Posts Tagged ‘Carbon cycle’

Man-made contribution to carbon dioxide in the atmosphere is just 4.3%

February 26, 2017

This new paper finds that CO2 concentration in the atmosphere has risen by 110 ppm since 1750, but of this the human contribution is just 17 ppm. With the concentration now at 400 ppm, the human contribution is just 4.3%. The results indicate that almost all of the observed change of CO2 during the Industrial Era comes, not from anthropogenic emissions, but from changes of natural emission.

The general assumption by IPCC and the global warming fraternity that natural carbon dioxide absorption and emissions are miraculously in balance and, therefore that man-made emissions are solely responsible for the increase in carbon dioxide concentration is deeply flawed (if not plain stupid).

Clearly this paper is not at all to the liking of the religious zealots of the “global warming brigade” and is causing much heartburn among the faithful.

Hermann Harde, Scrutinizing the carbon cycle and CO2 residence time in the atmosphereGlobal and Planetary Change, http://dx.doi.org/10.1016/j.gloplacha.2017.02.009

Highlights

•An alternative carbon cycle is presented in agreement with the carbon 14 decay.
•The CO2 uptake rate scales proportional to the CO2 concentration.
•Temperature dependent natural emission and absorption rates are considered.
•The average residence time of CO2 in the atmosphere is found to be 4 years.
•Paleoclimatic CO2 variations and the actual CO2 growth rate are well-reproduced.
•The anthropogenic fraction of CO2 in the atmosphere is only 4.3%.
•Human emissions only contribute 15% to the CO2 increase over the Industrial Era.

AbstractClimate scientists presume that the carbon cycle has come out of balance due to the increasing anthropogenic emissions from fossil fuel combustion and land use change. This is made responsible for the rapidly increasing atmospheric CO2 concentrations over recent years, and it is estimated that the removal of the additional emissions from the atmosphere will take a few hundred thousand years. Since this goes along with an increasing greenhouse effect and a further global warming, a better understanding of the carbon cycle is of great importance for all future climate change predictions. We have critically scrutinized this cycle and present an alternative concept, for which the uptake of CO2 by natural sinks scales proportional with the CO2 concentration. In addition, we consider temperature dependent natural emission and absorption rates, by which the paleoclimatic CO2 variations and the actual CO2 growth rate can well be explained. The anthropogenic contribution to the actual CO2 concentration is found to be 4.3%, its fraction to the CO2 increase over the Industrial Era is 15% and the average residence time 4 years.

Conclusions.

Climate scientists assume that a disturbed carbon cycle, which has come out of balance by the increasing anthropogenic emissions from fossil fuel combustion and land use change, is responsible for the rapidly increasing atmospheric CO2 concentrations over recent years. While over the whole Holocene up to the entrance of the Industrial Era (1750) natural emissions by heterotrophic processes and fire were supposed to be in equilibrium with the uptake by photosynthesis and the net oceanatmosphere gas exchange, with the onset of the Industrial Era the IPCC estimates that about 15 – 40 % of the additional emissions cannot further be absorbed by the natural sinks and are accumulating in the atmosphere.

The IPCC further argues that CO2 emitted until 2100 will remain in the atmosphere longer than 1000 years, and in the same context it is even mentioned that the removal of human-emitted CO2 from the atmosphere by natural processes will take a few hundred thousand years (high confidence) (see AR5-Chap.6-Executive-Summary).

Since the rising CO2 concentrations go along with an increasing greenhouse effect and, thus, a further global warming, a better understanding of the carbon cycle is a necessary prerequisite for all future climate change predictions. In their accounting schemes and models of the carbon cycle the IPCC uses many new and detailed data which are primarily focussing on fossil fuel emission, cement fabrication or net land use change (see AR5-WG1-Chap.6.3.2), but it largely neglects any changes of the natural emissions, which contribute to more than 95 % to the total emissions and by far cannot be assumed to be constant over longer periods (see, e.g.: variations over the last 800,000 years (Jouzel et al., 2007); the last glacial termination (Monnin et al., 2001); or the younger Holocene (Monnin et al., 2004; Wagner et al., 2004)).

Since our own estimates of the average CO2 residence time in the atmosphere differ by several orders of magnitude from the announced IPCC values, and on the other hand actual investigations of Humlum et al. (2013) or Salby (2013, 2016) show a strong relation between the natural CO2 emission rate and the surface temperature, this was motivation enough to scrutinize the IPCC accounting scheme in more detail and to contrast this to our own calculations.

