Plants gobbling up CO2 – 45% more than thought

From the Helmholtz Association of German Research Centres a clear indication for those “CO2 is plant food” scoffers that the plants don’t care what they think.

Productivity of land plants may be greater than previously thought

Researchers recommend the reworking of global carbon models in Nature

This press release is available in German.

For the news study the reseachers analyzed also datas of the Cape Grim air archive at CSIRO's Aspendale laboratories. The Air Archive is an irreplaceable collection of air samples from Cape Grim, northwest Tasmania. It is like a library or museum of air that provides valuable information about greenhouse and ozone depleting gases. Every three months, researchers have filled stainless steel flasks with about 1 000 litres of pristine air, which is then stored in the Cape Grim Air Archive at CSIRO Marine and Atmospheric Research in Aspendale, Victoria. The Cape Grim Air Archive was initiated by Dr Paul Fraser in 1978, knowing that one day scientists might be interested in measuring gases that at the time were not being (or could not be) measured. CSIRO Marine and Atmospheric Research near Melbourne in Australia undertakes research into the atmospheric environment and belongs to the Commonwealth Scientific and Industrial Research Organisation (CSIRO). Credit: Photo: Tilo Arnhold/UFZ

London – The global uptake of carbon by land plants may be up to 45 per cent more than previously thought. This is the conclusion of an international team of scientists, based on the variability of heavy oxygen atoms in the carbon dioxide of the atmosphere driven by the El Niño effect. As the oxygen atoms in carbon dioxide were converted faster than expected during the El Niño years, current estimates for the uptake of carbon by plants are probably too low. These should be corrected upwards, say the researchers in the current issue of the scientific journal NATURE. Instead of 120 petagrams of carbon, the annual global vegetation uptake probably lies between 150 and 175 petagrams of carbon. This value is a kind of gross national product for land plants and indicates how productive the biosphere of the Earth is. The reworking of this so-called global primary productivity would have significant consequences for the coupled carbon cycle-climate model used in climate research to predict future climate change.

Lisa Welp of the Scripps Institution of Oceanography at the University of California in San Diego and her colleagues evaluated the data for the global isotopic composition of the greenhouse gas CO2 over the last 30 years. This analysis indicated regular fluctuations between years and a connection with the El Niño phenomenon in the Pacific. Overall, El Niño years are warmer. They are also characterised by greater precipitation in South America and less intensive monsoons in Southeast Asia.

The researchers found a more rapid recovery of the

IMAGE:The global uptake of carbon by land plants may be up to 45 per cent more than previously thought. This is the conclusion of an international team of scientists, based…Click here for more information.

isotopic ratios following the El Niño events than assumed, indicating a shorter conversion time for CO2 in the terrestrial biosphere. On the basis of these data, the authors calculate the so-called global primary productivity (GPP). They now propose correcting this in the global models from 120 to 150-175 petagrams) of carbon annually.

Since 1977 the isotopic ratios in the carbon dioxide of the atmosphere (18O/16O und 13C/12C) have been measured in order to better understand the global carbon cycle, as the exchange processes between the biosphere, the atmosphere and the oceans are reflected in these values. “We assume that the redistribution of moisture and rain in the tropics during El Niño raises the 18O/16O ratio in precipitation and plant water and then signals this to the atmospheric carbon dioxide”, explains Lisa Welp the new approach of the researchers.

“Our atmosphere is a perfect blender. Changes in its levels of trace gases – such as carbon dioxide – reflect the overall release and uptake of trace gases from all sources. So if you measure the carbon exchange of a forest ecosystem, for example, you “only” get the net exchange of all the carbon taken up by the trees for photosynthesis and all the carbon released by the trees and soil “, writes Dr. Matthias Cuntz of the Helmholtz Centre for Environmental Research (UFZ) in his commentary in the same issue of NATURE. The gross-exchange fluxes, such as photosynthesis, are however accessible only with difficulty. “Global estimates therefore depend upon a number of assumptions. This includes, for example, how many of the CO2 molecules entering a plant are actually fixed by photosynthesis. The researchers of Lisa Welp’s team assume that around 43 per cent of all CO2 molecules entering a plant are taken up by the plant. If this were only 34%, the estimate would fall to about 120 billion tons of carbon – that is, to the currently accepted value”, for Matthias Cuntz reason of thought. In his opinion, the new findings do not completely upset the research to date. Nevertheless, they demonstrate an interesting new method for the determination of plant productivity over large areas. In future, the combination of several isotopic methods with conventional measurements represents a promising approach.

