understand that a warmer ocean allows more CO2 in the atmosphere to allow more biological activity through photosynthesis which provides more O2 for the animal kingdom to breath.

Jimbo

One wonders how the sea life down there tolerated all that extra carbon resulting in “ocean acidification”.

Their shells grew thicker?
http://www.whoi.edu/page.do?pid=7545&tid=282&cid=63809&ct=162
http://www.sciencemag.org/cgi/content/abstract/sci;320/5874/336
Stop the alarm over acidic oceans!!!
http://www.agu.org/pubs/crossref/2006…/2006GL026305.shtml

Bernie

I do not understand the notion of new and old carbon dioxide. If carbon dioxide was stored, how is it older or younger than the carbon dioxide that was not stored. Is this a press release gaffe?

charles nelson

‘…rare earth isotopes…. water mass tracer…you can tell where the water mass has formed….microscopic fish teeth….we’re getting a signal that looks very much like the southern ocean….’
‘Hey…wake up…wake up!’
‘Huh?’
‘You were talking in your sleep.’
‘What was I saying?’
‘Dunno…sounded like complete bollocks to me.’

So, cooler oceans sequester CO2 and warmer oceans release CO2. Who would have guessed?

Golf Charley

A fizzy drink, loses its fizz quicker, as it gets warmer. Another way to reduce the fizz quicker is to reduce atmospheric pressure. The reverse may also be true. Different laws of physics apply to oceans.
The fizz is CO2, and putting it into drinks, to make them fizzy, has yet to be targeted for cap and trade, so the fizzy drink industry must be capturing all its CO2 from the atmosphere, rather than producing CO2 by other means. Could the fizzy drinks industry share the secret, they could save the world?
I do not seem to be getting any of the Big Oil money that (allegedly) slushes around these sites, so can I get some AGW grant funding instead please?

Nigel Brereton

‘The concentration of carbon dioxide in the atmosphere during the glacial periods was about 200 parts per million, compared with 280 parts per million during a typical interglacial period, Martin said. Today that level has soared to about 380 parts per million, she said.’
My God is she going to have a bitch fit if CO2 doubles, even though it won’t affect temperatures as predicted.

DocattheAutopsy

Bernie said:
“I do not understand the notion of new and old carbon dioxide. If carbon dioxide was stored, how is it older or younger than the carbon dioxide that was not stored. Is this a press release gaffe?”
Nope. Stored carbon is a small percentage C-14, which eventually decays to N-14 through beta decay. We can use the isotopic ratio of a carbon source to determine its age up to about 50,000 years old. So, “old carbon” is simply carbon with depleted C-14.

Katherine

“When we did this, we got a signal that looks very much like the Southern Ocean,” she said. “It implies that all the carbon was being stored in the Southern Hemisphere
Doesn’t that just mean their samples were all from the south? Unless they’re implying that there were no fish in the north.

Garry

Bernie says October 25, 2010 at 2:58 pm: “If carbon dioxide was stored, how is it older or younger than the carbon dioxide that was not stored. Is this a press release gaffe?”
Not a press release gaffe, it’s just climate “science.”
’Twas brillig, and the slithy trace
Did gyre and gimble in the water mass;
All mimsy were the borogoves,
And the mome raths on old carbon.

latitude

poor UF, UF is trying so hard to be cutting edge climate science….
Watching all that money pass them by….

JDN

So, are they proposing a non-mixing portion of the ocean? If that’s it then it doesn’t seem plausible. Are there any examples of this that we can observe (besides brine pools in deep water which are probably maintained by the life forms that live in them).

Will Crump

[comment is way oversized -please break it up into smaller posts ~mod]

Jeff (of Colorado)

“The oceans have 60 times more carbon dioxide in them than the atmosphere”
Does this partly cause the sine wave in the CO2 graph from Hawaii? The Northern Hemisphere is removing CO2 while Antartica stops producing it?
So 1.3% change in ocean CO2 doubles/halves current atmospheric CO2. What percentage is lost or gained when long term climate warms and cools? This neatly correlates the delay between temperature and CO2.

