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Holistic Management can reverse Climate Change
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Multiple scientific studies from climate scientists and agricultural specialists show little or no significant gain in carbon sequestration on soils managed holistically to those with other grazing techniques. Even under the most favourable conditions, Holistic Management (HM) alone can only slow climate change by a small percentage, over a limited period, and certainly cannot reverse climate change. |
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Climate Myth...
Holistic Management can reverse Climate Change
“Holistic management as a planned grazing strategy is able to reverse desertification and sequester atmospheric carbon dioxide into soil, reducing atmospheric carbon dioxide levels to pre-industrial levels in a period of forty years.” (Allan Savory, 2014)
When Allan Savory gave his TED talk in March 2013, his philosophy of Holistic Management as a tool to reverse climate change was presented to a global audience. His bold claims of reviving deserts by simply using cattle to “mimic nature”, greening arid land and boosting productivity of farms globally, seemed a miraculous solution to the growing problem of desertification. Many people, especially farmers, have invested in his idea and firmly believe in it. However, carbon scientists and climate experts were sceptical.
What is Holistic Management?
Holistic Management (HM) was coined by ecologist Allan Savory and is termed as a “planning system that helps farmers, ranchers and land stewards better manage agricultural resources in order to reap sustainable environmental, economic, and social benefits”. It aims to strategically ‘mimic nature’ through planning, monitoring, and calculating factors which influence the grazing plan. Whilst these appear to be a good approach to cattle farming, there is little evidence or accurate description about how exactly HM works (Figure 1); and can work well enough to yield high productivity and carbon sequestration rates compared to other grazing techniques.
Figure 1: A basic summary of how Holistic Management (HM) works. A set stock group graze on land continuously for a period between 1-5 days (lightly coloured grass) and are then shuttled to a section of land which has been allowed to rest for around 2 months since grazing last occurred (Darkest coloured grass). The cattle are shuttled quickly between systems to ensure trampling of soil and supposed increase of water filtration. This system ensures that grass has long recovery time before it is grazed, and cattle are less selective in the grass they eat compared with continuous grazing. HM has several similarities to short duration grazing and intensive rotational grazing (Undersander DJ et al, 2002). Source: Vaughan S, 2019.
It has been proven that excessive continuous grazing with high stocking rates is a form of mismanagement, accelerating carbon depletion in previously carbon-rich soils and increasing the risk of desertification (Nordborg, 2016). The Savory Institute has claimed that grazing under Holistic Management is superior to continuous grazing. Savory has claimed over two-thirds of the world’s ice-free land is at risk of desertification, and only the use of HM can stop this process. He claims that 500 billion tonnes of carbon can be stored on roughly 5 billion hectares of land managed holistically over a period of 40 years, assuming soil can sequester carbon at a rate of 2.5 tonnes of carbon per hectare per year (Nordborg, 2016). Coincidently, 550 billion tonnes of carbon have been released since the start of the industrial revolution. Therefore, Savory has branded Holistic Management as a solution for climate change. To fully assess these claims made, it is important to consider how exactly atmospheric carbon can be converted into soil organic carbon. This involves looking at the carbon cycle, previous studies of Short Duration Grazing (SDG) and Intensive Rotational Grazing (IRG), and carbon sequestration data from managed soils.
Soil Carbon and the Carbon Cycle
Figure 2: The fast carbon cycle, showing the interchange of carbon between the atmosphere, land and the ocean. White numbers indicate stored carbon, yellow numbers indicate natural fluxes and red numbers are human contributions. Carbon is measured in gigatons per year (Source: NASA – The Carbon Cycle).
Soil is a major contributor to carbon storage in both the fast and slow carbon cycle (Figure 2). Whilst the slow carbon cycle takes 100-200 million years to move carbon between rocks, soil, oceans and the atmosphere, the fast carbon cycle takes approximately a lifetime(NASA). Plants and phytoplankton are the main drivers of the fast cycle, and oxygen is combined with sugar to release water, carbon dioxide and energy. The atmospheric CO2 is then fixed via photosynthesis into plant biomass. Soil carbon materialises because of direct growth and death cycles of plant roots and symbiotic relationships with mycorrhizae fungi, where proportions of carbon dioxide are lost through microbial respiration, and some of the original carbon is stored as humus (Ontl, T. A. & Schulte, L. A., 2012). If carbon input from photosynthesis exceeds carbon loss, the level of soil organic carbon increases over time. An average of 81% of carbon in the earth’s biosphere is estimated to be present in soil, with the remaining 19% stored in plants (IPCC, 2000).
The ratio of Soil Organic Carbon (SOC) and Soil Inorganic Carbon (SIC) is important in soil globally and particularly relevant to arid regions. SOC content plays a key role in preventing erosion of soils, temperature balance, increasing water retention and acting as a source of essential plant nutrients (Lal, 2004). Because of the low SOC content in arid regions, this plays a part in the increased risks of desertification. Lal (2004) coincidingly states that loss of SOC content is increased by accelerated soil erosion and mineralisation, on sloped soils and flat soils respectively, and that “global hotspots” of soil degradation are South Asia, the Andean Region, Central America, sub-Saharan Africa and the Caribbean. Not only this, but severely eroded soils are said to have lost between a third to two thirds of their original carbon pool, something which is commonly observed in tropical regions. In this case, improved management techniques are required to try and slow this SOC decline, but grazing may not be the answer. In addition, focus should be put onto slowing this existing decline, opposed to attempting to rescue soils with very little of their original SOC left.
Studies of similar grazing systems show little or no benefit to soil
As described in Figure 1, HM is synonymous with SDG and IRG. Several reviews of both SDG and IRG have provided evidence that intensive, short duration systems have damaging effects on soil, rather than beneficial effects. A review on the effects of SDG in 1999 (Holechek et al, 2000) found water infiltration was significantly reduced following hoof action of ruminants, and a detailed 5-year study in Canada (Dormaar et al. 1989) stated that hoof action did not significantly increase incorporation of litter into soil. This directly contradicts the apparent importance of hoof action in the HM technique. Further evidence comes in the form of nine out of ten studies in North America, which found SDG had no benefit in terms of livestock productivity. In addition, a similar report of over 50 grazing studies in Africa found little differences in productivity between continuous and SDG systems (Holechek et al. 2000).
What is interesting about these studies is that most of the research on SDG was published from 1980-2000 and found no credible results to support SDG and its supposed benefits over other management techniques. Considering the negative findings of these studies, it is no surprise that several forms of current “evidence” listed on the Savory website come in the form of anecdotal quotes from ranchers. Their testimony is most likely due to a productive year with high precipitation and therefore higher productivity (Holecheck, 1996); rather than a direct result of implementing HM. Furthermore, the HM technique has no set limits on stocking rates. Naturally, higher stocking rates – combined with favourable environmental conditions – will lead to increased profits for the ranchers directly, so if a good year happens to coincide with implementing HM, then it reflects well on HM as a grazing technique. However, it is important to focus on what the science tells us, and that is that SDG itself is not beneficial for Soil Organic Content (SOC) or soil productivity. It is dependent on factors out of direct control.
