CompostConsumerismDeforestationGlobal Warming/Climate ChangeSoil BiologySoil CompositionSoil Rehabilitation

Beware the Biochar Initiative

Turning bioenergy crops into buried charcoal to sequester carbon does not work, and could plunge the earth into an oxygen crisis towards mass extinction

by Dr. Mae-Wan Ho

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The story goes that charcoal buried in the soil is stable for thousands if not hundreds of thousands of years and increases crop yields. The proposal to grow crops on hundreds of millions of hectares to be turned into buried ‘biochar’ is therefore widely seen as a “carbon negative” initiative that could save the climate and boost food production.

That story is fast unravelling. Biochar is not what it is hyped up to be, and implementing the biochar initiative could be dangerous, basically because saving the climate turns out to be not just about curbing the rise of CO2 in the atmosphere that can be achieved by burying carbon in the soil, it is also about keeping oxygen (O2) levels up. Keeping O2 levels up is what only green plants on land and phytoplankton at sea can do, by splitting water to regenerate O2 while fixing CO2 to feed the rest of the biosphere [1] (Living with Oxygen, SiS 43).

Climate scientists have only discovered within the past decade that Ois depleting faster than the rise in CO2, both on land and in the sea [2, 3] (O2 Dropping Faster than CO2 Rising, and Warming Oceans Starved of Oxygen, SiS 44). Furthermore, the acceleration of deforestation spurred by the biofuels boom since 2003 appears to coincide with a substantial steepening of the O2 decline. Turning trees into charcoal in a hurry could be the surest way to precipitate an oxygen crisis from which we may never recover.

Burying charcoal to save the climate

The International Biochar Initiative (IBI), according to its website [4], was formed in July 2006 at a side meeting of the World Soil Science Congress at Philadelphia, Pennsylvania, in the United States, by people from academic institutions, commercial ventures, investment banks, non-government organizations and federal agencies around the world, dedicated to research, development, demonstration, deployment, and commercialisation of biochar on a global scale.

IBI has introduced biochar into the 2008 US Farm Bill, so it now counts among a handful of “new, high-priority research and extension areas”. IBI is also working with the United Nations Convention to Combat Desertification to promote biochar in the post-Kyoto climate agreement. And the United Nations Framework Convention on Climate Change has already included biochar in a section entitled: “Enhanced Action on Mitigation” to serve as basis for negotiations during pre-Copenhagen meetings [5].

Biochar is just charcoal, produced by burning organic matter such as wood, grasses, crop residues and manure, under conditions of low oxygen (pyrolysis). A number of different pyrolysis techniques exist depending on temperature, speed of heating, and oxygen delivery [6, 7], resulting in different yields of biochar and co-products, “bio-oil” (with energy content value approx 55 percent that of diesel fuel by volume) and “syn-gas” (a mixture of hydrogen, carbon dioxide, carbon monoxide, and hydrocarbons), which can be used to generate electricity, or as low-grade fuel for ships, boilers, aluminium smelter and cooking stoves.

IBI has encountered strong criticism as a “new threat to people, land and ecosystem” in a declaration signed by more than 155 non-profit organisations worldwide [8]. But patent applications have been made, and companies formed for commercial exploitation of biochar production. Intense lobbying is taking place for biochar to be included in the Kyoto Protocol’s Clean Development Mechanism for mitigating climate change [9, 10], so people implementing that technology would be able to sell certified emission reduction (CER) credits.

Things have moved forward so fast with so little public awareness and debate that critics are alarmed, especially over the proposal from some prominent advocates that 500 million hectares or more of ‘spare land’ could be used to grow crops for producing biochar [11, 12], mostly to be found in developing countries; the same as was proposed in the biofuels initiative several years earlier.

Biofuels proving disastrous

The biofuels ‘boom’ has already exacerbated climate change by speeding up deforestation and peatland destruction, loss of habitats and biodiversity, depletion of water and soil, and increased the use of agro-chemicals. Above all, it has generated poverty, land grab, land conflicts, human rights abuses, labour abuses, starvation and food insecurity as documented by BiofuelsWatch and 10 other groups [13, 14] (see also [15] (Biofuels: Biodevastation, Hunger & False Carbon Credits, SiS 33).  Calls for moratorium on biofuels came from Africa, the US, and the United Nations [16] (UN ‘Right to Food’ Rapporteur Urges 5 Year Moratorium on Biofuels, SiS 36).

Biofuel production – mainly bioethanol and biodiesel –  more than doubled between 2003 and 2008, driven by rising oil prices; while food prices rose 70 percent between 2005 and 2008 [17], according to data compiled by the international Monetary Fund. The UN declared 2008 the year of the Global Food Crisis (see [18] Food Without Fossil Fuels Now, SiS 39); food riots and fuel protests were rife. UK’s Environment Audit Committee joined the call for moratorium in January 2008 [19], and reiterated it in May 2008 [20].

Biochar is widely seen as the successor to biofuels on grounds that it will sequester carbon and improve soil fertility while also producing energy. Biochar is not just carbon neutral; it is “carbon negative”, according to its proponents, because buried biochar is stable for thousands, if not hundreds of thousands of years.

A lifecycle analysis published in 2008 [21] by John Gaunt and Johannes Lehmann, principal biochar proponent at Cornell University, New York, in the United States, considered both purpose grown bioenergy crops (BEC) and crop wastes (CW) as feedstock. The BEC scenario involves a change from growing winter wheat to miscanthus, switchgrass, and corn as bioenergy crops. The CW scenario considers both corn stover and winter wheat straw as feedstock. The energy balance is much more favourable than the production of biofuels such as ethanol from corn. The avoided emissions are between 2 and 5 times greater when biochar is applied to agricultural land than used solely for energy in fossil energy offsets. Some 41–64 percent of emission reductions are related to the retention of C in buried biochar (so the stability of biochar is important), the rest due to offsetting fossil fuel use for energy, fertilizer savings, and avoided soil emissions of N2O and CH4, as additional effects of biochar.  Unfortunately, the analysis is largely based on assumptions. Biochar is now found to be not quite as stable as claimed and can speed up litter decomposition in the soil (see below). The energy balance of pyrolysis is taken as that reported by one company; and there is lack of conclusive evidence in support of the supposed significant N2O reduction for at least ten years [6, 11].

Biochar is not ‘terra preta’

The biochar initiative was inspired by the discovery of ‘terra preta’ (black earth) in the Amazon basin [22, 23], at sites of pre-Columbian settlements (between 450BC and 950AD), made by adding charcoal, bone, and manure to the soil over many, many years (see Fig. 1). Besides charcoal, it contains abundant pottery shards, plant residues, animal faeces, fish and animal bones. The soil’s depth can reach 2 metres, and is reported capable of regenerating itself at the rate of about 1 cm a year. Similar sites are found in Benin and Liberia in West Africa, in the South African savannahs, and even in Roman Britain. According to local farmers in the Amazon, productivity on the terra preta is much higher than surrounding soils.

Investigations in the laboratory revealed that terra preta soils are rich in nutrients such as nitrogen, phosphorus, calcium, zinc, and manganese, and have high levels of microbial activities. Terra preta contains up to 70 times more black carbon (BC) than the surrounding soils. Due to its polycyclic aromatic structure, black carbon is believed to be chemically and microbiologically inert (but see later) and persists in the soil for centuries, if not thousands of years. During this time, oxidation produces carboxylic groups increasing its nutrient-holding capacity. Bruno Glaser and colleagues at the University of Bayreuth concluded that [24] “black carbon can act as a significant carbon sink and is a key factor for sustainable and fertile soils, especially in the humid tropics.”

Similarly, BC derived from terra preta sites in central Amazon differing in age from 600 to 8 700 years were chemically, biologically and spectroscopically indistinguishable, as consistent with their “extremely slow” rate of decomposition [25].

However, BC collected from 11 historical charcoal blast furnace sites from Quebec Canada to Georgia USA, were quite different from BC newly produced using rebuilt historical kilns [26]. The historical BC samples were substantially oxidized after 130 years in soils compared to the new BC, or new BC incubated for one year at 30 C or 70 C. The major alterations were an increase in oxygen from 7.2 percent in new BC to 24.8 percent in historical BC; a decrease in carbon from 90.8 percent to 70.5 percent; formation of oxygen-containing function groups, particularly carboxylic acid and phenolic functional groups; and disappearance of surface positive charge, to be replaced entirely by negative charges. New BC incubated at 30 C or 70 C for 12 months increased in oxygen concentrations to 9.2 and 10.6 percent respectively; and also had complete replacement of surface positive charges by negative charges.

These findings show that BC is a substantial oxygen sink, and could deplete atmospheric O2 fairly rapidly if massive amounts are produced in a hurry!

The main factor accounting for the changes was mean annual temperature, which was highly correlated with degree of oxidation. BC oxidation was increased by 87 nmoles/kg C / degree Celsius increase in mean annual temperature. BC oxidation to carboxylic groups accounts for the high cation exchange capacity of natural BC in the soil that the authors suggest is the basis of the enhancement in soil fertility.

So charcoal is not the same as terra preta that has been created over thousands of years by human intervention and natural geochemistry. The claim that biochar is a “stable carbon pool” in the soil that does not degrade for thousands of years is not borne out by the study, nor by a number of other studies (see below).

Naturally occurring black carbon has a far more complex relationship with the soil and the earth as a whole, as recent research is revealing. Moreover, black carbon pollution from fossil fuel and biomass burning associated with deforestation contribute as much to global warming as CO2, and climate scientist are proposing a reduction of black carbon emissions as a way of cooling the planet [27] (see Black Carbon Warms the Planet Second Only to CO2, SiS 44). That’s another reason the biochar initiative will spoil the climate, by increasing BC emissions.

Biochar increases loss of organic carbon from humus

A ten-year trial in Swedish forests showed that buried charcoal appear to promote the breakdown of humus, the decomposing plant matter on the forest floor [28], thus completely offsetting the carbon sequestered in the charcoal.  

David Wardle and colleagues at Umeå University started their experiment to investigate the effect of forest fires on soil ecology. They buried hundreds of litter bags containing humus, charcoal, or a 50–50 mixture of the two in several sites in the Swedish boreal forest.

Periodically, they weighed the bags and measured the concentration of carbon and nitrogen.  After just one year, they began to see an unexpectedly large decrease in mass from the bags containing the humus–charcoal mixture: 17 percent (the expected was 9 percent), compared to 18 percent in the bags with only humus and 2.5 percent in the bags with only charcoal Over ten years, the bags with mixed humus and charcoal released just as much carbon as did those containing only humus (130 mg per g initial mass), instead of only half as much as would be expected if charcoal had no effect on the loss of carbon from humus. The bags with charcoal had lost a small amount of its carbon (less than 5 mg per g initial mass) but gained about the same in nitrogen and microbial activity. The mixture did not gain or lose any nitrogen while humus released 2 mg N per g initial mass. 

The results show that burying charcoal can speed up the decomposition of forest humus during the first decade, thus offsetting nearly all of the carbon sequestered in the charcoal itself.

Biochar may not be a stable carbon pool

Caroline Masiello, marine chemist at Rice University Houston, Texas, in the United States, pointed to apparent discrepancy in the production and deposition of of BC on both sea sediment and on land [29]. BC production globally was previously estimated at 0.05 to 0.27 Gt/y [30], representing 1.4 to 1.7 percent carbon exposed to fire that’s converted to BC. The only documented loss process for BC is deposition in ocean sediments. However, the rate of total organic carbon deposited on the seafloor is only 0.16 Gt/y. Even assuming the lower end of the BC production rate, 0.05 Gt/y, would mean that BC should be 30 percent of ocean sediment organic carbon; but the actual measured amount is 3-10 percent.

