Could Biochar Carbon Removal Credit Revenue Increase Funding for Loss & Damage?

“Loss & Damage” is a relatively new term within the climate community.  It refers not just to the impacts being experienced ever increasingly as a result of too many heat trapping gases in the atmosphere, but also to the activities which can and should be undertaken to address these impacts, whether they are sudden or slow, after they occur. Importantly, it also seeks to address how those activities are funded. It is focused on insuring and assisting those suffering the most from climate change that contributed the least to emitting excessive carbon into the atmosphere. This pool of funds is completely separate from funding aimed at helping countries to either reduce emissions or proactively adapt to expected changes.

Perhaps unsurprisingly the amount of funds pledged by high emitting countries to date is woefully inadequate to meet the escalating costs of rescuing communities that have been hit by extreme events exacerbated by increased atmospheric GHGs. A recent example is huge flooding due to excessive rains in 2022 in Pakistan which caused more than $30B in damages and affected tens of millions of people. The US contributed less than $100M to recovery efforts.

Roughly 3 million hectares of crop land were impacted. Loss and Damage estimates for agriculture included 3.1M bales of cotton, 1.8Mt of rice and 10.5Mt of sugar cane. Not only were these crops lost leaving farmers with no revenue and increased food insecurity, but the damaged crops most likely led to significant GHGs as they rotted in wet fields.

Now imagine if there was a way to finance the collection and carbonization of rotting residues (I acknowledge that drying during wet seasons is a significant challenge). Given the growing number of biochar-based carbon removal methodologies and growing demand for removal credits, it may now be possible to fund some sort of biochar focused disaster recovery effort using portable carbonization equipment, some of which may be able to provide needed electricity and/or heat. This could provide numerous jobs for displaced people and the biochar could be used to replenish lost soil carbon or filter water or remediate toxins or any number of other uses depending on what the most pressing needs are post-disaster.

Large multi-national corporations that are dependent on the crops could purchase these credits which will help farmers to recover faster and hopefully incentivize them to stay in farming. Or countries could purchase removal credits from the impacted countries as a mechanism of meeting their NDC targets.

Perhaps an organization such as the UN Central Emergency Response Fund could act as a facilitator, broker or verification agency when it comes to understanding the potential biomass impacted and available for carbonization. And perhaps organizations such as Rotary or Samaritan’s Purse could train locals on how to make and use biochar in the most pragmatic way based on the specific impacts from the disaster.

Biochar production from disaster debris is already happening but at very small scale in Puerto Rico and the Philippines and likely elsewhere as well. Given the increasing number and scale of climate disasters, I’d say there is no better time than now to develop this idea and test the waters for funding!

The never-ending lure of biochar rabbit holes:

How biochar can enhance food security and safety

One of the charms of biochar is also a bit of a curse: its sheer versatility provides endless opportunities for diving down all manner of rabbit holes. After more than a dozen years in the biochar industry, it seems as if biochar has taken over a large part of my brain. I am not sure if it has helped or hindered my divergent thinking, but no matter what I read, see or hear, I end up more often than not, pondering if or how biochar could be utilized. I think this affliction needs a name and I think it should be ‘Biochar on the Brain” or BOTB. I wonder how many other sufferers there are.

Whether it is a blessing or a curse has yet to be determined but one thing is certain, the endless biochar rabbit holes I have been down over the last dozen years have opened my mind to new ways of thinking about biochar and opened doors to new industries in which biochar could play a role.

The most recent random rabbit hole took over my brain while reading ‘Eating to Extinction’ by Dan Saladino (a great read btw!). He describes the many threats to diversity in the plants and animals consumed by humans including a fungus called Fusarium Graminarium which leads to fusarium head blight (FHB) in grains and grasses. No sooner had I read about what it is and the enormous impact it has had on farmers, flora & fauna, than BOTB kicked in: is anyone researching this? The answer: of course they are!