Carbon sequestration is dependent on several factors
Carbon Sequestration is defined as the uptake of atmospheric carbon dioxide via photosynthesis, which is stored in the form of carbon and dead organic matter in soil (Lal, 2004), and its rate is dependent on the type, usage and treatment of the land. From the carbon cycle, there is certain evidence that soil carbon can act as a substantial carbon sink. In relation to HM, the supposed increased carbon sequestration achieved using Holistic Management allows a huge proportional of atmospheric carbon dioxide to be locked away in soil (Nordborg, 2016).
There are several reasons why HM cannot achieve his high sequestration rate. The primary reason is that carbon sequestration is not a simple concept. It is dependent on climate, temperature changes, history of grazing and soil nutrient content, among other factors.
Temperature has a large influence on carbon sequestration. With increasing temperature, the likelihood is that carbon loss from soil will outweigh carbon storage. There is a higher tendency for slower plant growth over a longer growing season, and drier, warmer soil that will likely release CO2 and methane into the atmosphere. This will create a net release creating a positive feedback loop for carbon loss (Johnston, C. et al. 2004).
Extending this viewpoint, one could argue that increasing CO2 will lead to increased photosynthesis and in turn, increased plant productivity and eventually higher rates of retention and sequestration of carbon in soils which currently lie in colder climates. This argument is supported by White et al (1999), where he states increased temperature and rainfall decrease may benefit boreal forest regions, and by various sources which agree that longer growing seasons in Northern Europe and America will improve harvests and may introduce new beneficial species (Sohlenius and Bostrom, 1999; Kleemona et al 1995). On the contrary, increased temperature will most likely prove detrimental to SOC content. Increased mineralization and susceptibility to soil erosion (Dalias et al, 2001) will be a common occurrence in less temperate regions. The soil will crust, have increased water runoff on the surface, and become less likely to store water, carbon, and other important nutrients. Moreover, and perhaps the most significant, is that peat and organic soils will add to growing carbon dioxide emissions with increasing temperature, switching from a carbon sink to a source.
Another problem with studies claiming large sequestration rates in soils is that soil is a sensitive, living environment. It is combined of fungi, macro and microfauna, animal matrix products, dead and living plant matter, all held within a matrix of several states (Johnston et al, 2004). Thus, measuring carbon sequestration in a living environment, which typically requires disturbing the soil, will likely give several false positives. Compared to this, simulations of carbon loss and gain in soils are not a much better solution to this problem.
Carbon is lost over time
As reported by Smith (2004), soils globally have lost somewhere between 40 and 90 billion tonnes of carbon historically, with the IPCC estimating around 30 billion tonnes have been lost from terrestrial ecosystems since the start of the industrial revolution. Even should these soils, under better management techniques, be able to re-sequester 90 billion tonnes, it accounts for only 16% of carbon emissions since the beginning of the industrial revolution(Nordborg, 2016). Soils also have varying degrees of carbon sequestration potentials. Global studies of potential of grassland soils to re-sequester carbon ranged from 0.5-1.9 billion tonnes of carbon per year (Lal, 2001 & 2004, Petri et al. 2010), with the upper limit equal to 20% of current emissions.
Several long-term studies of carbon sequestration and soil organic carbon content have also been conducted on grasslands. Two examples were studies of Soil Organic Content (SOC) in European grasslands over 10-50 years (Schrumpf et al. 2011) and a review of experimental soil carbon data from grasslands in the UK over a period of 25 years (Bellamy et al. 2005). Considering that European grasslands are not one of the areas that Savory has targeted for implementing large scale HM – as it is not at risk of desertification – it seems likely that positive sequestration rates would be expected, and thus giving HM a better chance of success compared to a harsher climate. However, no such results were apparent. The studies concluded that there was no significant change in SOC stocks (Bellamy et al. 2005) or that there was no clear trend in sequestration; decreases, increases, and periods of relative stability were observed (Schrumpf et al. 2011).
Realistic estimates of HM’s potential are 18 times less than Savory’s estimate
An extremely generous estimate for carbon sequestration on soils managed holistically was proposed by Nordborg. She uses the most optimistic assumptions such as:
- HM applied to 1 billion hectares worldwide;
- Plant growth measured as Net Primary Productivity (NPP) above and below ground is 3.8 tonnes of C per ha and year before introduction of HM;
- NPP doubles following implementation of HM;
- 10% of NPP is sequestered in the soil in the first year;
- Soil carbon sequestration declines from 10% to 2% to 0% after 50 years and then 100 years respectively.
Factors such as NPP rate at 3.8 tonnes of carbon per ha and year are based on the most optimistic rates, as the likelihood of this rate observable in grasslands worldwide is likely to be around 1.7 tonnes, and plant productivity is limited by temperature and precipitation in climates around the world (del Grosso et al. 2008). Another factor to consider is increasing anthropogenic carbon emissions and climate (see below). However, using the assumptions, a calculation of 26.5 billion tonnes of carbon was produced, which is approximately 4.8% of the total emissions of carbon since the industrial revolution. What is more staggering, is that this is 18-fold times less than the estimate proposed by Savory.
Figure 3: Graph displaying the billions of tonnes of carbon potentially gained on soils using Holistic Management on either 5 billion hectares of land over a period of 40 years (Savory Estimate) or 1 billion hectares of land over a period of 100 years using generous estimates (Nordborg Estimate). This is compared to the 90 billion tonnes maximum that is predicted to have been lost from soils (Smith, 2004) since the Industrial Revolution.
For a more appropriate assessment, this data could be compared to one of the Savory Institute’s ‘scientific studies’ that back up his claims. One explanation offered on the Savory Institute website is that of Itzkan (2014), where the upper limit of 2.4 tonnes of C per ha and year, over 3.5 billion ha, is based on before and after photograph inspection of the soils by the author. One of many “methods” which Savory has stated as reliable in backing up HM’s capability have included before and after photographs, anecdotal reports, and non-peer reviewed reports. These make up 26 papers of the 40 published on the website. (Savory Institute, Nordborg, 2016).
Methane emissions from livestock is overlooked
Methane (CH4) is an extremely potent greenhouse gas. It has an atmospheric lifetime of around 12 years and offers the largest potential for reduction in radiative forcing when compared to CO2. The ability of CH4 to absorb infrared radiation is 20-30% greater than CO2. Ruminants are the largest contributor of anthropogenic methane emissions and livestock production occupies the most land globally than any other land use (Ripple et al. 2014). The number of ruminants on earth, as of 2011, was estimated to be around 3.6 billion domestic ruminants, and an unknown, far lower number of wild ruminants. The number of ruminants is on average increasing by 25 million per year (FAO). Demand is also on the rise, with a projected increase of 69% consumption of beef on global scale (FAO). However, Holistic Management believes the idea of increasing ruminant population will not have an overall impact on climate change. Continually, an article on the Savory Institute website states several reasons to explain this, such as:
- Oxidation of methane by soils represents 10% of the total methane sink.