Furthermore, isotope studies of highly refractory BC detected 14C graphite BC in sediment from the Northeast Pacific coastal transept. This was not a product of fossil fuel combustion but the result of erosion of very old graphite from rocks and deposited into the ocean, which is at least in part derived from petrogenic graphite. If BC deposited in ocean sediments comes both from biomass burning and from recycled petrogenic graphite, even less of the annually produced BC can be accounted for in ocean sediments. So where does the rest of the earth’s annually produced BC go?

The same applies to BC on land. If BC has been produced since the last glacial maximum from biomass burning at the same rate as it is now produced, and if it is as stable as assume, it should account for 25 – 125 percent of total soil organic carbon pool. Instead, only a few measurements of BC or soil organic carbon ever reach 25 percent. A study of BC production during Siberian boreal forest fires made clear that not enough BC remains even after 250 years to account for all the BC produced during a fire [31] – estimated at 0.7 -0.8 percent of organic carbon – due to a combination of in situ erosion and translocation within the soil profile, with in situ degradation being the most likely.

In a later study, the amount of BC in organic carbon was compared in soils of three Siberian Scots pine forests with frequent, moderately frequent, and infrequent fires [32]. The researchers concluded that BC did not significantly contribute to the storage of organic matter, most likely because it is consumed by intense fires. They found 99 percent of BC in the organic layer, with a maximum stock of 72 g/m2. Less intense fires consumed only parts of the organic layer and converted some organic matter to BC, whereas more intense fires consumed almost the entire organic layer.

But appreciable degradation of BC can also occur in the absence of fires, by microbial action or photo-degradation. The stability of BC was investigated in a sandy savannah soil at Matopos in Zimbabwe, where some soil plots have been protected from fire for the past 50 years [33]. The abundance of BC in these plots was compared to plots that have continued to be burnt. The plots protected from fire had 2.0+5 mg/cm2 BC, about half of the 3.8+0.5 mg/cm2 found in plots burnt every 1-5 years. The half-life of BC at a depth of 0-5 cm of the soil protected from fire was estimated at < 100 years, and that of large particles <50 years. The results suggest that in well-aerated tropical soil environments, charcoal and other BC can be significantly degraded in decades to a hundred years.    

BC is best understood as a continuum of combustion products, ranging from slightly charred, degradable biomass to highly condensed refractory soot [28]. All components of this continuum are high in carbon content, chemically heterogeneous and dominated by aromatic structures. The reactivity of BC also varies along the combustion continuum. Charcoal decomposes much more rapidly than soot when exposed to chemical oxidants, such as acid dichromate, in the lab [33].

The results are also complicated by the different ways of producing charcoal and different methods of quantifying BC [28]. In studies on the National Institute of Standards and Technology reference materials, the values varied by a factor of 500, depending only on the method used in quantification.         

Research in the atmospheric chemistry community has shown that even soot, the most inert part of the combustion spectrum, can be chemically altered on a very short timescale through reaction with atmospheric oxidants. Reaction with ozone and other atmospheric oxidants create hydrophilic carboxylic acid groups on its exterior These reactions are so rapid that solubilisation of soot particles can occur in 30 min in the presence of 50 ppb (parts per billion) ozone, making it possible to dissolve soot in a solution of distilled water. Ozone concentration in rural air in the US ranges diurnally from 20 to 70 ppb. So soot can enter some of the Earth’s dissolved organic carbon pools.

BC has been measured by thermal techniques to be 5 to 12 percent of dissolved organic carbon in Chesapeake Bay, the Delaware Bay, and in adjacent Atlantic Margin. Another electrospray ionization with high resolution mass spectrometry applied to dissolved organic matter from a small stream in New Jersey and Rio Negro detected BC degradation products that were assigned chemical structures.

Biochar effects on soil fertility not always positive

Experiments carried out so far have yielded equivocal results on the ability of biochar to increase productivity. There have been positive effects claimed, at least in the short term, but also some negative impacts, at least partly due to nitrogen limitation [34]. In a small scale lab experiment, biochar appeared to increase nitrogen fixation by legumes, principally by increasing the availability of trace elements boron (B) and molybdenum (Mo), and to a lesser extent, K, Ca, and P, while lowering N availability and Al saturation. The results on productivity were not statistically significant, however.     

A report published in 2007 presented results on crop yields over four seasons [35]. Researchers at the University of Bayreuth in Germany, and EMBRAPA Amazonia Occidental Manaus in Brazil carried out a field trial near Manaus on cleared secondary forest with 15 different amendment combinations of chicken manure (CM), compost (CO), forest litter, chemical fertilizer (F), and charcoal (CC) applied once on rice and sorghum, and followed over four cropping cycles (see Fig. 2).

Chicken manure gave by far the highest yield over the four cycles (12.4 tonne/ha). Compost application came second at about half the yield, but was still four times higher than chemical fertilizer. The control, leaf litter (burnt and fresh), and charcoal treatments gave no grain yields after the second season, and were discontinued.

In combination with compost, charcoal amendment decreased yield by about 40 percent compared to compost alone, and only improved yield in combination with chemical fertilizer. The charcoal was derived from secondary forest wood bought from a local distributor, and applied at the rate of 11 tonne/ha. This corresponded to the amount of charcoal C that could be produced by a single slash-and-char event in a typical secondary forest on the dry iron-rich soil of central Amazonia.

The highest yields for all treatments were obtained at the first harvest, and except for chicken manure, yields declined rather sharply by the second harvest.

A second fertilization with chemicals was applied after the second harvest to all remaining treatments, but that did not improve the yields.

Plants fertilized with chicken manure had the highest nutrient contents followed by plants that received compost and/or chemical fertilizer. Chicken manure significantly improved the K and P nutrition compared to all other treatments, while charcoal applications did not show a significant effect on nutrient levels. Most importantly, surface soil pH, phosphorus, calcium and magnesium were significantly enhanced by chicken manure. Plots fertilized by chicken manure had pH higher than 5.5 and increased cation exchange capacity.

These results are disappointing for those looking to promote ‘biochar’ as a means of improving the yield of crops at the same time as sequestering carbon, which also turns out to be illusory.

The potential for an oxygen crisis is real

It is clear that biochar has not lived up to its promises as a stable C repository or enhancer of crop yields. On the other hand, the risk of oxygen depletion is real [1-3]. Biochar itself is an oxygen sink in the course of degrading in the soil [24. 32]; adding to the depletion of oxygen that cannot be regenerated because trees have been turned into biochar for burial. And worse, as in the biofuels boom that has already apparently speeded up deforestation and oxygen depletion since 2003 [2], if biochar is promoted under the Clean Development Mechanism, it will almost certainly further accelerate deforestation and destruction of other natural ecosystems (identified as ‘spare land’) for planting biochar feedstock, and swing the oxygen downtrend that much closer towards mass extinction.    

Editors Note: While a lot of work has been done in the field of BioChar, since this publication, that supports BioChar. We have not removed this article as it is a piece that details an opinion of BioChar in 2010.


  1. Though they may be true, your claims about biochar´s effects on soil fertility are misleading. Anyone who has looked past the superficial hype, knows that biochar is not a fertilzer. That does not negate the fact that it improves soil fertility by improving water and nutrient holding capacity.

    The experiments that you reference express a common trend in testing yield increase with biochar. Biochar does not show yield increase in the first few years unless it has previously been charged with nutrients (indictative again, of its functionality in HOLDING nutrients).

    Thank you for highlighting industrial biochar´s potential to support unsustainable monocultures for feedstock. Any large scale agricultural industry threatens to be unsustainable in this way and is directly in conflict with permaculture principles such as ´using small and slow solutions´. I would like to note that I spoke with several people at IBIs International Conference in Rio de Janeiro this year who are concerned about sustainable feedstock.

    I understand and agree with much of your perspective but think it is short sighted to demonize this technology so absolutely. I think biochar is an exciting and valuable part of the web of techniques appropriate in the world of permaculture and soil building.

    1. Biochar mus be researched and developed deeper, I understand fears over monoculture giant feedlots for producing biochar as a way for industry to make money and get a bypass for carbon storage, yet we need to think about using it as a technology not a save all. It has many uses that can be utilized for agricultural and industrial waste, used for healthier cooking stoves i countries where they use fires to cook with. The technology is a tool, not a save all. The permaculture community has techniques such as hugelkultor and mulching for use of biomass, but for large scale farms and lumber mills for example, we can use these by products to produce electricity and biochar. People globally prouduce charcoal for cooking very unsustainably, and cook with wood producing large amounts of smoke. This is not about cutting down the forests of British Colombia, its about utilizing biochar to use in certain situations where it can be of benefit.

    2. Everyone always trying to go agaist the natural order of things think about this :
      thousands of years ago we need no fertilizers to harvest food , there was no global warming , and the Earth was not being destroyed all facts
      The article is not just about the BC its about the over all health of the organism the planet, the future life on this planet, will be dead if we think so microscopic and keep trying to do thinks they way we are, so pledge on with BC and rest on these for profit idiots ideas and help our absolute destruction

  2. Erm, I still don’t consider it appropriate for readers to first have to register to get not just a mutilated form of the article.

  3. It seems to me that if you are going to make the claims that you do in this article– that the references should be available for less then 20 pounds– this is poor journalism lacking all sense of true unbiased investigation. You are clearly pushing you own agenda and making claims that have no basis in the reality of what people examining the production and utilization of biochar are doing or are about– there are no huge multinationals lurking in your forest dreaming about the huge sums of money they could make through turning the trees to charcoal. There are questions regarding the efficacy of the Wardle study. There are many studies that point to biochar utilization in soils being extremely positive and yet there is no reference to this. Of course hold our feet to the fire, make sure that the biochar process is being done with sound, sustainable methodologies but be intellectually honest in the same course of events.

  4. So then, the Amazonian terra preta char is stable over millenia and does increase fertility, right? Can’t we figure our more about how they made this stuff and just do it that way?

    Also, I don’t see how increased use of biochar necessarily leads to deforestation. Is increased use of corn leading to de-cornification?

    1. I think u are dead right – I’ve be playing in this field and what u say is what I have concluded as well – people pushing bio char only have totally missed the terra Pretta story

  5. You argue that biochar is different from the black material found in terra preta and your main argument is oxidation. If you read carefully your own sentences, you may see that oxidation of charcoal (biochar) is responsible for increasing the nutrient holding capacity in Terra Preta soils. So why would oxidation of biochar be different. You also mention a study done with charcoal collected in Canada and Georgia. “The samples were substantially oxidized after 130 years”. After 130 years – do you think that un-carbonized biomass would still be found in Georgia after 130 years? You use this numbers to argue against biochar stability. Partial oxidation after 130 years proves high stability in comparison to un-carbonized biomass, which would completely be oxidized after a much shorter period of time.

    It is clear that carbonization of forests would not create a carbon sink as long as they would not re-grow. Therefore we are talking about biomass that is dead. There is an abundance of decomposing plant material. Such plant material (crop residues etc.) is also frequently burned to get rid of it. What happens during decomposition or burning? This is an almost complete oxidation of the carbon contained in biomass and the carbon returns as CO2 into the atmosphere. Each atom of carbon (C) consumes to atoms of oxygen (O2). Agricultural expansion is reducing terrestrial carbon stocks (by converting forests to agricultural land) and thus increasing atmospheric CO2 and reducing O2.