How can biochar help minimize damage from this formidable fungi and its moldy mates? Biochar research points to at least three ways:

  • Once FHB is found in soils, it is nearly impossible to irradicate. It will lurk below the surface waiting for the right conditions (usually warm and wet weather) to be reborn.  However, there are some recommended mitigation measures, one of which is to burn or bury severely stricken crops. Instead of burning crops to ash, farmers should carbonize it and get carbon removal credits for doing so.
  • Using the resulting biochar in combination with microbial inoculants in the impacted soils may help suppress or control the negative impacts of the pathogen in future years (Liu et al.,  2023). This is particularly helpful in acidic or sandy soils as biochar may provide a liming effect and help hold on to nutrients which may improve plant defenses.
  • FHB can lead to mycotoxins which can lead to ill health in livestock (and humans) that consume contaminated crops. Biochar (activated charcoal) has long been used as a binder to immobilize toxins (e.g. mycotoxins, herbicides, etc.) enabling them to pass through a body with minimal negative impacts. [“Legend” has it that the reason the US FDA took activated charcoal off of the approved feed additives list was that a farmer was using it to mask tainted feed.]

Given warmer and wetter weather, fusarium and other pathogens will continue to threaten food security (yields can diminish by up to 75%) as well as food safety. The potential economic, health and geopolitical implications are enormous. If we can showcase how biochar has played a significant role in mitigating FHB for farmers in different geographies growing different crops, then I think we will see a more rapid adoption of biochar than we have seen to date.

So much of the attention focused on biochar lately is about its permanence compared to other carbon removal technologies. I would venture to say that few other CDR solutions can not only help bury carbon, but can contribute to a healthier, less fragile food future.

2023: My Biochar Whirlwind Year

Biochar interest and activity seems to be increasing at warp speed these days – and none too soon I might add given the climate weirding we witnessed this year! 2023 has been a bit of a farewell tour for me; not from the biochar industry but as the Board Chair of the International Biochar Initiative (IBI), a role that has enabled me to see and do a wide variety of things in this industry over the past 4+ years. Here are some 2023 highlights:

Webinars on biochar are far more common now than they were five years ago when I started doing them for IBI. I’ve enjoyed hosting dozens of these, and this year was no exception. I selected four topics along with some excellent speakers that discussed their work in areas that have the power to transform not just the biochar industry, but others such as wastewater treatment, carbon removal markets, the building trade, and land restoration. These webinar topics were:

  • Forever No More: Biochar and PFAS Mitigation
  • The 1,000 Year Question: Biochar CDR Permanence (and Climate Cooling Services)
  • Concrete Decarbonization: Biochar Leading a Net Zero Pathway
  • Biochar & Mine Reclamation: Cleaning Brownfield & Contaminated Water

All IBI Webinars are recorded and available for free to IBI members, so give the gift of IBI membership for the new year to someone who might benefit from these and so many more! I also helped to host a webinar held by AirMiners called Innovations in New Uses of Biochar and was invited to speak on Sander Reuderink’s CarbleCast about Biochar & Coffee.

Conferences that cover (or should) biochar are also proliferating of late. Some of those that I attended included:

  • Aspen Ideas: Climate – more general climate conference, mostly US focused
  • North American Carbon World – very carbon markets focused,
  • New York State Organics Summit – I was asked to introduce biochar to this community
  • Aim for Climate hosted a global conference in DC focused mostly on sustainable agriculture
  • Bio360 Expo in Nantes, France is one of the best convenings of biochar, bioenergy, biogas companies
  • Irish Bioenergy Association – I was asked to introduce biochar to the IrBEA community then found out that there is already a surprising amount of biochar activity in Ireland!
  • COP28 in Dubai, UAE – I attended as an observer on behalf of IBI and met quite a few folks working in the biochar space, though the biochar topic is still not on the COP Agenda, nor is it included in any NDCs.

Educational opportunities for biochar are also evolving, both in person and on-line learning options. I headed up the development and hosting of IBI’s first Biochar Academy in my hometown of Canandaigua, NY. We welcomed nearly 40 students from 20 countries for two weeks to do a deep dive into all things biochar. Within that 2 weeks, we also hosted a larger gathering of more than 100 attendees for a 2 day Field Day event with the help of NYS Soil Health group. One day was dedicated to in-person presentations about the use of biochar in agriculture and a second day included on-site visits to Spruce Haven Dairy farm using Biomass Control’s BioRefinery to carbonize digestate, a stop at Cornell’s Leland Lab to check out their high-tech research scale pyrolysis unit, another stop at Seneca Farms Biochar to see their flatbed reactor and learn about their success with wood vinegar and finally a visit to Hunt Country Vineyard, a highly sustainable vineyard that has been making & using biochar as well as hosting biochar workshops for years.