The now published study was carried out under the direction of Ralph F. Keeling, a professor of oceanography and the son of the late Charles David Keeling, after whom the so-called Keeling curve was named. This graph shows the concentration of CO2 of the volcano Mauna Loa on Hawaii since the year 1957. In the 1950s the CO2 fraction in the earth’s atmosphere was still around 315 ppm. In 2011, by comparison, it has already increased to 390 ppm. With his measurements Keeling was able to show for the first time that the concentration of the greenhouse gas increases in relation to changing land use and the combustion of fossil fuels. This new study underscores the importance of long-term measurements of the isotope 18O in the carbon dioxide of the atmosphere from the scientific point of view, as this occupies a key position between the carbon cycle and the hydrogen cycle.

###

Publications:

Lisa R. Welp, Ralph F. Keeling, Harro A. J. Meijer, Alane F. Bollenbacher, Stephen C. Piper, KeiYoshimura, Roger J. Francey, Colin E. Allison & Martin Wahlen (2011): Interannual variability in the oxygen isotopes of atmospheric CO2 driven by El Niño.

29 September 2011, Vol. 477, Nature 579, 579-582. doi:10.1038/nature10421

Matthias Cuntz (2011): A dent in carbon´s gold standard.

29 September 2011, Vol. 477, Nature 579, 547-548.

Links:

CO2- and Isotopic Measurement Program of the Scripps Institution of Oceanography, USA:

http://scrippsco2.ucsd.edu/data/atmospheric_co2.html

Atmospheric Measurement Program of the National Oceanic & Atmospheric Administration, USA:

http://www.esrl.noaa.gov/gmd

Cape Grim Baseline Air Pollution Station, Tasmania, Australia:

http://www.csiro.au/places/Cape-Grim.html

El Niño – Southern Oscillation (ENSO):

http://de.wikipedia.org/wiki/El_Ni%C3%B1o

==============================================================

Here’s an interesting illustration of the effect increased CO2 has on plants, and unlike Mr. Gores’s faked high school physics experiment, you can see this one in time lapse from start to finish as it actually occurred.

Advertisements

  Subscribe  
newest oldest most voted
Notify of

If plants keep sucking up all that heat-inducing CO2, my veggies will cook right on the vine; convenient. The popped corn is going to be messy though.

DCA

What impact will this have on Salby’s upcomming paper?
http://judithcurry.com/2011/08/04/carbon-cycle-questions/

Now they need to quantify the rates of uptake of the ocean’s greater biomass. Then they will find that natural processes control the atmospheric concentration of CO2 not anthropogenic.

So… We humans emit ~8.5 GtC worth of CO2 per year… And according to the Hockey Team, the rise in atmospheric CO2 since 1850 is attributed to humans because of a “simple accounting” of the natural carbon flux plus our emissions… And now we find out that all this time, plants were taking up 30 to 55 more GtC per year than the Hockey Team had accounted for…
It’s becoming increasingly obvious that the Hockey Team defines the natural carbon flux as whatever it needs to be in order for their simple accounting to work.
Next thing you know, we’ll find out that the d13C depletion since 1850 is actually a rebound from the d13C enrichment of the Little Ice Age.

DirkH

This means that the European CO2 market will be flooded with CDM credits and the prize for a CO2 permit will drop to zero real soon now… (more supply than demand).
(Just guessing – I don’t know how many Ugandans have actually been evicted for such CDM credits and whether it will affect that market severely. But I would expect it. So every careful investor will run for cover RIGHT NOW.)

Don Keiller

Who would have thought???
Give plants more CO2 and they “fix” it more effectively!!!!!!!!!!!
However a nice piece of work, using existing measurements in a novel way.
REAL SCIENCE!

