Biochar Bright Spots: Biochar Bricks

David Derbowka is one of my favorite kinds of charistas; creative, collaborative and cares about what matters most – a better climate future. David is an environmental engineer heading up his own company, PRSI, in a faraway place in Western Canada between Calgary and Vancouver. One of his areas of focus is phytoremediation of landfill leachate using fast growing poplar trees to soak up contaminants. Carbonizing these trees helps to reduce their bulk but some contaminants (e.g. metals) may remain ensconced within the carbon lattice.

Wanting to find a non-soil use for his biochar, David has been experimenting with using it in different materials such as bricks and drywall.  The samples he sent me many moons ago have traveled with me to all sorts of places including most recently to COP24 in Katowice, Poland.  I’ve told his brick story many times and plan to tell it many more times to come.  But now folks can hear about biochar bricks directly from David himself in this new youtube video.

Many folks enquire about recipes for using biochar in various building materials, wanting to save time and money leveraging what others have gleaned. For better or worse, many in the biochar world (and beyond!) are rather tight lipped when it comes to sharing this type of information, preferring to adhere to the capitalistic paradigm of prioritizing profits from patents. (This approach is a big part of what got us into our current carbon calamity.) David’s world view is the antithesis of that mode of thinking. As but one example, he recently shared his experiences openly and honestly with a group in South Africa that was looking to boost rural employment through green building materials.

These global, often times altruistic, collaborations are exciting to be a part of. They are what is needed to spread hope, knowledge and solutions far and wide. In this respect, I see David not only as a fellow pyrogenic lamplighter, but as one of biochar’s emerging ‘thousand points of light’ – an expression made popular by former President George H.W. Bush.  It was a modernized version of former President Kennedy’s “ask not what your country can do for you, but what you can do for your country”, which was a reinterpretation of the Three Muskateer’s (and the nation of Switzerland’s) motto: ‘all for one and one for all”. We need a XXI century version of this rallying cry (or maybe these days a meme would be more appropo!) that promotes a balance between taking and giving, between carbon spending and carbon banking, and perhaps hardest of all between profiting and planetary health.   

David’s recipe:


1 part Portland Cement

1 part water

3 parts biochar: note biochar should be soaked in water prior to mixing at a rate of 4 cups water to ½ cubic foot of biochar to reduce dust; particle size should be 1/8” or less.


  1. Mix water and Portland Cement together first
  2. Fold in three parts biochar.   A 1/2 inch electric drill makes this easier, but could be done with muscle power. If you find the mix too dry, add water, but very little, because it gets over wetted easily.  Too much water can slow curing and reduce compression strength.
  3. Pour biochar concrete mix into well oiled molds quickly after thorough mixing, returning a bit later to make perfect smooth finish.
  4. Once the product has hardened sufficiently (within 24 hours) cover with burlap soaked in water to keep it wet if possible.
  5. Wait 48 hours before emptying the molds or forms. 
  6. After removal, immerse bricks in water for two days.  During all moistening procedure, the char sucks up the water, and lets the portland finish curing
  7. Remove bricks and let them dry for ~ 27 days before using them.

NET Gestalt

Three NETs are better than one.
Reforestation, biochar & soil carbon sequestration can regenerate mine lands.

Every week more & more peer reviewed literature on biochar is published and 2019 will see the debut of a peer reviewed journal dedicated solely to biochar research. On average there are at least a dozen new papers each week making it impossible to stay on top of all the news coming out about biochar. Nevertheless, I persist! I confess that scanning new titles a few times per week has become a bit of an addiction. Most of the research is still behind paywalls, but a growing number of papers are open-sourced so the full report is downloadable. [If you’d like a monthly bibliography and good synopsis of the new research, consider becoming a member of IBI and you will get Bob Gillett’s monthly listing which also tells you which ones are free or behind a pay wall.]