- Large pre-agricultural populations of ruminants had methane levels cycling consistently between 350-750ppb.
- Methanotrophic bacteria break down roughly 1 billion tonnes of methane each year on well managed soils.
Figure 4: Figures a-d show the link between methane emissions and livestock, taken from Ripple et al (2014). a, Estimates of direct radiative forcing in 2008 for CO2 and non-CO2 greenhouse gases from anthropogenic sources. b, Projections of radiative forcing in four different scenarios: constant future emissions at 2008 levels (red); 80% reduction in only non-CO2 emissions (orange), 80% reduction in only CO2 emissions (blue), and 80% reductions in both non-CO2 and CO2 emissions (green). c, Estimated annual anthropogenic emissions from major sources of methane in recent years. Error bars represent 1 standard deviation. d, Global ruminant numbers from 1961 to 2011.
Atmospheric methane levels have more than doubled from 1750 to 1999. Its concentration has increased from 700ppbv to 1745ppbv and is steadily increasing at a rate of 7ppbv/year (IPCC, 2001). This is directly correlated with a steading increase of ruminants worldwide (FAO), natural gases, landfill, coal and the rice industry (Figure 4, Heilig, 1994), and increasing climate change is also likely to have played a part in releasing pools of methanetrapped in the oceans and under thawing permafrost (NASA). The Savory Institute’s point of methane cycling between 350-750ppb is true, and while the populations of wild ruminants is unknown and likely to be large, it is not as large as current farmed ruminant populations. A study by Hristov (2015) in the United States concluded that enteric CH4 emissions by presettlement ruminants, such as elk, deer and bison (estimated at 50 million) is 86% of the current emissions by farmed ruminants. As the level is similar, it seems likely that the shift occurring today in methane emissions is due to increase of ruminants combined with change in land use – especially in tropical regions, where native forests are cleared to make way for animal feed crop and grazing land – helped with the increase in climate change, which accelerates the loss of carbon from mismanaged soils.
Alternative non-grazing solutions offer more scientific promise
There are numerous scientific studies which agree that better management techniques can aid carbon sequestration in grasslands, improve soil organic content (SOC) and slow desertification (Follett, Kimble and Lal, 2001, IPCC, 2007, Jones, 2010). There are a few studies which showed that different management techniques, other than grazing, could influence the carbon sequestration rate of soil. In a study by Conant et al (2001), some of the 115 studies worldwide produced results of high carbon sequestration rates for some management practices, such as a conversion of cultivation to pasture, improved grass species and earthworm introduction. However, there are problems in stating this data as reliable. Grass species was the subject of one study (Fisher, 1994). The cultivated to pasture switch is likely to have a high rate due to restoring carbon lost in the previous conversion, and introduction of earthworms was the subject of two studies and is dependent on soil type. These studies are subject of very specific conditions and the results are not repeatable. In addition, the most important fact is that sequestration rates will be high in the first few years, in line with Nordborg’s estimate (Figure 3), but over an extended period carbon release is likely to increase with carbon storage. Therefore, it is not applicable to include “reliable” data on this matter if the study has lasted less than 40 years. For this reason, data from studies such as Schrumpf et al. 2011 is more reliable. Despite this, a more promising solution would be to conduct long term studies on grassland over long periods, using management practises listed in Conant’s paper and perhaps more techniques appropriate for the specific nature of the soils studied. For this reason, HM should be assessed long term alongside these studies.
Conclusions
From the wide range of scientific studies conducted into carbon sequestration in soils, contribution of ruminant methane emissions to the greenhouse effect, and the effect better grazing management has on productivity, there is little to suggest that HM has any significant contribution – positive or negative – on increasing carbon sequestration in soils both at risk or not at risk of desertification, or that it is any better than other similar grazing techniques implored on soils. From the research conducted into this topic, several conclusions are presented:
- Holistic Management, or any other grazing method, alone cannot reverse climate change – and at most, can slow the current rate of emissions over a limited period by less than 5% over a 100-year time-frame.
- The potential of soils to sequester atmospheric carbon is primarily dependent on climate and nutrient balance, and not grazing.
- Long term studies of carbon sequestration in grasslands show no overall loss or gainof carbon under favourable climate conditions.
- Methane release by domesticated ruminants is extortionate and has a significant effect on increasing the greenhouse effect.
- Allan Savory’s claims and statistics about the potential of HM on desertifying grassland are based on assumptions and anecdotes are therefore not scientifically reliable, repeatable or valid.
References
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Bellamy, P.H. et al., 2005. Carbon losses from all soils across England and Wales 1978-2003. Nature, 437(7056), pp.245–248.
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Last updated on by Seb V . View Archives
Related research from last year : The vast reservoir of carbon stored beneath our feet is entering Earth's atmosphere at an increasing rate, most likely as a result of warming temperatures, suggest observations collected from a variety of the Earth's many ecosystems.
I wrote a rather long detailed explanation why this rebuttal is flawed. But unfortunately it never posted.
I don't know why? Maybe it was too long?
Anyway the short version is this. Oxic soils under grasslands are net sinks not sources.
What reaction can you do to remove methane?
So that part is completely flawed and actually improving and expanding grasslands would help lower methane, not increase it.
The other mistake made here is in not understanding the difference between the catabolic processes of decay in the O-horizon of the soil profile and the anabolic processes of soil building in the A and B horizons of the soil profile.
One is biomass and primarily a function of saprophytic fungi (SF) vs the other which is the liquid carbon pathway of root exudates and glomalin and primarily a function of Arbuscular Mycorrhizal Fungi (AMF).
This makes the Roth C model not applicable at all. It simply doesn't apply in this case. It is a very good model for biomass decay, but it and any other biomass decay model are all flawed when trying to use them for the LCP.
Here is evidence from the past of this ecosystem function:
Cenozoic Expansion of Grasslands and Climatic Cooling
Gregory J. Retallack doi: 10.1086/320791
And here is a review of how we can apply the paleo record of this ecosystem function to modern times and near future AGW mitigation.
Global Cooling by Grassland Soils of the Geological Past and Near Future
Gregory J. Retallack doi:10.1146/annurev-earth-050212-124001
And here is empirical evidence of carbon sequestration rates in the field under various agricultural techniques and systems. A careful examination of the evidence with an understanding of how the Liquid Carbon Pathway functions makes it very clear which systems use the LCP and why the difference in rates seen. It also confirms that the average sequestration rate of ~5-20 tonnes CO2e/ha/yr holds true in environments tested around the world.