The Biochar School, hosted in Torino, Italy, continues to gather an international crowd to discuss mostly non-agricultural uses of biochar. I spoke about the various ways I have used biochar to build my Dwelling on Drawdown home. And I joined as a guest lecturer at Tejas Rajvihar‘s excellent on-line biochar internship program aimed at educating interested students in India about a wide range of topics to enable them to enter the biochar industry. [2024 will bring even more educational opportunities via IBI and Lulea University of Sweden is debuting an on-line Basics of Biochar course for Masters & PhD students.]

Amidst my treks for talks and time-off, I sandwiched in a surprising number of on-site visits to biochar producers and end-users both in the US and abroad. Seeing so many different biochar production scenarios and listening to their challenges and lessons learned has given me some great insight into the variability within this sector. In addition to those mentioned above, here of some of my 2023 biochar visits:

  • Terra Fertilis, Argentan, France. One of the only industrial scale biochar production facilities in France!
  • Biochar made from sawmill cut-offs where excess heat is used to dry lumber at Metzler Forest Products, Reedsville, PA – great demonstration facility!
  • The Clean Burn Company, Calistoga, CA is utilizing 5 Air Burners to reduce fuel loads and clear fire damaged trees. More info here.
  • Visted one of remediation sites being deployed by the Sierra Fund in Nevada City, CA – using biochar to reverse damage from hydraulic gold mining in California
  • Had a great visit with my friend & colleague, John Webster, owner of Go Biochar – Salt Lake City, NV
  • Arti – Prairie City, Iowa – manufacturer of pyrolysis equipment and a fantastic library of biochar made from a wide variety of materials.
  • TigerCat Carbonator 650 at White Feather Farm – Saugerties, NY. More info here.
  • As part of the Swiss Study Tour we visited :
    • Inkoh has a BioMacon pyrolysis kiln and they are using biochar in concrete
  • After the IrBEA conference I visited:
    • Arigna – traditionally a coal company is shifting to biocoal and looking to build a market for biochar in Ireland. They commissioned a large kiln in Q4 2023.
    • Arti Ireland has been road testing the Arti kiln for several years and are focusing on biochar use to replace peat which is being discontinued in Ireland as a growing medium.
    • C-Go (BioenerG) and C-Capsule in Wales, UK where they were doing emission testing for low-tech kilns being piloted in refugee camps in Uganda and elsewhere in Africa.
  • During COP28 I was lucky to meet biochar folks from:
    •  Viqa Investments that had recently started up a CarboForce pyrolysis unit at Camelicious, a dairy farm with 8,500 camels in Dubai, UAE. See my blog here for more details.
    • A Healthier Earth also had a very well-done biochar crop trial display in the Green Zone at COP.

Beyond webinars, conferences, educational programs and visits, I also spoke with countless start-ups, project developers and large global food (and fossil fuel!) companies looking to join the biochar industry. Acting as an advisor to projects looking at using biochar to cap oil wells in Colorado and using it in building materials has also been something that gives me great hope that this industry will continue to thrive in both the short- and long-term future!

It’s been a whirlwind, but I sincerely believe that this is the pace needed to scale in a time period that will make a material difference in rebalancing atmospheric carbon. I look forward to an equally productive 2024!

The scoop on carbonizing camel poop

Who knew large-scale camel dairy farms are a thing? Not me, until last week that is when I visited Camelicious, an impressive 8,500 head dairy farm in Dubai at the invitation of Viqa Investments (VI). They have just commissioned a small pyrolysis machine to convert a portion of the 10 kg of excrement produced per day per camel.

What do the currently do with the massive amounts of camel doo-doo? The droppings are dropped off at a local dump. One might think that all of this fecal matter might transform the sterile sand into more fertile fields, but the severe lack of water seriously impedes any microbial activity. I visited the dung dump, and it looked like a moonscape with no visible signs of life.

The VI team is experienced at managing a wide variety of waste streams and when asked about alternative management practices for the dromedary doo, they went from ideation to installation in eight short months (in my experience in the biochar world, this is lightning fast). They purchased and shipped a slightly used, containerized unit by CarboForce from Germany to kick off a pilot which will enable them to optimize material handling.