The majority of the research is still heavily focused on agricultural uses but other topics are beginning to show up with more regularity. Filtration is big, remediating metals and other toxins in soils is also a frequent topic. Unfortunately, it is still not common to read biochar papers on its use in livestock feed and building materials (good recent exception here). [HINT: sometimes if you search for ‘nano-charcoal’ or ‘biocarbon’ you may find a few more.]

This week my favorite freebie comes out of Appalachia where researchers are testing biochar to help regrow forests on former coal mining lands. This particular paper jumped out as I just wrote about Negative Emissions Technologies (NETs) and how biochar can be used synergistically with two of the other NETs: afforestation/reforestation and soil carbon sequestration. When it comes to climate change solutions, we need less siloed thinking and more NET gestalt (meaning an organized whole that is perceived as more than the sum of its parts).  The Fields-Johnson et al (2018) paper highlights this very concept perfectly. Here is how…

Reforesting land that was stripped or blown apart in the careless crusade for fossil carbon is challenging both from a soil tilth and toxins perspective. Considering how much land has been pillaged for short term profit using surface mining, a whopping 1.2M hectares in Appalachia alone, being able to re-establish armies of CO2 sucking soldiers (aka trees) would be an absolute tour de force in our fight to rebalance carbon, not to mention a huge boost for biodiversity, flood control and economic development.

Researchers in West Virginia showed that biochar applied either in the root system or top dressed at varying rates for 2 different types of year-old sapling trees could potentially double above-ground biomass. Saplings grown in 100% biochar even doubled the below ground biomass as compared to mine soils.

Even though this was confined to pot trials using mine soil, this is really quite incredible when you consider the down stream implications. Getting fast growing native species to grow in contaminated soils could draw down an enormous amount of CO2. The rough math using 2,500 trees per ha and assuming 20 kg of CO2 absorbed per tree comes to 50 metric tons of CO2 per ha per year! Multiply that by 1.2M ha and Appalachia’s former mine lands could breathe in 60 Million metric tons of CO2. Now apply that to all the mine lands waiting to be resuscitated around the planet.


But wait there is more. Soil carbon sequestration should also be considered.  The researchers applied biochar at three different rates: 2.3, 11.2 and 22.5 tons per hectare. The paper does not indicate the carbon content of the pine sawdust biochar but it is likely to be around 75% or more. At these rates the biochar could add 6.3, 30.8 and 61.9 tons of CO2e per hectare respectively. In Appalachia that would be 7.6M, 37M, or 74.3M tons of sequestered CO2e. The combination of photosynthesis and carbonization/sequestration could total more than 130M tons for the region!

Now imagine the Abandoned Mine funds set aside by coal companies being used to rebuild and rebalance carbon instead of adding insult to injury in the form of dumping fly ash or sewage sludge onto mine lands. Imagine carbon taxes on fossil fuel companies going towards rebuilding communities and eco-systems negatively impacted by drilling and desecrating landscapes. Combining reforestation, biochar & soil carbon sequestration to regenerate mine land is what I imagine an ideal NET gestalt looking like!

Safety NETs & Biochar

Humanity is in need of a safety net to pull us back from the carbon brink. But what might this net, or more likely nets, look like? The recent IPCC report may provide some clues.

The IPCC’s recent Special Report state’s that while steep and rapid emission reductions are critical, we have come to a point where carbon must be pro-actively pulled out of the air and stored safely elsewhere. Storage options are limited to land or oceans (though no doubt some would like a moonshot!). Land-based storage options include soils, deep geological storage or rocks – yes rocks!

The report lists a mere six negative emissions technologies (NET) that they feel may be capable of drawing down massive amounts of carbon. Biochar, for the first time is included in that shortlist. To recap the sequestration mechanism offered by biochar: carbonizing underutilized organic material, be it sewage sludge, city green waste, storm debris, invasive species, food waste or myriad other sources, converts recently photosynthesized atmospheric carbon into stable, long-lasting carbon that can be stored in soils or safely incorporated into man-made materials.