    Such depletion is also the case for fossil fuel burning. If coal (almost pure carbon) is burned (oxidized) each atom of carbon consumes to atoms of oxygen (O2). As long as the CO2 remains in the atmosphere there is a change that the plants can turn it into biomass and O2 again. Unfortunately human activity is reducing plant biomass on earth and there is a limited capacity to capture excess CO2 and store it in living biomass. Carbon capture and storage (“clean coal technology”) would bury the CO2 and remove two oxygen atoms with each atom of carbon underground. Biochar is different by keeping carbon rather stable not by sequestering CO2.

    The storage in living biomass is rather short term. Fifty to sixty billions tons of carbon are released from dead plant material every year. Luckily, almost the same amount is taken up by the growing vegetation again. The carbon cycle is almost balanced. This is almost 10 times as much as released by fossil fuel burning and consumes O2. If dead biomass (otherwise oxidized to CO2 by decomposition or burning) is transferred to biochar, we can reduce the speed of oxidation substantially. This would decelerate the decay (oxidation) and an improvement of soil fertility would accelerate carbon accumulation through the living plants. As such biochar would enhance carbon capture by photosynthesis and reduce the release by oxidation. This is the mechanism of biochar and was completely misunderstood by the author. The lengthy discussion on BC stability is therefore unnecessary. Important is to increase the half-live time of carbon captured by photosynthesis relative to the speed of decay of un-carbonized non-BC (baseline).

    Biochar can be found in almost any soil and is not airborne black carbon (BC) which is contributing to global warming. I hope that the author and readers would make this important distinction.

    The study by Wardle and colleagues is controversial and was discussed by other researchers. A substantial amount of carbon could have been released from the biochar in the first year. And Wardle’s results show the main decline in the first year. If fresh (newly produced) charcoal is used, a proportion of this carbon is not as stable as the rest. However, who proposed using biochar as a carbon sink in humus rich forest soils? There are many degraded and carbon depleted soils on earth and such a humus rich forest environment may not be suitable for biochar carbon sequestration.

    Biochar is not a fertilizer and cannot be compared with chicken manure. However the importance of soil organic carbon to sustain soil fertility is generally known. In a tropical environment the carbon applied as chicken manure is oxidized fast and nutrients are released. Biochar was described as an alternative to burning. Agricultural fires are very abundant everywhere on earth. Instead of burning the formation of biochar can capture a significant proportion of the carbon (and avoid greenhouse gas emissions). Biochar formation also consumes less oxygen because only the absence of oxygen produces biochar. In addition, such an approach offers the opportunity to generate renewable energy and return carbon and nutrients back to the fields. It is simply a better alternative to crop residue and biomass burning with very little gains.

    Biochar sequesters carbon by increasing the terrestrial carbon stock. Any practice reducing this carbon pool would never be eligible to gain carbon credits under the Clean Development Mechanism. Only re-growing biomass can establish a carbon sink. Carbonizing forests is not an option to reduce greenhouse gases! As fossil fuel burning, any reduction in the terrestrial carbon stock is depleting O2 levels. The intention of biochar carbon sequestration is to increase the terrestrial carbon stock!

  6. We should not introduce new techniques into the environment. There are always negative impacts we will never be aware of. We should stop using much of the available resources, reduce our numbers and impacts. Nature will recover itself without our “help”.

  7. since natural ozone production is widely known to be a process that takes place when sunlight warms soil surfaces, the fact that the terra preta is most commonly found in rain forest (shaded) areas may have something significant to do with it’s longevity in those areas. the biochar/global warming folks have plenty of green stuff in their pockets, they should expose some tp to sunlight and observe the effects.

  8. It took about a billion years for bacteria to create our oxygen atmosphere. So, the question is, how many years would it take for that to be reversed? Well, human activity (primarily land use change although fossil fuel burning, cement making and other activities play a role) contributes 2 parts per million (by volume) CO2 annually, thereby removing 2 ppmv O2. Answer: 500,000 years.

    Personally, I think we would be extremely lucky to find humans still here in another century or two. If they are, it may well be because they re-learned how to make terra preta, using biochar.

  9. Thanks for posting this, Craig.

    I think it’s safe to say that the whole thrust behind PRI is that it’s a solution-oriented outfit that isn’t married to any particular or specific technology, strategy, or technique on an idealogical basis. In general, if it works – great. If there are flaws/problems, then they need to be acknowldged and discussed to see if they can be meaningfully improved or resolved.

    We’re into truth – not tribe. There are folks married to the Biochar tribe, just like there are people married to the Biofuels/Agrofuels tribe, or the industrial ag tribe, or the Nuclear energy tribe, or…you get the point.

    Being dismissive or derisive isn’t an answer – if anything, you end up exposing yourself as a partisan.

    If folks have beef with Dr. Mae-Wan Ho, then the best thing to do would be to take it up with her. Judging from her past work, she seems to be pretty fair and even-keeled. If anything, she would appear to be a strong ally.

    At the very least, this piece provides some very interesting food for thought. But ultimately, we’re after the TRUTH in how to fix this mess we’re in – not “set-tripping” when the tribe is challenged.

  10. Yes, Dr. Ho is certainly solutions based. See this post, where I feature a book she put together: Food Futures Now. It was Dr. Ho who, 16 years ago first woke me up to the dangers of GMOs with her breakthrough ‘Genetic Engineering, Dream or Nightmare’ book, regarded as a “worthy successor to Rachel Carson’s ‘Silent Spring'”. Her GMO work is particularly valuable, given she’s an accomplished Geneticist herself. I very much appreciate the work of I-SIS in exposing greenwash and getting to root causes in well documented fashion.

    I don’t believe we’ll find any magic bullets in regards to earth restoration and humanity saving. We must learn to how to shape society in such a way that we can transition back to life on the land, with humble and noble ambitions that involve voluntary simplicity and concern for others (including future generations) and shape our educational systems to give us the knowhow to do so. The longer we persevere with this dream of wealth and liesure and unlimited access to energy, the harder it will be to retrace our steps.

    1. I think you’ve made some important points here Craig about living sustainably and simply together. It would be great if something as simple as biochar could solve so many of our problems, but we do need multi-faceted solutions. This is something we’re attempting at Atamai, in looking at the whole way that we live, interact and consume together.

  11. Apart from the very strange issue that we have to deal with a mutilated article on this site, there are numerous claims I find quite suspicious. First of all:

    Climate scientists have only discovered within the past decade that O2 is depleting faster than the rise in CO2, both on land and in the sea [2, 3]

    This presents the matter as if it were an unexpected thing. But it’s very basic chemistry: If you burn coal, you turn C and O2 into CO2. But if you burn hydrocarbons, then, you also get water, so you remove more oxygen than what ends up in the CO2. Methane has the highest H:C ratio, and there, burning one atom of C removes two O2 molecules from the atmosphere, giving us two H2O and one CO2 molecule. So, in comparison to coal, it removes twice as much oxygen per unit of carbon.

    This bit seems very strange for me, for reasons that would be too technical to discuss in detail here:

    and disappearance of surface positive charge, to be replaced entirely by negative charges

    This claim is extremely strange – graphite from rocks should contain C-14. C-14 is produced in the upper layers of the atmosphere when nitrogen captures a thermal neutron and subsequently emits a proton. It’s not produced at sea level, and given a half life of some ~5700 years, there shouldn’t be any in rocks at all:

    Furthermore, isotope studies of highly refractory BC detected 14C graphite BC in sediment from the Northeast Pacific coastal transept. This was not a product of fossil fuel combustion but the result of erosion of very old graphite from rocks and deposited into the ocean, which is at least in part derived from petrogenic graphite.

    It sort of goes on like that. This really is a quite strange article.

  12. It seems that nobody above, neither the author nor the commentators, have a perfect set of science to support their respective sides of the problem. So I’m going to point it in a purely philosophical direction:

    Why? We know that ordinary decomposition sequesters carbon in undisturbed soil. We know that organic matter in undisturbed soil supports broad communities of flora and fauna that promote soil fertility, retain moisture and support a level of productivity from which everyone can benefit. Isn’t bio-char, at best, the pursuit of a seemingly benign quick fix for the damage done by the malignant pursuit of instant gratification?

    Similarly, bio-fuels look for a benign solution to our energy consumption when the underlying problem is the unsupportable (but commonly held) idea that we should have a free supply of absolutely everything all the time: exotic food, luxurious housing, unlimited travel, etc.

    Looking for good extraordinary interventions to compensate for bad extraordinary interventions doesn’t seem like a solution when, it seems to me, the underlying problem is the human conceit that things can only be fixed by us acting, as opposed to just standing back, doing no harm and letting the natural processes we messed with correct themselves. I can’t think of a problem faced BY us that can’t be fixed by addressing the problem IN us.

  13. Thanks Scott – this is what I meant by my comment above. The concern I have with this seemingly unending series of suggested quick-fixes is it numbs society into thinking “we’ll find a way to continue living as we are”, that we’ll somehow geo-engineer our way out of this, instead of accepting the reality of the need for a serious, and rapid, shift in ambitions and lifestyles.

    All these supposed quick fixes do is have us making the kind of arguments that we’re seeing in this thread – and we’ll keep arguing as we ride over the precipice.

  14. All organic matter oxidises. Biochar oxidises a lot slower than other organic matter. Therefore it should _reduce_, not increase, the depletion of atmospheric oxygen which Mae-Wan Ho is concerned about.

    This seems a pretty basic error in Mae-Wan Ho’s argument.

    But, reading her last paragraph, it becomes clear that her analysis assumes the sort of unsustainable practice that none of the biochar advocates that I’ve been in touch with would support – basically deforestation for biochar production. This is an appalling misrepresentation, rejecting a promising technology because it can be misused. Surely it would make more sense to be calling for mechanisms which outlaw or marginalise this type of misuse, while encouraging more sustainable, locally-based use of the technology.

    It’s not biochar that’s the problem. It’s unsustainable forestry and unsustainable agriculture. Dr Ho got it right about GM crops, but on this issue she’s just spreading confusion.

  15. I agree with the previous too comments. There is no quick fix for the global warming problem. I also believe that there is no single solution. Energy conservation and a spare use of natural resources in particular those which are not renewable are certainly top priority. Bioenergy cannot sustain current energy consumption and biochar carbon sequestration not sequester the current greenhouse gas emissions.

    However, even if we would turn our emissions to zero in the next decades (which is very unlikely to happen) we may need efficient carbon sinks to reduce CO2 to save levels. We should discuss which of our options are the most efficient and the safest ones.

    “Why?” Because biochar formation is more efficient and can capture up to 50% of the carbon stored in biomass. In addition it allows for renewable energy production. Energy we need to reduce your dependence on non-renewable resources. Only a very small percentage of decomposing plant material enters the long lasting carbon pool in soil. The ordinary soil carbon is also more vulnerable in a warming climate. Therefore it is particularly difficult to keep high levels of organic carbon in tropical soils under hot and humid conditions. Permanence and vulnerability are issues to consider.