Different to the IPCC we start with a rate equation for the emission and absorption processes, where the uptake is not assumed to be saturated but scales proportional with the actual CO2 concentration in the atmosphere (see also Essenhigh, 2009; Salby, 2016). This is justified by the observation of an exponential decay of 14C. A fractional saturation, as assumed by the IPCC, can directly be expressed by a larger residence time of CO2 in the atmosphere and makes a distinction between a turnover time and adjustment time needless. Based on this approach and as solution of the rate equation we derive a concentration at steady state, which is only determined by the product of the total emission rate and the residence time. Under present conditions the natural emissions contribute 373 ppm and anthropogenic emissions 17 ppm to the total concentration of 390 ppm (2012). For the average residence time we only find 4 years.

The stronger increase of the concentration over the Industrial Era up to present times can be explained by introducing a temperature dependent natural emission rate as well as a temperature affected residence time. With this approach not only the exponential increase with the onset of the Industrial Era but also the concentrations at glacial and cooler interglacial times can well be reproduced in full agreement with all observations. So, different to the IPCC’s interpretation the steep increase of the concentration since 1850 finds its natural explanation in the self accelerating processes on the one hand by stronger degassing of the oceans as well as a faster plant growth and decomposition, on the other hand by an increasing residence time at reduced solubility of CO2 in oceans.

Together this results in a dominating temperature controlled natural gain, which contributes about 85 % to the 110 ppm CO2 increase over the Industrial Era, whereas the actual anthropogenic emissions of 4.3 % only donate 15 %. These results indicate that almost all of the observed change of CO2 during the Industrial Era followed, not from anthropogenic emission, but from changes of natural emission.

The results are consistent with the observed lag of CO2 changes behind temperature changes (Humlum et al., 2013; Salby, 2013), a signature of cause and effect. Our analysis of the carbon cycle, which exclusively uses data for the CO2 concentrations and fluxes as published in AR5, shows that also a completely different interpretation of these data is possible, this in complete conformity with all observations and natural causalities. 

I expect there will be a concerted effort by the faithful to try and debunk this (and it has already started).

But I am inclined to give credence to this work – and not merely because it is in general agreement with my own conclusions about the Carbon cycle. Back in 2013 I posted

Even though the combustion of fossil fuels only contributes less than 4% of total carbon dioxide production (about 26Gt/year of 800+GT/year), it is usually assumed that the sinks available balance the natural sources and that the carbon dioxide concentration – without the effects of man – would be largely in equilibrium.  (Why carbon dioxide concentration should not vary naturally escapes me!). It seems rather illogical to me to claim that sinks can somehow distinguish the source of carbon dioxide in the atmosphere and preferentially choose to absorb natural emissions and reject anthropogenic emissions! Also, there is no sink where the absorption rate would not increase with concentration.

Carbon dioxide emission sources (GT CO2/year)

  • Transpiration 440
  • Release from oceans 330
  • Fossil fuel combustion 26
  • Changing land use 6
  • Volcanoes and weathering 1

Carbon dioxide is accumulating in the atmosphere by about 15 GT CO2/ year. The accuracy of the amounts of carbon dioxide emitted by transpiration and by the oceans is no better than about 2 – 3% and that error band (+/- 20GT/year)  is itself almost as large as the total amount of emissions from fossil fuels.


 

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12,000 years of agriculture has only reduced tree numbers by 46%

September 3, 2015

There is a new paper in Nature which tries to count the number of trees in the world.

Crowther, T. W. et al., Mapping tree density at a global scale, Nature http://dx.doi.org/10.1038/nature14967 (2015)

They find that there are 3.04 trillion trees which is about 7 times larger than was previously thought. They further estimate that in spite of 12,000 years of agriculture, the number of trees in the world has only reduced by 46%.

But then I heard the lead author, Thomas Crowther, being interviewed on the BBC today. I was less than impressed by his apparent lack of common sense. “The scale of human impact is astonishing” he says.

Really?

There has been a less than 50% reduction of tree-numbers in 12,000 years of agriculture, with all the forest clearing that entails, to feed 7 billion people. A human impact of less than 0.0038% per year (or 3.8% per 1000 years) is claimed to be “astonishing”.

He also claims that their results do not impact “carbon science”. Again, Really?

Seven times as many trees as thought before is 7 times as much bio-mass existing as trees, which leads to 7 times as much carbon inventory locked-up in trees as thought before. It means 7 times more trees die every year than was previously thought. Which makes man-made carbon emissions an even smaller fraction (c. 4%) of natural carbon emissions.