D Caldwell

Jacob says:
October 25, 2010 at 2:48 pm
“So, does this support the theory that CO2 rises in response to warming (not causing it) ?That is: warmer temps cause sea ice melt, and this causes co2 release from the oceans that the ice hindered before?So, a rise of co2 concentrations follows the warming, and is not it’s cause it ?”
Jacob, any true climate scientist knows that natural, non-CO2 forcings are very weak and can only produce just a little bit of temporary warming – way less than 0.5C for sure. This little bit of non-CO2 forcing caused a release of CO2 from the oceans, which caused a lot more warming that set off a cascade of positive feedbacks, which ended the glacial period. Therefore, substantial increases in atmospheric CO2 always do the heavy lifting in any global warming scenario. All the climate models approved by true climate scientists confirm this.
Now you can clearly understand how all true climate scientists happily ignore that the actual data indicate warming at the end of each glacial period always preceeded increases in CO2 by several hundred years.

“isotopes of neodymium, a rare earth element not commonly found in marine sediments but preserved in microscopic fossil fish teeth.”
Interesting. Neodymium is the stuff the Chinese make superstrong magnets from. I wonder if fish use it for navigational purposes.

Did anyone see the Antarctica penninsula?. We´re looking for it 🙂
It starts from the same falsified hypothesis, or rather BELIEF from the church of GW, while stirring their CO2 incense burners. Holy betwetters! More of the same CO2 concoction, now from fish teeth!…

Sean

Interesting article and observations but I think that you have to note that CO2 sequesters naturally in the oceans (after all they were studying fish teeth) by precipitating out carbonate rocks such as limestone and dolomite. Calcium carbonate has an odd solubility, its less soluble in warm water than in cold. But even the solubility is not so simple as the CO2 in water can be carbonic acid or a bi-carbonate which actually increases the solubility of calcium in the presence of CO2. When you think about the southern oceans or any other oceans for that matter, you also have to keep in mind the currents take water loaded with carbonate and bi-carbonate ions and transport these toward the equator where the water is warmer leading to breakdown of the soluble calcium bicarbonate ions into CO2 (g) and calcium carbonate (s) so half the carbon dioxide gets precipitated out. (Think of all the limestone deposits in the tropics as well at the amount of limestone rock that is a permanent repository of formerly gaseous CO2. I personally like point out view from the edge of the Grand Canyon to anyone who doesn’t believe CO2 can be sequestered.) So I wonder out loud if the results of this study may indicate that the mechanism for transporting CO2 from the cold polar regions to the warm tropic regions might have been shut down during the glacial periods and when the glaciers melted, did it bring this bicarbonate saturated water back to the equatorial regions to release half the gas that was simple dissolved?

It is well understood that the CO2 is more soluble in water as the temperature of the water decreases. Since the Northern Hemisphere started having glacial cycles 2.6 million years ago it is no surprise that global CO2 levels have dropped. That the colder region of the planet should store more of the CO2 is expected.
It is nice to see the science line up properly with the real world. Of course too many believe that the falling CO2 levels is what “caused” the cooling. That is where science has failed.
John Kehr
The Inconvenient Skeptic

This finding also points to why CO2 lags temperature in paleoclimate temperature and CO2 reconstructions.
Does this mean I’ll finally stop hearing that the lag was just a measurement error because we all know CO2 is the primary driver of climate?

DonK31

A good explanation of why CO2 in the atmosphere is a trailing indicator of warming and cooling instead of a leading indicator.

rbateman

This would explain the lag of C02 in the Ice Ages. It takes time for it to travel to the Antartic, and it has to melt before the C02 can be released. So, an Antarctic that grows colder is busy dunking C02.