Drying livestock manure prior to thermo-chemical conversion is often a big issue but camels have evolved to minimize the amount of water they excrete. Compared to other domesticated animals their ‘output’ is not only fairly dry, but it is quite hard and round. A day or two in the scorching sun is sufficient for additional drying, but during scale up they plan to have a more mechanical drying solution. Given that camels live in sandy outdoor paddocks and that sand is not good for pyrolysis equipment nor for biochar, a separation step is necessary prior to drying.

Quenching biochar in parched climates can be costly and challenging. VI has figured out a nifty closed loop solution by adding in a mobile water treatment system called ReedBox which uses plants to filter a portion of the dairy’s wastewater which is then used for quenching.

Camel manure has a relatively low carbon content so the carbon content in the biochar is likely ~40%. Still when this operation is scaled up to convert all of the manure (~3.6 tons per camel per year * 8,500 camels = 30,600 tpy) into biochar at 30% yield means that 3,672 tons of stable (dare I say sTURDy) carbon (13.8 kt CO2e) could go a long way towards making this type of farm carbon neutral. Now imagine if this were the de facto manure management practice for the 39 million other camels around the globe!

What are they doing with the biochar? They hope to create different soil amendments to enable more food production in the UAE.

A Visit to White Feather Farm

White Feather Farm (WFF), located in the Hudsen Valley (Saugerties, NY) is a beautiful and bountiful farm growing more than 80 varieties of fruits & vegetables, many of which are donated to a local food pantry. It is a non-profit farm doing research and providing education on a wide variety of topics, one of which is biochar.

Their next-door neighbor is Rothe Lumber. Together they are solving the lumber yard’s excess organic waste problem and the farm’s dearth of organic matter in their soils. Their solution is using a massive pyrolysis machine called a Carbonator which converts much of the unusable tree residues, including tree root balls which are notoriously challenging to manage, into biochar.

WFF hosted a demonstration during Climate Week to showcase not only the Carbonator, but other smaller kilns which can be used (and I brought along a few including the one pictured below made by High Plains Biochar). They also demonstrated the growing number of ways they are using and testing biochar on their farm.

Yours truly showing how this High Plains Biochar Kiln works. Photo courtesy of Benjamin Von Wong.

Raw, chunky biochar is combined with compost in a GeoBin helping the pile to get hotter as well as to charge the biochar with various nutrients and microbial life. In roughly 2 months the compost is done and top dressed onto their veggie fields. Farm manager Dallas McCann and Bill Hilgendorf who manages most of the biochar side of things, say that results to date have been fantastic as their silty soils have been a challenge in the past.  

Dallas and Bill demonstrated how WFF is putting raw biochar deep into the subsoil in their hoop houses using a broad fork. Normally raw biochar is not recommended as it tends to scavenge nutrients needed by crops but adding it at the end of the growing season should allow the biochar to soak up excess nutrients and fill up its nooks and crannies with ‘wee beasties’ over the winter.

Another research project under way is using raw biochar to filter pond water in hopes of keeping algal growth low. They will be testing the saturated biochar to see if it has harvested excess nutrients from the pond and then testing the pond charged biochar in the next growing season. Should results be promising they will scale up to a more meaningful filtration system.

One last experiment we learned about is the possible use of biochar to control their recently arrived jumping worms, an invasive species of worm that can devour organic matter in soils leaving behind depleted soils that look like coffee grounds. There has been some early research suggesting that abrasive materials such as biochar or diatomaceous earth may create a less than ideal environment for these slithering, slimy invertebrates.

Durability Uber Alles

For much of the XX century Western Civilization bowed to the god of profit above all else. Externalities were vehemently, sometimes violently ignored. This mode of thinking brought many, though certainly not all, a vastly more comfortable lifestyle. Meanwhile many planetary systems upon which humans and most other flora and fauna depend suffered greatly. Unchecked pollution of water, air and soil exacerbated biodiversity loss triggered by converting vast swaths of forests to farmland around the globe.

As we round out the first quarter of the XXI century, profit still reigns supreme nearly everywhere though carbon is (finally) beginning to nudge its way into the balance sheet of more and more governments and corporations. Sadly, it looks like we may repeat the ill-begotten singularity of focus with carbon as was done with the god of profit.

The emerging myopic focus being lauded most loudly is known as ‘permanence’ (aka durability). While preventing carbon from converting back into carbon dioxide for as long as possible is definitely a most admirable trait, it should not be viewed as the only trait of relevance.