Crowther sounded like a vacuum cleaner salesman talking up his product. He kept emphasising the importance of his paper while denying that it had any implications for “politically correct science”. The estimate of the number of trees is interesting and could be something to build on for carbon cycle calculations. It also suggests that alarmism about bio-diversity of trees is ill founded. But some of their conclusions are just stupid and geared to getting more funding by demonstrating “political correctness”.

Reasonably interesting science but with idiot conclusions.

Oh dear!

Abstract: The global extent and distribution of forest trees is central to our understanding of the terrestrial biosphere. We provide the first spatially continuous map of forest tree density at a global scale. This map reveals that the global number of trees is approximately 3.04 trillion, an order of magnitude higher than the previous estimate. Of these trees, approximately 1.39 trillion exist in tropical and subtropical forests, with 0.74 trillion in boreal regions and 0.61 trillion in temperate regions. Biome-level trends in tree density demonstrate the importance of climate and topography in controlling local tree densities at finer scales, as well as the overwhelming effect of humans across most of the world. Based on our projected tree densities, we estimate that over 15 billion trees are cut down each year, and the global number of trees has fallen by approximately 46% since the start of human civilization.

Carbon Cycle: Emissions from forest clearance underestimated, land absorption underestimated

May 23, 2014

Two new papers just published show that the carbon cycle is far from being certain. We still have large uncertainties regarding the sources of carbon dioxide emissions and their magnitude and the sinks where, and mechanisms by which, carbon dioxide is absorbed. One in Global Change Biology. shows that emissions due to forest clearance have been underestimated by some 40% while the second in Nature suggests that there are large land sinks for carbon dioxide in the Southern Hemisphere (paywalled but reported here) which have largely been ignored by climate models.

  1. The amount of carbon lost from tropical forests is being significantly underestimated, a new study reports. In addition to loss of trees, the degradation of tropical forests by selective logging and fires causes large amounts of “hidden” emissions. 
  2. they find that land sinks for CO2 are keeping up with the increase in CO2 emissions, thus modeled projections of exponential increases of CO2 in the future are likely exaggerated. 

The “settled science of climate” is a an edifice tottering on two unproven hypotheses:

  1. That carbon dioxide concentration in the atmosphere is a key driver of global temperature, and
  2. That man-made emissions of carbon dioxide (primarily fossil fuel combustion) are the key contributor to concentration in the atmosphere.

If either of these two assumptions are incorrect, the entire edifice of climate science and climate policy comes tumbling down.

The first now looks decidedly weak. For almost 20 years now global temperatures have stagnated (and show a slight negative trend) while carbon dioxide emissions from combustion have increased sharply. Carbon dioxide concentration has also continued to increase but at a much lower rate than the rate of man-made emissions. No doubt carbon concentration has some impact but it is clearly far from being a key driver of global temperature.

The second assumes that “natural emissions” and absorption are roughly in balance and therefore it must be fossil fuel combustion which is responsible for the increase of carbon dioxide concentration. But the Carbon balance of the earth is far from certain. Volcanic de-gassng of CO2 has been grossly underestimated. The mass of CO2 absorbing bio-mass in the oceans has also been underestimated and remains still highly uncertain.

The error bands surrounding “natural” emissions are of the same magnitude as man-made emissions. Absorption of Carbon dioxide by the oceans and the biological life (algae) in the oceans are, at best, relatively uncertain estimations.

ktwop: Even though the combustion of fossil fuels only contributes less than 4% of total carbon dioxide production (about 26Gt/year of 800+GT/year), it is usually assumed that the sinks available balance the natural sources and that the carbon dioxide concentration – without the effects of man – would be largely in equilibrium. 

…… Carbon dioxide emission sources (GT CO2/year)

  • Transpiration 440
  • Release from oceans 330
  • Fossil fuel combustion 26
  • Changing land use 6
  • Volcanoes and weathering 1

Carbon dioxide is accumulating in the atmosphere by about 15 GT CO2/ year. The accuracy of the amounts of carbon dioxide emitted by transpiration and by the oceans is no better than about 2 – 3% and that error band (+/- 20GT/year)  is itself almost as large as the total amount of emissions from fossil fuels. ….. 

The demonisation of fossil fuel combustion is based on belief and not on evidence. The carbon dioxide assumptions which are the foundations of the climate orthodoxy are unsound.

Fish biomass 10 times greater than thought (and fish “fix” carbon dioxide from sea water)

February 8, 2014

A new paper suggests that the biomass of mesopelagic fish which dominate the total biomass of fish in the ocean is 10 times higher than previously assumed. Instead of being about 1,000 million tens the researchers suggest it could be 10,000 million tons or even more.