Biochar, along with only two other NETs, afforestation/reforestation and soil carbon sequestration are ancient, proven processes which provide many other benefits beyond sequestration. The other three NETs; Bioenergy with Carbon Capture & Storage (BECCS), Direct Air Capture with Carbon Storage (DACCS), and Enhanced Weathering, have yet to be proven scalable, and may come with unintended consequences and enormous cost.

A limiting factor for many of the proposed NETs is land. There is only so much bare land that can effectively be converted to forests, agricultural land that can store carbon without endangering food production or biodiversity, or remote lands that can safely store carbon captured from bioenergy production smoke stakes or pulled from thin air.

While the IPCC’s report lists soil (presumably agricultural) as biochar’s storage medium, this is not entirely accurate. Much of the earlier biochar research focused on agricultural uses in soils, but increasingly it is being shown that biochar can be put to good use in urban soils for storm water management and in contaminated soils (e.g. mine lands, brown fields, landfills etc.) thereby expanding the amount of land where biochar can be sequestered. Also, it is important to note, that biochar is increasingly being eyed as a material to put into various man-made materials as a means of displacing non-renewable, expensive or high carbon footprint materials. These products have productive lives above the soil before finding their way into the soil. This includes many shorter-lived products such as kitty litter, bio-plastics or filtration carbon which may end up in landfills where it still sequesters carbon and may even reduce methane emissions. Longer-lived biochar-based products are gaining attention in the form of building materials which not only serve as carbon sinks but can provide insulation for housing and other environmental benefits.

One other thing to note with biochar is that it can increase the sequestration potential of both afforestation/reforestation and soil carbon sequestration. When used to plant trees, biochar can not only speed up growth, but it has been shown to provide increased resistance against disease pressure, so trees may live longer. While developing healthy forests, thinning is a must, and this provides the fodder for biochar which can then be put back into forest soils helping to further boost soil fertility and water management while sequestering more carbon.

Soil carbon sequestration includes changing destructive agricultural practices such as tilling and also the incorporation of organic material into soils. Combining biochar with other relatively short-term carbon materials (e.g. manure, crop residue, compost, etc.) can not only provide longer-term carbon sequestration, it can help hold onto nutrients longer which reduces other negative environmental impacts such as groundwater contamination or eutrophication.

So as the need for carbon safety nets grows and our window of opportunity shrinks, let’s make sure we chose NETs that are in fact safe, sustainable and offer a high possibility of success. For a more in depth perspective of this topic, please have a read of this article on the Biochar Journal.

Biochar at COP24

Last week I attended the UNFCCC (COP24) in Katowice, Poland as an observer on behalf of the International Biochar Initiative (IBI). It was my first time attending and the first time in a long time for IBI. The intent was to both highlight biochar as a viable climate change tool and to evaluate the level of interest and knowledge about biochar amongst the attendees.

As a first-timer, the conference can be a bit overwhelming. The event draws more than twenty thousand attendees from around the globe (and its attending carbon footprint is barely acknowledged!). There are many different types of events going on simultaneously including opened and closed negotiating sessions,educational side events, national pavillion events, exhibits, press events, non-sanctioned events at nearby hotels and much, much more.

It is impossible to really get a comprehensive perspective of everything going on in just a few short days but I came away with the overall impression that there is far more talk than action going on. People are busy making pledges, quantifying baselines and emission sources, and planning ways to reduce and finance those reductions.  But when it comes to the hard work of actually cutting emissions, rebalancing atmospheric carbon and acclimating to our new climate reality, the pace seems heartbreakingly slow, the price tag excessively high, and the politics insurmountably grid-locked.

If I had to distill everything down to a few key messages that stood out for me they would be: 1) addressing the climate crisis must be done in collaboration with achieving the UN Sustainable Development Goals (which I have blogged about previously here), and 2) the focus for funding is equally divided between climate change adaptation and mitigation – and mitigation seems to be weighted more heavily on emissions reduction activities than on carbon drawdown at the moment.

