From the DOE/BROOKHAVEN NATIONAL LABORATORY
Synchronized leaf aging in the Amazon responsible for seasonal increases in photosynthesis
High-tech photography in the Amazon reveals that young leaves grow in at the same times as older ones perish
UPTON, NY-One hundred and fifty feet above the ground in the Amazonian rainforest, a vast ocean of green spreads out in every direction. The rainforest canopy is made up of mostly tropical evergreen trees, which take in enormous amounts of carbon from Earth’s atmosphere. Understanding the carbon cycle in these forests – how carbon is stored in plants and soil and then returned to the atmosphere – is crucial to creating accurate models that predict how global climate will change in the future. Key to that puzzle is understanding photosynthesis in tropical forests.
“We want to understand whether photosynthesis in tropical evergreen forests is driven primarily by seasonal climate or by the internal dynamics of the rainforest,” said Jin Wu, a post-doctoral research associate at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory. Wu is the lead author on a study completed while he was a Ph.D. student with senior author Scott Saleska, Associate Professor of Ecology and Evolutionary Biology at the University of Arizona, published online in the February 26 issue of Science.
Wu, together with other members of Scott Saleska’s lab and international collaborators from Brazil, Australia, and Japan found that new leaf growth is synchronized with old leaf loss in the dry-season of the Amazon rainforest. This shifts the makeup of the tree canopy towards younger leaves, which display higher photosynthetic capacity, and explains the large observed seasonal increases in photosynthesis throughout the ecosystem.
Climate models have long represented the tropics in an overly simplistic way, often due to the lack of data from these hard to reach regions. That view assumed that tropical forests have consistent canopy greenness throughout the year–unlike the dramatic seasonal changes in temperate forests, heralded by vibrant reds and yellows.
“At the landscape level, it always looks evergreen,” Wu said. But broad-scale images–for example, those taken by satellites–often can’t discern the ground level subtleties that have a large impact on the level of photosynthesis. “Evergreen doesn’t mean there are no internal dynamics,” Wu said.
Seeing the trees through the forest
To better examine the impact of these internal dynamics on photosynthesis, Wu and his colleagues used all available data from four sites in the Amazon with a wide range of tree species, rainfall gradients, and soil types: three spots near the equator along the Amazon River, and one water-limited site on the southern side of the Amazon.
At these sites, the researchers measured variables that allowed them to calculate the aggregated photosynthesis rate across the whole forest. They found that the derived photosynthetic capacity from these measurements is seasonal. That is, though the forest is evergreen, the internal photosynthetic machinery changes throughout the year.
To determine what caused these changes, they used tower-mounted cameras perched over the treetops to survey a plot about a third of a mile square, observing the changing quantities and qualities of leaves in the canopy crowns. They found that leaf area increased significantly during the dry season, but these increases precede photosynthetic capacity by at least 1 month, which is increased twice as much as would have been expected from the increase in leaf area alone.
“It’s not just the quantity of leaves that makes a difference. In tropical evergreen forests, the overall quantity of leaves doesn’t change that much, so the quality of leaves is an important driver in photosynthesis,” Wu said.
Leaf age matters
To investigate the quality of the leaves, expert tree climbers accompanied the researchers as they trekked into the jungle, scaling the trees to tag individual leaves from the time they emerge and take photographs weekly and then monthly. This work revealed important changes in leaf biophysical and physiological properties through their life cycles.
“Photosynthesis is like a metabolism,” Wu said. “As human beings, our metabolic rates are strongly age-dependent. Leaves are similar. During their first two months, leaves expand and acquire more chlorophyll, becoming greener.” But Wu and his team found that leaves don’t reach their photosynthetic peak until they are fully expanded at two to five months old. At that point, they are more efficient in absorbing light and more efficient in converting light to food — that is, stored carbon. After six months, their photosynthetic rates decline as they enter ‘old’ age.
The effect of leaf age on physiology explained the surprisingly high seasonal changes in photosynthetic capacity.
Wu said that incorporating these details about tropical evergreen leaves into earth system models will allow for more accurate predictors of carbon exchange and, ultimately, their feedbacks to climate.
Taking the Tropics Into Account
“Tropical rainforests are biologically really important, but our understanding is so limited because the available data is very limited,” Wu said.
He is continuing his PhD research as a post-doc in a program designed to remedy the paucity of data from this region, the Next Generation Ecosystem Experiments – Tropics (NGEE-Tropics). This project is supported by the DOE Office of Science and led by Lawrence Berkeley National Laboratory’s Earth Sciences Division with partner institutes including Brookhaven.
NGEE-Tropics is an ambitious 10-year project to dramatically reduce the uncertainty in climate models and increase scientific understanding of how tropical forest ecosystems will respond to climate and atmospheric change.
Wu was recently in Panama, getting up close and personal with the rainforest. Together with Brookhaven scientists Kim Ely, Shawn Serbin, and Alistair Rogers, he is studying the impact of the El Niño-Southern Oscillation (ENSO) on the response of photosynthesis to drought, and building relationships between important physiological properties that drive model uncertainty and other observations.
“If we want to advance our understanding about the terrestrial carbon cycle in tropical forests, we need to know what types of leaves are present at what times of year, and their physiological properties,” he said. “We can improve our models with this data, and better understand what to look for in the future with remote sensing from tower-mounted cameras, aircraft, and satellites.”
###
Cutting down or burning the Amazon rain forest and other tropical jungles has increased CO2.
But increasing CO2 stimulates the CO2 uptake in the remaining forest.
Was watching some documentary on PBS and they showed some scientist in the canopy with a CO2 meter. If I recall the reading was something like 450ppm.
Surface and near-surface CO2 varies greatly during the day in forests and other areas with live biomass, and often varies from much higher to slightly lower than the global atmospheric average. When the sun is not shining animals, non-photosynthetic plants and bacteria are producing CO2 while photosynthetic plants are not removing it. When the sun is shining photosynthetic plants are removing CO2, but solar heating leads to convection that mixes the local near-surface air with air from above.
The other part of the CO2 cycle in tropical rain forests is the decay of dead leaf litter on the forest floor.The rate of CO2 production on the floor is high when it is hot and wet and lower when it is dry. The canopy uses most of what is produced on the floor but not all the time. Some is added to the global upper atmosphere. Remember the blob of CO2 over the Amazon revealed by the CO2 measuring sattalite.
They say the camera adds 50 ppm.
Adds 50ppm? I sought it was only 10ppm? It must be the new HD Cams.
The “science is settled”.
So I have ben advised, repeatedly, although it looks slightly different from here.
Auto
Oh well. The watermelons seek their fifteen minutes of fame – and a subsequent lifetime of shame.