  16. To my mind there are several arguments being mixed up here, to just deal with three. One is that the only solution to problems with human damage to climate is to de-populate the earth and the few remaining remnants of the human race live simply, -this position implies rejection of all other solutions, – Bio-char, renewable energy, re-cycling etc, it is an extreme position, reminds me of Puritan absolutism, and should not be brought in as a refutation of any proposed other solution as it denies human agency and development, ie has nothing to do with the price of fish in the Chinese egg market.
    Second is the argument for composting above all, – I live in the wet tropics, I observe that almost all the compost I introduce to my soil is gone in a year, whether I successfully use some of it to grow lush crops or not, and the soil in the rainforest has very little dead organic material in it compared with the absolute cascade of dead vegetation raining down on it night and day.
    Typically nutrients are mainly stored in the living forest so clearing is disastrous.
    So any farming in the tropics usually has to constantly put huge amounts of compost in the soil or articial fertilizers etc.
    The Mayans and Incas and others who made Terra Preta, obviously had this problem and evidence is strong they very consciously used TP as a precursor to settling new areas such as the Amazon.
    So this is the Third point, many contributors to these discussions harbour the unconscious belief that ancient peoples had no understanding or wisdom, that somehow our materialistic wisdom is all wisdom and we are at the pinnacle of evolution.
    Well we are the latest human beings around, few alive are even 100 years old but unless we learn from the past we are probably doomed so I would like to suggest that to put oneself in the place of an inhabitant of a Mayan city for eg, most actions were probably decreed by the priests, how you got rid of your cooking fire ashes/charcoal, garbage, sewerage wastes and dead bodies was laid down, – possibly the sewerage was collected in clay pots, the charcoal and ash placed therein to reduce smell and because the priests said so, then taken out and buried in the fields, the pots being smashed as they were unsanitary, and maybe the pot shards also helped the soil structure, and all other garbage taken out, including dead bodies and animal bones, and buried as part of the recipe.
    Thus the charcoal was primed with nutrients, and held much of same despite the high speed breakdown and subsequent leaching by rain of nutrients in those tropical regions.
    Well, we may have different agendas at this time, but we can not just expect to take out one single element, the charcoal, and put it back in the soil and expect the same result as the original Terra Preta, a much more holistic approach is required.
    Geoff Thomas.

  17. “All these supposed quick fixes do is have us making the kind of arguments that we’re seeing in this thread…”

    Most arguments in this thread seem to make more sense than the original article. I guess I missed the memo about biochar supposedly being the silver bullet-solution to the world’s problems. I just thought it was a nifty way to vastly prolong the soil-enhancing effects of biomass C using century-proven techniques.

    Apparently it’s also suspected of being part of a nefarious plot to allow humanity to get away with a host of evil deeds, excess “leisure” now being one of them. (When did “leisure” become a four-letter word?! I thought permaculture was always about getting things done the smart, less laborious way.)

  18. Forgive me Geoff, but I don’t see anyone proposing reducing the number of humans on the earth, only reducing the per-capita damage that we do and trying to shift the paradigm from technology as deity to personal responsibility. Sure, there will be a natural limit to human population and we may or may not have surpassed it but looking at these broad, experimental interventions when we haven’t even picked the low-hanging fruit seems rather misguided.

    Ancient peoples did have a lot on the ball but they did not have the problem of 6 billion people on the planet, many of whom are convinced that material wealth, cheap jet flights, air conditioning and prepared foods represent advancement. A simple shift of focus is (I think) what us cautious skeptics are advocating. Not soilent green.

  19. JBob – a question: are you making biochar on your farm? If yes, please tell us all about your observations! Done on a small scale, and carefully monitored for the benefit of all (all in your particular climate niche at least) would be of great interest. Well documented, objective, small scale observations would be very valuable here.

    If you’re not doing on a small scale right where you are (as most are not), then who are we waiting for and/or expecting to do this? If not right where we are, in climate-specific small scale implementation/testing/observation and tweaking, then the answer is large, centralised, money-oriented endeavours – which raise concerns for me in several areas, where I must question where we’re going with this. Dr. Ho’s article is aimed at raising concern over plans for enormous implementations of biochar – including in what have been already-disastrous ‘Clean Development Mechanisms’ – on huge acreages worldwide.

    But patent applications have been made, and companies formed for commercial exploitation of biochar production. Intense lobbying is taking place for biochar to be included in the Kyoto Protocol’s Clean Development Mechanism for mitigating climate change [9, 10], so people implementing that technology would be able to sell certified emission reduction (CER) credits.

    Things have moved forward so fast with so little public awareness and debate that critics are alarmed, especially over the proposal from some prominent advocates that 500 million hectares or more of ‘spare land’ could be used to grow crops for producing biochar [11, 12], mostly to be found in developing countries; the same as was proposed in the biofuels initiative several years earlier.

    We’ve seen what large scale ethanol production has done – I’ve seen Sumatra’s palm plantations from horizon to horizon, all planted after clearing rainforest to make way for palm oil to fuel European and other nations’ ‘green’ fuel quotas. Tiny Indonesia became the third largest CO2 emitter, after China and the US, for these reasons.

    A few thoughts off the top of my head:

    1) Where do we get the material to make biochar? Crop residues?

    I don’t believe in the term ‘crop residues’ – in the sense that in a sustainable system there are no wastes. Sustainable farming systems rely on cycling nutrients, not putting them out of reach of plants. It is admitted by biochar advocates that biochar is not a fertiliser – it is a carbon-storage medium. In a small scale system, can we afford to take on-farm crop residues and their embedded nutrients out of the carbon cycle? It is recommended to mix compost with biochar, and I recognise the nutrient holding capacity of biochar in this respect. But if we’re making biochar AND compost, where is all this biomass coming from? Does a small scale endeavour have sufficient biomass for both? Generally just making compost utilises all spare biomass available in a system. Indeed, until our worn out land has improved in fertility, people are often tempted to, or do, import off-farm biomass either in pre- or post-composted form. As such, I can easily see that incorporating biochar would necessitate making it an off-farm purchased input – which feeds into the biochar advocate’s centralised business model; one that is not necessarily altruistic, but profit-centric, and leads one to question where THEY are getting the biomass to manufacture this biochar. Turning millions of ‘spare’ or ‘set aside’ land into biomass production, as is being lobbied by biochar advocates/industrialists/entrepreneurs, specifically for saleable commercial biochar leads to other questions about management of THAT land, and how THAT biomass is produced. Is this organic biomass production, or typical industrialised biomass production? Some suggestions include utilising manure from industrial animal systems. In all these areas what we can easily see is a continued ‘patching’ of present unsustainable, cruel and profit-centric systems rather than a systemic rethink and rework.

    2) Biochar is not humus. It is still unclear how humus and charcoal interact. Studies show mixed results in different soil types and climates. Some studies show biochar speeding up the breakdown of humus, others show decreases in yields as the biochar binds nutrients that the plants need, etc. Moisture, pH, presence, or not, and type of microorganisms, etc. all play roles here that are not fully understood. There is still a lot of mystery surrounding the supposed benefits of biochar, and what regions and conditions they’re suitable for. It’s fairly clear this is not a one-size fits all solution – which is consistent with everything I’ve learned about life systems within the biosphere. Again, small scale, and situation-appropriate are the watchwords, and the rapidly growing cadre of biochar advocates, seeing financial models in all of this, are quick to dismiss this in favour of ramping up uptake of this silver bullet solution to their own personal gain. There will be well-intentioned biochar advocates out there, thinking about small scale documented test plots, but for every one of these there will be more business-savvy self-interested folk who need a financial model built into everything they do, and in this area the whole economy-of-scale factor moves in to obscure the need for morality and objective biological scientific observation. The one-size-fits-all mentality works best for them.

    Can biochar be beneficial everywhere? This is unknown. Do large scale biochar advocates itching to secure carbon credits care? Can they be scientifically objective?

    3) I believe we need to move to low to no-till farming. How do we get biochar into the earth without breaking it up?

    4) If done on a large scale, how to we move, distribute and bury all this biochar? What energy source will be used to fuel the vehicles and implements to undertake this?

    5) Biochar is not Terra Preta

    Soils need living carbon as humus — Vandana Shiva

    Burning trees and biomass has ironically emerged as a “solution” to climate change.

    Following the false solution of industrial bio fuels we now have the waste left from production of bio fuels as the next magic bullet. The process used is pyrolysis – incineration that chemically decomposes organic materials by heat in the absence of oxygen. Through pyrolysis organic matter is transformed into gases and small quantities of liquid, used as bio fuels. The waste is a solid residue containing carbon and ash. This waste has now been given the elegant name “biochar”. It is being wrongly treated as the same as “Terra Preta de Indio” — the black soils created by the indigenous people of the Amazon by burying charcoal over hundreds of years. Charcoal in every soil and every ecosystem can prove to be an ecological disaster.

    “Biochar” is basically the next new trick of global investors to make money on the global market of carbon trading. As the biochar website clearly states “A prerequisite for the above mentioned management practices is access to the global carbon trade.” The global carbon market which has a potential to grow to $ 1 trillion by 2020, and this is what is driving “biochar” — not love for the soil, nor the wisdom of indigenous people.

    The collapse of Wall Street in 2008 should be enough reason for governments and people to be cautious about the charcoal solution. We cannot afford to have an economics of greed and fraud drive false solutions to climate change.

    But there are many other reasons for not falling into the biochar trap. It is based on a scientific fraud.

    The central argument for promoting the burning of biomass to make charcoal to put into soil is based on totally false assumptions such as only “2% of carbon from plant biomass enter the soil as carbon through humus” and “30% of soil carbon from humus escapes in the first year and 80-90% in the second year in organic practices which return soil carbon through recycling of biomass.”

    These assumptions go against all scientific evidence that shows that organic farming increases soil carbon, and the carbon stays in the soil.

    Data from the Rodale Institute and from Navdanya indicate that regenerative and organic practices can increase soil carbon, dramatically and stable carbon compounds remain in the soil for years.

    The Rodale long term farm trial research shows a 30% increase in soil carbon over 27 years in organically farmed soils. Chemically formed soils did not increase soil carbon; in fact in certain cases they loose it.

    Navdanya’s research carried out across arid, semi arid, sub humid and humid ecosystems shows that compared to chemical farming organic practices increase soil carbon up to 102% and increase soil microbial activity up to 63%.

    It is this microbial activity which stabilises soil carbon.

    Sir Albert Howard had recognised that humus is at the heart of soil fertility. According to Howard, “Humus is an essential material for the soil if the first phase of the life cycle is to function.
    There is another reason why humus is important. Its presence in the soil is an essential condition for the proper functioning of the second contact between plant and soil — the mycorrhizal relationship.”

    In total ignorance of the living soil and its complex ecological processes, the “biochar” proponents are proposing a solution based on killing and burning trees and turning living carbon into dead carbon.

    On the basis of their blindness and false assumptions they state that “The drawback of carbon enrichment with conventional (referring to organic) methods is that carbon levels drop rapidly again as soon as a required careful management is not sustained.”

    This is a ridiculous argument. Good organic farming is a way of life, not a one time fad.

    The biochar promoters are also wrong in lumping together all systems of agriculture. Good farming can create agro ecosystems as permanent as natural ecosystems. As Sir Albert Howard has observed in the Agricultural Testament.

    “In the Agriculture of Asia we find ourselves confronted with a system of peasant farming which in essentials soon became stabilised. What is happening today in the small fields of India and China took place many centuries ago. The agricultural practices of the Orient have passed the supreme test — they are almost as permanent as those of the primeval forest of the prairie, or the ocean.”

    Organic farming is the lasting and sustainable solution to climate change and food security, not blanketing the planet with charcoal.

    Biochar is part of two non-sustainable practices that need to be phased out if we have to avoid catastrophic climate change. One is agriculture based on chemical farming and monocultures; the other is monoculture tree plantations. Biochar will be used with synthetic nitrogen fertilisers which are a major source of nitrogen oxide a greenhouse gas three times more powerful in global warming than Co2. And expanding tree monocultures to then burn trees for bio fuel and charcoal is a threat to soil, to biodiversity and the climate.

    Nature created humus to recycle carbon. Farmers have maintained carbon balance through good organic farming over centuries. And the contemporary organic movement has shown how we can both increase food security and climate balance through ecological processes. Biochar is another expression of arrogant ignorance which assumes nature got it wrong. It is a blind and reductionist solution which reduces both climate and soil to carbon, forgetting the millions of soil micro-organisms that make a living soil and the trace elements and micronutrients what give life and health to plants and humus. This is carbon reductionism, not ecology.