While it would be disingenuous to claim that the messages coming out of such a conference were filled with hope, perhaps because I was there representing biochar, I still came away from the experience optimistic.  The optimism was surely not due to the popularity of biochar as very few people were even aware of its role in climate change mitigation or adaptation. Yet almost without exception when we were able to engage people in meaningful dialogue about the benefits of biochar production and use, there was broad interest in learning more and in bringing that knowledge to communities facing immediate, not future, impacts of our changing climate. 

At a meeting so focused on overwhelming problems, I think people were starved for solutions that are simple, scalable and shovel ready. Biochar, as I have said many times, is no silver bullet. But it definitely deserves a seat at the table when it comes to conferences such as this. However espousing the benefits of biochar needs to shift from a mere exhibit booth to being in front of the room where case studies and climate math can be discussed and used to inspire others to adopt and adapt. That’s my goal for next year’s conference! Ideas welcome for how to make that happen.

Biochar: The Rx for drug disposal?

This week I attended an eye-opening local meeting related to reigning in substance abuse within my County. I learned a ton, not least of which was that the people that work in this field deserve the utmost resect. More and more drop boxes are popping up but apparently liquids cannot be disposed of in drop boxes.  Liquids can be dropped off at drug collection events but those occur only a few times per year. All collected drugs are weighed and then shipped over to be combusted at an incineration plant an hour away. Not the most environmentally friendly disposal method.

But what got my biochar juices flowing at this meeting was a new disposal options for liquid pharmaceuticals.  The meeting organizer passed around a product that allows you to pour liquids into a bag filled with some unnamed material capable of neutralizing drugs, enabling it to then be disposed of in the normal trash collection process. Pills can also be disposed of in this manner as long as water is added to dissolve the pills.

The name of the product is DeTerra which immediately got me wondering what was inside the bag. Turns out it is nothing more than activated carbon (patented of course), biochar’s costlier carbon cousin. [A 3-pack, each capable of neutralizing 90 pills or 12 oz of liquids, costs $21. The package sent around the meeting room could not have weighed ¼ lb, translating to more than $60 per pound. Yowza.]

Although far more drugs find their way into waste or ground water via human or animal excretion, disposal of unused drugs is still a huge issue.  The days of naïvely recommending that unused or expired drugs be flushed down the toilet to keep them out of harm’s way are long gone. Unfortunately many people still haven’t gotten that memo, so it still happens. A lot. The environment suffers, aquatic life suffers, and we thoughtless humans that are creating the problem, suffer the consequences. 

In the developing world this problem is likely even more of a concern as many areas don’t have waste water treatment systems. Biochar could offer a low cost, locally made and safer alternative for liquid or pill disposal. Once the drugs are immobilized in the biochar they would still need to be disposed of safely. Enclosing the drug laden char in some type of container (e.g. zip lock bags, metal barrels, etc.) would be the best option and keeping it out of soils used for growing food would still be an imperative.  I have yet to see this discussed in any peer reviewed papers or tested in practice, but my gut tells me this would be a far safer alternative than some of the more common disposal practices

Biochar Workshop – April 28th – JOIN US!

Do you have a hankering to learn how to convert your hard-to-compost organics into something useful? This upcoming workshop will not only show you how to carbonize all sorts of unloved biomass that you have littering your yard or farm, but it will also show the various ways that your biochar can be used.  In collaboration with Hunt Country Winery and Dr. Johannes Lehman of Cornell University, I will be co-hosting a hands-on biochar workshop on Saturday, April 28th from 11 – 3pm.  The event will be held at the lovely and very sustainable Hunt Country vineyard in Branchport, NY. Attendees will get to see all the impressive measures Hunt Country has taken to become more sustainable, they are true leaders within the state when it comes to renewable energy use (e.g. extensive geothermal and solar usage on-farm) and other sustainable initiatives.

Attendees will also learn about the depth and breadth of expertise at Cornell University when it comes to biochar.  Cornell has a world-class pyrolysis machine now capable of making biochar out of many different forms of biomass.  They also have top-notch laboratory skills.  This is a rare opportunity for New Yorkers – though we welcome non-NYers too – to come ask questions of your land grant university’s finest!