Leaf aging and replacement should not matter much to the long term trend of global CO2 since this is a periodic cycle that does not cause a long term change in the amount of carbon stored in biomass.
The issue isn’t long-term trends global CO2…the issue is climate models, especially on regional-scales.
Regional CO2 blows around the world. Regions have CO2 (all levels of the troposphere combined) deviating only a few percent from the worldwide average.
Also, regions with CO2 sourcing and sinking by biomass have this alternating with the seasons (or maybe another cyclic factor in tropical rainforests), so what happens as a result there due to cycles does not contribute to even regional long term changes of CO2.
Donald L. Klipstein:
You say
Simply, you are claiming that CO2 in the carbon cycle does not contribute to even regional long term changes of CO2.
The same argument applies to regions of high anthropogenic (i.e. man-made) CO2 emission; i.e.
The anthropogenic CO2 does not contribute to even regional long term changes of CO2 in the atmosphere if the CO2 sequestration by biomass (on land and in oceans) is sufficient to remove all local CO2 emission (both ‘natural’ and anthropogenic) from the air. This is because the anthropogenic CO2 enters the carbon cycle and any ‘excess’ CO2 in the carbon cycle is transported to deep ocean. This total local sequestration is indicated to be the case by the lack of ‘high’ atmospheric CO2 concentrations in regions of high anthropogenic CO2 emission measured by OCO-2.
Richard
Richard Courtney:-
Do you have any data to support the claim that the “excess” CO2 was transported to the deep ocean. And explain “excess” because as I see it there is no such animal; CO2 levels having varied enormously over the past 500Ma so there is no average /normal level to be in excess of.
OCO-2 showed that the southern ocean was the highest producer of CO2 probably due to outgassing due to temperature rise during the southern summer. More CO2 means bigger plants means more CO2 used.
richardscourtney says that OCO2 observations do not show high concentrations of CO2 where anthropogenic CO2 production is occurring. I have yet to see a full-year color-coded map of OCO2 observations posted in WUWT. OCO2 observations over less than a year have their dominant CO2 variations from the global average being seasonal sources and sinks that largely cancel out over a whole year.
Donald L. Klipstein:
You say
The WUWT Search facility could be your friend.
The penultimate plot of this essay is labelled by our host saying
and is followed by the final item of that essay which our host labels
Richard
richardscourtney says:
The anthropogenic CO2 does not contribute to even regional long term changes of CO2 in the atmosphere if the CO2 sequestration by biomass (on land and in oceans) is sufficient to remove all local CO2 emission
There may be huge regional net sinks in the biosphere, but the overall removal of CO2 by the biosphere as a whole (land and sea plants, bacteria, molds, insects, animals) is only a small, but growing sink for CO2 of about ~1 GtC/year. That is about 10% of human emissions:
http://www.sciencemag.org/content/287/5462/2467.short
The same for the oceans: ~0.5 GtC/year are captured by the ocean surface and ~3 GtC/year are sinking in the deep oceans, to practically never return.
Thus about half of human emissions as mass, not as original molecules, remain in the atmosphere: it doesn’t matter if human emissions are captured locally by the next available tree or ten years later by the sinking waters near the poles. The total net sink capacity of the whole biosphere plus oceans is what is measured at about half the human emissions…
Why does the OCO-2 satellite doesn’t fully capture human emissions? That is a matter of resolution. Its resolution is about 0.1 ppmv. Human emissions globally are 0.01 ppmv/day. Only where human emissions are concentrated in large areas, the satellite has sufficient resolution. The satellite also can focus on specific areas for a longer period, which makes its resolution better, but I don’t know if they have used that feature already.
The regions of huge natural emissions in the upwelling zones of the equator and during El Niño periods as we have (had) now, also the tropical forests. The regions of largest sinks are near the poles. That gives a continuous flux of CO2 between the equator and the poles of about 40 GtC/year. The overall balance of this continuous flux is ~3 GtC/year (2.2 +/- 0.4 GtC/year in 1995) more sink that source, based on pCO2 measurements all over the oceans:
http://www.pmel.noaa.gov/pubs/outstand/feel2331/mean.shtml
Thus while natural emissions and sinks are huge, both continuously between equator and poles and seasonally, CO2 levels like from the OCO-2 satellite themselves don’t say much about CO2 fluxes and even less on the CO2/carbon balance… One need additional information like as is provided by tall towers which measure up and down fluxes over large areas and pCO2 measurements over the oceans…
richardscourtney wrote:
“The WUWT Search facility could be your friend.
The penultimate plot of this essay is labelled by our host saying
Eric Swenson provides this map in comments showing CO2 over the entire year from From September 2014 to October 2015”
Thanks!
This map is labelled as 2014/10/01 to 2015/09/22 – close enough to a full year.
The blue areas are mainly colder ocean areas where the oceans are most effective at sinking CO2 from the atmosphere.
The industrial areas of eastern Asia and eastern USA show up as significant CO2 sources.
Another CO2 source seems to have been western and central Canada having had an extremely bad fire season that year, and its CO2 blew southeastward into the northeast USA.
CO2 was elevated east-northeastward from the Asian industrial areas, but in a strangely spotty pattern. Maybe there is divergence and reconvergence of wind path, as in the wind often goes from one hotspot to another, but changes its route from one to another as weather systems pass through. There is such a thing as persistent high and low pressure systems, including blocking patterns that can last for months.
This CO2-rich air could have been descending into the high pressure area associated with The Blob but along an unsteady path, which may account for a CO2 hotspot near The Blob.
Hotspots in Russia may have been from regions with an unusually hot and dry summer, which did happen, which easily favors a bumper crop of wildfires.
There are hotspots of CO2 in parts of the tropical rainforests and nearby parts of Africa and South America – perhaps from widespread burning for clearing land.
I do not yet know of an explanation for the major hotspot of CO2 east of Greenland. However, the map projection here seems to exaggerate the size of it due to its Arctic latitude. Note that Greenland appears at least as large as Australia. Notably the map goes to more extreme latitudes northward than it does southward, and in latitude ranges where it only goes north it seems to “look funny” with possibly exaggerated CO2 deviations and maybe other inaccuracies. I have yet to search for the inclination of this satellite’s orbit and that may affect its accuracy at extreme latitudes.
johnmarshall:
You very reasonably ask me for clarification of my post in this sub-thread when you write
There is no data but there is a logical argument.
I think the problem arises because I lacked clarity concerning the meaning I intended when I used the word “excess”. I wrote
In that statement, my meaning of “excess” is that any CO2 emitted to the air locally is “excess” to local sequestration when it is greater than the CO2 sequestered near its emission site(s).