    Biofuel waste as biochar /charcoal is dead carbon. What we need to increase is living carbon in plants and in humus. An anti-life world view cannot protect life. We need to think like Gaia to defend her. — Tribune India


    I just thought it was a nifty way to vastly prolong the soil-enhancing effects of biomass C using century-proven techniques. — JBob

    You call them century proven techniques, but we’re still unsure what those techniques were and if they’re applicable everywhere. And I’m sure they’re not applicable in large scale implementations, just as little else is in a world of greatly diverse microclimates and organisms.

    As George Monbiot said (

    Just burying carbon bears little relationship to the complex farming techniques of the Amazon Indians who created terras pretas. Nor is there any guarantee that most of the buried carbon will stay in the soil. In some cases charcoal stimulates bacterial growth, causing carbon emissions from soils to rise.


    None of this is to suggest that the idea has no virtues; simply that they are outweighed by hazards, which the promoters have either overlooked or obscured. Nor does this mean that charcoal can’t be made on a small scale, from straw or brashings or sewage that would otherwise go to waste. But the idea that biochar is a universal solution which can be safely deployed on a vast scale is as misguided as Mao Zedong’s Great Leap Backwards. We clutch at straws (and other biomass) in our desperation to believe that there is an easy way out. — George Monbiot


    Apparently it’s also suspected of being part of a nefarious plot to allow humanity to get away with a host of evil deeds, excess “leisure” now being one of them. (When did “leisure” become a four-letter word?! I thought permaculture was always about getting things done the smart, less laborious way.) — JBob

    Leisure is not evil, I never said it was. My mentioning of leisure is due to the fact that we’re running out of cheap energy, and we’ve forgotten what the world, and our day, looked like before we had it. As Richard Heinberg says, one gallon of fuel might enable you to drive 30 or more miles, and you’ll do it in less than half an hour. Try pushing the same vehicle that same distance on your own, i.e. with any fuel. It’ll take you weeks. Try pushing it uphill. It’ll take you forever. The leisure we’ve ‘enjoyed’ (I’d say misused) over the last century has been based on cheap energy. That era is coming to an end. We’ve effectively had a hundred labourers for every person on the planet, in the form of this cheap energy. It’s enabled us to eat, drink and be merry, whilst eating popcorn and watching movies. Even our labour has been in front of a computer. Someone from two centuries ago, if he was to suddently travel through time and appear next to me as I’m typing now, and ask me what I was doing, would be unable to comprehend my answer: “I’m working.” Even my work is based on energy.

    Leisure in times past was not really separate from work. They didn’t have day jobs followed by NHL and sitcoms, they had families working together on practical realities – combining effort with fun, work with socialising. When I look at the traditional dress I photographed on this post – – I see women working after the sun has set, doing things they didn’t HAVE to do, but that was still labour in itself. They were creating culture, and doing their best to enjoy their work and interactions as they could amongst necessary duties. Our reality is we’ve lost the skills they had in our pursuit of impractical and normally detrimental ‘liesure’ pursuits.

    The world is in for a shock if it fails to understand the embodied energy requirements in our current understanding of leisure, and, more importantly, the embodied energy requirements in just supplying our needs.

    Back to biochar – get all hung up on reductionist science if you like, but I prefer to join the dots and look at the big picture. I again ask the question, where are we going with this? Do we want to go there? By all means, do some back yard tests – but please document it well, be objective, share your knowledge, and don’t expect what you do in your back yard to work in the back yard on the other side of your state, let alone the other side of the planet.

  20. I would like to raise awareness that these negative and frequently false assumption about biochar have one single source. This is the organization “”. As you can see in the references (For those who can access them)

    Also I want to correct the impression that there is little well documented small scale observation and scientific studies. This studies involving all aspects of biochar including soil biology. A literature search needs to include “charcoal” because the name “biochar” is only a few years old. An overview on published scientific literature can be found at:

    In fact the soil microbes play a very important role to make biochar work. This has been studied in Japan where biochar is traditionally used and was also observed in the 19th century and recently rediscovered by a group in Israel. They found beneficial microbes if charcoal is added to soil (Elad et al 2010 Phytopathology 100, 913-921)

    Take a search for “charcoal” in this book published in 1846

    “Farmers have maintained carbon balance through good organic farming over centuries.” I agree with that and carbonized materials are often part of that management (not only Terra Preta). The use of charcoal is not new and can be found in traditional farming knowledge. For example, in northwest Cameroon, grasses are intentionally carbonized, and reportedly, tribal communities in India use a similar carbonization technique, known as the Raab system.

    The production of biochar can supplement biomass composting and does not necessarily compete. The nutrient contents of biochars may be enriched by co-composting with nutrient rich materials. Such applications were already recommended by Allen in 1846. In general, nutrient rich materials or materials with high moisture content make good compost, whereas materials with low nitrogen content are less suitable for composting. Woody materials are rather resistant to decomposition, requiring long composting times and additional nitrogen fertilization. Therefore, such biomass waste is frequently burned or deposited of in landfills. These biomass sources are ideally suited for biochar production and can either be mixed with compost or used as a bulking agent during composting. Recent research has shown that co-composting of biochar with nitrogen rich manures reduces nitrogen losses due to ammonia (NH3) volatilization by up to 50%.

  21. Answer to Scott Harris, who rightly doesn’t see any posts directly advocating large scale de-population, – the problem is the 6.5 billion people, if the current farming practices are scrapped then there is not enough food for the current world population, so large numbers of people will die, and whilst dieing try to make other people die instead. it is like trying to make the bullet guilty of the murder or destiny or chance.
    As Bill McDonough said in his Bioneers 2000 talk, “if we have to have a small carbon footprint we must forego wetlands”.
    We have a big problem mother earth, we can’t solve it by thinking small.

  22. the problem is the 6.5 billion people, if the current farming practices are scrapped then there is not enough food for the current world population, so large numbers of people will die, and whilst dieing try to make other people die instead.

    This is an issue people struggle to comprehend, but which is very real. It is this predicament we’ve been leading up to for the last sixty years, that needs to be carefully, but rapidly reversed. Doing so requires a shift in our political/economic/social structures in a WWII type mobilisation — i.e. concerted, and fast — if we’re to avoid complete social meltdown, revolution, overwhelming fascism, and broadscale instense suffering, disease and death, etc. This is why this site incorporates discussions on economics and politics, etc. — something too many permies rail against me for doing.

    I would far prefer a broadscale and cooperative move towards re-localisation and the rebuilding of objective community infrastructure and support systems (including community supported research stations to develop and train people in situation-appropriate methods and technologies) than see large scale money-oriented schemes that seek to just patch things up so we can continue our present trajectory just a tad longer.

  23. I’m sorry, Geoff but that is an assumption based on information that the people who benefit from industrialized agriculture promote. New, patented food plant varieties and petro-chemically based techniques and chemicals haven’t been put in place to benefit mankind and overall they don’t. They are ways to obtain market share for a small number of rich corporations. It simply isn’t a scientific fact that they increase yields overall or, most importantly, make more nutrition available. We have an extraordinary excess of food and all world hunger is due to failure to distribute that excess for political reasons. Perpetuating the idea that our relatively tiny minds can do better than billions of years of natural experimentation is what cause the problem. Trying to apply the same failed theory, even when it manifests in soundbites from Bill McDonough, is repeating the same process and expecting a different outcome.

    It may have been a grammatical error but even the statement “we have a big problem mother earth” is a pretty telling statement. We have a big wonderful “mother earth” and our troubles lie in thinking we’re smarter than it. It doesn’t matter what everyone is doing. It matters what each person is doing. It’s easy to say that we have a technical problem because it affords an opportunity for most people to pass the problem off to someone else or to a central authority. It’s harder to approach and amend a moral/ethical problem but that is the root of the problem.

  24. Scott, yes, industrial agriculture provides nutrient deficient ‘food’, and does so very inefficiently, but I have to agree that just dropping it today will cause immense suffering and death. More than fifty percent of people today live huddled in cities (a significant consequence of the so-called ‘Green Revolution’), dependent on food supplies coming in from, in some countries (like the US of A) a primary producer base of less than 1% of the population. To feed everyone in a world of ever-decreasing energy, we need to 1) get people onto the land, and more, 2) we need these people to learn how to work it sustainably.

    Point #1 requires a massive shift in social consciousness and cooperation (how to get land back out of the hands of the people who presently have it concentrated into their corporate ownership hands), and how to get people settled in a transition that doesn’t have them starving in the process, and point #2 requires an holistic understanding of natural systems, resource constraints and a systematic establishment of training centres.

  25. “Point #1 requires a massive shift in social consciousness and cooperation…”

    This cannot be done without a massive and widespread understanding about our human behavioral ecology. We cannot change without a deeper understanding about whom we are and why we act like we do. At least this is the message from Terje Bongard, who sees it as his mission to spread this knowledge. After reading his new book I agree with him.

    Also, thank you all commenter’s for this very interesting discussion about bio char!

  26. I’m sorry Craig, I never maintained that Charcoal was to be manufactured in bulk nor Terra Preta either, no particular path was advocated, but I do have one to suggest and numbers of folk are beavering away at it all over the world.
    This is the Gasifier stove movement, it is directed at the two or 3 Billion people who cook with bio mass, – wood, rice husks, whatever, – these simple little stoves, now starting to be made by villagers in the jungle, produce 30% more heat from the same wood, – 30% less forest needing destroying, and leave a quantity of charcoal in the bottom when the cooking is over.
    This charcoal can be then dug into the garden and when the inspector comes once a year to measure the charcoal they could be paid what would be to them a lot of money, – they would also benefit by their soil gradually improving and the wealthier folks would be contributing by paying for the carbon credits. win win.

  27. The concept that we can not solve our problems but the earth in it’s wisdom is able to, seems to me to be a religious belief, you have just substituted Gaia for God.
    I think we are part of the earth and the earth is part of us, – my religious belief if you like, and if we cause problems then we have to solve them, it is an important part of the human race growing up, – taking responsibility for what we do.
    I think at this time we are much more accepting of the concept that there is no limit to knowledge and understanding than the human race has ever been, that we may have more problems is just the opportunity for us to grow and solve them.

  28. Craig,

    Just to clarify, is anyone disuputing the fact that terra preta soils are a good thing? I don’t think so. Do we know how to replicate them exactly? I gather that we don’t. Is carbon a big part of their success? Yes. So let’s keep learning more about this, building on what we already know (which is more than most of this anti-char crowd wants to admit.)

    I’ve made and used some biochar on my place. I quickly realized that making this stuff in reasonable quantities is prohibitively laborious with my DIY system. I didn’t get around to doing replicated trials. A small-scale device that will let farmers pyrolize waste materials, capturing some usable gas also, would be welcome. At present my biochar manufacturing is limited to dousing the rare brushpile fire with water well before all the coals burn up. Very low labor, reasonable yield. Right now all the dozens of truckloads of woodchips I’ve saved from the landfill are mulch in my new food forest, where it is doing marvelous things.

    Your quote from Vandana Shiva borders on demagoguery. Why he makes all the worst, baseless assumptions about biochar advocates and systems is a mystery to me. I’m not a biochar expert, but what I’ve read fully recognized the importance of microbes, organic matter, sustainable forestry, and other sources of N fertility. Then he pretends that rapid oxidation of OM is of no concern whatsoever in any climate. “Organic farming can do it.” It is perfectly well established that OM is very difficult to increase much on a large scale in hot, wet climates. This is the great potential advantage of biochar.