Curiously (or not if you follow the money behind it) permanence seems to be all everyone is talking about these days. It has begun to outweigh any and all other considerations and criteria for supporting certain carbon removal strategies. Somewhat arbitrarily it seems to have been determined by many influential carbon removal buyers that 1,000 years is the new holy grail for durability, though others acknowledge that removing carbon from the carbon cycle for a century or even a decade has value and should be valorized.

Consideration as to when these removals will actually happen is barely discussed. Given the intense and earnest messaging around how critical the next decade (or less) is in terms of averting the worst impacts of the climate crisis, one might think near term delivery and scalability would factor in at least as high as durability.

Considering all of the other critical problems humanity is facing such as increasingly depleted and toxic soils, our ability to feed a burgeoning population while adapting to the many new climate vagaries, competition for ever scarcer resources, and the need to shift quickly and cost effectively away from our dependance on fossil fuel energy, one might think that co-benefits of carbon removals such as those provided by reforestation, afforestation and biochar would factor at least as high as durability when considering what CDR to invest in.

Considering the mounting mountains of unloved organic materials from sewage sludge to food waste to excessive forest residues looking for safer, end-of-life options, one might think win-win (or even win-win-win) solutions that convert problematic organics into carbon removal opportunities would factor into decisions about what carbon removal strategies should be selected and funded.

At such a critical juncture in human history, all removal solutions should be on the table. That should go without saying. But in a time and resource constrained world, prioritization is paramount. What is doable now and how do we scale it cost-effectively should be at the forefront of investment decision making. Climate change mitigation, while exceedingly important, is not the only crisis needing our immediate attention and funding. Likewise, carbon permanence is important, but it is far too simplistic (and dangerous) to focus so much attention on this aspect to the detriment of all others. (What is that expression about all eggs in one basket?) Complex problems require more than a single, overarching focal point or rallying cry. We can and we must learn from the lessons learned from focusing solely on profits. If we don’t the suffering experienced over the last century will look like child’s play compared to what we will experience in the coming decades.

Decarbonizing Coffee

I have been fascinated by the challenge of decarbonizing coffee for many years. Initially this took the form of diving deep into the research literature on biochar and coffee combined with scanning the globe to see who was doing what with biochar in the real world of coffee growing, milling, roasting and ‘merching’. This culminated in a 2015 white paper which was later updated in 2018. A few years later I started working with some very forward-thinking folks at CarCafe (a subsidiary of VolCafe which is owned by ED&F Mann a global food company) to figure out low-cost, low-tech ways to reduce GHG emissions at small-holder farmers – mostly focused on improved residue management and reduced fertilizer use which is where the vast majority of emissions come from on farms (and a recent study showed that roughly 44% of the entire supply chain emissions are at the grower/milling stages).  Over the past few years, we’ve taught 100+ farmers plus a hotshot group of ‘tecnicos’ (agronomists -mostly- that help farmers to grow more efficiently and sustainably) how to make and use biochar on the farms.  

Most recently I was invited by a friend who formerly headed up a protect at Coop Coffees, an organic coffee trade organization, to attend a gathering in Jaen, Peru with various coffee cooperatives that had gone through a multi-year GHG benchmarking process for 250 smallholder farmers in several LatAm countries. Ostensibly I was invited to introduce them to biochar and how it could help reduce emissions. As it turns out a few of them are well on their way on their own biochar journey and ‘francamente’ (this seems to be an oft used word in Peru which made me smile when I started counting how many times it was used!) it was inspiring to learn more about what they are doing. How could I not share their biochar stories at least a small part of them?

Sol y Café is an impressive coop with more than 1000 farmer partner/owners. While coffee seems to be their mainstay, selling ~200 truckloads per year, they have expanded into cacao, aquaculture on a few farms, and at their central hub they now have an elementary school and small-scale livestock farming (i.e., rabbits, guinea pigs and apparently a somewhat mythical creature which is half goat, half sheep (as with donkeys they cannot reproduce). They make their own EM1 formulations and other fertilizers and soil amendments, they have an impressive coffee tree nursery and a good-sized vegetable garden which grows food for the school and worker’s cafeteria. They also have the tiniest alfalfa field I have ever seen which grows food for the bunnies and guineas.