As you say, “More CO2 means bigger plants means more CO2 used”. Yes, that is one (major) ‘sink’ for CO2. But, I repeat, any CO2 emitted to the air locally is “excess” to local sequestration when it is greater than the CO2 sequestered locally. This excess gets moved by weather (i.e. winds) so finds itself over the sea where the seasonal variation of atmospheric CO2 concentration is immense because CO2 is pumped in-and-out of the oceans by seasonal temperature variation. The net flow from the ocean surface layer is to deep ocean BECAUSE any excess CO2 emitted to the air is transported to the oceans.
This transport of any “excess” CO2 to deep ocean is supported by the observation you cite’; i.e. “OCO-2 showed that the southern ocean was the highest producer of CO2 probably due to outgassing due to temperature rise during the southern summer”.
And I draw your attention to my post to another sub-thread in this thread because it is pertinent to the rapidity of sequestration and, therefore, the possibility of any CO2 emitted to the air locally being “excess” to local.
I hope this clarification is adequate and would welcome your response if it is not.
Richard
Richard thanks for your reply.
As far as oceanic CO2 is concerned, there is no guarantee that any atmospheric CI2 is adsorbed, it depends on water temperature also there are thousands of undersea volcanic vents emitting CO2 much of which is dissolved due to the high pressures involved. This water mixes with the ocean bottom waters, at around 2C, to dissolve directly. There is no atmospheric passage of this CO2.
A biologist, name escapes me, who claimed that “within 20mins of driving down his drive the ‘excess’ CO2 produced by the car would have been used by the border plants”.
johnmarshall:
Thanks for that. I tend to agree with your biologist.
However, those who cling to the ‘overloaded sinks’ hypothesis
(a)
grasp at the fact that there are regions of high atmospheric CO2 near some places of high anthropogenic CO2 emission,
(b)
ignore that there are regions low atmospheric CO2 near some places of high anthropogenic CO2 emission, and
(c)
make excuses for regions of high atmospheric CO2 where there is very low anthropogenic CO2 emission.
If you don’t believe me they do this then see as example the post from Donald L. Klipstein replying to my informing him of where to view an annual OCO-2 plot: his reply includes these gems of attempted excuses for lack of agreement between regions of peak CO2 (which he calls “hotspots”) and regions of great CO2 emission from human activities
Well, “wildfires” and/or “burning for clearing land” cannot be the cause of the “hotspot” over the sea near Greenland!
More importantly, his post says
That asserts that where industrial areas are NOT regions of peak CO2 it is because winds move the CO2. And it grasps at a very flimsy straw when it says, “Maybe there is divergence and reconvergence of wind path, as in the wind often goes from one hotspot to another, but changes its route from one to another as weather systems pass through”.
My point addresses those excuses and is that if winds are displacing the anthropogenic CO2 then the any displaced “excess” CO2 will be sequestered when it reaches regions of significant oceanic sequestration. (I remind that my meaning of “excess” is that any CO2 emitted to the air is “excess” to local sequestration when it is greater than the CO2 sequestered near its emission site(s)).
Richard
Leaf aging and replacement really doesn’t matter much to the long term trend of global atmospheric CO2 ppm.
Excerpted quote from above article:
If the “new” leaf canopy in the Amazonian rainforest requires a two (2) to five (5) months lag time before it reaches its photosynthetic peak (peak CO absorption) ….. then it has to be an assumed fact that the “new” leaf canopy in the forests of the Northern Hemisphere Temperate Zones surely also requires at least a one (1) to two (2) month lag time before it reaches its photosynthetic peak (peak CO absorption).
And iffen there is a one (1) to two (2) month lag time to achieve peak CO2 absorption by the “greening” of the Northern Hemisphere Temperate Zone forests ……. then the CAGW claim that the “cause” of the spring and summertime decrease in atmospheric CO2 as defined by the Keeling Curve Graph is nothing more than “junk science” agitprop.
http://i1019.photobucket.com/albums/af315/SamC_40/keelingcurve.gif
Samuel,
The huge seasonal change is in the extra-tropical forest in the NH, not in the tropical forests…
Samuel
You are correct. The curve that you see on the Mauna Loa curve is simply annual transport recording. It has absolutely nothing to do with sink, storage, conversion. It is simply reading annual transport variances. There is no clear understanding of the carbon cycle (as yet) it is all myth. They dont have a clue.
CO2 at Mauna Loa peaks in May, because it increases from decomposing biomass until northern hemisphere forests start going gangbusters with their photosynthesis – and that largely happens in May. Northern hemisphere forests keep on absorbing CO2 well into September, and their leaves become much less active in October – and CO2 no longer decreases and starts increasing again. This has been the explanation at least as far back as in the 1970s, before there was a manmade global warming issue.
Ferdinand,
In that you failed to mention it, …… then apparently you are utterly ignorant of the fact that there is also a huge seasonal change in the average humidity of the extra-tropical forest in the NH, not in the tropical forests…
Donald L. Klipstein said:
Donald,
You are simply mimicking a “biological impossibility” that you were nurtured to believe is a fact of science. DUH, the decomposing of the dead biomass in the northern hemisphere forests is severely limited and/or restricted during the winter months from September to May simply because said biomass is too dry, too cold or frozen to permit any biological decomposition by bacteria or other microbes. Don’t you know what the primary reason is for owning a refrigerator/freezer?
Donald, ….. the decomposing of the dead biomass in the northern hemisphere forests begins at a rapid pace just as soon as the Springtime temperatures increase above 40F …… which occurs at least one (1) month prior to any photosynthesis activity by the live biomass.
And Donald, that rapid pace …… is “temperature zone” dependent, ….. to wit:
http://vignette2.wikia.nocookie.net/horticultureandsoilscience/images/3/31/Zones2.jpg/revision/latest?cb=20120130150848
Donald L said:
Donald, you got that one correct, ….. it was the explanation that the atmospheric scientists (aka: biological “dummies”) thunked up to explain the bi-yearly cycling of atmospheric CO2 ppm that was defined by the Keeling Curve graph. And it has served their purpose even though they got it 100% wrong.
Donald, there are only three (3) “steady & consistent” bi-yearly cycling activities that occur in the natural world …….. and one (1) of them is the bi-yearly cycling of the equinoxes, ….. the second one (1) is the bi-yearly cycling of the atmospheric CO2 ppm …… and the third one (1) is the bi-yearly increase/decrease in the surface temperature of the ocean waters in the Southern Hemisphere. And all three (3) of those “cycles” are controlled by the orbit and axial “spin” of planet earth.
Samuel C Cogar says rapid decomposition of biomass requires temperatures above 40 F. There are forested areas in the northern hemisphere where the average temperature over an average January is that warm, let alone forested areas that get humid wintertime warm spells. And, the inset in the Mauna Loa graph shows the most rapid increase in the annual cycle is from March to April – which sounds like when a lot of northern forests are warming to 40-plus F but photosynthesis is not yet going gangbusters.