Latitude

duh…………..
Why do they think CO2 levels are so low in the first place
Plants, algae, bacteria, plankton, etc take up fertilizer until it becomes limiting

I posted yesterday some investigation from Portuguese scientists where they demonstrated that Port vines love that extra CO2! Two of their main conclusions:
“The elevated [CO2] concentration increased net photosynthetic rate (A), intrinsic water use efficiency (A/gs), leaf thickness, (…) Yield, cluster weight and vigour showed an increase in elevated [CO2] treatment but yield to pruning mass ratio was unaffected.”
“This study showed that the predicted rise in [CO2] did not produce negative effects on the quality of grapes and red wine. Although some of the compounds were slightly affected, the red wine quality remained almost unaffected.”
Post, mainly in Portuguese:
http://ecotretas.blogspot.com/2011/09/vinho-do-porto-com-mais-co2.html

PearlandAggie

As if any data will really change their beliefs….

R. Shearer

Mr. Bussjaeger, we are 200 years and maybe 1C away from the year without a summer. Don’t worry about your vegetables cooking on the vine.

1DandyTroll

It’s funny how proper forest and farming management can help suck up EPA defined bad stuff. Ever since we started going away from crappy socialist forest and farming management techniques by using certain types of fast growing grass, crops and trees, to suck all that really bad stuff out of the ground they also suck more CO2 out of the air.
Although it is quite weird, the communist hippies want everything to just lay were it falls and no branch, tree or hindu kush bush is to be harvested for green energy production even, all the while promoting green energy and less EPA toxic stuff like CO2 in the air. 0_o

Chris D.

“They now propose correcting this in the global models from 120 to 150-175 petagrams) of carbon annually.”
Nuh-uh! The science is already settled so move along and get with the program already.

Latitude

This value is a kind of gross national product for land plants and indicates how productive the biosphere of the Earth is.
=================================================================
Algae, phyto, bacteria, etc take up a lot more…….
If this “adjustment” is just for land plants, and it’s that far off…………

ChE

You don’t say.
Suppose this might have something to do with the world’s rising agricultural productivi… Nah. Crazy idea.
REPLY: Actually NASA has documented that the entire biosphere is booming.
http://wattsupwiththat.com/2011/03/24/the-earths-biosphere-is-booming-data-suggests-that-co2-is-the-cause-part-2/
-Anthony

David Middleton says:
September 29, 2011 at 10:25 am
And according to the Hockey Team, the rise in atmospheric CO2 since 1850 is attributed to humans because of a “simple accounting” of the natural carbon flux plus our emissions…
The new finding only shows that the total flux in and out is larger than expected, but that is only throughput and not of the slightest interest for the material balance. It is the difference between what the biosphere takes away and what the biosphere emits that makes the balance.
And that is known, be it with large margins of error, based on the oxygen balance. When plants grow, they produce oxygen (about 1.2 molecule for 1 molecule of CO2 captured). Conversely, when in fall leaves and plant parts are decaying or soil bacteria at work the whole year round, that uses oxygen.
The net result of the oxygen balance is that the whole biosphere (including ocean plants, animals, insects, bacteria) takes about 1.0 +/- 0.6 GtC/yr out of the atmosphere. That is in quantity about 1/6th of what humans emitted in the same period. The oceans take about 1.6 GtC/yr, that is about 1/3rd of the human emissions. Both together thus take about halve the human emissions (as mass) out of the atmosphere. The rest of the human emissions (as mass) accumulates in the atmosphere, already 150 years…
See: http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf

Paddy

Does this study call into question the assumptions regarding the half-life of atmospheric CO2 emissions? As I recall the GCMs assume that CO2 resides in the atmosphere for 100+ to 200+ years after emission. I recall that there are also empirical ch studies that conclude the CO2 half-life is 5 to 7 years. Which is correct or closer to actuality?

Frank K.

I must confess that I would feel very guilty if I tried to STARVE the plants of the Earth by reducing my CO2 footprint. I therefore will plan to increase my production of CO2 many-fold by stocking up on my wood pellets, which will be burned this winter to produce heat (for me) and lots of CO2 for the plants. Its a win-win scenario for the biosphere!