An increasing number of New Yorkers are becoming interested in biochar and want to move beyond just learning.  Gatherings such as this one allow individuals to meet, mingle and begin collaborating with other like minded New Yorkers.  You will be able to make your own biochar and start testing it in your soils, your compost and beyond. Come join us for several hours of education, a sumptuous lunch and stay on for happy hour!

To register for the event, head on over to the Hunt Country events page. 

Hope to see you there!


Incineration vs Pyrolysis: pariah vs pioneer

Recently I met with my State Senator to discuss a proposed incineration plant for a beautiful part of the Finger Lakes; the home of the white deer, the former Seneca Army Depot.  My goal for the meeting was to provide input on a much more sustainable waste management technology: pyrolysis. In preparation for the meeting, I read up on the differences between incineration and pyrolysis.  Though they both involve incomplete combustion, one is viewed as a pariah while the other a pioneer.

The reason that incineration is getting any play at all these days, after nearly two decades of very few new incineration plants in the U.S., is likely due to State legislation that will soon ban large scale organics to landfill.  It’s also aided by the fact that more and more landfills are reaching capacity and neighbors are not keen to extend them or approve new ones due to toxic leaching and most notably persistent noxious odors emanating from the rising mountains of garbage. Incineration is also able to generate energy, though not in a net positive way.  Claims that incineration is a renewable source of energy is more than a little disingenuous.

Serendipitously I found that researchers in London, Ontario, Canada have already compared incineration versus carbonization specifically for managing sewage sludge. They looked at fast and slow pyrolysis and looked at the leaching potential of chars generated from each type of pyrolysis (spoiler alert: slow p chars leach less).  They concluded that pyrolysis is likely to be both economically and environmentally better than incineration. [Inserted chart incorporates some of their pros/cons but I’ve added to this.]

Compared to toxic ash that is generated from an incinerator where metals are mobile and may end up in landfill leachate, to a great extent pyrolysis immobilizes metals into the pore structure of the char.  Given the metals content and the lack of consistency of the feedstock, this char may not find a ready market for amending soils, especially soils used to grow food or graze animals.  But increasingly research is showing that various types of chars can be used for non-soil uses (e.g. composites, filtration, batteries, adsorbant for leachate etc.). The economics for pyrolysis over incineration will likely get better once large-scale markets for this type of biochar are developed.

Beyond the economics and environmental impacts though is the social impact. Those proposing incineration plants soon find themselves as social pariahs.  Town hall meetings bring out droves of residents who are angry or afraid as their daily lives will be negatively impacted, not to mention the harm to soils, crops, and in my neck of the woods, tourism. Yes, they will likely find people willing to work in the plant as the area has few big employers, but its hard to imagine those working there will be bragging about it.

Now imagine a pyrolysis plant focused on producing clean, renewable energy and biochar instead of an incinerator.  It will not be able to process all of the inorganic or toxic materials that an incinerator plant can, so volumes may not be as high. But there is plenty of organic waste in the form of sludge, manures, tree waste – especially after disasters like Sandy and winter storms, spoiled cardboard, old pallets and food waste to keep a pyrolysis plant charring away.  Heat or electricity can be generated and instead continuing the legacy of a linear economy, a closed loop biorefinery could be born.  Ancillary businesses that convert the biochar into different products such as building materials could be created. 

More and more academic institutions in New York are starting to work with pyrolysis and biochar. Cornell has been at it the longest and has a world-class reputation for biochar used as a soil amendment. RIT has been exploring pyrolysis as an alternative for food waste management and I’ve been working with various teams of engineers at RIT and the University of Rochester testing biochar based building materials and composites. There is always much excitement from young engineers when they first learn about biochar.  It’s something they like to be associated with and many continue to help educate others about it once they go off to their first jobs, some locally but many abroad. The choice between being a pariah, perpetuating an old and dirty technology or investing in a pioneering, regenerative XXI century bio-economy that other regions will want to emulate, should be a no-brainer.  In the last few months I’ve been part of an increasing number of conversations within NYS, around the country and around the world where individuals and companies want to create this type of concept.  It would be fantastic if the Finger Lakes could be on the leading edge of carbonizing organics.