I gave a short demo on how to produce biochar from a variety of unused biomass found at the central coop and discussed various ways they could use it. Turns out, however, they are already experimenting with a LOT of biochar made from coffee parchment by another coop in the region, Norandino. This small scale, continuous feed machine was recently fabricated in Peru in collaboration with Swiss engineers and has been used to carbonize both coffee and cacao residues. Our Sol y Café hosts showed us the various ways they have been experimenting with the parchment biochar, a very light-weight, consistently small sized type of biochar. To be honest I have never seen so much biochar used in such a small space and I was (francamente) curious as to why they used so much of it as the soils, at first glance, seemed quite dark already. Looks can be deceiving apparently as they told us their veggie plots were rice paddy fields not so long ago and are heavily cracked hard pan soils laden with salt and excess calcium. They were on a quest to remediate these issues organically and were hoping biochar could help. Given they had received a lot of biochar at no cost (for now!), they decided to go big! For each half row, they used 5 ‘quintales’ (coffee sacks) of pure biochar then blended it with homegrown compost. It doesn’t appear that it was tilled into the ground, but they seem fairly protected from erosion and there is a sunscreen overhead. I wish they had done controlled trials which may happen in the future but after several weeks the plants seem very productive, and the Sol team seems quite happy with the growth as well as reduced need for watering.

Prior to receiving the parchment biochar, they apparently learned how to make small amounts of biochar from another coop in Honduras, Comsa, that has an unusual way of making biochar which I have not seen and am still waiting to learn more about it. Comsa also taught the folks at Sol about EM1 and their on-site international school was the model for the recently built one at Sol. This type of collaboration versus competition was so refreshing to see. It is definately the way to spread ideas quickly so you can iterate on customizing what works in different cultures and share improvements.

At the end of my short biochar production demo, I asked the 2 – 3 dozen folks if there was interest in on-farm biochar production and I do believe there is interest, not only as a way to upcycle residues but also to reduce fertilizer purchases. As prices have skyrocketed over the past year, farmers are looking for all manner of ways to reduce their dependency on fertilizers, organic or otherwise. The great side benefit is that the biochar they make and use to reduce fertilizer can help them to both mitigate and adapt to climate change. And soon, very soon, through the Artasanal C-sink methodology being finalized by Carbon Standards International, smallholder farmers that make their own biochar from on-farm residues and use it on their farms, will be able to tap into the ever-expanding carbon removal marketplace.

[NOTE: my Spanish is rusty so I am still verifying a few things I thought I understood from various conversions so I may have to update a few parts of this post!]

Dwelling on Drawdown Part IV – About Grout (with biochar, of course!)

I absolutely love it when I come across contractors willing to consider more sustainable ways of doing things. Too often in my Dwelling on Drawdown (D0D) home-building journey the opposite has been my experience. But recently when I had my shower floor installed by Charlie B from Skip’s Custom Flooring, not only was Charlie willing to consider using biochar in the project, he was downright enthusiastic! I was a bit shocked to find out he’d been reading up on biochar for years and was hoping to build a kiln to char through lots of tree debris on his acreage. (Biochar is still mostly unknown in my part of the world.) We discussed possible ways of using biochar on this small project and tested it as a tint for the grout. Charlie also had other ideas about how biochar could be used in buildings but also knew that it is likely used in certain types of pottery (see La Chamba pottery from Colombia, or Raku from Japan). That was news to me – yet another tantilizing biochar rabbit hole for exploration.

The grout sample dried nicely so we mixed up a batch to use on the 48sf shower floor. It took a lot more biochar than I thought we’d need and we never got it to turn black though that wasn’t really my intent on this project. Roughly one pound was added to 2 gallons of grout . I’ve used Aries Clean Technology’s powdered biochar for other D0D projects and was a little surprised that it didn’t turn a darker shade of grey as it definately tinted my walls a very dark black as I’ve written about before. The only difference Charlie observed was that the mix was a bit ‘greasier’ than a more commercially available tinted grout, meaning it was slightly more difficult to wipe off the tiles when grouting was finished.

Black iron oxide or magnetite is what is commonly used as a black tint for grout and a whole host of other materials. Both natural and synthetic types are used in everything from construction materials, paints, coatings, and plastics, cosmetics, pharmaceuticals and even ceramics, and toners (Pfaff 2021). Imagine if we could start displacing some of that with different types of biochar?! We just need to understand the tinting abilities of different types of biochar across they gray to black spectrum. On our recent EPA project focused on using biochar in drywall we observed quite a variation in coloring based on feedstock types, particle size and obviously amount used.