Fish are a critical link in the Carbon cycle and especially the removal – by “fixing” as carbonates – of the carbon dioxide in sea water. They act to neutralise acidity and increase alkilinity. The level of carbon dioxide dissolved in sea water itself affects the capacity of the ocean surface waters to absorb more carbon dioxide. A change – by a factor of 10 – in the fish biomass is a not insignificant change to the carbon fluxes through the ocean and to the carbon cycle.

Xabier Irigoien et al, Large mesopelagic fishes biomass and trophic efficiency in the open oceanNature Communications, 2014; 5 DOI:10.1038/ncomms4271

EurekAlert: With a stock estimated at 1,000 million tons so far, mesopelagic fish dominate the total biomass of fish in the ocean. However a team of researchers ….. has found that their abundance could be at least 10 times higher. The results, published in Nature Communications journal, are based on the acoustic observations conducted during the circumnavigation of the Malaspina Expedition. … Mesopelagic fishes, such as lantern fishes (Myctophidae) and cyclothonids (Gonostomatidae), live in the twilight zone of the ocean, between 200 and 1,000 meters deep. They are the most numerous vertebrates of the biosphere, but also the great unknowns of the open ocean, since there are gaps in the knowledge of their biology, ecology, adaptation and global biomass. 

… Xabier Irigoien, researcher from AZTI-Tecnalia and KAUST (Saudi Arabia) and head of this research, states: “The fact that the biomass of mesopelagic fish (and therefore also the total biomass of fishes) is at least 10 times higher than previously thought, has significant implications in the understanding of carbon fluxes in the ocean and the operation of which, so far, we considered ocean deserts”.

Mesopelagic fish come up at night to the upper layers of the ocean to feed, whereas they go back down during the day in order to avoid being detected by their predators. This behaviour speeds up the transport of organic matter into the ocean, the engine of the biological pump that removes CO2 from the atmosphere, because instead of slowly sinking from the surface, it is rapidly transported to 500 and 700 meters deep and released in the form of feces.

Irigoien adds: “Mesopelagic fish accelerate the flux for actively transporting organic matter from the upper layers of the water column, where most of the organic carbon coming from the flow of sedimentary particles is lost. Their role in the biogeochemical cycles of ocean ecosystems and global ocean has to be reconsidered, as it is likely that they are breathing between 1% and 10% of the primary production in deep waters”.

According to researchers, the excretion of material from the surface could partly explain the unexpected microbial respiration registered in these deep layers of the ocean. Mesopelagic fishes would act therefore as a link between plankton and top predators, and they would have a key role in reducing the oxygen from the depths of the open ocean.

The mechanisms by which fish create carbonates and contribute to the “fixing” of carbon dioxide is through feces.

Fish feces reduce ocean CO2 levels

 .. when fish drink seawater they excrete calcium as calcium carbonate — a chalky substance that can make seawater more alkaline and diminish the carbon dioxide in the water. ….. the bulk of the world’s fish species, excluding sharks and rays, produced the carbonate to counter the salt they ingested in seawater. The carbonate binds to the salt and is expelled as pellets, which dissolve in the ocean. … (We) knew before that something in the water was producing carbonate, but believed it came from other sources, such as microscopic marine plankton near the bottom of the food chain. But (we) didn’t understand why they were seeing so much of the carbonate at shallower depths. ……. most conservative estimates suggest three to 15 per cent of the oceans’ carbonates come from fish, but this range could be up to three times higher.

File:Oceanic divisions.svg

Oceanic divisions (Wikipedia)

Man-made global warming is just presumption

December 18, 2013

Presumptions, presumptions everywhere but no evidence to be seen.

