Carbon, on the uptake

From the University of Bristol

Carbon cycling was much smaller during last ice age than in today’s climate

Atmospheric carbon dioxide (CO2) is one of the most important greenhouse gases and the increase of its abundance in the atmosphere by fossil fuel burning is the main cause of future global warming. In past times, during the transition between an ice age and a warm period, atmospheric CO2 concentrations changed by some 100 parts per million (ppm) – from an ice age value of 180 ppm to about 280 ppm during warm periods.

Scientists can reconstruct these changes in the atmospheric carbon stock using direct measurements of atmospheric CO2 trapped in air bubbles in the depth of Antarctica’s ice sheets. However explaining the cause of these 100ppm changes in atmospheric CO2 concentrations between glacial and interglacial climate states – as well as estimating the carbon stored on land and in the ocean – is far more difficult.

The researchers, led by Dr Philippe Ciais of the Laboratoire des Sciences du Climat et l’Environnement near Paris, ingeniously combined measurements of isotopes of atmospheric oxygen (18O) and carbon (13C) in marine sediments and ice cores with results from dynamic global vegetation models, the latter being driven by estimates of glacial climate using climate models.

Dr Marko Scholze of the University of Bristol’s School of Earth Sciences, co-author on the paper said: “The difference between glacial and pre-industrial carbon stored in the terrestrial biosphere is only about 330 petagrams of carbon, which is much smaller than previously thought. The uptake of carbon by vegetation and soil, that is the terrestrial productivity during the ice age, was only about 40 petagrams of carbon per year and thus much smaller: roughly one third of present-day terrestrial productivity and roughly half of pre-industrial productivity.”

From these results, the authors conclude that the cycling of carbon in the terrestrial biosphere – that is, the time between uptake by photosynthesis and release by decomposition of dead plant material – must have been much smaller than in the current, warmer climate.

Furthermore there must have been a much larger size of non-decomposable carbon on land during the Last Glacial Maximum (the period in the Earth’s history when ice sheets were at their maximum extension, between 26,500 and 19,000 years ago).

The authors suggest that this inert carbon should have been buried in the permanently frozen soils and large amounts of peat of the northern tundra regions.

###

Paper

‘Large inert carbon pool in the terrestrial biosphere during the Last Glacial Maximum’ by P. Ciais, A. Tagliabue, M. Cuntz, L. Bopp, M. Scholze, G. Hoffmann, A. Lourantou, S. P. Harrison, I. C. Prentice, D. I. Kelley, C. Koven and S. L. Piao in Nature Geoscience

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Lars P.
November 21, 2011 4:10 am

“The uptake of carbon by vegetation and soil, that is the terrestrial productivity during the ice age, was only about 40 petagrams of carbon per year and thus much smaller: roughly one third of present-day terrestrial productivity and roughly half of pre-industrial productivity.”
The work has the value to document the big difference between the pre-industrial productivity and today productivity.
If glacial was 50x, the pre-industrial was 100x and now we are at 150x, 50% more then pre-industrial values. Further analysis could show how much of it is attributable to the last 150 years warming and how much to more CO2, but it is very important to see the difference to pre-industrial level.
It is vital to highlight this point in view of any discussions about reducing CO2 to pre-industrial levels.
Conclusion: people who want to do it would like to exterminate 1/3 of current living beings on Earth.
And the follow-up question : how much extra living beings can the planet host with some more CO2? 500ppm? Can we get to 200% pre-industrial values?

Gail Combs
November 21, 2011 4:57 am

…..In past times, during the transition between an ice age and a warm period, atmospheric CO2 concentrations changed by some 100 parts per million (ppm) – from an ice age value of 180 ppm to about 280 ppm during warm periods….
If this was true there would be no trees and certainly nothing like mammoths during the last ice age. At 180 ppm Class 4 plants (grasses) could possibly survive but would not have the “energy” to produce seed. At 200 pm CO2 trees starve http://biblioteca.universia.net/ficha.do?id=912067 (That link of course has since been purged from the internet – SURPRISE – not)