Donald,
Shur nuff, and so does every Public Health Agency in every civilized country on this earth.
To wit, the US of A ……
Trees are important, but not for the government-funded climate gravy train-inspired idiotic reasons they give.
From some extended and for the world climate important regions we don’t know that much. For example: Siberia and Amazonia. This article is very informative about actual processes in plant growth that are taking place in the Amazon and somewhere in the future it could be important to know about. Anyhow the article is changing the idea of the ‘always steady growing’ rainforest. New leaves might have other interesting features, think about reflectance or evapotranspiration. The fact that in the Amazon rain forest new leaves grow periodically – like in the temperate regions – was new to me.
?New to you does not mean new. Well known. Who said tropical growth was steady? Important to know that growth fluctuates. wow bet farmers never ever knew that.
I was not really aware there was much seasonality in the tropics.
Nor me – this is the sort of scientific investigation that needs to be done BEFORE jumping to an erroneous conclusion based on incomplete data.
Darn it, I meant INSTEAD of jumping to an erroneous conclusion!
I thought it was funny you put it that way…
Wet season:dry season. In regards to vegetation growth, very seasonal
Wet and dry seasons are not a characteristic of equatorial rainforests as a whole, but their northern and southern fringes and adjacent savanas.
Manaus definitely has a wet and dry season, from high of over 13 inches of rain in March to low of under 2 inches in August:
https://en.wikipedia.org/wiki/Manaus#Climate
Its climate is considered monsoonal, so I checked Iquitos, whose climate is rated equatorial:
https://en.wikipedia.org/wiki/Iquitos#Climate
More equable, but still a wet and a less wet season, ranging from average of over 12 inches in April to 6.48 in Aug. IOW, never really dry. Most of the Amazon basin is however strongly seasonal, even much if its jungly parts, as wells as the fringe and savanna, as you say.
Drought in this century has been blamed on man-made “climate change”, but recent dryness pales in comparison with the 1870s natural disaster.
Learn something new everyday Tom
Some parts of the tropics don’t have much seasonality, in other parts it’s extreme
All part of the great web of life
The alarmists need a long carbon residence time in the atmosphere. link They say we have to quit emitting CO2 now because the carbon dioxide we emit now will hang around in the atmosphere for centuries. Research that shows that plants react quickly to remove increased CO2 from the atmosphere thwarts that. The research described in this story could actually be important. It could be part of the slow chipping away at CAGW by real science.
I heard a radio interview with Katharine Hayhoe a couple of weeks ago. She said that talking to skeptics was like playing whack-a-mole. She would think she had dealt with one issue only to have the skeptic raise another one. LOL CAGW alarmism only works if the alarmists are allowed to ignore inconvenient facts. I’m cheering for the synchronized leaf aging research because it will likely result in more ‘inconvenient’ facts with which to pummel CAGW.
Yes – three cheers for that research. It is serious, scientific fact-finding – and really interesting to my mind.
There also may be a significant mid-to-high latitude aspect of leaf timing that has not been accounted for (to my limited knowledge). Regionally (southern to central Canadian prairies-parkland zone), we frequently have a killing frost after trees have set new leaves in spring. The leaves are lost, but the trees produce a second set, much reduced both in size and number. Regions experiencing late frosts must lose a good portion of the normal photosynthesis. (As a secondary consideration any tree ring analysis likely would interpret this as drought). In fall a different reaction occurs. Even if the first killing fall frost is delayed by as much as 6 weeks, the leaves begin turning yellow to brown at the time when a frost normally is expected. In other words, photosynthesis begins declining even before a frost. An “extended” summer season, therefore, doesn’t result in much additional activity vis-a-vis the carbon cycle. If an extended summer coincides with drought the trees can have full leaf drop before frost. This is not unimportant in that millions of hectares of aspen forest are involved.
@R2Dtoo, 7:47 am, dreaded by all fruit growers from grape to cherries it can have a devastating effect on crops because the ripening of fruits can be delayed or even lost.
Lifetime of atmospheric CO2 exceeding equilibrium with (seasonally smoothed) natural sources and sinks, if approximated by exponential decay, has a half-life around 40 years. This article supports a tau (time constant) of 59 years, which means a half life of 41 years for an injection (or pulse) of CO2 into the atmosphere: http://wattsupwiththat.com/2015/04/19/the-secret-life-of-half-life/
This WUWT article by Ari Halperin supports a half life of 40 years: http://wattsupwiththat.com/2015/11/24/co2-residence-time-said-to-be-40-years-not-1000-as-noaa-claims/
The Bern model says that the decay is faster initially and slower later on. Part but not all of the slowdown is due to warming decreasing solubility of CO2 in the oceans, and I think the warming considered here is exaggerated. Another reason for non-exponential decay is that the upper part of the ocean takes above-equilibrium CO2 from the atmosphere but then must do a slower process of transferring it to the deeper ocean.
Donald L. Klipstein:
You say
Except that observation indicates a ‘half-life’ in the atmosphere of less than a year for a pulse of additional CO2 into the atmosphere.
A pulse of extra CO2 was injected into the air in 1989. The additional CO2 above trend was 9,000 million tonnes (equivalent to 2,500 mT of carbon or nearly half of annual anthropogenic CO2 emission). In a remarkable piece of detective work, Tom Quirk discerned the source of this ‘pulse’ was ocean biota. But the source of any ‘pulse’ of additional CO2 is not relevant to its ‘half-life’ because the CO2 sequestration mechanisms don’t know the sources of the CO2 molecules they sequester.
The pulse of atmospheric CO2 concentration above trend began in 1989, peaked in 1990 but was gone by the end of 1991. This is total sequestration of the pulse of additional CO2 in three years. A ‘half-life’ of 6months provides 98% sequestration in three years.
Richard
richardscourtney said:
“Except that observation indicates a ‘half-life’ in the atmosphere of less than a year for a pulse of additional CO2 into the atmosphere.”
This pulse was small enough to be less than normal short-term variations caused by factors such as ENSO, or regions of the world having an unusually warm/cool/wet/dry year. Have a look at a Mauna Loa graph to see the annual squiggle and bumps and dips from the trend that last a couple years.
Donald L. Klipstein:
I pointed out that the ‘pulse’ of CO2 into the air in 1989 to 1991 demonstrated a ‘half life’ of less than a year.
You have replied saying
The magnitude of the ‘pulse’ is not relevant especially when it is comparable to the magnitude of anthropogenic emissions.