  1. There is a presumption among the global warming orthodoxy – but no evidence – that increasing carbon dioxide concentrations in the atmosphere causes significant warming of the Earth’s surface.
  2. There is a presumption that carbon dioxide emissions from human activities (primarily by the increase in fossil fuel combustion since the 1950’s) is the primary cause of the increase of concentration in the atmosphere. This presumption is based on the assumption that the oceans and the forests absorb just as much carbon dioxide as they emit. This balance is an assumption and is based on the argument that pre-industrial concentrations of carbon dioxide in the atmosphere were largely constant. The actual emissions from the forests and the oceans are each an order of magnitude greater than man-made emissions of carbon dioxide. The margin of error in the estimates of amounts of carbon dioxide emitted (and absorbed) by the oceans and the forests is greater than the emissions from fossil fuel combustion. The emissions due to volcanic activity are not well understood just as the rate at which  carbonate sediments are laid down by the oceans is unknown (which in turn affects the concentration of what is dissolved in the oceans and therefore how much gets absorbed by the oceans from the atmosphere). Carbon dioxide released or absorbed by tectonic activity is unknown. There is a presumption based on some limited evidence that approximately 40% of what is released by fossil combustion is accumulating as atmospheric concentration. There is no presumption, however, that increasing carbon dioxide concentration in the atmosphere must lead to an increased absorption rate.
  3. Fossil fuel combustion and man-made carbon dioxide emissions as well as the atmospheric concentration have been increasing at least since about 1950. For the last 17 years this increase has continued but global temperatures have not increased. For the last 10 years the global temperature has shown a slight decline. It is therefore presumed that the original presumption still holds and that the extra heat is presumed to be hidden in a variety of places  (the deep oceans for example) other than at the Earth’s surface. There is no presumption that these observations are fundamentally in conflict with the original presumption.
  4. It is entirely logical that warming of the earth will cause the ice caps to melt and sea levels to rise just as global cooling will cause the ice sheets to expand and the sea levels to fall. It is presumed by the “establishment” that observed short-term reductions of ice extent are not due to natural variation but are proof that man-made global warming prevails. But when ice extent increases – as is happening currently – it is presumed to be due to natural variability and not relevant to the underlying trend due to man-made global warming.
  5. It is postulated by the establishment that extreme weather events are more likely to occur due to man-made global warming (and are not due to natural variability). But when extreme weather events show a decline – as they are doing currently – then any such decline is presumed to be due to natural variability.
  6. A preponderance of “cold records” being broken – rather than “heat records” is presumed to be proof of man-made global warming causing extreme weather events.

Presumptions do not a science make – especially when the evidence available increasingly conflicts with the presumptions.

Volcanic CO2 Levels Are Staggering

November 18, 2013

The carbon balance of the earth is far less understood – or quantified – than “climate scientists” would have us believe. The two largest sources and sinks (forests and the oceans) are generally assumed to be largely in balance. Volcanoes are estimated to produce a very small amount of carbon dioxide. Carbon in rocks brought up from the deep mantle by tectonic activities are assumed to be in balance with the return of sediments and rocks into the deep mantle by subduction. These assumed balances of the big numbers means that the relatively small numbers for emissions from fossil fuel combustion and changing land use then become dominant in explaining the observed increase of carbon dioxide concentration in the atmosphere. But these assumptions include many uncertainties:

Carbon dioxide emission sources (GT CO2/year)

  • Transpiration 440
  • Release from oceans 330
  • Fossil fuel combustion 26
  • Changing land use 6
  • Volcanoes and weathering 1

Carbon dioxide is accumulating in the atmosphere by about 15 GT CO2/ year. The accuracy of the amounts of carbon dioxide emitted by transpiration and by the oceans is no better than about 2 – 3% and that error band (+/- 20GT/year)  is itself almost as large as the total amount of emissions from fossil fuels.

But it now appears that even the carbon dioxide emissions from volcanoes have been grossly underestimated. Not only have the emissions from erupting volcanoes been underestimated but it also seems that many volcanoes emit carbon dioxide almost continuously and invisibly (a diffuse degassing).

Volcanic CO2 Levels Are Staggering 

Robin Wylie, University College London   |   October 15, 2013

…. Until the end of the 20th century, the academic consensus was that this volcanic output was tiny — a fiery speck against the colossal anthropogenic footprint. Recently, though, volcanologists have begun to reveal a hidden side to our leaking planet.

Exactly how much CO2 passes through the magmatic vents in our crust might be one of the most important questions that Earth science can answer. Volcanoes may have been overtaken in the carbon stakes, but in order to properly assess the consequences of human pollution, we need the reference point of the natural background. And we’re getting there; the last twenty years have seen huge steps in our understanding of how, and how much COleaves the deep Earth. But at the same time, a disturbing pattern has been emerging.

In 1992, it was thought that volcanic degassing released something like 100 million tons of COeach year. Around the turn of the millennium, this figure was getting closer to 200. The most recent estimate, released this February, comes from a team led by Mike Burton, of the Italian National Institute of Geophysics and Volcanology – and it’s just shy of 600 million tons. It caps a staggering trend: A six-fold increase in just two decades. ……

….. As scientific progress is widening our perspective, the daunting outline of how little we really know about volcanoes is beginning to loom large. ….