Conservation practices to mitigate and adapt to climate change
Jorge A. Delgado, Peter M. Groffman, Mark A. Nearing, Tom Goddard, Don Reicosky, Rattan Lal, Newell R. Kitchen, Charles W. Rice, Dan Towery, and Paul Salon doi:10.2489/jswc.66.4.118A
Managing soil carbon for climate change mitigation and adaptation in Mediterranean cropping systems: A meta-analysis
Eduardo Aguilera, Luis Lassaletta, Andreas Gattinger, Benjamín S.Gimeno doi:10.1016/j.agee.2013.02.003
Enhanced top soil carbon stocks under organic farming
Andreas Gattinger, Adrian Muller, Matthias Haeni, Colin Skinner, Andreas Fliessbach, Nina Buchmann, Paul Mäder, Matthias Stolze, Pete Smith, Nadia El-Hage Scialabba, and Urs Niggli doi/10.1073/pnas.1209429109
Managing Soils and Ecosystems for Mitigating Anthropogenic Carbon Emissions and Advancing Global Food Security
Rattan Lal doi: 10.1525/bio.2010.60.9.8
The role of ruminants in reducing agriculture’s carbon footprint in North America
W.R. Teague, S. Apfelbaum, R. Lal, U.P. Kreuter, J. Rowntree, C.A. Davies, R. Conser, M. Rasmussen, J. Hatfield, T. Wang, F. Wang, and P. Byc doi:10.2489/jswc.71.2.156
Grazing management impacts on vegetation, soil biota and soil chemical, physical and hydrological properties in tall grass prairie
W.R.Teague, S.L.Dowhower, S.A.Baker, N.Haile, P.B.DeLaune, D.M.Conover doi:/10.1016/j.agee.2011.03.009
Please note that all of these have published results higher than this so called rebuttal claims is impossible. That's measured results. So right there is enough to show this rebuttal is empirically wrong.
Of course they all show other measured results much lower too. And those also have strong reasons why.
If they are primarily using biomass decay, then the carbon sequestration is positive but much smaller than when the primary biological pathway is the LCP. So there is your empirical evidence and also your explanation why.
RedBaron, your other comment is to the "blog post" announcing this new "rebuttal" here: https://skepticalscience.com/holistic-management-rebuttal.html
Thanks David, but no. That is also a pretty basic answer. I wrote out a long version that took about 3 or 4 hours to write. It vanished. Unfortunately I did not save a draft. So I'll not be doing that again. Anyone with questions just ask and I'll handle them one at a time instead.
Might actually help if you understood what holistic management is before you critique it. Hint: It isn't short duration or rotational grazing. Might also help if you referenced more current soil science.
Carbon sequestration, utilztion and sequestration is driven by photosynthesis, plant diversity and soil biology. The more soil biology, and specifically arbuscular mycorrhizal fungi (especially relative to bacteria), the more carbon capture and utilzation. Soil microbial science has had a major paradigm shift since more new metagenomic tools have been developed to gene microbial DNA. Sadly your paper references a lot of soil science pre-paradigm shift that doesn't account for the roll of soil microbiology, which pretty much drives everything including the carbon, nitrogen and water cycles (1,Paul et al 2018).
There are two pathways for carbon utilzation: one the decompostion pathway, and the second the microbial carbon pump [MCP] (2.Liang et al 2017). The decomposition pathway is what's respires. This is labile carbon. The microbical carbon pump store carbon as deep as roots tips go. This is "deep carbon" that is what's sequestered and doesn't respire. As long as there is ground cover, respired carbon is what actually leads to more photosynthensis than atmospheric carbon so respired carbon is NOT lost to the atmosphere (3). Respire labile carbon is recycled with more of it being exuded by the roots as deep carbon. Diversity contributes a diversity of root depths and different exudates to a wider array of soil microbes. (4,5 Eisenhauer et al. 2017 and Zhalninal et al. 2018)
The carbon saturation argument fails to acknowledge that via photosynthesis and the MCP more soil is formed. Soil too is formed from the top via decomposition and from the bottom (a-b horizon) via microbial necromass (6. Kallenbach et al 2016). As long as photosynthesis is occuring with diverse plant feeding microbes those microbes die and form more soil organic matter (SOM). More SOM contains more soil organic carbon (SOC) . So soil may reach equilibrium, but more soil is always accumulating from the top and bottom that can capture more carbon. The key for this to occur is to keep root mass in the soil.
This is where grazing management comes into play. Contrary to what you wrote, holistic management and short duration grazing are NOT the same thing. Nordborg relies on Briske and Holechek both of whom looked at short duration grazing systems. Holistic Management is actually a comprehensive system to evaluate land to determine goals and paths for both ecosystem and economic restoration that may or may not involve holistic grazing based on the appropriateness of cattle (or other ruminants) in that ecosystem. So, it helps to actually understand what one is critiquing before actually makes a critique or relying on others' critiques. Dr. Richard Teague also wrote a response to the critique of Briske called "Deficiencies in the Briske et al rebuttal of the Savory method" (6). In this response Teague also notes that Briske is comparing grazing systems and doesn't seem to understand what holistic management is.
In subsequent research, due to prejudice against Savory, in order to get published Teague coined the term AMP management. AMP stands for "adaptive multi-paddock" and is sometimes shorted further to adaptive grazing or adaptive management. Many of the more recent crtics in doing there analysis seem to be unaware that holistic and AMP management are the same thing, so they exclude papers are AMP management when they proclaim that there is no research to back up holistic management. This is a common, though mistaken, refrain. The body of research supporting AMP and HM actually continues to grow (plus is supported by a lot of the more recent soil science). Here's a stack of more recent range science papers supporting HM/AMP aggregated on Defending Beef's ISSUU page: issuu (dot) com/defendingbeef/stacks/c2202fc5e40d4766902627af9453909b
Now holistic management that includes holistic grazing, unlike short duration or rotational grazing, isn't a prescribed system. When cattle or other ruminants are moved, they are monitored and not allowed to eat more than half the forage. Why half? Because anything more than half drastically reduces the amount of root mass. When root mass is maintain, the microbial carbon pump is also maintained, thus carbon exudates are continuously pumped into the soil. Extra plant growth not consumed is trampled down where that forage decompose and becomes part of the decompostion pathway and providing valaublae ground cover which reduces evaporation. The carbon pumped into the soil also improves the soil structure, allowing for more water to infiltrate and be retained, and ths allow for more plant growth. The area just grazed may not be regrazed for anywhere up to six months to a year depending on regrowth of plants. Again this is closely monitored , and animal movement is based on 'reading the land" through careful observation...again NOT a prescriptive system like SDG or rotational grazing.
Curious, author have you ever been on a ranch of any kind? How about one that uses holistic managament? My guess is that you're only reading literature and have no real idea how any of this works. You should take a page from author Barry Estabrook's recent article on Savory. In this article, Estabrook listened to both advocates and critiques. Then Estabrook went and visited a Savory hub for himself and saw the results. which were undeniable....