…According to Barnola et al (1987) the level of CO2 in the global atmosphere during many tens of thousands of years spanning 30,000 to 110,000 BP were below 200ppm. If this were true then the growth of C3 plants should be limited at the global scale because their net Photosynthesis is depressed as CO2 concentration in air decreases to less than about 250ubar (less than about 250ppmv)(McKay et al 1991) This would lead to the extinction of C3plant species . This has however not been recorded by paleobotanists (Manum 1991).” http://www.co2web.info/stoten92.pdf

“…Plant photosynthetic activity can reduce the CO2 within the plant canopy to between 200 and 250 ppm… I observed a 50 ppm drop in within a tomato plant canopy just a few minutes after direct sunlight at dawn entered a green house (Harper et al 1979)” Source

Another study on wheat (a grass) in open fields showed the CO2 level 2 meters above the crops was reduced to a near constant 300 ppm during the day but fluctuated during the night. Again indicating a lower threshold of 250 ppm ~ 300 ppm and certainly not indicative of below 180 ppm.

WHEAT: The CO2 concentration at 2 m above the crop was found to be fairly constant during the daylight hours on single days or from day-to-day throughout the growing season ranging from about 310 to 320 p.p.m. Nocturnal values were more variable and were between 10 and 200 p.p.m. higher than the daytime values.
Source

From the people who know and depend on the truth – FARMERS
Hydroponic Shop

…Plants use all of the CO2 around their leaves within a few minutes leaving the air around them CO2 deficient, so air circulation is important. As CO2 is a critical component of growth, plants in environments with inadequate CO2 levels of below 200 ppm will generally cease to grow or produce… http://www.thehydroponicsshop.com.au/article_info.php?articles_id=27

….With the advent of home greenhouses and indoor growing under artificial lights and the developments in hydroponics in recent years, the need for CO2 generation has drastically increased. Plants growing in a sealed greenhouse or indoor grow room will often deplete the available CO2 and stop growing. The following graph will show what depletion and enrichment does to plant growth:
GO TO SITE for CO2 vs Plant Growth GRAPH
Below 200 PPM, plants do not have enough CO2 to carry on the photosynthesis process and essentially stop growing. Because 300 PPM is the atmospheric CO content, this amount is chosen as the 100% growth point. You can see from the chart that increased CO can double or more the growth rate on most normal plants. Above 2,000 PPM, CO2 starts to become toxic to plants and above 4,000 PPM it becomes toxic to people….. http://www.hydrofarm.com/articles/co2_enrichment.php

Keith in another WUWT discussion brought up another good point the effect of partial pressure of CO2 at higher elevations on plants.

Speaking of carbon dioxide as plant food there is something else often missing in discussions of CO2 concentration. That is CO2 and its relation to altitude. Humans have trouble breathing near the top of Mount Everest even though the “concentration” of oxygen in parts per million is the same as at sea level. This is because the total density of the air is less so the actual amount of oxygen available per cubic meter is also less. The same holds true for carbon dioxide. Air density at 1000 meters altitude is about ninety percent of its sea level value, and crops grown at that altitude have access to ninety percent of the CO2 at sea level despite the fact that the “concentration” as usually given is the same. Half of the land surface of the earth is about 840 meters above sea level, and the absolute concentration of CO2 there is therefore ninety percent less. http://www.ecowho.com/blogs/120/CO2_global_levels_rising%2C_is_this_a_problem%3F/-b33b2

Now when will Engelbeen come to valiantly defend this very important pillar of CAGW? After all low CO2 is the KEY to CAGW.
Dr. Jaworowski tried to do the study to determine the accuracy of the Ice Core CO2 data but the funding was turned down because it was feared his study would “Disprove” the CO2 readings from the ice cores and we couldn’t have that now could we???

Dixon
November 21, 2011 5:00 am

Ice core measurements a “direct” measure of past CO2 concentrations? I’d hate to see a convoluted measure then!