Ferdinand
This is the classic IPCC view of the carbon cycle.
http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions.htm
Has anything we have learnt since AR4-including this latest study-changed the totals or the proportions?
tonyb

Chuck Nolan

So, it’s worse than we thought.
We thought we were only putting out so much CO2 and now we find it was 45% more than what we thought because the bushes were cleaning up 45% more than we thought. I knew it would turn out to be Bush’s fault. And for sure, it’s worse than we thought.

Jeff

Sweet!
Everyone plant a couple fast growing trees problem solved. Or is it? With all the extra trees we now sink more carbon and by the AGW theory I have just thrown us into an ICE AGE. I won’t be able to sleep tonight knowing that I may have ended the world..
All silliness aside how many trees would you have to plant to bring atmospheric CO2 levels down to the ever changing (Norm) of around 300ppm?

Bart

Latitude says:
September 29, 2011 at 11:00 am
‘If this “adjustment” is just for land plants, and it’s that far off…………’
And, who is to say that the “adjustment” is the final word?
All that had been done to date was to create a narrative with which the data at hand superficially agreed, to a rough order of approximation. I expect the warming plank of AGW to fall first, as Global Cooling kicks into high gear in the next decade. Eventually, the subsequent decline in CO2 concentrations will drive the final stake through the heart of the entire scientific farce.

DirkH

Ferdinand Engelbeen says:
September 29, 2011 at 11:13 am
“”The new finding only shows that the total flux in and out is larger than expected, but that is only throughput and not of the slightest interest for the material balance.”
Thanks for the clarification, Ferdinand!

So, just like plants in a greenhouse where CO2 is artificially raised, the plants “in the wild” will also take advantage of an increased CO2 level.
Now, I don’t like the “c” word (“conspiracy”), but it sure looks like this activity by planet-wide flora is more than mere coincidence.
We need to be vigilant. That extra fruit hanging from a tree maybe be part of their grand scheme.
Are the Triffids on the march?

John F. Hultquist

Jeff says:
September 29, 2011 at 11:44 am
Sweet!

Trees! Many trees have brown/black trunks and dark green leaves. Plant them at a mid-to-high latitude (say the northern tier of US states and farther north) and the intercepted energy can raise the temperature more so than light colored plants (say dead grass in fall and winter), reflecting water, and snow.
About 10 years ago planting trees was the thing that was going to save the planet. Then studies were done. We haven’t heard much about it since.
http://usgovinfo.about.com/b/2006/12/18/trees-in-wrong-places-could-hasten-global-warming.htm

JJ

“And that is known, be it with large margins of error, based on the oxygen balance.”
Uh, when the (undoubtedly underestimated) margins of error are approximately the same size as the measurement, dont you think that throwing the word ‘known’ around is a bit cheeky?
When plants grow, they produce oxygen (about 1.2 molecule for 1 molecule of CO2 captured). Conversely, when in fall leaves and plant parts are decaying or soil bacteria at work the whole year round, that uses oxygen.
“Both together thus take about halve the human emissions (as mass) out of the atmosphere. The rest of the human emissions (as mass) accumulates in the atmosphere,”
Uh, no it doesnt. Currently, the carbon budget is not closed. The rate of increase in the atmospheric CO2 concentration cannot be accounted for – it is much slower than would be expected according to the accounting you propose. By about 50%. Currently, we cannot even pretend to account for an amount of anthropogenic carbon equal to the amount we think we see as an increase in atmospheric concentration.
The issue of the carbon budget is nowhere near ‘known’.

Ged

Whoa, look at how happy that plant in 1270 ppm CO2 was, it was positively dancing! (yes, actually, plants do move and that wasn’t a wind, it was the plant moving itself around. Such motions are usually much slower than we can have the perception to watch in real time)
That was really cool watching–what struck me was the huge reduction in germination time: that would make an enormous impact on agriculture.

@Ferdinand Engelbeen says:
September 29, 2011 at 11:13 am
Ferdinand, they aren’t measuring the natural flux in Bender et al.,2005. They are calculating it based on assumptions from the measured rise in CO2. The O2/N2 ratio matches the CO2 rise… Which is not diagnostic of CO2 sourcing.
“The O2/N2 ratio of air is falling because combustion of fossil fuel and biomass both consume O2. The observed rate of decrease is less than the calculated rate of O2 consumption by combustion. The difference is due almost entirely to net O2 production (and corresponding CO2 uptake) associated with the growth of the land biosphere.”
The observed decrease in O2 “decrease is less than the calculated rate of O2 consumption by combustion” and presumably much less than the calculated rate of fossil fuel consumption and biomass consumption. However, the rates of biomass O2 consumption and biospheric O2 production are essentially guesses based on the presumptively well-known rate of O2 consumption from fossil fuels.
If half, or more, of the CO2 was the result of oceanic out-gassing related to the warm up from the Little Ice Age, the O2/N2 ratio could very easily behave the same way.