…. We now know that the CO2 released during volcanic eruptions is almost insignificant compared with what happens after the camera crews get bored. The emissions that really matter are concealed. The silent, silvery plumes which are currently winding their way skyward above the 150 or so active volcanoes on our planet also carry with them the bulk of its carbon dioxide. Their coughing fits might catch the eye — but in between tantrums, the steady breathing of volcanoes quietly sheds upwards of a quarter of a billion tons of CO2 every year. 

We think. Scientists’ best estimates, however, are based on an assumption. It might surprise you to learn that, well into the new century, of the 150 smokers I mentioned, almost 80 percent are still as mysterious, in terms of the quantity of CO2 they emit, as they were a generation ago: We’ve only actually measured 33.

If the 117 unsampled peaks follow a similar trend, then the research community’s current projection might stand. But looking through such a small window, there’s no way of knowing if what we have seen until now is typical or not. It’s like shining a light on a darkened globe: randomly, you might hit Australia, and think you’d seen it all – while on the edge of your beam, unnoticed, would be Asia. Our planet’s isolated volcanic frontiers could easily be hiding a monster or two; and with a bit of exploration, our estimate of volcanic CO2 output could rise even higher.

You’d think that would be enough. That might be my fault — I tend to save the weird stuff until the end. Recently, an enigmatic source of volcanic carbon has come to light that isn’t involved with lava — or even craters. It now seems that not only is there CO2 we can’t get to, there’s some we can’t even see.

Carbon dioxide is always invisible, but its presence can be inferred in volcanic plumes — betrayed by the billowing clouds of water vapour released alongside it. Without the water, though, it’s a different story. The new poster-child of planetary degassing is diffuse CO2 — invisible emanations which can occur across vast areas surrounding the main vents of a volcano, rising through the bulk of the mountains. This transparent haze is only just beginning to receive proper attention, and as such we have very little idea of how much it might contribute to the global output.

Even more incredibly, it even seems that some volcanoes which are considered inactive, in terms of their potential to ooze new land, can still make some serious additions to the atmosphere through diffuse COrelease. Residual magma beneath dormant craters, though it might never reach the surface, can still ‘erupt’ gases from a distance. Amazingly, from what little scientists have measured, it looks like this process might give off as much as half the CO2 put out by fully active volcanoes.

If these additional ‘carbon-active’ volcanoes are included, the number of degassing peaks skyrockets to more than 500. Of which we’ve measured a grand total of nine percent.

Related: Deep Carbon Emissions from Volcanoes

 

Further uncertainties in the Carbon cycle

July 4, 2013

The Carbon cycle is far from being fully understood or quantified. The absorption and release of carbon dioxide by the oceans and from biological plants and fungii – both on land and in the ocean – are a long way from being established. The amount of Carbon locked up in the earths crust is equally subject to great uncertainty.

A new paper shows that deep soils hold much higher levels of carbon than is usually assumed.

R. J. Harper, M. Tibbett, The hidden organic carbon in deep mineral soilsPlant and Soil, July 2013, Volume 368, Issue 1-2, pp 641-648

Abstract: Current estimates of soil organic carbon (SOC) are based largely on surficial measurements to depths of 0.3 to 1 m. Many of the world’s soils greatly exceed 1 m depth and there are numerous reports of biological activity to depths of many metres. Although SOC storage to depths of up to 8 m has been previously reported, the extent to which SOC is stored at deeper depths in soil profiles is currently unknown. This paper aims to provide the first detailed analysis of these previously unreported stores of SOC. ….. Mean SOC mass densities for each of the five locations varied from 21.8–37.5 kg C m−2, and were in toto two to five times greater than would be reported with sampling to a depth of 0.5 m.

PhysOrg reportsCurrent estimates of soil organic carbon are based largely on measurements to depths of 30 cm. This approach has evolved in North America and Europe, where soil is generally more shallow. 

However, many plant species have roots extending many metres deep, suggesting there is also carbon stored at such depth and inspiring researchers to explore the storage potential of deeper soils in older landscapes such as the Amazon or Australia. Researchers in the Amazon had previously sampled soils to 8 m. 

The researchers took soil measurements from samples taken to almost 40 metres deep at a range of sites in south-western Australia. They found that small amounts of carbon were present throughout the soils all the way to the bedrock, and that deep soils store up to five times more carbon than is normally reported.

Lead researcher Professor Richard Harper, an expert in water management and sustainability at Murdoch University said the findings extend our concept of the amounts and potential of carbon stored in soils.

“This carbon has been previously overlooked, and this opens up several lines of inquiry – for example, what happens to this carbon with land use change such as deforestation and reforestation?” Professor Harper said.