Now as for methane, using your logic, we should drain all the remaining wetlands and peat bogs plus kill all beavers since wetlands emit copious amounts of biogenic methane as do beaver ponds. Now the argument as to whether there were or were not more wild ruminants is a silly one since there's no real real accounting to prove either side. In North America, we have guestimates of bison, elk, pronghorn, moose, deer, big horn sheep, etc population that may or may not exceed current domesticated populations of domesitcated ruminants both in number and in mass. In Asia and Europe, the ecological memory is much more distant since the large herds of auroch, bison, stepped bison, irish elk, etc were exterpated a much much longer time ago. What's much easier to argument is that we had much greater regions of wetlands than we do have today as well as a lot more beavers making ponds full of methanogens making methane. Microbial, thermogenic and pyrogenic methane comes from a multitude of places like cockroaches, shellfish, coal bed gas, fracking, centipedes, burning biomass, decomposing organic mass, landfills, etc. Despite all of these emissions, the vast majority of this methane is oxidized by hydroxyl radicals in the troposphere (and to a lesser exent in the stratosphere). A small amount is oxidized by methanotrophs in the soil. The geosink though is very small.
But here's the thing, Carbon flows, and shift forms.....
Due to hydroxyl radical oxidation, enteric and most other forms of microbial methane really are part of the carbon cycle so it's a constant amount. CO2 from the atmosphere is converted to sugars plant use to make cellulose, lignan and exudates. Cattle eat the cellulose. A quorum of bacteria/archae including methanogens in the rumen convert that cellulose to H2, short chained fatty acids and CH4. The SFCA's are used for energy, and the CH4 is burped. That CH4 collides with OH (hydroxyl radicals) which steals a hydrogen atom and thus breaks down to H2O and eventually back to Co2 which again then goes to photosynthesis to make the grasses and twigs cattle and other ruminants eat. It's a cycle ...loop. ...not an aggregating process. If cattle or ruminants don't eat the grasses, those grasses still oxidize or decompose back to CO2 directly or to CH4 which then is oxidized in the geosphere by methanotrophs or the troposphere by hydroxyl radicals back to CO2 which then also cycles.
Or, in other words, enteric methane from ruminants and other microbial sources is part of respiration. It's just a few extra steps from CO2 to cellulose to CH4 back to CO2 back to cellulose. So these sources of CH4 are not what are causing methane levels to rise again after 2007. What is? Natural gas from fracking which confused some researchers in their top down analysis becuause fracked gas has a C12 isotope signature. (Thermogenic -fossil fuel- methane sources typically have only C13 heavier isotope signatures). So if you really want to reduce methane levels, switch electrical generation to green energy ...and get rid of fracked natural gas and coal generation of electricity.
Anyway, sorry got lazy with my references in the second half of this response. My references for methane include Prinn, Rigby, Howarth, etc.
1). Paul, D et al. 2018. Molecular Genomic Techniques for Identification of Soil Microbial Community Structure and Dynamics
2).. Liang, c et al 2017 the importance of anabolism in microbial control over soil carbon storage
3). Farming the CO2 Factor, Eco-Farming Daily 10/10/2018
4). Eisenhauer et al. 2017. root biomass and exudates link plant diversity with soil bacterial and fungal biomass
5). Zhalnina1, K et al. 2018. Dynamic root exudate chemistry and microbial substrate preferences drive patterns in rhizosphere microbial community assembly
6). Kallenbach et al. 2016. Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls
I have quite a good knowledge of this area. I'll just state my opinions to start... Allan Savory's rhetoric and claims are rather over the top - and this rebuttal is rather 'under the top'. It throws the baby out with the bath water.
The 'climate myth' as stated is (probably) still a myth but strip the hyperbole away from the myth-as-stated and there is still a useful technique left which I think this rebuttal unfairly denigrates.
Much of the substance of these rebuttals uses straw man arguments and fallacious analogising. I think it should be removed from Skepticalscience.com because it is rather 'denialist' in the way that it argues. Post Vegan @5 gives a good explanation of why this rebuttal is mostly invalid.
It is no doubt true that just holistically managed grazing alone can not be enough to suck all that excess CO2 from the atmosphere. Similarly, increasing soil organic carbon in agricultural crop fields - I don't think anyone could reasonably argue that our industrial agriculture has not greatly reduced 'natural' levels of SOM - is also not (using accepted figures from such as Lal) enough to do the job. We already know that greatly reducing fossil fuel emissions is also not enough, on its own, to do the job. I think we need all three, plus extras!
A couple of comments to facilitate the discussion. First, let me set some context. (This post could go at the bottom of any rebuttal.)
The aim of Skeptical Science is to communicate what we as a species know (and don’t know) about climate change, and to call out claims which misrepresent what we as a species know about climate science.
This raises the question of how we, as a species, can know something. Clearly, there are things that we do know – that the earth is round and orbits the sun. A few people dispute these things, but we consider it nonetheless as something that is known. So how do we know that we know?
The answer is laid out in lay terms in this talk by science historian Naomi Oreskes, and in many more academic talks she and others have given on the same subject. The problem is that people are human, and have incomplete information and cognitive biases. So we can’t trust people. Scientists train themselves to focus on evidence, but are still people, and so not very reliable. Scientific papers are a little more reliable, because of two additional social factors – when we attach our name to a paper, some of our reputation goes with it, and also the paper should be rigorously critiqued by (when the system works) independent scientists looking to find holes in our work. But science is hard, so we still expect many individual papers to be wrong. The best measure of what we as a species know comes from an assessment of all of the scientific literature on the question, because more diverse and more dispersed groups are less subject to groupthink and other biases.
When we address a claim on SkS, we have to have a standard against which to evaluate a claim. And the most reliable standard is to compare that claim against the whole body of scientific opinion relevant to that claim. We expect a diversity of opinion, but we can assess the breadth of diversity on a particular question. We can then identify whether a particular claim is representative of the scientific knowledge on a particular question, or whether it is part of a spectrum of diverse opinions. In the latter case we can further identify whether the claim falls in the middle of that spectrum, on the edge, or is an extreme outlier with little other support.
Obviously this can’t be done by citing individual papers, it must be done on the basis of an extensive review. Hence the lengthy citation list. We expect to find outliers on any question – I’ll discuss some of these later. However, we also expect multiple systematic reviews to reach similar conclusions, so comparison with the IPCC reports is an important starting point.
So, that raises two questions:
I'll try and look into the first of these in my next post.
Firstly, we need to establish the scope of the question. There is scientific discussion as to whether holisitic management provides significant benefits over other managed grazing techniques (and of course there is no doubt that managed grazing provides benefits over mismanaged grazing). Conclusions vary both by location and by the field of the researchers, with sociologists (who talk to the farmers) more positive than experimental agriculturalists (who rely more on measurements). While extremely interesting from a scientific viewpoint, this is not a relevant question for Skeptical Science.
The question which is key to the work of Skeptical Science is whether Savory’s very specific claims about the ability of holistic management to extract CO2 from the atmosphere at levels sufficient to reverse climate change are credible. Savory claims that over a period of 40 years the application of holistic management could remove 500 Gt of CO2 from the atmosphere.