How else could biochar be used in bathrooms? The plan for the shower walls is tadalakt plaster with a just a touch of biochar to tint it a lighter shade of gray. I’ve tested it out and it works great with a wide variation of grays possible (see picture). Next up though is my sink vanity top which is being custom made using epoxy and biochar. The epoxy artist has already done a test run and is now very interested in using biochar as his black tint is about $60 per pint! More on that soon.

[I know my BURN co-author would remind me that it can be used in composting toilets. Though I I didn’t go that route for my Dwelling on Drawdown, I do have an ‘emergency’ toilet in the basement with biochar in a bucket!]

Biochar’s debut at the United Nations

Two minutes. Two whole minutes to introduce biochar to United Nation’s delegates from around the globe. Far too little time but at least it was on the agenda of the 7th multi-stakeholder ‘Science, Technology and Innovation for the UN Sustainable Development Goals. Thematic session 5, the one I was asked to join as a ‘discussant’ (had to look up what that meant), was focused on ‘Emerging carbon dioxide removal (CDR) technologies for addressing climate change’.

In addition to a high level (very high level, remember two minutes!!) overview of your particular CDR, panelists and discussants were asked to address one of the five guiding questions used for the session which included:

  1. CDR technologies are needed at the local (industrial or power plant), national (NDC), and global scale (reaching net zero global emissions). What partnerships are best at each level?
  2. For companies and funders– how do you plan to scale up your technologies to make a difference at the global scale of 1-10Gt/yr?
  3. How can we better support the innovation ecosystem around these technologies?
  4. How can the UN contribute to a showcase of emerging demonstration projects and best deployment practices of CDR technologies?
  5. How can the UN contribute to a responsible discussion of the potential consequences, costs and trade-offs of various technologies, their interactions with various SDG goals, and their ethical and governance issues alongside conventional mitigation and adaptation strategies?

It’s always interesting to prepare for different audiences but being given such a short period of time, I had to hone my biochar ‘elevator pitch’ down to this:

Biochar is likely the oldest anthropogenic CDR solution yet few have ever even heard of it. Indigenous cultures across the globe figured out thousands of years ago how to carbonize biomass and fill it with nutrients to enrich soils and feed growing populations.

Biochar is safe, scalable and shovel-ready. It is already being produced by smallholder farmers in Africa, Asia and Latin America and it is being produced at industrial scale in Europe, China and North America.

Normally plants decompose and return all of their carbon to the atmosphere, but when heated using high temperatures and low oxygen through a process called pyrolysis, up to half of the carbon is converted into highly stable carbon that can last for centuries when deposited in soils or other long-lived products such as concrete or asphalt. It can also help reduce methane from livestock farming, landfills and even the oil and gas industry. It can immobilize heavy metals and other toxins in soils. It can harvest excess nutrients in contaminated water bodies. And it can help farmers and cities to both adapt to and reduce the impact of climate change while supporting 12 of the UN SDGs.

Importantly biochar may be able to help countries increase their climate ambition and we are building a standardized framework for countries to quantify how much carbon could be sequestered based on available, unused biomass which includes livestock manure, crop residues, disaster, demolition and forestry debris and even sewage sludge.

Given the huge appetite for carbon removal credits and the extremely limited supply, biochar production is scaling quickly to meet current demand while bringing needed revenues to smallholder farmers and other producers.

But we need your help to get the word out, to build markets for biochar, to showcase current projects or future possibilities, to secure funding for scaling and to encourage countries to develop biochar based decarbonization plans.

I would love to hear what others would focus on if only given two minutes!

Dwelling on Drawdown Part II – C walls

Converting walls to carbon caches could be compelling when you consider just how much wall space there is in the average US home. Shifting from a high embodied carbon material such as drywall, to a carbon storing material could create a colossal carbon sink opportunity while also reducing current emissions from manufacturing materials such as drywall and making homes generally healthier at the same time.

The vast majority of inside walls in the US are covered using drywall (also called plaster board or wallboard), which is largely made from gypsum. The average American home, which is now close to 2,500 sf contains roughly 11,225sf of wall space.  A typical US home might therefore have 15,000+ lbs of drywall. The environmental impacts of mining, transporting and end of life for 15M tons of wallboard produced per year are enormous. Though it is recyclable, most of it heads to a landfill where it proceeds to off-gas sulfur dioxide, nitrous oxide (though this is also called laughing gas it is no laughing matter as it is a potent GHG), carbon monoxide and odors that you do not want to be smelling!