“There is likely more carbon stored in the world’s soils than previously considered. What will happen to this carbon – that is, will it be released as a result of either land-use change or climate change – is unknown. This is what we are working on now,” he said.

 

Carbon dioxide idiocy – perhaps the EPA should make flatulence punishable

June 26, 2013

Reading Obama’s “Climate Plan” almost  drives me to despair at the idiocy of man!

Obama climate action plan

exhaust gas compositions

 

But only almost.

We have always had idiots and even evolution will not eliminate idiocy. And because like most “policy” statements from whoever is President of the United States, it is 90% rhetoric and 10% substance. He has enough weasel words in there to approve the Keystone XL Pipeline and he will not stop the burning of shale gas or the production of shale oil or the export of coal!! He will continue wasting money on nonsense and subsidising useless things which will prolong the lunacy for a little while.

Every living thing converts carbon to carbon dioxide  – the new pollutant. And the argument that it is a matter of scale does not hold. But perhaps we and all our animals can wear Carbon Sequestration masks? And maybe Obama could make flatulence punishable?

The oceans determine the carbon dioxide concentration and not man. I suppose that it will only be when the carbon dioxide concentration in the atmosphere begins to fall – as it will within 2 decades  – that the lunacy might begin to end.

Carbon Cycle still has many uncertainties

June 20, 2013

How much of the increase in carbon dioxide concentration in the atmosphere is due to the use of fossil fuels is not as certain as many would like to believe. The role of the oceans both in the emission and the absorption of carbon dioxide is far from being understood or quantified. Emissions due to fossil fuel combustion are of the same magnitude as just the error band surrounding the emissions from the oceans and  from the emissions due to transpiration. The primary sources of carbon dioxide in the atmosphere are the oceans and transpiration. The assumption that these emissions are in balance with the absorption by the oceans and plant life is just an assumption based on an assumed equilibrium which is far from certain. I posted a few weeks ago

…. The general assumption is that about 40% of man-made carbon dioxide shows up as this increase with the remainder being absorbed by the enhanced action of sinks.

SOURCES AND SINKS OF CARBON DIOXIDE

The justification for this conclusion is supported by measurements of the falling proportion of  13C  in the atmosphere which is taken to signal the appearance of CO2 from fossil fuel emissions. …… 

The correlation of changes in δ13C with ENSO events and the comparison with a simple model of a series of cascades suggest that the changes in δ13C in the atmosphere have little to do with the input of CO2 emissions from the continuous use of fossil fuels.

Even though the combustion of fossil fuels only contributes less than 4% of total carbon dioxide production (about 26Gt/year of 800+GT/year), it is usually assumed that the sinks available balance the natural sources and that the carbon dioxide concentration – without the effects of man – would be largely in equilibrium.  (Why carbon dioxide concentration should not vary naturally escapes me!). It seems rather illogical to me to claim that sinks can somehow distinguish the source of carbon dioxide in the atmosphere and preferentially choose to absorb natural emissions and reject anthropogenic emissions! Also, there is no sink where the absorption rate would not increase with concentration.

Carbon dioxide emission sources (GT CO2/year)

  • Transpiration 440
  • Release from oceans 330
  • Fossil fuel combustion 26
  • Changing land use 6
  • Volcanoes and weathering 1

Carbon dioxide is accumulating in the atmosphere by about 15 GT CO2/ year. The accuracy of the amounts of carbon dioxide emitted by transpiration and by the oceans is no better than about 2 – 3% and that error band (+/- 20GT/year)  is itself almost as large as the total amount of emissions from fossil fuels. ….. 

Two new papers – in completely different fields – highlight the uncertainty in carbon dioxide emissions from the oceans and from plant and animal life:

1. Interannual variability in sea surface temperature and fCO2 changes in the Cariaco Basin Y.M. Astor et al, Deep-Sea Res. II (2013), http://dx.doi.org/10.1016/j.dsr2.2013.01.002i

The Hockey SchtickA new paper published in Deep-Sea Research finds the ocean is a net source of CO2 to the atmosphere, the opposite of claims by climate alarmists that the ocean removes CO2 from the atmosphere. According to the authors, “At the [research] site, the ocean is primarily a source of CO2 to the atmosphere, except during strong upwelling events.” The paper also notes, “Astor et al.(2005) observed the interactions between physical and biochemical parameters that lead to temporal [over time] variations in fCO2 [CO2 flux from the] sea, finding that even during periods of high production, the CO2 flux between the ocean and the atmosphere decreased but remained positive, i.e. CO2 escaped from the ocean to the atmosphere.” 