The fact is that the 1989 to 1991 CO2 pulse demonstrated a ‘half-life’ in the atmosphere of less than a year for a pulse of additional CO2 into the atmosphere. The sequestration processes do NOT know the sources of the CO2 molecules they sequester.
A CO2 pulse ‘half life’ of less than a year demonstrates that limits on sequestration are NOT causal of the observed rise in atmospheric CO2 concentration. Therefore, the Bern Model, the Engelbeen model and all other models which assess ‘input’ and ‘output’ as determinants of atmospheric CO2 are wrong.
The disturbed equilibrium model of Rorsch, Courtney & Thoenes or the similar model of Salby may not be wrong.
Richard
That would be true only for a LTI (linear time invariant) system. The CO2 budget is, for sure, not LTI.
Here’s a link to a graphic showing the carbon budget. There are a couple of things to note:
1 – The budget has numbers to a precision that isn’t warranted.
2 – To attribute the increase in atmospheric CO2 to human emissions, it is necessary to assume that nothing else changes much. ie. CO2 has a long residence time.
Both 1 and 2 above are risable.
Richard,
We have discussed that out on another thread: you are comparing the fast, but limited influence of temperature and light scattering (Pinatubo) on the CO2 rate of change with the much slower decay rate of an excess CO2 pressure in the atmosphere, which indeed is ~40 years over the past 55 years.
The first decay rate is huge (~2 ppmv/year), but levels out to (below) zero within 1-3 years. The influence of the Pinatubo also was huge, but was completely gone within 2 years. In all these years, human emissions still overwhelmed the extra sink rate:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/pulse_1988_1992.jpg
Thus Richard, your conclusion of a fast sink rate is only applicable to the limited influence of temperature and the one-time influence of the Pinatubo, not on the fate of any extra CO2 above the long time equilibrium between oceans and atmosphere…
Ferdinand:
You assert to me
NO! I AM NOT!
I am saying that a pulse of additional CO2 emitted to the atmosphere by ‘nature’ had a magnitude equivalent to about half the anthropogernic emission and it demonstrated a ‘half life’ in the atmosphere of less than a year.
The CO2 sequestration mechanisms do NOT know if CO2 is ‘man-made’ or ‘natural’ and, therefore, the CO2 sequestration mechanisms do not and CANNOT select anthropogenic CO2 for different sequestration.
The CO2 sequestration mechanisms treat ALL CO2 the same.
The observed ‘pulse’ demonstrated a ‘half life’ of additional CO2 in the atmosphere of less than a year while the smooth rise of atmospheric CO2 concentration continued; i.e.
the ‘half life’ of additional CO2 injected to the air is observed to be less than a year.
This observation falsifies your assumption that the continuing rise of atmospheric CO2 concentration results from the anthropogenic emission overloading the sequestration processes so the ‘half life’ in the air of additional CO2 emitted to the air is ~40 years. NO because the ‘half life’ is observed to be less than a year.
Your untrue arm-waving about “comparing” the sequestration rates of different processes is not relevant to the fact that the ‘half life’ of additional CO2 injected to the air is observed to be less than a year.
Richard
commieBob:
I completely agree all the points you make to me. However, your true and good argument is a different issue from the fact that the ‘half life’ of a pulse of CO2 injected into the air is less than a year in the air.
Richard
What was learned from the pulse of 14C reseased into the upper atmosphere by the bomb tests in the 1950-1960’s?
Does anyone have the numbers for half life or residence time obtained from that?
OK I’ll answer the question myself.
As so often there is an excellent WUWT article on this very subject (bomb test 14C clearance):
http://wattsupwiththat.com/2013/07/01/the-bombtest-curve-and-its-implications-for-atmospheric-carbon-dioxide-residency-time/
The answer is an exponential relaxation time of about 10 years.
Relaxation time: The time required for an exponential system to return 1/e (0.368) of its initial value of equilibrium after perturbation.
belousov:
You ask
Residence time of CO2 molecules and ‘half life’ of a CO2 pulse are different issues.
The atmospheric CO2 residence time is the average time a molecule emitted to the air stays in the air before it is removed from the air.
The 14C data (following the nuclear bomb tests) indicates the molecules of a pulse of CO2 are removed from the atmosphere in an average time (i.e. have a residence time) of ~5 years.
A pulse of CO2 molecules injected into the air increases the concentration of CO2 in the atmosphere. That concentration takes time to reduce and the ‘half life’ is the time required for the concentration to return to half the level it had prior to the injection of the pulse.
The value of ‘half life’ is calculated by e.g. IPCC and Engelbeen as a method to fit the observed continuing rise of of atmospheric CO2 concentration to the CO2 sequestration models they promote. In this thread Engelbeen claims a ‘half life’ of ~40 years.
In this thread I have been explaining that the CO2 ‘half life’ in the atmosphere is observed to be less than one year and, thus, the observed ‘half life’ falsifies the models promoted by Engelbeen and the IPCC.
Richard
Richard,
Re. half-life, don’t you mean not half the concentration before the pulse, but half of the pulsed increase?
For example, were the initial concentration 300 parts per million dry air molecules, raised to 400 ppm in a pulse, would not the half-life be the time that the concentration took to get back to 350 ppm rather than down to 150 ppm?
Or have I misunderstood you?
GM
This WUWT article by Gosta Pettersson explains the clearance definition clearly. It is indeed the time to reach half the excess, not half the total concentration:
http://wattsupwiththat.com/2013/07/01/the-bombtest-curve-and-its-implications-for-atmospheric-carbon-dioxide-residency-time/
Gloateus Maximus:
You say to me
YES! Thankyou.
I knew what I meant and failed to see the error of my words.
You are right – that is what I meant – and I what I wrote is wrong.
Again, thankyou for correcting my error.
Richard
Richard,
You’re most welcome.
Thank you for your important contribution to this issue.
commiebob
The statement regarding CO2 remaining in the atmosphere for centuries is totally unfounded. They have no evidence to support this. There is no clear understanding of the carbon cycle let alone half life duration.
Check out the discussion above between richardscourtney, Donald L. Klipstein, and Ferdinand Engelbeen. All sides of the discussion are able to present plenty of evidence.
All sides will be able to present a convincing argument and it is hard to find the precise errors in those arguments. It is also unlikely that anyone will change their position based on evidence presented by the other side.
In any event, I agree with your statement:
Just talking about ‘half life duration’ makes the implicit assumption that the system is linear time invariant (LTI). Nothing about the climate is LTI. 🙂
commieBob –
I agree that many are so entrenched in their belief that they will not be swayed no matter how logical and data filled their argument.
However, I find that those who admit that we (they) don’t know everything about the subject have a more believable stance than those that imply that it is all figured out.
We do not have all that effects climate figured out and we do not have atmospheric CO2’s place within those effects figured out.
commieBob:
You say to kiwikid
NO!