Biochar’s unmatched versatility in mitigating & adapting to climate change

Listening to a webinar on Agriculture & Climate Change Adaptation hosted by the New York State Department of Environmental Conservation, I was at once enlightened and yet disheartened.  Sadly biochar received nary a mention. To fill the void, allow me to present my perspective on how biochar can help not only with climate change adaptation but also with climate mitigation.

Climate Mitigation

Mitigation comes in two basic flavors: reducing and rebalancing.  The vast majority of interest and investment seems to focus on reducing; i.e. lowering current emissions of various greenhouse gases (GHGs). There are many, many ways to do this but using less energy and/or using cleaner energy (e.g. solar, wind, geothermal, hydro, etc.) are amongst the most common recommendations. Reducing is absolutely critical to mitigating the worst forecasts, but it is far from sufficient. Rebalancing is perhaps even more important. Rebalancing means shifting excess atmospheric CO2 back from whence it came: terra firma (I will leave the discussion on ocean sequestration and release to others).

Biochar can help on the reduction side in a variety of ways. Renewable energy in the form of heat, which can be converted into electricity, is created during the production of biochar. Sometimes a portion of this heat is used for drying feedstock prior to carbonization, but the vast majority of it is available to displace fossil fuel derived energy.

Further on the reduction side, we can look to fertilizer use, especially Nitrogen (N), which comes with a particularly heavy carbon footprint both on the energy-intensive production side, but even more so on the application front.  Excessive N use is rampant around the world as farmers desperately try to maximize annual yield in soils long since exhausted of inherent nutrients. Microbes convert nitrogen into nitrous oxide (N2O) which is 300x more devastating to the climate than CO2. Biochar blended with either organic nutrients (e.g. manure, urine, compost) or with synthetic fertilizer can reduce the amount of fertilizer needed as it provides a bonding structure for the nutrients that slowly releases them and prevents unwanted leaching into groundwater or as GHG into the atmosphere.

Biochar can also reduce methane (CH4) emissions from at least two significant sources: bovines and rubbish. The world’s 1.5 billion cows as well as other livestock belch out an alarming amount of CH4, a GHG 25 to 80 times more potent than CO2. In the US, livestock is the 2nd highest source of CH4 emissions after Natural Gas. Research has shown that adding biochar to livestock feed can materially reduce enteric methane emissions as well as provide other health benefits to animals.  It can also serve as a low cost delivery mechanism for getting biochar into soils (via manure). Similarly research has shown that biochar used at landfills, either as daily cover or as part of a capping material when landfills are retired, can also reduce CH4 emissions.

Biochar can also reduce significantly emissions by diverting organic materials from going to landfills, which represent the 3rd largest source of CH4 emissions in the US.  Carbonization minimizes biomass volume by 75 – 90% depending on the production parameters.  In the right circumstances, this can reduce transportation tremendously and it can also prevent CH4 from being generated at landfills in the first place.

On the rebalancing front, biochar can help mitigate climate change in two critical ways: by boosting photosynthesis and by interrupting or massively slowing down the normal carbon cycle. Using biochar to plant trees or crops has shown that plant survival and growth are improved which can boost overall photosynthetic activity.  The CO2 absorbed by plants is stored until they die and then it normally decomposes back into CO2 and re-enters the carbon cycle.  However, if the trees or plants are converted into long lived products (e.g. furniture) or carbonized into biochar, the natural carbon cycle is interrupted.  When biomass is carbonized, up to 50% of the carbon absorbed during the tree or plants lifetime is converted into stable carbon and if the resulting biochar is put in the soil or embedded in other long-lived products (e.g. building materials), it will not return to the atmosphere for many centuries. This is an example of what is commonly referred to as carbon sequestration.