Dave Springer
November 21, 2011 5:06 am

Lars P. says:
November 21, 2011 at 4:10 am
“The work has the value to document the big difference between the pre-industrial productivity and today productivity.”
Yes, that leapt off the page at me too. According to the authors biologic activity was 40 petagrams carbon during glacial period, 80 petagrams during pre-industrial, and 120 petagrams today.
So the primary producers in the food chain are 50% more productive today than 200 years ago. This is the highest figure I’ve seen. Typically 15% to 30% is bandied about for the agricultural windfall of increased atmospheric CO2 but that doesn’t take into account longer growing seasons from CO2 induced surface warming nor reduced water requirements. So this is a VERY interesting admission coming from the nattering nabobs of anthropogenic negativity.
I must agree with your conclusion that these people don’t give a fig about global warming all they care about is reducing the human population. That can’t be done so long as primary production in the food chain keeps rising – useless eaters can’t increase in number without an increase in food supply. As long as we keep pumping CO2 into the atmosphere the biosphere just gets more and more active, winters get more and more mild until the Antarctic continent is covered by temperate forest again, and the biologic carbon cycle is several times greater than it is today.
I call these people ice-huggers. They’re lunatics. The last thing they want is a green planet. They want a planet that is cold and unfriendly to life including human life.

1DandyTroll
November 21, 2011 5:07 am

I don’t know what is most embarrassing: The university of Bristol using past low against “present perfect pre industrialized day” average or that they excluded past eras with higher average than 280.

November 21, 2011 5:23 am

Around 93% of the accumulation of CO2 in the atmosphere is natural and most of that is from inorganic sources (the equatorial oceans). Click on my name for details.

November 21, 2011 5:30 am

Ferdinand Engelbeen has a very good point, that he made above.

Bill Illis
November 21, 2011 5:50 am

We also have to conclude then that the size of the plant biosphere, creates its own balance of CO2 in the atmosphere.
When the mass of the vegetation biosphere increases (like it did in the Cretaceous for example), this increases the CO2 balance in the atmosphere. Changes in the distribution/type of plants can also therefore affect the balance of CO2. The evolution of grasses 24 million years ago seems to have reset the natural CO2 balance in the atmosphere at a lower level (from 1200 ppm to 270 ppm) (which is where it has been for the past 24 million years, a little known fact in the climate science community).

Gail Combs
November 21, 2011 6:01 am

Aside from the plants during the Ice Age showing the CO2 reading are way off there is another elephant in the room.
It is called Water Vapor.
95% of the green house effect is caused by WATER not CO2. It is up to 4% where as CO2 is a puny 0.036% That is why water is left out of the IPCC reports. (Another lie by omission) http://www.geocraft.com/WVFossils/greenhouse_data.html
Next what did the last ice age to to the water content of the atmosphere???

Glacial Climate and Sea Level
The North American and European ice sheets of the last glaciation began forming after a prolonged cold stage with increased precipitation (mostly snow in this case) took place. Once the ice sheets began forming, the cold landscape altered typical weather patterns by creating their own air masses. The new weather patterns that developed reinforced the initial weather that created them, plunging the various areas into a cold glacial period.
The warmer portions of the globe also experienced a change in climate due to glaciation in that most of them became cooler but drier. For example rainforest cover in West Africa was reduced and replaced by tropical grasslands because of a lack of rain.
At the same time, most of the world’s deserts expanded as they became drier….

http://geography.about.com/od/climate/a/glaciation.htm

So there goes the change of 100 ppm in CO2 having any effect because it would be completely swamped by the water vapor changes! Not to mention the effect of the Milankovich cycles that would directly effect those changes in the amount of water vapor.

The influence of these cycles on insolation (INcident SOLar radiATION) at different latitudes has been calculated by Berger (1991), and Laskar (1993). Below is Berger’s solution for 65 degrees north latitude from the present to 1 million years ago. In the Northern Hemisphere, peak summer insolation occurred about 9,000 years ago when the last of the large ice sheets melted. Since that time Northern Hemisphere summers have seen less solar radiation. http://deschutes.gso.uri.edu/~rutherfo/milankovitch.html

Of course we KNOW the sun has nothing to do with our climate because climate scientists tell us that is so. /sarc>
So as usual these [self-snip] scientists are busy chasing grant money with the get out of peer review CO2 card and not doing real science.