CodeTech

Unbelievable…
People who profess to be Science Professionals do not understand one of the most fundamental characteristics of life itself.
Life seeks food. Availability of food is the limiting factor of life. Plant life is no different. In fact, plants, unlike animals, can usually live to reproduce at amazing extremes of size… either really small or really, really large.
This is the main reason I personally have always laughed at the CO2 hand-wringers. As CO2 levels rise, for whatever reason they are rising (no, the science is not “settled” on that), the flora of the world benefits hugely and does its level best to reduce the level. As long as food increases, plants will grow. And not just forests, but all plant life, everywhere. Plant absorption of CO2 could double or triple within 24 hours if it was beneficial. Think about it: what if all those tiny little seeds that you know will become weeds in your garden suddenly burst into life? What if every dandelion or grass seed actually started growing into a plant?
Which is why ANY scheme to reduce CO2, including dumping crap in the oceans or CO2 scrubbers or, outright dangerous and directly wasteful and harmful: sequestration, is a stupid, stupid thing to do.
Limiting CO2 emission is stupid, and believing that limiting CO2 emission is a good thing to do belies a fundamental ignorance of everything to do with Science and Nature.

P Walker

Paddy ,
I suspect that the empirical observations are closer to reality .

oldseadog

Chuck,
No, it’s better than we thought.

Olen

How long before they want to pump oxygen into the ground and then hydrogen?

Latitude

Ferdinand Engelbeen says:
September 29, 2011 at 11:13 am
The new finding only shows that the total flux in and out is larger than expected,
=============================================================
They are not talking about flux……
They are talking about CO2 incorporated into the plant mass
“The researchers of Lisa Welp’s team assume that around 43 per cent of all CO2 molecules entering a plant are taken up by the plant.”

Mark

I can’t tell if this finding is good or bad for my potential carbon credits………..

jeanparisot

Do any of the climate models incorporate a variable for the biomass CO2 sink?

climatereason says:
September 29, 2011 at 11:36 am
Has anything we have learnt since AR4-including this latest study-changed the totals or the proportions?
Hi Tony,
One of the points is a better indication of the distribution of CO2 between the main sinks: the oxygen balance is at the edge of the analytical possibilities of the method (1 ppmv change in 200,000 ppmv!), but the longer the time frame, the more accurate the results become.
The main result is that the biosphere before the 1990’s probably were a net source of CO2 (based on a few samples of ancient air taken in flasks), but since then an increasing sink. The oceans also increase in sink capacity, but plant uptake increases faster.
More detailed work is underway with tall towers, where fluxes over larger areas are measured. And the satellites are at work, the Japanese one is looking at the total air column to the surface, but I haven’t seen anything beyond some preliminary results.

kim

What’s good for General Plant, is good for the U. S. of Animals.
======================

Dale

The plants are wrong! The models tell me that CO2 uptake is 120. Someone tell the plants the truth!

JJ says:
September 29, 2011 at 12:33 pm
Uh, when the (undoubtedly underestimated) margins of error are approximately the same size as the measurement, dont you think that throwing the word ‘known’ around is a bit cheeky?
The magins of error are huge, because of the accuracy of the oxygen measurements, but nevertheless, one can say that the world is “greening”, as the biosphere is a net sink for between 0.4 and 1.6 GtC/year. Which in general is confirmed by satellites.
Currently, the carbon budget is not closed. The rate of increase in the atmospheric CO2 concentration cannot be accounted for – it is much slower than would be expected according to the accounting you propose. By about 50%.
I don’t see the problem here. As long as the increase in the atmosphere is less than the human emissions, then nature is a net sink for the difference. No CO2 escapes to space, thus as no carbon can be destroyed or made, the oceans and/or vegetation take the difference away. It is only of academic interest what the distribution between these two main sinks is, even if vegetation was a net source, that only means that the oceans are a larger sink, as these must remove halve the human emissions and what vegetation emits.
It would be different if the increase in the atmosphere was larger than the human emissions. In that case, both humans and nature add to the atmospheric CO2 increase.