I do not know if the observed continuing rise in atmospheric CO2 has a mostly natural or a mostly anthropogenic cause, but I want to know. And if anybody can provide me with significant evidence one way or the other then I will ‘come off the fence’.
Empirical evidence refutes the hypothesis of ‘overloading’ of CO2 sinks by anthropogenic emissions’, but that does not disprove an anthropogenic cause of the rise.
One of our 2005 addressed this
(ref. Rorsch A, Courtney RS & Thoenes D, ‘The Interaction of Climate Change and the Carbon Dioxide Cycle’ E&E v16no2 (2005) ).
A redistribution of the CO2 between ‘compartments’ of the carbon cycle would provide the observed rise in atmospheric CO2 contribution, and such a redistribution would result from an alteration of the equilibrium state of the carbon cycle system. Some processes of the system are very slow with rate constants of years and decades and, therefore, the system takes decades to fully adjust to a new equilibrium. The most likely cause of such a change to the equilibrium is the rise in global temperature over recent centuries which is recovery from the Little Ice Age. However, it is possible (although very unlikely) that the human emissions of CO2 has altered the equilibrium.
The suggested alteration to the equilibrium state of the carbon cycle is the ONLY explanation that fits all observations.
Richard
We saw this seasonality in those satellite images of atmospheric CO2 concentration that appeared on WUWT a few months ago. And it’s really no surprise. There is a seasonality in the equatorial jungles but, as they say in the article, it’s a wet/dry seasonality rather than the warm/cold that we’re used to in the places where most of us live.
What IS surprising is these guys actually going out and collecting data from the real world. Not something that climate science has relied on very much with all the models that are the basis of the whole AGW edifice. Real data plus reasonable interpretation – minus foregone conclusions equals real science. Keep it up, we need more of it.
“… in the places where most of us live.”
Excuse me but this is the internet and we are talking about GLOBAL climate change. So the “us” would be the whole of humanity. Most of us actually lives in the tropics.
“Excuse me but this is the internet and we are talking about GLOBAL climate change. So the “us” would be the whole of humanity.”
From the Wiki,
“The vast majority of the world’s human population resides in temperate zones (if defined as comprising the subtropics as well), especially in the northern hemisphere because of its greater mass of land.”
In the dry tropics (where I live), Sea Almond (Terminalia catappa) can, but don’t always, turn themselves “on and off” several times throughout the year. Not so much “seasonality” as rapid response to irregular variation, eg out-of-season precipitation, or longer periods of high humidity but no rain. I suspect other species do the same. (Sea Almond outside the kitchen window so I observe it every day).
“Climate models have long represented the tropics in an overly simplistic way, often due to the lack of data from these hard to reach regions.”
I would say that climate models has long represented everything in an overly simplistic way – and been dead wrong. I don´t think the focus of Jin Wu is even close to being significant, but I guess he will earn good wages, and see interesting places.
By the way, the focus of inductivism is to explain. The focus of science is bipolar – being creative and being cruel. Being creative in coming up with an idea about how things might work, and being cruel in coming up with tests which might show that the idea is wrong. The explanatory power if an idea is proportional to the severity of the tests it has survived.
Ahh. So somebody else has an avocado tree. Because that is exactly what happens. Then the leaves serve as mulch and retain soil moisture and slowly add nutrients to the rain leeched soil.
All of this has some bearing on whether old forests fix as much CO2 as young/new forests. The argument for biomass is largely based upon the assumption that new/young forests take up more CO2 than do old/mature forests. However, I am sceptical as to whether that is truly the case. I suspect that forests, including their interaction with the water cycle, is much more complex than we presently know and understand, and accordingly, that they are not being properly modelled.
I went China a few years back and took part in resaerch on this subject. It was under the banner called. EARTHWATCH. Whist it seemed to promote the manmade CO2 warming meme, eg asked us to calculate our footprint, the work was actually very, very, hands on. Collecting data by going into the forest, counting bugs, speciating dead leaf matter, canopy health, trunk radius, etc,. Ie the basis of scientific understanding. Hence I was impressed by method rather than the message. But I think the message was to gain westerner money and conscripted labour in order get the leg work done. Stil, the raw data is there for the right minded to interpet.
I observe this every year in the Caribbean. In “winter” here, the leaves of all broad leaf trees dry and fall while new leaves are coming in. Overall, as in the article, the forests appear to remain green. Anyone with a swimming pool notes that a pool cleaning lasts no more than an hour or two during this time and part of your swim involves gathering floating leaves before they sink (they seem to be heavier than water once wet). Like so much climate industry science, phenomena already broadly known by millions, get “discovered”.
Hubris prevents them from asking people who live in these places. I’m sure botanists can be found in Brazil who could have told them this synchronization of leafing out (probably a non-botanist like myself could dig up some 50 year old paper or two on such findings. Perhaps there is contribution of a refinement of the timing and intensity of the photosynthetic cycle, but I’m virtually certain someone specializing in these forest species knows of the cycle. What else has a botanist really to do?
I see this fraternity doing this kind of eureka stuff in my field, geology, all the time. It made me a skeptic a long time ago, simply because of their “discovery” of already well documented knowledge (or idiot interpretations of what they think they are talking about). I hope a bunch of botanists come forward on this thread. If they don’t, I’m not very impressed with the observational skills, thoroughness or rigor of botany. Was there a botanist involved in this study?
The same is true with evergreens .Pine needles are constantly being replenished. Old needles drop, and new needles take their place. It takes years (probably more than 10) for these to rot and be broken down into soil, but where I have a holiday home in Spain, it is very dry. The process may well be quicker if these needles became wet mulch, as they probably do in wetter higher latitudes.
I unfortunately have 3 large pine trees near my pool and the amount of needles they drop is horrendous. Every year, I remove several BIg Bags of fallen needles. Also at this time of the year, they drop much pollen. My swimming pool has a very thin skin of pollen dust and needs the pump to be run 24/7 to remove this. At the moment it is probably running for only 3 hours a day so it is not being removed, and one struggles to see the bottom at the deep end because of the film of yellow pollen. It will be like this for about month. Not a great problem because it is presently too cold to swim.
But the point is that even in pine forests, the carbon cycle is continuous. They produce CO2 as old needles drop and rot, and they take up CO2 as new needles grow and replenish the old.