    I do agree, however, that there is very likely much deception involved in the carbon credits schemes floating around. Government decree is about to shift billions of dollars around, it is certain that secret deals and political machinations will determine who latches onto that teat. But I see no need to throw out the biochar baby with the carbon credits bathwater.

  29. Respect is due to you, Craig

    Any technology that fails under the category of being exclusively “proprietary” or someone’s “intellectual property” I’m extremely suspicious of. Just about all of our technology is a really bad imitation of something that occurs in nature, anyway – even the best of it.

    Just something to keep in mind.

  30. Surprising to see such lively discussion.

    I’ve commented on a previous article on biochar before and why it’s the logical choice.

    1) It has a longer half-life than compost. This means it lasts longer before it degrades and returns to the air as a gas. People will disagree about the length of that half-life, 130 to 1000 years. It makes very little difference. As long as it doesn’t return to air in the short term, and remains MORE stable than humus, then it is the logical choice especially if it is made from waste products.

    2) I am a pharmacist. We use charcoal’s lattice like structure in medicine to treat poisonings. It is in charcoal’s nature to trap and store chemicals (and therefore nutrients with regards to soil). When you apply this knowledge to soils, its much the same. In any soil, charcoal will draw and trap nutrients, leading to a reduced yield. If the charcoal is saturated first in a nutrient rich solution (such as urine) and then applied to a field very few of the field’s nutrients will be drawn out into the charcoal. The trials in the article did not take this vital character into account.

  31. Does burning large volumes of organic matter to make biochar net benefits that are that much better (if, in fact, better at all) than if you were to simply create large volumes of high-quality, biologically active compost from which living humus is produced and aerated compost teas could be made – which we know works very effectively?

    This question needs to be definitively answered because we’re going to end up having people battling over organic wastes and nutrient streams to make both products – actually, it’s already happening.

    For example, 1 cubic meter of biologically active inoculum compost can be used to make enough compost tea for 100 hectares, which is a pretty remarkable “force multiplication”.

    Here’s another interesting link on the topic from Woods End Laboratory…

  32. Here are some interesting articles from one of Scandinavia’s most influential permaculturists, Folke Günther. He seems to be quite positive about biochar.

    – Montbiots’ rejection of biochar:

    – In production: why charcoal is an excellent way to counteract atmospheric carbon dioxide:

    – The simplest of the simple charring methods; the retort stove:

    – Cooking on the retort stove:

    If somebody wants to contact Folke Günther, here is his home page with email:

  33. I recently spent some time in the Philippines countryside and was impressed with the constant haze from the many small fires that locals used to burn just about everything from plastic bags to dead leaves, twigs, agricultural waste, etc. If the option, is biochar versus compost, the question is not decided for me yet. If the question is biochar versus smoldering piles of dead leaves throughout the developing world, I’d take biochar (or perhaps rocket stoves).

    In fact, the black carbon as a major contributor to global warming refered to by the author is (from the study I am familiar with) not charcoal, but soot from the billions of cooking fires and trash fires in the developing world. To this extent, pyrolytic stoves as an alternative to smoky fires seems the preferable option to me.

    Whether corporate culture can be trusted to do the right thing when it comes to biochar is a different matter, but then corporations care rarely be trusted to do the right thing …

  34. I have come to the conclusion that both Dr. Mae-Wan Ho and George Monbiot are guilty of poor logic with their accusations against Biochar, – to put it into context, a recent study found no till gardening on heavy clay soil caused much increased Nitrous Oxide emissions,
    Nitrous Oxide Emissions Respond Differently To No-Till Depending On The Soil Type
    – does this mean we should ban permaculture because of the huge amounts of clay soil in the world which will soon be emitting ghastly quantities of Nitrous Oxide because it will soon be permacultured?
    With the logic employed by Mae Wan, yes, but in fact we should first look at whether other elements in a permaculture garden may counter-act the no-till Nitrous Oxide tendency, or if not, we now know thanks to the above discussion that if the permaculture activist first puts adequate (activated) biochar in the clay soil he/she intends to permaculturalise to absorb the Nitrous Oxide then two things are achieved, first that Permaculture can still proceed, and secondly that Permaculture and Biocharing can work together, and that alone is reward for Craig’s hosting of this discussion within as it were Permaculture’s bosom.
    Many thanks Craig and a Happy New Year, hopefully such openness may also allow some future reconciliation as well with Bill McDonough…
    Geoff Thomas.

  35. There are quite a lot of really interesting perspectives being discussed here, and it would be a shame to throw the baby out with the bathwater. This topic is relatively new to me, but there are obviously characteristics of biochar / charcoal / activated carbon that have generated enough interest in its potential to contribute to our management of soils / more sustainable systems and possibly address issues such as carbon build-up in the atmosphere and oceans. However, we need to acknowledge there will be positive and negative feedbacks impacting / determining the efficacy of our approaches, the eventual pattern of things and outcomes. Let’s see what we can learn as to the benefits and costs of utilising biochar. In my mind, biochar has certain qualities such as exceptional surface area and seems to have excellent potential for ideal microbial / fungal habitat and nutrient storage. How (and how much) we produce that biochar may be an issue though. Are there other more effective ways to achieve the same effect in the soil / environment? Are there things we’re already doing (that we could do a lot better) where we wouldn’t need to produce whole new streams of material flows just to produce economically viable quantities of biochar? Anyway, keep the dialogue going, it’s a pretty interesting topic – thanks for the article, and thanks everyone for all the comments and feedback.

  36. I have posted some of my concerns, via many external reference, at another article about biochar here and would boil down my feelings about the biochar issue to this:

    On one end on the continuum, biochar might have some good properties; on the other end, it’s potentially dangerous and irreversible.
    This makes biochar seem like dressing up a problem as a solution, or like trying to fit a square peg into a round hole.

    And there are so many unanimously-accepted tried-and-true practices.

    Also, and perhaps just as importantly; local, small-scale experiments/practices, such as with biochar, all around the world, by many people, is not exactly local or small-scale anymore. It is large-scale global. Add to this government and industry support for biochar, and we may set up a truly catastrophic situation!

    That said, I strongly recommend against biochar.

  37. Dear Caelan MacIntyre, i would have thought any fair minded person who read through the range of comments in the discussion above would have let go of the paranoia about catastrophe, we all know drinking too much water will kill you, but that is not an argument against drinking water.
    And although there are some accepted practices, they do not work in some situations, nor do they address some major problems that Biochar does address.
    Your comment is very vague, like any fear mongering, if you want to get down to specifics, we can see if you have any substance or are just mistaken.

  38. @Geoff Thomas:
    I have gone out of my way to read (and post links to some of) a fair bit of very serious literature from various sources concerning biochar, rather than rely on personal anecdote.

    One quote is from Vandana Shiva, incidentally, who, like Bill Mollison, is the recipient of the Right Livelihood award, among many others. When she voices strong concerns against biochar, along with many signatories from various organizations, I think it is important to take heed, and, where appropriate, re-evaluate one’s practices, values and attitudes with Care of Earth and People as top priority.

    When in doubt, err on the side of caution.

    Here’s another article about it on PRI, incidentally.

  39. Biochar: Can it put the tea industry back in the black?

    The answer to this specific question is Unlikely or a definite No, if it is the SL Tea Industry. However, Biochar can improve crop production, improve quality, reduce the cost of production and improve estate productivity.

    The SL Tea Industry (TI) started with the planting of Camellia sinensis almost 150 years ago beginning with the deforestation of lands under natural forest cover. Today there are 190,000 ha in bearing (CBSL 2010) under this crop. Let a plucker demonstrate the art of plucking the green tea leaves and it will be the two leaves and a bud that will be picked. Sri Lankans know this and it is not a secret. What is essential is good made tea and it can be produced with good quality tea green leaves. Then why is this simple method which every tea green leaf plucker is well aware of not practiced in order to produce good tea?. The main reasons, I believe are;

    1. Average low yields.
    2. High and rising costs.
    3. Adverse effects of climate change.
    4. Reduced demand due to competition from other beverages.

    The average low yields can be improved by replanting all the low yielding Tea but, will not be done due to the high investment involved. The other three reasons are beyond the control of the plantation management. What then is the solution to overcome the sad situation on the Tea plantations?.

    One is to let small holder growers manage and produce the green leaf as they are obviously better off than the large plantations and already supply 60% of the total production. Second solution is Biochar, which will no doubt show definite improvements. But, is Biochar able to improve the 190 m. ha of Tea in bearing appreciably to put the TI in the black?. Can the SL TI get back in the black with such an improvement?. The big doubt is;

    1. What is the total volumes of biochar required and the cost per unit area of land for its application?.
    2. What is the total area under Tea to be given this application and how long will it take for the required volumes of biochar needed to be produced?.
    3. Are the Tea plantations able to meet this cost of the investment?.

    The replanting of Tea has not been undertaken due to financial constraints. Will the application of Biochar have to overcome this same obstacle?. However, Biochar will be able to improve the extent of the best yielding Tea based on the promising results indicated so far. Further, I believe care must be taken not to arbitrarily increase the yields as over production may not be worthwhile improving the yields. I understand that the required annual production in SL to supply the demand is 340 – 350 m. mt. If this is correct, at least the supply needed is known and the goal should be to produce it from the best extent under Tea to achieve the goal of “Putting the SL TI in the black”.

    The present SL TI is dependant on the production of green leaves from 190,000 ha. What about the low yielding extent under what is known as Uneconomical Tea (UT)?. Is it to be abandoned or diversified?. If it is to be diversified, with what or how?. Has there been any worthwhile diversification of UT so far?. Once again, it is a matter of investment and returns.

    The TI in SL started with the deforestation of natural forests. If this deforestation has had adverse effects to the country, reforestation with suitable species is one of the obvious solutions to diversify the UT taking into account the capital investment as well as the returns expected. Are there any suitable tree crops and if so, why has this never been carried out?.

    Two species that must be seriously considered are Pentadesma butyracea and Garcinia indica (Kokum). The seeds of both yield a vegetable fat in good demand from globally important major industries. Pentadesma is more suitable in regions where the rainfall is high and Kokum even in the dry zone. Pentadesma is the more suitable tree crop for the UT and the potential is briefly described below.

    1. The species is suitable for afforestation, comes into bearing in five or six
    years and continue to be in good bearing for well over a century. It can be
    established on a plantation scale and by small holder growers. It is suited in
    regions where the rainfall is high. This species is the one that can be
    established at the lowest cost to obtain the best benefits to the economy and
    to the environment, which is equally important.

    2. The vegetable fat extracted from the seeds with fairly simple technology
    is a substitute for cocoa butter. The demand for it will be from the
    cosmetic, food and confectionery industries. It is suitable for the production of biodiesel.

    3. When in good production, the yield is likely to be the highest from any species
    giving a v. oil or fat and will have the lowest cost of production.

    The growing of Pentadesma will at least partly restore the lands under a good cover of a tree crop, with added benefits of carbon sequestration under CDM.

    Identified major companies are willing to buy this fat for the food and confectionery industries as well as for the production of biodiesel if there is sustained production of large volumes of the commodity. The interested companies are from EU, USA and S. Korea.

    I must reiterate that while Biochar can improve the better Tea plantations, Pentadesma can do the needful in the UT. The result will be an improved SL TI, producing Good Tea with improved economic benefits to the individual plantation and the country as a whole.

    “Biochar and Pentadesma, together, can put the SL tea industry in the black”. A question mark is not necessary!!.

    If you care to seek, you will find the truth!