JJ
November 21, 2011 6:28 am

Ferdinand Engelbeen says:
Sorry, I disagree. Some skeptics don’t like the ice core CO2 data (or even the current atmospheric CO2 data), because they are one of the cornerstones of the AGW scare. But that are real data.

That are real data that don’t say what they are claimed to say. The alleged pre-industrial CO2 cap of 280 ppm is a convenient ‘err’ in the assessment of ice core data. The temporal resolution of those data is not sufficient to support such claims.

pofarmer
November 21, 2011 6:44 am

What I would like to see, is whatever they use to “baseline” or “proof” the ice core information. Any links would be helpful, because I’ve certainly looked, and can’t find it.

ferd berple
November 21, 2011 6:52 am

“Atmospheric carbon dioxide (CO2) is one of the most important greenhouse gases and the increase of its abundance in the atmosphere by fossil fuel burning is the main cause of future global warming.”
According to the unproven theory of AGW.

Pamela Gray
November 21, 2011 6:56 am

Here is why CO2 neither cools nor heats over short or long periods of time. The oceanic and atmospheric teleconnection used to produce weather pattern variation oscillations has far greater sustaining energy needed for such oscillations than puny CO2 has. If there is any warming or cooling that can be attributed to CO2, it will quickly be overrun, outrun, wiped out, and beaten to the mat by an “ill wind this way blows”.
So, in my opinion, the mortal wound in the paper is this: The authors fail to present the background weather pattern systems in place at the knee bends of rising/falling CO2. They must first rule out the first encountered pathology (intrinsic active weather pattern variation oscillations) before making their case regarding CO2. None of these scientists ever do this in their gloom and doom papers. They walk into a sh**-filled room and look for mice turd, whilst ignoring the sheepish elephant standing in the corner.

petermue
November 21, 2011 7:08 am

New studies:
“At night it is colder than outside”.
“The higher, the splash.”
The LSCE was founded in 2006. Seems they’ve achieved a lot of experience within 5 years to come up with such a crap to justify their raison d’être… and to cry for more $$$ funds.
*yawn*

davidmhoffer
November 21, 2011 7:34 am

“ingeniously combined measurements of isotopes of atmospheric oxygen (18O) and carbon (13C) in marine sediments and ice cores with results from dynamic global vegetation models, the latter being driven by estimates of glacial climate using climate models.”>>>
So….global vegetation based on a computer model based on input about climate from another computer model….
The “ingenious” part would be figuring out how to get that past peer review. Oh wait, we have pal review now. OK, so what was the ingenious part then?

Steve Keohane
November 21, 2011 7:38 am

Carbon cycle? What of the carbon sinks? I have yet to see any mention of the ongoing process of the calcium carbonate deposits on igneous rock, that have to be a current process. We have a lot of basalt in western Colorado. The exposed boulders, as well as buried rocks get covered from the top down in calcium carbonate. How many tons does this comprise?
Gail Combs says: November 21, 2011 at 4:57 am Excellent point about atmospheric pressure due to altitude.

Dave Springer
November 21, 2011 7:49 am

“The researchers, led by Dr Philippe Ciais of the Laboratoire des Sciences du Climat et l’Environnement near Paris, ingeniously combined measurements of isotopes of atmospheric oxygen (18O) and carbon (13C) in marine sediments and ice cores with results from dynamic global vegetation models, the latter being driven by estimates of glacial climate using climate models.”
GIGO squared. I love it. A whole new level of abuse in computer modeling.

kadaka (KD Knoebel)
November 21, 2011 7:52 am

From Gail Combs on November 21, 2011 at 4:57 am, quoted in “Hydroponic shop” section:

Because 300 PPM is the atmospheric CO content, this amount is chosen as the 100% growth point.

Been awhile since it was only 300ppm, that value isn’t even on the “official” Mauna Loa graph, now we’re almost at 400ppm. Is that a very old reference, an “unmixed” local reading, or just mistaken?