Adaptation focuses on strategies that can be employed to deal with the impacts currently being experienced as a result of climate change. A growing number of adaptation strategies are being employed from relocation of populations impacted by rising seas, to changes in planting schedules and/or crop types, to improved drainage or more successful integrated pest management.  As with mitigation, biochar can help adapt to the impacts of climate change in a variety of ways, a sampling of which are provided here.

Climate change is wreaking havoc on global food security. Droughts, floods and storms are both more common and more fierce. Increased heat, disease and land degradation are amongst the other threats to food security, compliments of climate change. Biochar can help improve crop yields, plant resistance to pests and pathogens and retain water longer in areas prone to droughts, all of which will help to build more resilient food production systems. Biochar also helps reduce the amount of water needed for irrigation which, in an increasingly water constrained world, is critical.  Some research is showing that it can help to recharge and filter ground water supplies which can lead to healthier crops and improved human health.

Storm water management is becoming enormously crucial especially in flood-prone areas.  Biochar is being successfully used as a strategy to manage urban stormwater from Seattle to Stockholm, but can also be used by farmers in drainage ditches or potentially in lieu of expensive tiles, and by gardeners and home owners in rain gardens.

Fierce and frequent fires such as those swallowing up Southern California at the moment threaten lives and landscapes. Drought is turning trees to tinder and invasive species bring unwanted biomass which also increases the risk of wildfires. Biochar made from beetle-kill pines is underway in places like Colorado and teams of volunteers in Oregon have been thinning vast amounts of brush to reduce fuel loads (more info here).

Communities that have suffered devastating impacts of hurricanes or monsoons could, as I’ve noted before, greatly benefit from biochar in many ways.  From dealing with debris to generating desperately needed power to remediating toxified soils and replanting ravaged perennials, biochar can help rebuild and regenerate.

Some biochar scenarios straddle both mitigation and adaptation. These include its use in regenerative agriculture which focuses on building soil fertility and increasing biodiversity; reforestation or afforestation; and urban agricultural practices such as green roofs and tree establishment.

This is far from an exhaustive accounting of biochar’s benefits when it comes to climate change mitigation and adaptation but it should provide the reader with an overview of biochar’s unmatched usefulness and versatility.

NOTE: This blog post has been cross-posted in the Biochar Journal.

Biochar’s boundless versatility: from ‘fillee’ to filler

The versatility of biochar seems, at times, limitless. As the ever expanding uses of biochar continues, research is showing that biochar can be used either as something to be filled by other substances or as something to fill in other substances.

For most of biochar’s ancient and recent history it has been viewed predominantly as a “fillee” or carrier with countless pores to be filled with a wide variety of substances.  Charging biochar’s nooks & crannies with nutrients, either organic (e.g. urine, manure, compost) or synthetic, can transform biochar into a slow-release fertilizer. Saturating pore space with water can convert biochar into something that can provide a low-cost, long lasting irrigation pathway. Filling pore space with other substances, such as herbicides, can improve efficiency of the herbicide while also reducing leaching. Packing biochar pores with microbial inoculants has shown that biochar can perform as well as or even better than other inoculum carriers such as peat moss or vermiculite. Suffice to say that biochar’s role as a long lasting pack mule is rather well established.

However life on the flip side of the fill equation is not nearly as well established as of yet but research is definitely beginning to show that biochar holds promise as a filler in various types of composites. Fillers have traditionally served to lower the cost of composites, but they can also improve various properties of plastics, paper, paints and more. Fillers come in many forms with calcium carbonate, wood flour and saw dust being amongst the most popular.  More recent research has shown that biochar can reduce costs while simultaneously improving different mechanical and electrical properties in different types of composites. While much work remains to be done to understand which of biochar’s chemical, physical or biological properties are most relevant to improving various different properties in different types of composites, this new frontier of biochar research is bringing new talents (e.g. engineers of all sorts) into the biochar arena.