  40. There has been a recent discussion over at The Oil Drum about biochar.
    Over there, I go by the name, Tribe Of Pangaea- First Member.
    The more I dig into biochar, the more concerned I am becoming about it, as well as its questionable perceived connection with permaculture.

  41. With fossil fuels, humans are playing with fire, both literally and figuratively, and biochar seems to (wish to) continue on with this tradition– to stretch business-as-usual out– if under an ostensible greenwash.

    One study suggests that the amount of oxygen dissolved in the oceans may decline, with adverse consequences for ocean life… climate feedbacks within the Earth system amplify the strength and duration of global warming, ocean heating and oxygen depletion. Decreased oxygen solubility from surface-layer warming accounts for most of the enhanced oxygen depletion in the upper 500 m of the ocean. Possible weakening of ocean overturning and convection lead to further oxygen depletion, also in the deep ocean.
    ~ Wikipedia

    …anoxic events occur when the Earth’s oceans become completely depleted of oxygen (O2) below the surface levels… geological record shows that they happened many times in the past. Anoxic events may have caused mass extinctions. These mass extinctions were so characteristic, they include some that geobiologists use as time markers in biostratigraphic dating. It is believed oceanic anoxic events are strongly linked to lapses in key oceanic current circulations, to climate warming and greenhouse gases.
    ~ Wikipedia

    Since the beginning of the industrial revolution we have removed .095% of the oxygen in our atmosphere. True, that is only a tenth of one percent of the total supply, but oxygen makes up only 20% of the atmosphere… according to OSHA rules on atmospheres in closed environments, “if the oxygen level in such an environment falls below 19.5% it is oxygen deficient, putting occupants of the confined space at risk of losing consciousness and death.” What happens if the world’s atmospheric levels of oxygen fall to 19.5% or lower?
    …We currently make estimates of how many years we have left before excess carbon dioxide becomes a bigger problem than it already is but we aren’t really sure of their accuracy. However, to the best of my knowledge, we don’t have estimates of how long it might be, if oxygen continues to be depleted at its current rate, until it might become a problem.
    ~ Mike Johnston; ref., Dr. Ralph Keeling

    The previously-mentioned discussion-thread on the concerns with biochar at The Oil Drum is now archived for future reference.

  42. Deforestation for Biochar does not make sense. Since 1990 290 million hectars of wood had been destroyed, with an capacity for CO2 fixing between 30 to 60 billion tons per year, better to say C-Fixing and O2 releasing. It ist the amout of yearly CO2 “production” by fossil fuels worldwide.
    Dispite this, I gues there may be a chance to produce biochar out of bark and other organic “waste” such as sewage sludge or residues from biogasproduktion by sort of hydrthemic carbonisation. This has the further advance of killing pathogenous bacteria such as clostridia and the oxygen is released from the lignins,

    1. Yes Martina, even thinking about loggers using their saleable timber for Bio Char is laughable, timber is so much more valuable in the market place that one has to realise that the suggestion was similiar to ‘coughing causes radioactive death’ or some such nonsense, it was just hysterical hype by someone who did not think but felt vaguely threatened by someone with a different point of view. Using the unwanted parts of the trees after the timber has been removed to make bio-char certainly makes more sense than bulldozing it into heaps then setting fire to it (the current practice in most parts of the world, – alas) but even that is criticised by some of the anti bio char lobby. The point is that the oxygen would be fixed to the carbon anyway if just burnt, (or even allowed to rot) but it would be in the atmosphere causing global warming rather than in the ground growing vegies or trees or such for thousands of years.

  43. I rather doubt that biochar will be responsible for depletion of O2 levels in the atmosphere and oceans. The commercial/industrial harvesting of trees for commercial/industrial scale production of biochar on the other hand could. The deforestation and creation of biochar would potentially create a exponentially increasing decrease in O2 levels by both binding O2 to C and also reducing the conversion of CO2 into O2 due to loss of photosynthetic biomass. When done in a manner that is geared towards limiting waste , both biomass and off-gas, biochar has a relatively low CO2 foot print as most of the C is left in the biochar with mostly water, methanol, and pyroligneous acid produced as by products. If done at low temperatures, 300-400C, the off-gases produced by the pyrolysis of many biomass materials is enough to maintain the temperature for pyrolysis to occur produce more volume of biochar as less biomass is converted to CO2 and fine particulate that are released into the atmosphere. I have made and used some biochar, and there is some severe nitrogen depression when adding only the biochar to the soil. I have also soaked biochar in compost tea, which gave favorable results.

    1. One of the main points in the article was that biochar will rapidly decrease atmospheric oxygen. A little back of the napkin math:

      – There are ~1×10^18 kg of O2 in the atmosphere.
      – The paper suggests that 24% of biochar is oxidized, compared to expected.
      – To drop the atmospheric O2 levels 0.5%, one would need to produce 2.5×10^16 kg of biochar.

      That’s an awful lot.

    1. There is biochar available in BC and Alberta – and most elsewhere. There are just small networks at this point – as there is little centralized production. Send me an email if you want to connect on biochar supply in Western Canada.

      kdriver (at) prasinogroup (dot) com.

  44. The thing that struck me, reading this article, was the hopelessly linear thinking employed. Surely if we’ve learned one thing about ecology (or any of the life sciences come to that) it’s that we have to consider problems holistically and look at the ramifications on a multitude of different feedback loops all of which interlink. Even our obsession with atmospheric carbon levels misses the mark by a mile. The crux of the problem is deforestation. Everything stems from that. You remove the planet’s capacity to maintain the optimum balance of gases in the troposphere, you denude soils of fertility, water-holding capacity and even life and how are you NOT going to have a problem?! If the human race is going to produce lots of greenhouse gases, then that needs to be balanced by an increase in forests, not a decrease. Biochar has it’s place as part of a multi-factorial solution to restoring soil fertility. Its ability to speed the breakdown of organic material into soil has a role to play in helping restore denuded soils, surely? Halting the ongoing destruction of natural forests worldwide and planting trees – ones that build soils and restore water systems rather than deplete them – has to be about the closet thing we have to a magic bullet.

  45. Just to try an keep it simple, in my research of charcoal (biochar) as we think of it now, was once used to heat our homes in the form of coal. Farmers then realized it was good for there crops, this was before the chemical fertilizers and the dust bowl days, So in the 1800’s it was known to be good here in this country, but of course it was much to exspensive. If we look at the subject of biochar from a 3rd world view we can see it creates fuel for the trully poor who live where the forests have been depleted and theres not much would left to cook there meals with. By using sugar cane, bamboo, or any gardening refuse or any form of biomass, they have learned to make eco fuel or charcoal brickets or pellets to cook with now that dont cost a lot and can cook with very little smoke, many still cook in doors with very little ventilation, so in that respect its healthier for them. At the same time they put it in the terribly depleted soils

  46. Well this is the only article I have ever seen saying Biochar is bad. I am open to more if you have any. I have a website that is pro biochar and I have been working with it for 5 years now. I also see many mistakes made by many scientists so I am not a big fan of scientists and University researchers. I also sustain-ably manage a neglected plantation forest and biochar the thinnings.

    Lots of my anecdotal evidence can be found here on my website

    Thank you in advance for showing me more on this topic

    Charmaster Dolph Cooke

    1. Hi Dolphe, you are on a permaculture site, Permaculture went through an anti-Biochar moment, as expressed in the leading article, but a member was open minded enough to allow ALL comments on this permaculture site, the which comments seem to have resolved many of the criticisms and misapprehensions, ie that Biochar would level the worlds forests to create Biochar, without understanding that it is only the residue that Biochar is interested in, – the waste, the fallen trees, the agricultural and city waste, – so much more than the actual trees, who can just keep on growing as they do.
      It’s just a simple thing, when we all get down to it, how to get more carbon into the ground.

  47. It seems as though you are saying that the only way people are making biochar is to clear cut a forest and that doing so will deplete oxygen. What if people were making biochar without cutting down a single tree to make it? If you were to take that into consideration before writing your article, perhaps your conclusion (which is based pretty much on the fact that trees getting cut down depletes oxygen) would be a little bit different?

  48. Since when did the permaculture movement become anti-biochar? Sure, a few people have been, but I’m sure there are plenty of permaculturists like myself who look to technology to minimise waste. Bill Mollison is one, and David Holmgren another who both advocate for design solutions to fix energy and waste problems.
    I am currently on a property we had bought with blue gums under contract. The forestry company harvested the trees, but left enormous amounts of trash and more than 95% of trees regrowing. The solution by farmers around here is to burn-spray-burn. What does that do for O2 and CO2 levels?
    I want to pick up the trash, chip it, and put it through pyrolysis. Why is my approach so bad for the environment? Surely it’s better than burning it, which it will do if a bush fire comes through. Incidentally, the trash is over a meter deep in sections and makes it impossible to get around the plantation.
    My understanding of permaculture is that the trash is a resource to be utilised. By converting it to heat and selling electricity into the grid, isn’t that what permaculture is all about? That’s certainly what I got out of my PDC all those years ago.

  49. Yes Richard, making biochar is much better than burning it. Biochar is fine used this way. I think there was some hysteria about burning up all the worlds forests to make biochar. But that’s just scare-mongering. Small scale biochar especially when used instead of burning organic litter is a great benefit.

    1. This article is an interesting phenomenon. It is some form of “viral”. It pops up on the first page of almost every key phrase search with the word biochar in it. That means that this article is very often the first thing that is read when “biochar” is searched.
      In the light of current knowledge lent by time and comments posted, does the Permaculture Research Institute believe that it is responsible behavior, and in the best interest of humanity to leave the article as it is?
      I urge you to please consider an update to the article. Even without an updated content revision by the author, an editorial disclaimer at the top could make a world of difference. In doing so, you would still maintain your prime status in Search Engines, and you could also maintain your integrity as an institute towards a greater good.
      Biochar does not have the capacity for intention. It is humans that provide that. It seems clear enough now that biochar as a material and as a process offer great tools for us in farming, environmental management, and possibly even in climate change mitigation. It should also be clear now that the vast majority of those involved in biochar are doing so with good intention and with good practice. However, nothing is completely immune to bad intentions, so if you ever see entities acting with ill intentions, call them out. But, please review this article so that you do not throw the world of biochar out with the “bad corporation” bathwater.
      Thank you,
      – Josiah

  50. An interesting article and responses to it.

    The first point I’d like to make is that bio char should be made from waste carbon products which would normally go through the carbon cycle–so I agree that growing bio mass specifically for the production of bio char is a bad idea. There is enough wood waste generated in the developed world at least, to make bio char to one’s hearts content.

    Second, bio char absorbs significant amounts of water and nutrient from humus and so yes it follows that humus will break down (not oxidise) more quickly in the presence of bio char. However, there is a point where the bio char is not able to accept any more nutrient and at that stage the humus break down will stabilize and return to its normal expected rate.

    My final point is to do with the by products in terms of
    A recent study conducted by Pudasaini et al(,d.dGc ) found that the simple act of adding bio char to soil used to grow Capsicums increased yield by 31 to 32 % without even pre-loading the bio char with nutrient. It also significantly reduced the leaching of K and Ca leaching in the soil samples.

    My final comment relates to the syn-gas and bio diesel byproducts. There is also another by product in terms of wood vinegars that can be use as a natural pre-emergent spray. These byproducts allow us to use more fully the whole bio mass and can go some way towards producing power, transport fuel and natural herbicide replacements.

    Adding bio char, made from waste bio mass, to soil, compost (my preferred method) or as part of producing long term soil fertility methods (Terra Preta) can have only good impacts.