R. Gates

Jacob says:
October 25, 2010 at 2:48 pm
So, does this support the theory that CO2 rises in response to warming (not causing it) ?
That is: warmer temps cause sea ice melt, and this causes co2 release from the oceans that the ice hindered before?
So, a rise of co2 concentrations follows the warming, and is not it’s cause it ?
______
This is the common logical falacy that is propagated by many AGW skeptics. Namely that a temperature rise prior to CO2 increases proves that CO2 cannot cause warming. Yes, rises CO2 levels follow temperature increases in many instances in the geological record, but then once the CO2 begins to increase, it functions to extend and amplify the warming. Furthermore, it is glaciation that serves to increase CO2 levels through a slowing of the hydrological cycle. To say that a rise in CO2 can not affect an increase in global temperatures simply because is sometimes lags a rise in temperature is one of the biggest logical falacies that I see coming from the skeptical community. CO2 can act as a positive feedback to a general warming that may have been initiated through astrononomical (i.e Milankovitch) or other natural cycles.

One idea holds that it [CO2] was building up in the Southern Ocean around Antarctica, where extensive sea ice on the surface of the ocean initially prevented the exchange of gasses into the atmosphere, Martin said. The other possibility is that the same process occurred in the Northern Hemisphere with ice sheets in the North Pacific Ocean, she said.

How can they vacillate like that? They do assert that they got a “a signal that looks very much like the Southern Ocean.”
Mind you, I can’t see how anyone can get a “signal” that has any geographical features, let alone those of the Southern Ocean.
Nevertheless, the UF news item insults the readers by concluding,

“Now we have a better understanding of how the system worked,” she said.

James Sexton

TallDave says:
October 25, 2010 at 4:30 pm
This finding also points to why CO2 lags temperature in paleoclimate temperature and CO2 reconstructions.
Does this mean I’ll finally stop hearing that the lag was just a measurement error because we all know CO2 is the primary driver of climate?
========================================================
In our wildest fantasies. Maybe one day when people can understand the insignificance of a ton, better yet, a gigaton of CO2. Can someone relate a gton of CO2 to ppm?

Zeke

tallbloke says:
October 25, 2010 at 4:10 pm
Interesting. Neodymium is the stuff the Chinese make superstrong magnets from. I wonder if fish use it for navigational purposes.

Yes that is another kettle of fish. What are all of these magnetic nanocrystals doing in nearly every organism, even those who don’t seem to use any kind of navigation system wrt the geomagnetic field of the earth?
http://elements.geoscienceworld.org/cgi/content/abstract/5/4/235
Biomineralization of magnetite crystals has even been found to be occuring in the human brain.
http://www.pnas.org/content/89/16/7683.abstract
“elemental analyses identify minerals in the magnetite-maghemite family, with many of the crystal morphologies and structures resembling strongly those precipitated by magnetotactic bacteria and fish. These magnetic and high-resolution transmission electron microscopy measurements imply the presence of a minimum of 5 million single-domain crystals per gram for most tissues in the brain and greater than 100 million crystals per gram for pia and dura.”
Perhaps “much further research is required to understand fully the origin and function of biomagnetism.”

Bernie

DocattheAutopsy & Garry:
Thanks for your responses. But I still am confused. At what point does Carbon achieve its age? Can you point me to a basic explanation on carbon dating? This article has raised some confusing points.

Gareth

This finding would suggest that coming out of the Little Ice Age could cause a substantial increase in CO2.
This finding would also suggest that there is no runaway CO2-induced warming effect otherwise there would have never been repeated glacial periods.

jorgekafkazar

[comment is way oversized -please break it up into smaller posts ~mod]
I’ve found that any comment over two screens long is usually either a rant or has a high BS content, so I rarely read anything that long. Save your breath. Brevity is the soul of wit.

George E. Smith

“”””” “The oceans have 60 times more carbon dioxide in them than the atmosphere, so when we worry about what’s happening with carbon dioxide in the atmosphere, we often look to the oceans as a potential source or sink.” “””””
How does that grab you the total atmospheric CO2 is 1/60th of the amount in the ocean.
So if ALL of the atmospehric CO2 were to dissolve in the Ocean it would change the pH by some huge amount that would simply dissolve all shellfish and corals.
So it’s really worse than we thought.
Hey I do like the proxy technique though; that sounds pretty clever..
But I don’t think ocean acidification needs to be taken care of before election day.