November 21, 2011 8:18 am

It is completely wrong to assume that CO2 measurements from ice cores have anything to do with absolute values. They can show trends and highs and lows, but they are NOT quantitative in any way. Jaworowski, the leading expert has stated that there is 30–50% losses of CO2 during the traumatic process of core extraction. If you back calculate the losses, you end up with CO2 concentrations the same or higher than now.
It is only the IPCC that likes to pretend that ice core data, clearly indirect data, is quantitative—it is NOT!

Kelvin Vaughan
November 21, 2011 8:28 am

Atmospheric carbon dioxide (CO2) is one of the most important greenhouse gases and the increase of its abundance in the atmosphere by fossil fuel burning is the main cause of future global warming.
Has someone invented a time machine?

November 21, 2011 8:54 am

Models, models, models and proxy data feeding into more models that feed into ignorance and ideology. And what came first the swamp or the permafrost. As a northerner I am inpatient with southerners trying to tell us how things are and were in the arctic.

More Soylent Green!
November 21, 2011 9:02 am

Ferdinand Engelbeen says:
November 21, 2011 at 1:30 am
charles nelson says:
November 21, 2011 at 12:12 am
I think that the study of gases ‘trapped’ in ice core samples is akin to reading tea leaves…you can see whatever you want to see.
Sorry, I disagree. Some skeptics don’t like the ice core CO2 data (or even the current atmospheric CO2 data), because they are one of the cornerstones of the AGW scare. But that are real data. The problem is in the interpretation by some to make it a scare…

I think it’s the pro-AGW “concensus” people that have a problem with the ice-core data. They’re in denial that warming proceeds increases by CO2 levels by an average of 800 years. The two hardly go hand-in-hand. The data shows first it warms and then CO2 goes up.
Which means from the AGW supporters standpoint, it undermines one of their bases arguments.

More Soylent Green!
November 21, 2011 9:05 am

Henry Galt says:
November 21, 2011 at 1:43 am
“… its abundance in the atmosphere by fossil fuel burning is the main cause of future global warming …”
How marvellously, wonderfully, cosy, fluffy bunnykins it must feel to be so certain. Of anything.
Prats.

There is of course, not a single supporting fact for that statement. It’s accepted as fact.
Any when some other pinhead(s) does a survey of the literature, this study will be counted as one more that supports the so-called “consensus view.”

Interstellar Bill
November 21, 2011 9:06 am

Come now, we all now what actually happened
to end the last interglacial:
The Neandertal-IPCC said 280 ppm
was stressing out the Ice-Age big game they ate,
so they established a fire-rationing committee.
They had such great success in reducing their emissions
that they pulled 100ppm out of the atmosphere.
“Oops! All those glaciers marching south?
Trees don’t grow any more either.
How can that be? It wasn’t in our models!”
Now we know why the Neandertals died out.

Gail Combs
November 21, 2011 9:54 am

Lars P. says:
November 21, 2011 at 4:10 am
“The work has the value to document the big difference between the pre-industrial productivity and today productivity.”
____________________________
Dave Springer says:
November 21, 2011 at 5:06 am
Yes, that leapt off the page at me too. According to the authors biologic activity was 40 petagrams carbon during glacial period, 80 petagrams during pre-industrial, and 120 petagrams today.
So the primary producers in the food chain are 50% more productive today than 200 years ago. This is the highest figure I’ve seen. Typically 15% to 30% is bandied about for the agricultural windfall of increased atmospheric CO2 but that doesn’t take into account longer growing seasons from CO2 induced surface warming nor reduced water requirements. So this is a VERY interesting admission coming from the nattering nabobs of anthropogenic negativity…..

______________
That is an interesting point, guys. It goes along with the charts of grain (cereal) production showing an increase from about 2.5 tonne/hectare to almost 7 tonne/hectare http://wattsupwiththat.files.wordpress.com/2011/11/goklany_srex2.jpg
It is from the WUWT article: http://wattsupwiththat.com/2011/11/19/the-odd-omission-in-ipccs-summary-for-policy-makers-for-srex-on-extreme-weather-and-climatic-events/#more-51451
It is nice when information from completely different areas dovetail.