So lets start with the IPCC report (AR5 WG3), since it is a comprehensive assessment by some of the best people in the field. Chapter 11 reviews the potential for CO2 mitigation from agriculture and land restoration, with figure 11.13 being particularly relevant. According to this figure, the potential CO2 emissions mitigation from grazing land management, land restoration and livestock is about 2 GtCO2eq/year, or about 5% of our current emissions at the highest carbon price of $100/tonne. If we were to achieve this level of mitigation continually for 40 years, that would be 80 GtCO2eq or 22 tT C, or 5% of Savory’s estimate. Taking the upper 1 sigma bound only leads to a small increase in this value.
Note however that this is based in part on reductions in emissions rather than uptake, and ignores the issue of non-permenance of additional soil sequestered carbon (section 11.3.2), both of which reduce the expected mitigation potential.
Are there estimates of the long term carbon sequestration potential of soils under improved grazing or other management schemes? Eagle et al (2010), which is the primary source for the Delgado paper cited by Red Baron, lists two 40 year studies (table 23), with one showing no change from altered grazing practices, and the other showing a small increase in sequestration (0.66 tCO2eq/ha yr, 0.2 tC/ha yr) from a change in grazing. For single year studies, Eagle finds the CO2 sequestration potential of rangeland as uncertain and varying in sign from study to study.
The two Retallack papers cited by Red Baron don’t seem to be relevant – the first deals with very long timescales (~10Kyr). The second contains a brief speculative section at the end, but does not offer any data except for a citation to Sanderman (2010), who in turn cites Connant (2001), which was a source work for this rebuttal and found vary variable results from different studies. Sanderman also notes that “On average, 1-2% of plant residues become stabilised as humified soil organic matter for significant periods of time (Schlesinger 1990).” highlighting the importance of the permenance issue.
I'll try and work through a couple more of the suggested papers this evening.
@6 Nick,
Even Savory doesn't claim that. He clearly states in many interviews that part of HM includes renewable energy and reducing emissions as a holistic approach to AGW mitigation. There are some people out there claiming a silver bullet, but Savory is not one of them actually. This is from his plan:
Kevin C wrote: "Chapter 11 reviews the potential for CO2 mitigation from agriculture and land restoration, with figure 11.13 being particularly relevant. According to this figure, the potential CO2 emissions mitigation from grazing land management, land restoration and livestock is about 2 GtCO2eq/year, or about 5% of our current emissions at the highest carbon price of $100/tonne. If we were to achieve this level of mitigation continually for 40 years, that would be 80 GtCO2eq or 22 tT C, or 5% of Savory’s estimate."
For those readers who don't know, 'Kevin C' is a heavyweight climate scientist. I think the IPCC figures given above relate to 'conventional' soil restoration and grazing management. As I wrote, I think Allan Savory claims too much in his headline statements, but I'm pretty sure his figures include large contributions from reversing desertified and highly degraded land which is probably not covered, or fully conceived of, in the IPCC chapter. Whether his techniques can do that, of course, is a subject of debate...
It's a truism that many giant agricultural fields have very low soil carbon in them nowadays due to the way they are cultivated - much lower, percentage wise, than the soil would have had when first cultivated. Industrial agriculture has denuded carbon from the soil and the quantities are thought provoking. As a thought experiment, just assume that all land we use for food crops and livestock on earth has a SOM of, say 3%. Given that, if we could increase that average up to, say, 6% then a relatively simple calculation shows that just about all current greenhouse emissions could be absorbed by this increased 'sink', but also that some way could be gone towards sucking historic CO2 emissions back out the atmosphere.
There are, of course, known limits to increasing soil organic matter conventionally, as has been mentioned. For example, just piling on endless tonnes of compost has only a temporary effect - bacteria 'respire' much if it right back out again in to the atmosphere as CO2 - unless one simultaneously addresses recreating the bacterial and fungal etc ecosystems that conventional agriculture has degraded. Building up them the long lived humic acids and glomalins creates soil carbon that is much more resistant to breakdown. I don't think this aspect is covered by the IPCC chapter.
Nick Palmer:
Statements like "which is probably not covered, or fully conceived of, in the IPCC chapter" and "I don't think this aspect is covered by the IPCC chapter" do not make for a very convincing argument. Either it is covered or it is not.
Since the IPCC includes very experienced scientists who have certainly heard about all aspects of soil science it seems to me that it would be covered. If it was not covered, the proponents of holistic management could have asked questions and gotten it in.
I just came across this ABC News (Australia) video and it may or may not relate directly to the ongoing discussion on this thread.
Boorowa farmer, David Marsh, began his journey into regenerative agriculture in the 1980s, after a drought brought him to the edge of ruin. He began adopting regenerative practices in 1999, increasing the amount of native vegetation and tree coverage on his property from just 3 per cent to 20 per cent.
Regenerative farming has helped transform the landscape of dry properties, ABC News (Australia), Mar 14, 2019
Holistic management isn't something one can really understand by reading papers on a computer screen, especially when one relies on papers that don't know the difference between holistic management and short duration grazing [SDG] or rotational grazing [RG]. The whole argument above is built on a house of cards since the author bases a large part of the analysis on Nordborg, who in turn relies on Briske and Holechek. All of these people make the same error. So let me reiterate, holistic management (aka AMP management) and short duration grazing or rotational grazing are not the same thing.
I didn't fully understand what holistic management was until I attended a few HM workshops and visited a few ranches using these management practices. Savory's talks and book weren't very useful since Savory's writing and speaking styles tends towards the use of a lot of run on sentences with non-parallel structure that tend to obfuscate rather than clarify. His TedTalk was one of his more persuasive talks since because of the time constraint, he was forced to be succinct. Though in this talk, many of the points, he’d normally qualify, were stated without any qualifications.
Now most people think HM is just another way or system to move cattle. But HM (more specifically holistic grazing), is primarily a process to restore and regenerate land utilizing a holistic ecosystem view. Holistic grazing, also called adaptive grazing, should also be thought of as regenerative or ecological grazing. Holistic grazing mimics nature, regenerates land and restores ecosystem function.
When starting with HM, the land’s existing conditions are assessed, goals are then determined, and a plan is implemented. That plan is constantly re-assessed and modified to achieve the plan's goals. Goals include improving soil health, greater plant and wildlife diversity, improved forage, improved animal welfare, improved hydrology, increased ground cover, etc. Ranchers using HM are as much soil farmers as they are meat producers. HM isn’t prescriptive. Movements are adapted to the land conditions. Every ranch will have its own unique plan to achieve its goals. Now systems like SDG and RG are systems, with specific movements patterns based on specific set timing irrespective of specific land conditions with the primary goal being cattle weight gains.
With holistic grazing, ruminants are an essential tool for achieving these restorative and regenerative goals. Ruminants are "all-in-one" tools. They are mowers, seed pushers, ground "indentors", composters, fertilizer spreaders, nutrient cyclers and soil builders. Moreover these four-legged decomposing spreader nutrient cyclers, in the field, don't require any fossil fuels.