A simple question: How much increased growth/a is required to completely balance the annual emissions of carbon due to burning of hydrocarbons? I am being hypothetical here to define what is possible. It could be that there is no possible chance of vegetation alone countering the imbalance to any great extent. We know that there is usually a lag period before many negative feedback kicks in. There may be a leveling off of ACO2 sometime soon. Wouldn’t that upset the apple cart 🙂
In recent years, fossil fuel burning and cement production added annually CO2 that has 9-9.8 gigatons of carbon. In an oversimplification of carbohydrates as CnH2nOn, they are 40% carbon by mass. Protein and fat have a higher percentage of carbon, especially fat which averages around 78% carbon. Most biomass is mostly carbohydrates and water with smaller percentages of protein, fat and other chemicals. Overall I think biomass, especially most vegetable matter, is less than 40% carbon by mass. This means we must increase the amount of biomass in the world by more than 22.5-24.5 gigatons annually in order to remove the CO2 from fossil fuel burning and cement production. This means more than 3 metric tons per person annually.
Michael Carter,
As Donald already said, you need a lot of extra growth to compensate for human emissions…
What is measured is that the extra CO2 in the atmosphere today indeed increases growth of vegetation, but that is only ~1 GtC/year, or about 10% of human emissions:
http://www.sciencemag.org/content/287/5462/2467.short
Doesn’t that number directly imply no more than 10 year residency in the atmosphere for added CO2? If additional phytoplankton growth is not included in that gigaton estimation then it’s less than 10 years.
John Harmsworth,
The ~1 GtC/year uptake is based on the oxygen and δ13C changes in the atmosphere, which is the net result of (near) all life on earth: land and sea plants, bacteria, molds, insects, animals…
The net uptake is not the result of the momentary CO2 emissions within a year, it is the result of the total CO2 increase in the atmosphere of currently ~110 ppmv above the long term equilibrium with the oceans surface for the current average temperature. The increased pressure in the atmosphere (and to a lesser extent in the oceans) results in a higher uptake by plants. If human emissions would stop in some year, the sink rate would be the same in next year, a little less in the year after that, etc… until equilibrium with the ocean temperatures is reached again.
There is a simple formula to calculate the e-fold decay rate for any disturbance of a linear process (the uptake of CO2 out of the atmosphere seems to be quite linear with the increase in pressure above equilibrium):
disturbance / effect = e-fold decay rate
where “effect” is the net effect of the disturbance on the process
in this case the net sink rate:
110 ppmv / 2.15 ppmv/year = ~51 years e-fold decay rate
or ~40 years half life time.
Of the above 2.15 ppmv/year (~4.5 GtC/year) sink rate, about 0.5 ppmv/year (~1 GtC/year) is into the biosphere, the rest is in the oceans.
John Harmsworth wrote:
“Doesn’t that number directly imply no more than 10 year residency in the atmosphere for added CO2? If additional phytoplankton growth is not included in that gigaton estimation then it’s less than 10 years.”
That is not true, because increased plant uptake by 1 GtC/year is not the result of one year’s worth of manmade emissions but all manmade emissions. Cumulative manmade emissions from fossil fuel burning and cement production are about 400 GtC as of the end of 2014 according to the Tyndall Centre. This figure is 545 GtC including land use changes since 1870. About 230 GtC of that remains in the atmosphere after removal by ocean and land sinks. And the increase of plant growth is removing only 1 GtC of that 230 GtC per year, meaning a time constant tau of 230 years or a half life of that times the natural log of 2 or 159 years, if this increased plant growth were to be the only thing removing CO2 from the atmosphere.
Ferdinand Engelbeen wrote in part:
“There is a simple formula to calculate the e-fold decay rate for any disturbance of a linear process (the uptake of CO2 out of the atmosphere seems to be quite linear with the increase in pressure above equilibrium):
disturbance / effect = e-fold decay rate
where “effect” is the net effect of the disturbance on the process
in this case the net sink rate:
110 ppmv / 2.15 ppmv/year = ~51 years e-fold decay rate
or ~40 years half life time.”
The half-life is the exponential decay rate times the natural log of 2. 51 years exponential decay rate means half life of 35.5 years.
Overall, this seems to me that the half-life of an injection of CO2 into the atmosphere is in or near the range of 35.5-41 years, assuming that the behavior of above-equibrium atmospheric CO2 is close enough to exponential decay.
Reforestation or deforestation directly impact climate & weather that area in terms of change in precipitation, groundwater aquifers, temperature, humidity & wind. Increase or decrease in CO2 has no impact as such as the greenhouse effect is saturated at pre-industrial CO2 level. All greenhouse gases change with time due to several causes at any given location & region.
Dr. S. Jeevananda Reddy
The effect of CO2 is not saturated, not even according to MODTRAN. And Dr. Roy Spencer does not dispute in his own website the IPCC figure of 3.7 W/m^2 per 2x change of CO2. He disputes the feedbacks.
The energy received under different wavebands are highly variable with the prevailing weather conditions under a given climate system and general circulation pattern. Also greenhouse gases composition vary with them. Also, energy follows the 11-year and multiples of 11 year cycles.
Under such circumstances, if we plot and see on clear days — not affected by ecological changes — over the last 130 years, you will not find any increasing trend in temperature — where ecological changes are of important, you find trend and not associated with greenhouse effect. That means, greenhouse effect is taking place at sustainable level. Here we must remember the fact that energy available at Hyderabad will not be influenced by greenhouse gases at Washington D.C. and vice versa.
IPCC is looking at global average condition. To fit model predictions, groups are adjusting temperature anomalies and thus, it is clear that the feed back mechanism is only a hypothetical state — trial and error — and not real state.
Dr. S. Jeevananda Reddy
Maybe, he is wrong. One possible explanation as to why temperature changes during the 20th century do not match the rise in CO2, is that the effect of CO2 is largely saturated.
If temperatures do not increase over the course of the next 10 years, there may well be a re-assessment of Climate Sensitivity to CO2, and inherent in that re-assessment will be its forcing, and whether this has been over-assessed, and whether in practice the effect of CO2, at current levels, is largely saturated.
<if temperatures fall this re-assessment will probably take place sooner.
Whilst the future is unknown and yet to be written, I can foresee that 2020 could be interesting times indeed.
Carbon storage? I have always read that clearing a tropical rainforest results in a very poor soil. If the only carbon storage there is wood and leaf litter, a sustainable logging would be the best way to remove CO2 from the atmosphere.
It depends what yo do with the logs.
We produce twice as much CO2 as it is left in the atmosphere. Half of it is removed by greening deserts and savannahs and by
http://joannenova.com.au/2016/02/phytoplankton-suck-co2-out-of-sky-dump-to-ocean-floor/
A significant amount of the ocean sinking of CO2 becomes bicarbonate ions.
Tropical forests typically have very quick decomposition and recycling of dead organic matter versus temperate forests where soil and surface organic matter accumulate for decades or centuries before coming into balance with decomposition. This is why there is so much downed dead wood in many old growth forests and why the organic soil horizons become so thick.