Honest ABE

Matthias Cuntz? That name sounds familiar. I think he may have been related to an old girlfriend of mine.
Geez, that is an even worse last name than Bastardi.

Legatus

Ferdinand Engelbeen says:
September 29, 2011 at 11:13 am
“”The new finding only shows that the total flux in and out is larger than expected, but that is only throughput and not of the slightest interest for the material balance.”
A question, where did all these supposedly harmfull hydrocarbon feuls come from, anyway? Did they just magically appear? No, they started out as mostly plants. This shows that carbon going into plants does not nessissarily all return to the atmosphere, as we can see that a considerable amount ended up in the ground and stayed there. Therefore, your statement is proven false by the existance of hydrocarbon feuls. Note also that huge amounts of gas type fossil feuls have recently been discovered, enough for many hundreds, perhaps even thosuands, of years, all that carbon had to come from somewhere.
Howwever, there is throughput, WE are doing the throughput. We are returning to the air all the carbon that those nasty greedy plants stole and hid away in their secret stash.

Caleb

RE: David Middleton says:
September 29, 2011 at 10:25 am
Thanks, Dave, for that link.
It would be very interesting if the d13C increase, which is seen by Alarmists as a humanity-caused effect, truely did occur during the last warm-period before the last ice age, because humanity could not have caused it back then.
This would focus true scientists upon other possible causes of d13C increases and decreases, and increase our scientific understanding. I really do think that these studies of isotope differences give us a really neat tracer to use as a tool.
The problem with some Alarmists is that they are so eager to prove mankind is the culprit that they develop a sort of blind spot, and are unable to see other options.

Kasuha

This sure is very interesting research asi it shows that not as much CO2 might be getting dissolved in water as thought. It doesn’t change the global CO2 air concentration trend though.
I guess its main message is that we should plant more trees?

The arguments demonizing “carbon” sound exactly like Malthus’ warning against population growth.
More CO2 is better. The biosphere is starved of it.
There is no evidence of any global damage or harm as a result of the rise in CO2. Therefore CO2 is harmless. But there is ample evidence of increased agricultural production due to more CO2. Therefore CO2 is beneficial.
Thus, CO2 is harmless and beneficial at current and projected levels. More is better, and there is zero evidence of any downside to increasing this essential trace gas.

I wonder how many extra petajoules of solar energy the biosphere (both land and water based) is consuming to produce this observed increase in growth rate???
No wonder global temperatures have flat-lined over the last twelve years!

David Middleton says:
September 29, 2011 at 12:34 pm
Ferdinand, they aren’t measuring the natural flux in Bender et al.,2005. They are calculating it based on assumptions from the measured rise in CO2. The O2/N2 ratio matches the CO2 rise… Which is not diagnostic of CO2 sourcing.
They don’t calculate the natural fluxes at all, because that is not of interest. They calculate the difference between the total natural uptake and the total natural release. That is what the oxygen balance gives. Fossil fuel consumption is reasonably known (maybe underestimated) from sales (taxes!). Combustion efficiency is known from most processes, so one can calculate how much oxygen fossil fuel burning uses. In reality, the amount of oxygen used is less than that, thus the whole biosphere is a net producer of oxygen. That includes all known and unknown fluxes, including forest fires, rotting wood, ocean plants, food eten by animals, etc…
Thus without knowing any natural flux in detail , we know that the biosphere as a whole is a net absorber of CO2. And preferentially 12CO2. Thus enriching the atmosphere in 13CO2, but we see a steep decrease in 13C/12C ratio.
Ocean CO2 uptake or release doesn’t change the O2 balance, as that is a matter of simple direct solubility, but it changes the 13C/12C ratio, because of fractionation at the surface. The current ocean releases would increase the 13C/12C ratio of the atmosphere, but we see a steep decrease…
The simple conclusion: both oceans and vegetation are net sinks for CO2, sequestering about halve the human emissions (as mass, not as original molecules).