Now the connection between grazing management and carbon sequestration is soil biology, specifically what practices improve biology and which one’s don’t improve biology. Soil biology drive carbon utilzation, respiration and sequestration as well as water infiltration and retention. As the most recent soil science has been finding when root mass is maintained, as I noted above, plants continue to exude exudates into the soil. When plants are grazed more than 50%, the plants lose most of their root mass. This is why cattle in HM or AMP systems have to be frequently moved. The tops of plants also have the most nutrition. Additionally when ruminants eat the tops, they are less exposed to worms and other potential pathogens closer to the soil. All the animal movements are based on field observations of plant growth and ground cover, not a specific pattern or timing as with SDG or RG systems. So once again, HM and SDG/RG are not the same thing.
Cattle’s urine, manure and saliva function as inoculates that increase plant growth. Ruminants, including cattle’s ancestors’ auroch, co-evolved with vegetation in grassland ecosystems. Grasses have nodes, so when bit they regrow from those nodes. The manure in healthy grassland ecosystems is broken down quickly by different types of dung beetles that quickly move the dung into the earth and thus reduce any methane off gassing. This helps build soil. But the primary mechanism for building soil, again as I noted previously, is microbial necromass accumulation. Up until recently, the general belief was that top soil takes hundreds of year to accumulate through mineralization. MacArthur Fellow, and geologist Dr. David Montgomery in his last two books, The Hidden Half of Nature and Growing a Revolution, does an excellent job of dispelling this belief by illustrating how better soil conservation agricultural practices, including livestock integration, speed up top soil formation significantly. So, as I noted in my prior response, more soil accumulates and captures more carbon. There isn’t a finite amount of soil, so there isn’t a finite of carbon capture, thus the whole premise of “saturation” is a flawed one except for in a degenerated system where no more soil is accumulating.
Better land management, including better grazing and agricultural practices, also maintain arbuscular mycorrhizal fungi [AMF] networks. When land is over grazed, tilled or treated with syn N, those AMF networks are destroyed. These networks connect plants and per preliminary research seem to play a huge role in the amount of carbon that can be sequestered. Dr. David Johnson, a microbiologist at New Mexico State University, did two self-financed research studies that showed massive increases in carbon sequestration coupled with decreased carbon respiration when fungi to bacteria ratios were improved. Johnson’s carbon sequestration numbers were 10 to 20 times those of Lal. Johnson’s numbers were so good, that one of the conservative peer reviewers didn’t believe those numbers, so both of Johnson’s paper were not accepted for publication. Though currently, several places across the globe including the new regenerative Ag program at Cal State Univ. Chico, are replicating Johnson’s studies to (hopefully) validate Johnson’s numbers. In the meantime, Johnson has made his composting methodology reading available online for anyone to replicate. This is a non-proprietary, non-licensed methodology, so Johnson doesn’t gain a dime directly from his processes. Here’s a good recent talk by Johnson at Cal St. Univ. –Chico where he discusses his research: Regenerating the Diversity of Life in Soils: Hope for Farming, Ranching and Climate
I've writen more about the importance of soil biology in this blog entry : It's the Soil Biology, Stupid.
Climate scientists and soil scientists as well as botanists really need to get out of their respective silos and talk to one another. Obviously we live in an interconnected (rather than reductive) world. For example: Carbon dioxide converted to glucose via the krebs cycle gets exuded and feeds soil microbes, which in turn, improves soil structure thus allowing for more water infiltration and retention. Thus more plant growth. More plant growth versus bare ground means more cooling immediately at the surface level. Plus plants transpire monoterpines like isoprene and pine which when oxidized become nuclei essential for rain cloud formation. Thus consolidation of water vapor leads to cooling as well as more cloud formation which reflects solar radiation…and thus more cooling. The more soil is recarbonized, the less evaporation and the more plant growth, so less water vapor and more cloud formation. Capiche?
Anyway, I’ll be writing something about these interconnections soon, until then here’s something else I wrote that is a more systems view of methane: Ruminations- Methane math and context.
All this reductive thinking like noted in the author’s myth busting gives everyone who is more mindful a lobotomy. We should be asking more questions rather than trying to “prove” all the time that others are “wrong”.
Still working through the paper list slowly:
My expertise in temperature data does not transfer to animal husbandry. All I'm doing is reading papers carefully and looking for numbers which are actually comparable (to whatever extent possible) and relevant to the question.
@12 John Hartz,
Yes Cell grazing from your link is an early form of Savory's work. It is not the same as HM, because quite a bit more work went into developing HM since the early days when Savory developed cell grazing from Voisin's rational grazing. But yes they are closely related. It is quite possible to get exactly the same results in soil carbon sequestration.
Cell Grazing
Cell Grazing the first 10 years in Austrailia
One other thing, as noted in my blog entry on methane, Ruminations-Methane math and context, spikes in atmospheric methane emissions correlate with industrialization, conventional natural gas use, and most recently the fractured natural gas industry. From 1998 to 2007, atmospheric methane levels had leveled out. During this period of time, global cattle inventories increased. Since 2007, global cattle inventories have decreased yet atmospheric levels of CH4 have again started to rise. So there is NO correlation between global cattle inventories and atmospheric CH4 levels. What started in 2006? You betchya, fracking. Typical microbial sources of methane (methanogenesis from archae- methanogens) have C12 isotopic signatures of methane while thermogenic sources of methane (fossil fuels) have C13 isotropic signatures of methane. But fracking and coal bed gas also have C12 isotopic signatures. This has led to some confusion in top down analysis of methane sources, especially when very rudimentary inventories of CH4 isotopes have been used. There's a lot of overlap in signatures, but in general some studies have been attributing CH4 to the animal Ag sector that should really be attributed to the natural gas fracking sector. (Note bottom up analysis of CH4 tends to over count and place blame on those sources of methane easier to extrapolate - like cattle- rather than sources of methane harder to account for like leaky gas pipes or the number of cockroaches).
Just a quick note: I spent 6 hours doing research based on 1 comment yesterday. I've started on PV's comments, which contain some very useful context which help understand some of RB's paper list.
I can only devote 1-2 hours a day to this over the next 3 days, but I am hoping to make a further contribution either today or tomorrow.
A further brief update: I'm still looking into this but there were multiple unplanned demands on my time next week, and I have a conference next week.
The papers of Teague et al are central to this discussion, and following the downstream citations looks to be a productive way forward.
A recent example is Stanley et al (2018), which also finds high rates of C sequestration over 4 years. They suggest that these rates may be sustained for several more years, but also imply that the rates will not be sustained indefinately - maintainability of sequestration rates (which in turn is closely coupled with permenance of the sequestered carbon) is one of the central issues with Savory's initial claim.
The other problem is extrapolation from single or similar locations to a global scale. Abdalla et al (2017) and Sherry & Ritchie (2013) both highlight the fact that the impacts of grazing may change sign between locations based on the presence of C3 vs C4 grass species, with Abdalla also noting substantial variation between climatic zones.