All biological processes are moderated by the combination of temperature and moisture. Tropics generally have much higher species densities in all taxa than temperate zones.
https://en.wikipedia.org/wiki/Laterite
What happens to tropical soil under deforestation.
Who would’a thunk it? Imagine something as…well as global as global climate change/stasis/drift (take your pick) would have so many teeny-tiny, interlocking, miniscule, extensive, uniform, contradictory, sympathetic, antagonistic components that are in a constant state of perhaps dynamic flux? How about we develop a comprehensive understanding of it and all of its components BEFORE we predict/project its inevitable progression? If history is any indication it might get warmer before it gets colder, maybe. That’s my hypothesis anyway. However there’s a good possibility that the surface temp of the planet was somewhere around 3,000 F (I’m an American so I can’t tell you what that is in C’s) in the far distant past and, for sure, there’s been some significant cool since then so NAGC (non-anthropogenic global cooling) seems to be the overriding trend but that’s only a theory. If that were a graph it might appear to be a left-handed hockey stick.
Pine trees do something like this too. They may be evergreen, but that doesn’t mean they don’t drop dead pine needles and replace them with new ones.
Yes, indeed!
As a member of the generation that invented sex, I can attest to the thrill of discovering things that people had overlooked for millennia.
Who could ever have imagined that in the topics where seasonality is marginalized, plants that produced new leaves as old ones died would survive and reproduce more than the ones that, say, dropped all their leaves and had photosynthetic down time before growing new ones?/wink.
more proof that we don’t know natural flows well enough to measure the effect of fossil fuel emissions
http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2654191
I recall a study using satellite data that found a pall of CO2 over the Amazon rain forest, & other tropical rain forest, with less over heavily populated areas such as the eastern US.
The suggestion was that contrary to popular conception, rain forests were net emitters of CO2. I’m pretty sure I saw it here.
Are you sure that it was not methane? For several months each year much of the Amazon is flooded. The trees have evolved to tolerate this. At these times anaerobic decomposition occurs emitting methane. I am not sure if this process emits CO2 too but it would not surprise me
http://www.livescience.com/49196-nasa-satellite-oco2-carbon-maps.html
CO2 over tropical rain forests on this map. Was noted earlier on from a Japanese satellite CO2 map as well.
BioBob
The elevated CO2 over the rainforest is due to bush fires. These are also captured by satellites.
CO2:
http://s18.postimg.org/9sow40zo9/CO2_Concentration_October_2014.png
Fire:
http://s30.postimg.org/owsc8ddcx/FIRE_October_2014.png
The CO2 emissions and the fires they correlate with in the maps here appear to me as seasonal phenomona around the southern edge of tropical rainforests during the dry season. Note the location and time of year.
Yet another thing not in the
conclimate models. Oh boy. Are we up to a thousand things ignored by the models yet? (clouds are my favorite)We have had several decades of argumentation over CO2. A trace gas in the atmosphere of which the human added component is a trace of that trace. Any honest look at the situation shows that on net CO2 does not warm the planet but that CO2 is essential to life itself on this planet. CO2 should be at least 3 times its current concentration in the atmosphere. Plants in real greenhouses tell us that 1200 ppm or so is great for growth. (and plants need less water at high CO2 levels I am told)
Bold prediction: As the next “little ice age” (God, I hope it is not worse than that) begins sometime in the near future we will be able to look at the underlying physics again and this time, perhaps, not found a false religion on the magical properties of CO2.
Off topic – but very interesting and encouraging:
BREAKING
Again a bitter defeat for green fanatics in a Swiss national referendum!
The Swiss voters decided today to built a second car tunnel trough the GOTTHARD mountains in the Swiss alps despite a keen anti-campaign by green activists (who simply hate car traffic and fossil fuel consumption) and the rather green biased MSM of Switzerland:
http://www.swissinfo.ch/eng/february-28-vote_alpine-road-tunnel-set-to-win-majority-vote/41988542
This is the second defeat for green activists in a Swiss referendum within a short time span after the truly crushing rejection of a much higher CO2 tax (instead of VAT) only one year ago. Details see here:
http://wattsupwiththat.com/2015/03/09/green-fiasco-92-of-swiss-voters-reject-carbon-tax-in-referendum/
So we see, despite very intensive and nearly daily green anti-CO2 propaganda in the Swiss MSM, the voters of Switzerland are not as suggestible and brain-washed as green zealots would like it to be… 🙂
“…new leaf growth is synchronized with old leaf loss in the dry-season of the Amazon rainforest.”
Anybody who lives in the tropics for at least 12 months knows that. It does not apply only to the Amazon rain forest.
Interesting comments which lead to thoughts of CO2 becoming limited above the the green mantle and the ocean surface as CO2 is consumed. My guess is the cooling action by CO2 radiating in the 13 to 17 micron bands helps the slightly heavier and now slightly cooler CO2 molecule to sink downwards to replace CO2 molecules used in the life cycle of plants and phytoplankton.
The CO2 level in the atmosphere is increasing by about 2 ppmv each year, implying that more CO2 goes into the atmosphere than goes out. The atmosphere however isn’t a finite “vessel”, we know it expands/contracts.
My question then is: has anyone considered the expansion and contraction of the atmosphere in the esteemed models, or is it yet again an item left out?
JohnWho,
CO2 is expressed as ppmv: parts per million by volume. That means that the CO2 level is a ratio between the volume of CO2 and the total volume of air. No problem with any expansion of the atmosphere, as the ratio remains the same.
There is one caveat: CO2 is expressed as ppmv in dry air, to make it easier to follow the fluxes. That means that near the (ocean) surface, the real levels are a few % lower, while high in the dry troposphere/stratosphere, the ppmv’s are equal for “wet” and “dry” air…
Thanks for the reply Ferdinand. I understand that, but an expanding and contracting atmosphere, even during a time when the CO2 level remains relatively constant, might still have some effect on overall temperature or climate.
I’m just offering up the possibility.
JohnWho,
Some years ago (don’t remember the source), I have read something about the expansion of the atmosphere as result of global warming. Not sure if they included that as input into their calculations too…
Except that any modest change in co2 (never mind local seasonal variation) has an insignificant impact on climate. Even doubling total average atmospheric co2 has only a modest effect. So the claim that this bit of knowledge about previously unknown local seasonal variation in co2 will be important for climate research is just one of the many thousands of examples of researchers making tenuous claims to climate implications because that is where the money is. If there is no better reason to be doing this research then it shouldn’t be funded.
Dang! I didn’t include that. 😎
I’m sure the advances in computer programming that have produced the current batch of computer climate models have advanced enough to account for all of the unknowables.
(Or maybe the advances in computing have only accentuated the error of a programming variable that has never been corrected?)