Regardless of whether its role is as a filler or fillee (not to be confused with a female horse), the added bonus of using biochar is that it is able to sequester carbon, and potentially other elements such as heavy metals which could be detrimental to the environment, for decades to millennia while also providing the other more immediate benefits described above. Biochar’s ‘ambidextrous’ nature when it comes to fill, increases exponentially its potential as a carbon sequestration tool. No longer constrained solely to use in soils, however plentiful those opportunities might be, above ground carbon sink opportunities abound for biochar in civil infrastructures as well as every day consumables (see soap pictured above).  What other filler or fillee material can boast this much bang for the buck?

Following the biochar bright spots


Early in September I had the privilege of leading a biochar study tour to Stockholm, Sweden on behalf of the IBI. I have long been enamored with the Stockholm Biochar Project (SBP) for many reasons and was thrilled at the opportunity to see up front what I believe is one of the first of what will hopefully be many replicable biochar ‘bright spots’ (as the Heath brothers call them in their book ‘Switch’). The crux of the project is this:  convert urban yard and garden waste into heat for the district heating system and biochar for urban tree planting and storm water remediation.

What makes the SBP different from so many other biochar production scenarios is that, through years of trial, error and persuasion, a small but dedicated team has succeeded in building a strong, consistent, non-seasonal demand for biochar. Having proved the various benefits of using biochar in structured soils [which consists of: 1 part biochar, 1 part compost, to 6 parts gravel by volume], the city has been importing biochar from different biochar vendors in the UK and Germany by the truckload for a growing number of urban landscaping projects for several years. While initially intended to improve urban tree survivability, an unintended but enormously valuable consequence of using gravel based, biochar-enhanced structured soils was the significant reduction in storm water sent to the city’s wastewater management system.  Not only has this reduced municipal wastewater management costs but urban perennials including trees and shrubs, are thriving as compared to those that were dying in heavily compacted soils. Assisted with grant funding from winning the 2014 Bloomberg Mayor’s Challenge, the city took the next step in creating a closed loop biochar production facility to replace the imported char with char they can produce from underutilized biomass.


Urban trees provide a variety of eco-system services estimated at more than $500M in value for a megacity.  Amongst other benefits these benefits include: improved air quality and human health, production of oxygen, CO2 storage, wildlife habitat, reduced heat island effect and energy usage and improved property values. Not having to replace urban trees every decade that die due to compaction issues can also translate into a huge savings for cities.

The Bright Spots approach looks at entrenched problems through the lens of: let’s find out what is working to solve problems and how we can do more of it using specific tasks and behaviors that support new directions. Replicating biochar production is no longer the problem for scaling the biochar industry.  More and more examples of biochar production are popping up all across the globe using different technologies and different biomass for biochar production.  The challenge, as I’ve said before, is replicating the consistent, preferably local, demand for biochar at a price that makes biochar production financially viable. What the SBP folks have done is identify and educate a large prospective end user for biochar, i.e. urban landscapers, on the benefits of using biochar. While not all cities are likely to value urban trees the same way that Stockholm does, especially those located in drought-prone areas, many cities do place a high value on trees and thus provide funding for tree & perennial planting and maintenance.

Many cities have been or will be forced to plant new trees to replace those afflicted by the ever increasing number of invasive insects such as the emerald ash borer which is decimating ash trees or the Asian long-horn beetle which is responsible for felling maples, box elders and willow trees across the country.  Many cities, especially coastal cities, are also desperately trying to figure out how to reduce flooding which has been exacerbated by the perpetual pursuit to pave combined with rising sea levels.  Using biochar enhanced structured soils can help with both of these.  Planting trees in these soils has improved tree survivability, and some research is beginning to show that planting trees using biochar in soils can even help fend off certain pests by enhancing the thickness of leaves.  It can also help to significantly reduce flooding, which after seeing the devastation in places like Florida, Texas and Louisiana, could be worth billions in averted rebuilding costs.

Given all of that, doesn’t it sound like it is time to call up a few folks  responsible for planting trees at your local municipality to schedule a time to chat with them about tree planting and biochar?