Extrapolation of local results to the globe and short term results to a 40 year period are therefore problematic. This may explain why even the large sequestration potential suggested by my extrapolation of Teague is much greater than the result of Lal who actually provides global and multidecadal estimates.
Given that naive extrapolation of the work of Teague still leads to an estimate of the carbon sequestration potential 4 times lower than that claimed by Savory, it still looks as though Savory's claim is indefensible and requires a rebuttal. I think Seb and I could probably improve the tone and nuance of the rebuttal in the light of some of the newer papers on AMP/MP, but unless there are some global/long period results we have missed I don't see that the conclusions of the rebuttal on the sequestration claim are going to change very much.
I'm very happy to look at more papers, but addition papers quoting the same local or short term results we have already seen don't really help. Non-naive global and/or long term sequestration projections are the most helpful information.
For the full picture it would be necessary to include opportunity costs if comparing feedlot to AMP like in Stanley et al (2018). The AMP system needed 120% more land than feetlot. This additional land could have been used to sequester carbon in other ways, if not used for AMP. This would lower the amount of sequestration relative to feedlot.
I have not calculated this yet. Some estimates for such opportunity costs have been given in Searchinger et al (2018).
@20 liberator,
That study does not include Methanotroph activity in their CH4 analysis. So their methane analysis was flawed compared to feedlot. But they did report soil sequestration of CO2e resulting as a net negative. So they got that part right at least, even using imported alfalfa hay, which is not needed in HPG, unlike certain other AMPs. Important to note too that the rang of soil sequestration they found was within the 5-20 tonnes CO2e / ha/ yr found elsewhere. Once they finally get the methane cycle right too, the differences will be even more profound.
@Kevin C,
Thanks for the time and effort. Here is more fuel for the fire.
Can Soil Microbes Slow Climate Change?
Converted to CO2e that is ~ 40 tonnes CO2e/ha/yr. About double the average reported by Jones and 4x what was reported by Teague, but nearly the same as the high outliers. Jones also took the raw results and measured that only 78% was stable humic polymers and I don't see where or if Johnson did that.
It's not HPG, but it does show the biophysical capacity of microorganisms in the soil to sequester high rates of carbon.
From Red Barons's Scientific American report: "As with all of Johnson’s work to date, this result has appeared only in the form of reports and other “grey literature.”
Grey literature is not allowed in the IPCC report because it is considered unreliable. Johnson needs to replicate his work and publish the results in a peer reviewed report. Hardly part of the scientific consensus.
Michael, I dont believe you are correct about grey literature. Eg see here.
I understand that in certain cases it might not be wise to use "grey literature". However it is also not reasonable to expect the same results repeating published papers be published over and over again in every state and/or country too. At some point there has to be an understanding that yes indeed this is a legit way to sequester large quantities of carbon deep in the soil, and all that remain is to project the number of acres we use it on. The biophysical aspect of what Savory discusses is well established enough that this is all that remains!
Will we change Ag or not? The more we change to holistic management, the more carbon gets sequestered! And also since agriculture is about 20-25% of emissions, it means a reduction of emissions too.
Oh and I just ran across this again.
Impacts of soil carbon sequestration on life cycle greenhouse gas emissions in Midwestern USA beef finishing systems
convert to CO2e 3.59 x 3.67 =
13.1753 tonnes CO2e/ha/yr and yet again another replication of the work Jones recorded, dead center in the 5-20 tonnes CO2e/ha/yr.
And that doesn't even count the fact that we could simultaneously take a similar acreage of corn out of production replacing it with grass. So we are reducing emissions and increasing sequestration simultaneously. Twice the efficacy at 1/2 the cost!
Clearly the Myth that needs debunked from this website is the Myth that HPG doesn't work.
Redirected from: Video: Is CO2 actually dangerous?
@33 nigelj,
Yes I understand I am lacking in diplomatic social graces. I apologize. I also do understand you are trying as well. Again my fault for poor communication skills.
You still have it wrong though....fundamentally.
"graze cattle in ways that promote plant growth..." so therefore by obvious implication they sequester more carbon. Hello?"
Plant growth is good for primary productivity sure. However, biomass is not sequestered carbon. It is fixed carbon and sometimes stored carbon. Both of which really are near net neutral on the carbon cycle, especially when viewed in geological timeframes.
The sequestrated carbon in a grassland follows a completely different biochemical pathway. They both start with photosynthesis, but the pathway you descibe and the one most commonly known does indeed end in primary productivity of biomass. The other pathway is quite unknown by nearly everyone and was only just discovered in 1996 by Dr Sara F. Wright, a scientist at the USDA Agricultural Research Service.
Later termed the "Liquid Carbon Pathway" it starts with photosynthesis but approximately 40% of the total products of photosynthesis are diverted to root exudates to feed symbiotic arbuscular mycorrhizal fungi who then build an underground communication network with newly discovered stable soil glue called glomalin.
Liquid carbon pathway unrecognised
Mycorrhizal Fungi: The World’s Biggest Drinking Straws And Largest Unseen Communication System
Glomalin: Hiding Place for a Third of the World's Stored Soil
Carbon
More importantly when glomalin eventually degrades, rather than returning to the atmosphere as CO2, as much as 78% becomes humic polimers tightly bound to the soil mineral substrate. This carbon generally can not easily return to the active carbon cycle. It will over geological time either erode and become sedimentary rock or fossilize in situ.
Cenozoic Expansion of Grasslands and Climatic Cooling
The novel part to all this being the evolution of C4 perennial grasses that are up to 2-4 times as efficient at photosynthesis as C3 plants and yet have much less biomass than a forest or brushland. The mystery of where, when and why all that sequesters carbon in the soil is being worked out now. It's all very exciting new research. It turns out that under the right conditions more carbon is diverted into this newly discovered pathway than the total primary biomass productivity of a forest!
This is a case where people in the field like Voisin, Savory, and many ranchers observed a phenomenon they couldn't accurately descibe. No one knew why or how it was happening. The soil building qualities and increases in soil carbon were measurable, but until Dr Wright's breakthrough, no one even guessed how it happened. This is part of the reason for such strong pushback by scientists like Belsky and Briske. The phenomenon was observed for well over 100 years before we even had an idea what was going on in grassland soils.
Mollic Epipedon
So you see? What people are seeing as modest increases in grassland productivity when bison (or properly managed cattle) graze an area is actually for AGW mitigation purposes a sign that below the ground something very much more significant is happening unseen.
The methane cycle is equally as complex and also a net sink in upland oxic grassland soils! So that means properly managed cows actually reduce methane, they do not contribute to it at all. It's a complete myth that has become a Vegan talking point, but it does not reflect the science.
Soil microorganisms as controllers of atmospheric trace gases (H2, CO, CH4, OCS, N2O, and NO)
I actually very much appreciate your posts because when you get it wrong I then know I have somehow again poorly communicated this new information. So please don't take it personal.