Covering walls with carbon storing materials is not new. Wood has long been used in many cultures, though it has fallen out of favor with many builders and homeowners. More recently we are seeing other carbon storage materials such as straw board or hemp begin to emerge.

One of the parameters for building my drawdown dwelling was to avoid drywall to the maximum extent possible and to utilize a variety of carbon storing materials instead. The exterior walls are built using straw bales – it took less than 2 acres roughly half a year to grow my walls – plus lumber of various flavors; dimensional, composite, etc. Interior walls (window sills and floors too) have been covered with rescued wood from barns and fences as well as locally and regionally harvested ash, cherry, maple and pine – a veritable forest or at least the ghosts thereof. All were sustainably harvested and putting them inside homes is a sure fired way to prevent the carbon absorbed during the tree’s lifetime from converting back into CO2 for as long as the house shall live!

As I am in the biochar world, I really wanted to have a biochar plaster wall similar to the one done at the Ithaka Institute headquarters in Switzerland. I procrastinated until all other interior walls were done which allowed me to get more comfortable with plastering in general. Now after two days of burnishing (i.e. rubbing walls gently with a mildly wet sponge to smooth lines, heal cracks and remove surface particles), the plaster is thankfully still on the wall and, all modesty aside, looks gorgeous (except for the tarps on the windows and the not completely finished window trim). Although originally I thought this was beyond my abilities, this is a project anyone can do but for those fastidious few, I warn you it is dirty to do (but pretty to view!).

Before taking the plunge, my co-conspirator and plaster master, Jill and I did some testing using different sized biochar, both of which came from Aries Clean Technology (Many Thanks Nancy at Aries!). Aries makes biochar from urban wood waste in Tennessee, and I knew they produce an IBI certified, very fine powdery size (2 – 300 microns) biochar that I’d wanted to test in plaster. They also had a chunkier size (<1/8”) which was worth exploring. Using the same recipe [50/30/20 v/v biochar, sand, clay] results in very different colors and textures which you can see in Figure 1.

Figure 1: On the left is the powdery biochar plaster which had a texture almost like frosting and on the right is much greyer and more like oatmeal.

The oatmeal version took quite a while longer to dry than the frosting.  In speaking with my colleague who pioneered this technique in Switzerland, he advised that the chunkier plaster can be used as a base coat to increase insulation and the finer biochar plaster makes a nice finish coat. Alas I already had a base coat, so decided to move along with the blacker finish coat. [For those that don’t fancy black walls, you can cover it using clay paint which comes in a variety of colors.]

We premeasured each ingredient and added them dry into a large bin before adding water. In hindsight, I would recommend wetting the biochar and/or clay beforehand to reduce dust while blending (kind of like slaking lime).  

We started with a 5 gallon bucket of Aries Green Tech powdery biochar, plus the requisite amount of sand and clay. We used roughly 3 gallons of water to get it into something just a bit heavier than frosting. This took quite a lot of time with a drill and paddle mixer to get to the right consistency and make sure everything was well blended. (If you are doing a bigger wall it would be easier to use a hydraulic mixer.)  I recommend doing this outside as there is a certain amount of splattering and in the beginning some of the particulate matter does get airborne. This ended up being not quite enough to cover a 80 – 90 square foot all, so we made up another smaller batch in a 5 gallon bucket.  

All in all, there is likely about 10 lbs of carbon (the Aries powdery char has 85% carbon) or about 36 lbs of CO2e; not a huge amount, but it was a very thin layer (1/8” – ¼”) and a pretty small wall!

Now let’s do some carbon math. Say this thin layer contains about .1 lb of carbon per sf (.367 lbs CO2e). That could easily be doubled or tripled as the average drywall width is 1/2″. Now imagine putting that on a majority of the 11,225sf of wall space in each home. Now multiply that by the nearly 1 million new homes built each year. That is big C storage opportunity with multiple side benefits. Those are the (C) walls we need to start building!

Side note: doing this type of project turns many a sponge and all clean up water very, very black. Knowing that the black comes from biochar means that tossing the black water out onto the soil or down the drain puts a guilt-free smile on my face knowing that it will enrich the soil and septic system!