James Sexton

R. Gates says:
October 25, 2010 at 4:39 pm
Logical falacies? Ok, I’ll play…..
“……..but then once the CO2 begins to increase, it functions to extend and amplify the warming. …….”
=======================================================
So what then, pray tell, stopped the death spiral? Because we all know CO2 causes an increase in the temps, and the increase of the temps causes ice melt, and ice melt causes increase in temps because of the albedo. Such a vicious, vicious never ending cycle of doom! So, please tell me, at what point did the process halt, and how did it halt?
Logical falacies?

rbateman

R. Gates says:
October 25, 2010 at 4:39 pm
Yes, rises CO2 levels follow temperature increases in many instances in the geological record, but then once the CO2 begins to increase, it functions to extend and amplify the warming. Furthermore, it is glaciation that serves to increase CO2 levels through a slowing of the hydrological cycle.

Sure am glad I didn’t have a mouthful of coffee when I read that !
Well, darn it all, that must mean that C02 will finish the Ice Ages once and for all.. just as soon as its done warming and accelerating all the sequestered C02, there will never ever be another Ice Age due to all that released supercarbonisticoxyextrametitglacious blistering the Planet.
Ok, so I’m being a bit rough here.
Tell me, how does this accelerant not runaway and peel the crust off the Earth?

Richard Sharpe

George E. Smith says on October 25, 2010 at 5:23 pm

“”””” “The oceans have 60 times more carbon dioxide in them than the atmosphere, so when we worry about what’s happening with carbon dioxide in the atmosphere, we often look to the oceans as a potential source or sink.” “””””
How does that grab you the total atmospheric CO2 is 1/60th of the amount in the ocean.
So if ALL of the atmospehric CO2 were to dissolve in the Ocean it would change the pH by some huge amount that would simply dissolve all shellfish and corals.
So it’s really worse than we thought.
Hey I do like the proxy technique though; that sounds pretty clever..
But I don’t think ocean acidification needs to be taken care of before election day.

So, what fraction of a doubling of CO2 in the atmosphere would end up in the oceans and what would that do to the pH?

FijiDave

Now hang on, you lot!
Billions of dollars, quadrillions of man-hours, squadrillions of words, and there is still an argument over whether or not twelve man-made carbon dioxide molecules per one million molecules of air is catastrophically heating the atmosphere?
Can this be for real?
Really, as just an ordinary bloke, I shouldn’t have to know that carbon dioxide absorbs long wave radiation, and re-emits it. Should I have to know that this re-radiating of heat by the CO2 molecule is isotropic and the heat can ping off in any direction including up?
Should I have to worry about whether the National databases holding temperature records around the globe are up to standard and that the publicised temperatures from same are honest?
Ice flows, polar bears, glaciers, water vapour, methane, ozone and a million other esoteric minutiae associated with climate should, unless one is keen on such things, merely exist on the fringes of one’s consciousness.
Most people deal with facts. 1 kilogram equals 2.2046 pounds, E=MC2, for example. Radio propagation is proven by the fact that everyone’s cell phone magically receives information without a bundle of wires. We trust that the science is empirically demonstrated, and use our cell phones without having a clue how it works. How is it that one can’t say the same of climate science?
Why hasn’t the expenditure of billions of dollars, the endeavours of thousands of scientists, or the babble of millions of bloggers over the last three decades been able to pin the beast down so that ordinary folks like me can say, “Yep! We’re warming up through our careless production of CO2. We’d better do something before it’s too late!”
Well, it hasn’t, because it can’t.
And if I’ve got some facts wrong, well tough titty, as I’ve other things to do.

Robert of Texas

Carbon-14 mostly comes from low energy neutrons colliding with nitrogen in the upper atmosphere. Higher energy nuetrons can also produce C-14 if they are slowed down first, or strike something like ice, but this is not considered a major source of naturally occuring C-14 in our environment.
C-14 has a half life of about 5,700 years. You can use it to determine the age of a carbon source back about 50,000 to 100,000 years depending on the technique.
I am mystified that people think they can tell the “average” age of carbon in the atmosphere. It depends on the raito of carbon isotopes of course, but also on the production rate which many seem to think is a constant. I can’t imagine neutron bombardment being a constant over large time periods. You also have to consider whether their are any biases of c-14 over other carbon isotopes in mineral creation, biological use, and degassing or absorbtion under a wide variety of temperatures and conditions.
Because there is more c-14 in the oceans (expressed as a ratio) than in the atmosphere, some think this proves its “old carbon” from the burning of fossil fuels, which were buried and losing their C-14 steadily to decay. Well, maybe. Or maybe there is some other reason why the ocean has more c-14. I wonder if anyone has actually studied the production of c-14 in ice and water in the environment – or we just assume its too rare to be of importance. Just one of those naggin details.