Gail Combs

ChE says: @ September 29, 2011 at 11:11 am
You don’t say.
Suppose this might have something to do with the world’s rising agricultural productivi… Nah. Crazy idea.
____________________________________________________________________
REPLY: Actually NASA has documented that the entire biosphere is booming.
http://wattsupwiththat.com/2011/03/24/the-earths-biosphere-is-booming-data-suggests-that-co2-is-the-cause-part-2/
-Anthony

_______________________________________________________________________
BUT,But, but Monsanto claims the increased productivity is because of THEIR GM plants…..

DirkH

Smokey says:
September 29, 2011 at 1:42 pm
“More CO2 is better. The biosphere is starved of it.”
It is a wonderful feeling each morning to commute to work and see the trees flourish under the healthy influence of my car’s exhaust, I tell ya. Soon they’ll be rivaling the wind turbines in height!

Legatus says:
September 29, 2011 at 1:34 pm
This shows that carbon going into plants does not nessissarily all return to the atmosphere, as we can see that a considerable amount ended up in the ground and stayed there.
That is what I said too: some 1 GtC/year of CO2 is sequestered in more permanent carbon storage (peat, roots,…) . No matter how high the seasonal fluxes in the biosphere are: 120 GtC or 155 GtC back and forth between plants – atmosphere – oceans and back. The height of the fluxes is not important, only the net difference between the fluxes is important.
The point is that we burn carbon buried millions of years ago from an atmosphere at that time which had 10-12 times more CO2 than today. Thus we are enriching the atmosphere of today with extra CO2. No problem for plants, to the contrary, but it has some effect on temperature. How much, that is a matter of debate (my opinion is that the effect is modest and mostly beneficial). But there is very little doubt left that humans are the cause of the increase of CO2 in the atmosphere over the past 160 years…

Gail Combs

JohnWho says: @ September 29, 2011 at 12:13 pm
So, just like plants in a greenhouse where CO2 is artificially raised, the plants “in the wild” will also take advantage of an increased CO2 level.
________________________________________________________________
Yes the plants will suck the CO2 down to 200ppm (where growth stops) within about 20 mins of sunrise in a greenhouse that does not have CO2 raised to 1000ppm to 15000ppm artificially. Another study indicated the same thing happens in open fields. The CO2 in the air near the leaves also drops to 200ppm. (If some one wants I could try to dig out the studies)
It would seem that WIND bring in fresh CO2 may be the actual limiting factor. I wonder if anyone has bothered to do the study.
The idea that the CO2 is “Well mixed” in the air is a bit misleading but what else is new in IPCC “science”

Paddy says:
September 29, 2011 at 11:29 am
As I recall the GCMs assume that CO2 resides in the atmosphere for 100+ to 200+ years after emission. I recall that there are also empirical ch studies that conclude the CO2 half-life is 5 to 7 years. Which is correct or closer to actuality?

The 5-7 years is how long a certain CO2 molecule (whatever its origin) resides in the atmosphere before being exchanged by another CO2 molecule from the oceans or vegetation. That doesn’t change the total amount of CO2 in the atmosphere, only changes the origin of the CO2. The residence time is in/outflux divided by total mass or 150/800 or ~18% which gives a residence time of over 5 years. Not to be confused with an excess decay time, that is how long it takes to remove some extra injection of CO2 out of the atmosphere again.
The 100+ years is based on how long it takes to remove an excess amount of CO2 (whatever its origin) in the atmosphere back to “equilibrium”. That takes much longer than 5-7 years, as the current amount which is sequestered is only 4 GtC/year, while humans still emit 8 GtC/year. If we stop all emissions today, the next year would see a drop of 4 GtC (2 ppmv), then 3.8 GtC the year after, etc. until we reach the old “equilibrium” level of 290 ppmv in the atmosphere. The half life time of that process is about 38 years (e-folding time = excess CO2 divided by the current sink rate = 220/4 or 55 years). Far longer than the empirical evidence (which is for a complete different item), but far shorter than the IPCC’s thousands of years for some fractions. The latter is based on an expected saturation of the (deep) oceans, of which there is no sign up to today.