The paper corroborates prior work by SalbyHumlum et alFrölicher et alCho et alCalder et alFrancey et alAhlbeckPetterssonand others demonstrating that man-made CO2 is not the driver of atmospheric CO2. This new work confirms the primary source of atmospheric CO2 is out-gassing from the oceans, which is due to decreased solubility with increased temperature.

2. Michael S. Strickland, Dror Hawlena, Aspen Reese, Mark A. Bradford, and Oswald J. Schmitz. Trophic cascade alters ecosystem carbon exchangePNAS, 2013 DOI:10.1073/pnas.1305191110

EurekAlert: …. The study, conducted by researchers at the Yale School of Forestry & Environmental Studies, comes out this week in the Proceedings of the National Academy of Sciences. It looks at the relationship between grasshoppers and spiders—herbivores and predators in the study’s food chain—and how it affects the movement of carbon through a grassland ecosystem. Carbon, the basic building block of all organic tissue, moves through the food chain at varying speeds depending on whether it’s being consumed or being stored in the bodies of plants. However, this pathway is seldom looked at in terms of specific animal responses like fear from predation. …… 

….. The study found that the presence of spiders drove up the rate of carbon uptake by the plants by about 1.4 times more than when just grasshoppers were present and by 1.2 more times than when no animals were present. It was also revealed that the pattern of carbon storage in the plants changed when both herbivores and carnivores were present. The grasshoppers apparently were afraid of being eaten by the spiders and consumed less plant matter when the predators were around. The grasshoppers also shifted towards eating more herbs instead of grass under fearful scenarios.

At the same time, the grasses stored more carbon in their roots in a response to being disturbed at low levels when both herbivores and carnivores were present. In cases where only herbivores were present, the plants stored less carbon overall, likely due to the more intense eating habits of the herbivores that put pressure on plants to reduce their storage and breathe out carbon more. These stress impacts, then, caused both the plants and the herbivores to change their behaviors and change the composition of their local environment.

Global cooling in the cretaceous shifted the global carbon cycle

June 17, 2013

A new paper in Nature Geoscience showing that global cooling is as significant as global warming.

‘Atlantic cooling associated with a marine biotic crisis during the mid-Cretaceous period’. A McAnena, S Flogel, P Hofmann, JO Herrle, A Griesand, J Pross, HM Talbot, J Rethemeyer, K Wallmann and T WagnerNature Geoscience, DOI: 10.1038/NGEO1850, published on: 16th June 2013

From Newcastle Univeristy’s press release:

Global cooling as significant as global warming

A “cold snap” 116 million years ago triggered a similar marine ecosystem crisis to the ones witnessed in the past as a result of global warming, according to research published in Nature Geoscience.

The international study involving experts from the universities of Newcastle, UK, Cologne, Frankfurt and GEOMAR-Kiel, confirms the link between global cooling and a crash in the marine ecosystem during the mid-Cretaceous greenhouse period.

It also quantifies for the first time the amplitude and duration of the temperature change.  Analysing the geochemistry and micropaleontology of a marine sediment core taken from the North Atlantic Ocean, the team show that a global temperature drop of up to 5oC resulted in a major shift in the global carbon cycle over a period of 2.5 million years.

Occurring during a time of high tectonic activity that drove the breaking up of the super-continent Pangaea, the research explains how the opening and widening of new ocean basins around Africa, South America and Europe created additional space where large amounts of atmospheric CO2 was fixed by photosynthetic organisms like marine algae. The dead organisms were then buried in the sediments on the sea bed, producing organic, carbon rich shale in these new basins, locking away the carbon that was previously in the atmosphere.

The result of this massive carbon fixing mechanism was a drop in the levels of atmospheric CO2, reducing the greenhouse effect and lowering global temperature.

This period of global cooling came to an end after about 2 million years following the onset of a period of intense local volcanic activity in the Indian Ocean.  Producing huge volumes of volcanic gas, carbon that had been removed from the atmosphere when it was locked away in the shale was replaced with CO2 from the Earth’s interior, re-instating a greenhouse effect which led to warmer climate and an end to the “cold snap”.

The research team highlight in this study how global climate is intrinsically linked to processes taking place in the earth’s interior at million year time scales. These processes can modify ecospace for marine life, driving evolution.

Current research efforts tend to concentrate on global warming and the impact that a rise of a few degrees might have on past and present day ecosystems.  This study shows that if global temperatures swing the other way by a similar amount, the result can be just as severe, at least for marine life.

 


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