James Sexton

rbateman says:
October 25, 2010 at 5:49 pm
R. Gates says:
October 25, 2010 at 4:39 pm
Sure am glad I didn’t have a mouthful of coffee when I read that !
======================================================
Yeh, well, I had a mouth full of beer and now my keys are sticking!!! I think he did that on purpose!

Joe Lalonde

Anthony,
Sometimes these theories have me ask more questions than what answers they give.
If there is a great amount of precipitation in the last Ice Age, then would that not dilute the CO2 readings? It could be far more.
Meltings can also give the opposite by concentrating the CO2 into the ground layers.
The current CO2 seems to be changing the wind speeds at the planets surface and in doing so would change the speed of heat disipating from the planets surface depending on cloud cover and weather conditions. But there is definately a pressure build-up in our atmosphere. Global Warming was blamed for growth up mountains when in fact, the built-up pressure is climbing the mountain.
CO2 is a dangerous gas in pushing normal lighter gases into the atmosphere generating compression with cloud cover.

Man! For a minute, there, I thought somebody had discovered fizzy ice. This would have been really big stuff because then I could pour my scotch whiskey over fizzy ice cubes and not have to dilute it so much with fizzy water.
But, then, AGW has been a real disappointment.

James Sexton

Joe Lalonde says:
October 25, 2010 at 6:41 pm
“Anthony,
Sometimes these theories have me ask more questions than what answers they give.
……………
CO2 is a dangerous gas in pushing normal lighter gases into the atmosphere generating compression with cloud cover.”
======================================================
Yes, they should, the theories always leave me with more questions, too. It simply illustrates that we don’t know enough to make a determination about anything yet. Our knowledge of what makes up our climate is woefully inadequate to make any significant definitive statements. While I’m not Anthony, I’d try to answer (as best I could)but, your last statement, leaves me a bit perplexed as to your meaning.

Colin from Mission B.C.

FijiDave says:
October 25, 2010 at 6:21 pm
Well said, FijiDave. Thanks for speaking for Everyman. I couldn’t have said it better myself.

Chuck

Well done.
That which was proved is proved.again.
The Polar Region ice caps and glaciers are the Earth’s freezers.
Simple! Simple! Simple!.

Nevertheless, the UF news item insults the readers by concluding,

“Now we have a better understanding of how the system worked,” she said.
Note: “worked” (past tense). Can’t help but add the implication that, sadly, the system doesn’t work like that anymore.

docattheautopsy

Bernie says:
“DocattheAutopsy & Garry:
Thanks for your responses. But I still am confused. At what point does Carbon achieve its age? Can you point me to a basic explanation on carbon dating? This article has raised some confusing points.”
There’s not really a base “age”, per se, but a point at which carbon-14 is saturated by neutron bombardment, as Robert of Texas explained.
Carbon-14’s base is the amount of Carbon-14 in living organisms. Since we’re all eating carbon, and essentially we get carbon from plants, who get it from atmospheric CO2, we continuously pass carbon through us, so there’s an equilibrium amount of carbon in us, sustained by us eating and passing carbon from our system.
The atmospheric CO2 is, by current research, losing Carbon-14 because fossil fuels over 50-70k years old have lost the C-14 to time, so the ratio of C-14 to C-12 is much lower than what we get from the carbon cycle.
The wikipedia article is actually OK and pretty simple to follow.
http://en.wikipedia.org/wiki/Carbon_Dating
I’m on the fence about C-14 concentrations in the atmosphere coming from fossil fuel sources, simply because the data I’ve seen falls within the margin of error and it’s not conclusive, although it is persuasive, so I’m waiting for better data to come out.