    The issue of global oxygenation is a direct result of deforestation and ocean damage caused by humans and it is a different and important issue to making bio char from waste bio mass.
    Permaculture is about looking at the world through changed eyes and the notion of growing large amounts of bio mass specifically to produce large amounts of bio char is old world thinking.

  51. I just want to add 3 basic rules:

    Rule 1: Always try to put back into your soil what you have taken out of it. EG mulch and compost
    Rule 2: Always try to bring up deeply buried nutients to surface for plants benefit. Eg mined fertiliser or use fertiliser trees with deep root system. Stay away from sea weed let them store Co2 in the occen and not realeasing it.
    Rule 3: Do not ever try to accelerate oxidation such as burning or chemical chain reaction.

  52. I bet a lot of those studies either use the wrong type of char or unmatured char or both.

    If you positive results, the source material should be comprised of purely organic substances and the biochar needs to be:

    1. Pyrolysized (burned in the absence of oxygen) at about 500° Celsius

    2. Matured – Just like compost, the maturation process can take from a couple weeks to several months and can be done in a variety of different ways, just like compost, or better yet, as an ingredient in compost.

  53. Great replies all around. I thought I would contribute my 2 cents here as well. Our planet and all the organisms and creatures on it big or small are way more then most realise. The earthworm is by far the best soil worker that anything in man made technology can match.
    Its a perspective and our end goal that we must redefine. From short term profit to long term prosperity we have to shift. This is relevant to everything we do.
    Biochar and Tera Preta are simply utilising long term housing for all those micro-organisms that are part of the long term agriculture equation. As we know that half-life of organic compost is around 5-10yrs and modern fertilizers are nothing short of destruction of the soil which get washed away leaving the earth bone dry over long periods of use.
    As the article points out the dangers we must not overlook why it is so. Question and understand the entire process. Figure out a way to make Tera Preta without harming the environment and utilize this natural process for the benefit of all species on the planet.

  54. I have appreciated this thread for raising good questions and teaching me a few things about biochar. Since I am not a scientist, it’s challenging for me to evaluate the chemistry expressed here.
    But I do have some hands-on experience to contribute to the discussion:
    I have seen with my own eyes and tasted with my own mouth the produce I have grown using terra preta -like soil. It’s delicious and bounteous compared with the same vegetables grown in my regular garden soil. Making this soil is not a quick-fix, as the labor involved in collecting scrap carbon (I use end pieces of 2 by 4s found on craigslist and free cycle), burning the wood, fermenting kitchen scraps with bokashi, creating effective micro-organisms to add to the mix, feeding the worms, collecting manure… well, it all takes time. But it’s grounding outdoor time – I especially love cooking on my outdoor stove. Others who come to my workshops and “Stone soup” potlucks become inspired to make their own stoves, and one of them has offered to help others do so. It’s a community happening.
    David Holmgren, co-founder of permaculture, writes about how our sustainability practices will need to shift over time. Right now there are many sources of waste carbon, at least here in Portland, Oregon. Arborists will drop chips at your house for free if you ask them to. It makes sense to turn this carbon that would otherwise be burned or decompose into biochar, reducing our dependence on fossil fuels for cooking and at the same time sequestering carbon and making fertile soil.
    Biochar, created and used wisely on a small scale, can be one part of the solution to our climate crises, combined with reducing our personal use of fossil fuels, and taking to the streets in non-violent civil disobedience to help stop the flow of fossil fuels. We need to work every angle, each of us focusing on what we are called to do, and supporting each other emotionally and practically in this critical collective work.
    I love that there are different viewpoints expressed on this site. I encourage all of us to monitor our tone to help make this a place of mutual education among folks who all care about our precious planet. Thanks for listening.

  55. How could the biochar take up more oxygen then the trees from which it is made originally produced? Trees gain carbon from carbon dioxide in the air. They split this up and so free the oxygen. When the charcoal recombines with oxygen, there would be a net zero change, not a steep negative. As far as the trees being cut down for biochar; if they were planted for the purpose, another batch is planted, and even a small amount of the carbon from the biochar stayed in the soil long term, the result would be a net increase in oxygen and decrease in carbon.

  56. Searching for Biochar I keep finding this “Annual net emissions of carbon dioxide (CO2), methane and nitrous oxide could be reduced by a maximum of 1.8 Pg CO2-C equivalent (CO2-Ce) per year (12% of current anthropogenic CO2-Ce emissions; 1 Pg=1 Gt), and total net emissions over the course of a century by 130 Pg CO2-Ce,” Published Nature Communications 1, Article number: 56 (2010). The authors claim this as “we estimate the maximum sustainable technical potential of biochar to mitigate climate change.” The authors do not provide what 1.8 giga tonnes reduction in CO2-CE mitigates other than what one may assume. Now it’s almost 2018 and the percentage of 12% is not valid. 2017 projections 40 to 45 gt. Is there any substantiated quantitative evidence biochar has reduced CO2-CE emissions into the ecosystem. Nature has a way to balance / correct the system which many prefer to ignore,

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  59. Page 167 of the Bion experiments by Wilhelm REich should provide a bit of insight here… the char IS releasing carbon, yes, but that carbon becomes biological carbon, namely soil biological life. The reason this is not measured is because its not eve accepted as a potential reality, and studying the phenomenon pitted Reich against Pasteur and his germ theory, and as this was widely accepted his research, as a ‘non-scientist (he was a psychoanalyst originally) irrespective of backing by a french university research team with professorial support, his findings were dismissed.

    This would indicate that the acceleration of decomposition of forest floor humus is due to the accelerated evolution of colonies of microbial and bacterial life, which consequently go on to eat what is available to them.

    To understand this it is key to understand , as Reich saw, that the carbon breakdown into the vesicular structures that Reich called ‘bions’ lead to these bions becoming foodstuff for protozoa amoeba bacteria and othe microbial communities, thus their decomposition of forest floor litter would accelerate with their rising population.

    Hence it is not enough to study one or two aspects, the char decomposition must be accounted for by simultaneous measurement of the soil biological life, and this must be further accounted for as per contributions to nutrient release at the root of plants and their synthesis and concurrent oxygen production, as a result.

    The problem with team human s that we see part of the puzzle, take it as whole, and then seek to exploit an only partial understanding. This always leads to issues.

    In this case, we see a factor caused by this exploitation of partiality, becoming life threatening, and then the solution, in true ‘high modernist’ form (see ‘Seeing Like a State’) the solution becomes a contributing factor to the worsening of the initial predicament.

    And of course thats logical, because its the same fault again, partial understanding based on specialist-orientated knowledge accumulation.

  60. This article should be retracted. It’s 2019. Fallacies that could be posited without criticism almost 10 years ago– due to incomplete research — can no longer be defended due to the profusion of research and field experience. Oxygen shortage, indeed.

    Update it and correct it.

    Or take it down.

  61. This article warns about biochar, the very thing that Morag recommends in her video ‘soil repair as climate activism.’ Can you explain how to use it in a way that takes carbon down into the soil rather than increasing it in the air?

  62. I think this article really misses the point of the potential for biochar to mitigate GHG emissions and improve soils, among many other things. The thought that biochar would be produced from biomass specifically made for that purpose and that there is a risk of this process becoming the dominant way in which biochar is produced globally, is a wild assumption. On an industrial scale, it doesn’t make any sense to produce biochar in this way, especially when there is plenty of available waste biomass feedstocks for biochar that occur from agriculture, forestry, and biosolids/manure. Biochar produced on an industrial scale is about value-adding to a relatively free waste product and diverting it from landfill, open field burning or other methods in which it is oxidised and releasing GHG emissions. That is the only ecological/economic case that is tenable on an industrial/large scale. In a scenario that land is occupied by crops specifically grown for biochar, the value of biochar itself is not enough to cover the capital investment of the kilns and processing equipment (thousands to hundreds of thousands of dollars), the cost of labour and maintenance of crops, and the transportation of the end product. Even the value of carbon credits would not be enough to offset the cost of production using that method. You would achieve better value (from products and carbon credits) by just converting land for forestry. Private companies and government investors understand this. I know this only states the economic case but obviously and unfortunately, that is what drives large industrial enterprises. The same logic applies for smallholders, but even more so, given that biochar becomes cheaper to produce as the scale increases. So industrial biochar is not at risk of becoming a behemoth that consumes forests and displaces land similar to bioethanol – which represents an entirely different business case.
    Regarding the lack of unequivocal evidence of biochar showing improved crop yields. You are right, there are some studies showing nil/negative results. But as most will appreciate, there is not a one size fits all in agricultural technologies. Soils vary, crops vary, climate and study conditions vary, not to mention the production and characteristics of biochars vary considerably too. Plenty of meta-analyses have shown significant results indicating biochar benefits soil and crop productivity. Also, stating that chicken manure out performs biochar is total red herring. Biochar, typically, is natively low in nutrients. It is a soil conditioner, not a fertiliser, and acts as a substrate to store nutrients, microbes, liquids and gases etc.
    Regarding biochar as an oxygen sink, the carbon/oxygen balance and interactions associated with biochar in soils is complex and hard to study and is not clearly derived from analysing the composition of sediments or looking at the surface charges of biochars. The balance also largely depends on the characteristics of the biochar and the conditions under which it matures. Biochars are stable on relatively short time scales, decades to centuries, and not so stable on others, say millennia. However, biochars are orders of magnitude more stable than organic material that undergoes composting or material that is burnt with oxygen. Which is why it is considered carbon negative under most production methods and fit for purpose in achieving reductions in GHG in the present and near future.
    Biochar is not a silver bullet to improve soil health and combat climate change. Much simpler and effective methods also exist, like planting trees. Biochar does fill a niche as a relatively low-technology that can be carried out on industrial to single household scales, has the potential to reduce a vast amount of emissions from a variety of GHG emissions sources, add value to an expensive and cumbersome array of biomass waste streams, improve soil health, increase the water-holding capacity of soil and improve the efficiency of fertilisers. Biochar has also shown much success as a feed supplement for livestock to improve the gastrointestinal health of animals and feed efficiency, and in reducing methane emissions from ruminants. Further, biochar is increasingly being used to partially substitute Portland cement (which is a massive GHG source). In developing countries, biochar is used as a way to purify contaminated drinking water and a number of programs are being rolled out in various regions to replace normal open fire cookstoves with small biochar cookstoves that emit much lower gas and particulate emissions, producing biochar as a product. Both of these uses would constitute an enormous health intervention in the developing world and make a strong case for biochar technology alone. This list of beneficial uses is quite incredible for such a simple (yet remarkably complex) material.
    Anyway, the article to me is highly speculative and relies on some pretty tenuous assumptions. I’m interested in a skeptical dialogue about these sorts of panacea-like technologies that are touted, although the message here is perhaps too alarmist and not well supported.

  63. Just wow. There is so much wrong information in the article, and I would NOW maybe even assert, outright lies, that I don’t know where to begin. My first clue was when the author began intermixing the terms “charcoal” and “biochar”–they are NOT the same thing! My next clue was the lack of verifiable references. While I don’t have time to read all of the other comments, I suspect that maybe others who are also outraged at this article have spent the time to give readers REAL information about biochar. READERS, JUST KNOW THAT THIS ARTICLE IS WROUGHT WITH MISINFORMATION.

  64. I suppose what this Dr is missing is that mostly waste products are used to make char & that O2 would be used to decompose these materials anyway & that the overall increase in plant biomass that could result of the incorporation of this technique into agriculture would be able to mitigate the O2 used.

    I see this article as a short sighted & mindless approach to take down a technique that could be beneficial. It is clear that agriculture based on the burning of fossil fuels is in need of reform.

    Who paid this guy?

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