Biochar 101: Climate Savior or False Hope?

If someone told you a charred black substance could help save the planet from the worst ravages of climate change, it’d be hard to believe, yet foolhardy toย ignore.

Biochar, a form of carbon sequestration, has been sold by its promoters as an almost magical way to reverse climate change. Yet not only was the marketing protocol that would help scale up biochar production in the U.S. rejected by science peer reviewers in March 2015, but big oil companies like ConocoPhillips and ExxonMobil โ€” among the biggest climate change culprits โ€” also have made a big bet that they can use biochar to โ€œoffsetโ€ their carbon pollution footprint.

Biochar’s most enthusiastic promoters have touted it as a panacea to humanity’s increasing carbon woes.ย Some enthusiasts go so far as to refer to the substance as โ€œblack gold.โ€ย Some may recall theย 2008ย Time Magazineย feature storyย promoting this curious form of charcoal, produced by burning organic matter under lowย oxygenย conditions.

In reality, the science of biochar is nowhere near a consensus point, with some studies actually calling the entire premiseย into question. Further, well-intentioned biochar advocates have seen their optimism paired with individuals and businesses โ€” including Big Oil โ€” standing to make a major profit before the science is settledย on the risks andย consequences.ย 

But first, the basics: what isย biochar and what do proponents say it canย do?

Biocharย 101

Biochar is a type of biomass or biofuel, meaning it’sย derived from living or recently living organisms. That’s juxtaposed, of course, with fossil fuels, derived from ancient, long-deadย organisms.

The 2008ย Timeย Magazineย articleย describes biochar in layman’sย terms:ย 

Burn almost any kind of organic material โ€” corn husks, hazelnut shells, bamboo and, yes, even chicken manure โ€” in an oxygen-depleted process called pyrolysis, and you generate gases and heat that can be used as energy. What remains is โ€ฆย biochar.

Theย Permaculture Research Institute of Australiaย provides a more technical description:

Biochar is โ€ฆ 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, resulting in different yields of biochar and co-products, โ€˜bio-oilโ€™ (with energy content value approx 55 percent that of diesel fuel by volume) and โ€˜syn-gasโ€™ (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, aluminum smelter and cookingย stoves.

Biochar is as much a process as a product. The new biochar-promoting academic textbook, Biochar for Environmental Management: Science, Technology and Implementation, describes it thisย way:

Biochar is the product of heating biomass in the absence of or with limited air to above 250ยฐC, a process called charring or pyrolysis also used for making charcoal. The material distinguishes itself from charcoal or other carbon products in that it is intended for use as a soil application or broader for environmetnalย management.

And even with these few definitions, what is and what isn’t biochar (or โ€œbiochars,โ€ but more on that later) sits very much at the center of the scientific debate over whether the substance can serve as a credible climateย solution.

โ€œBiocharโ€ vs.ย โ€œBiocharsโ€

At the 2013 North American Biochar Symposium attended by DeSmog, Cornell University professor and International Biochar Initiative board vice-chairman Johannes Lehmann explained these oft-used definitions are overly simplistic inย nature.

Lehmann’s main beef: It’s wrong to refer to โ€œbiocharโ€ as a singular thing. That’s due to the myriad soils it can be placed in and the various substances from which it can be made. Lehmann prefers the termย โ€œbiochars.โ€

โ€œThey can be so variable that it’s almost useless to talk about biochar in the singular,โ€ Lehmann said during his keynoteย address.

A Feb. 6, 2014ย article published by Capital Press secondedย Lehmann.

โ€œBiochar is the umbrella term used to describe the material created with the application of heat and pressure,โ€ the piece explains. โ€œThe process also produces heat and gas. The properties of biochar vary depending on the process and the ag materialย used.โ€

The Ohio State University Professor Rattan Lal, a former Nobel Peace Prize winner, agreed with the more broad-sweeping definition in his study titled, โ€œBiochar and Soil Carbon Sequestration,โ€ and published in April 2016 in the book, Agricultural and Environmental Applications of Biochar: Advances and Barriers.

โ€œIn fact, biochar is not a unique product, but is composed of a wide range of materials ranging from slightly charred organic material to highly condensed refractory soot, including char, charcoal, bone char, carbon ash, carbon black, activated carbon, and other carbonized materials,โ€ wrote Lal.ย โ€œBiochar is simply biomass-derived charcoal used as a soilย amendment.โ€

The Sales Pitch: Too Good to Beย True?

Some biochar promoters sayย they model the substance’s developmentย after theย Terra Pretaย methods of ancient farmers in the Amazonย basin.ย 

These farmers burned agricultural wastes (the โ€œbioโ€ part of the equation) at a high heat with little oxygen, producing a dark, carbon-rich charcoal (the โ€œcharโ€). This dark, solid byproduct was then planted back into the fields, enriching theย soil.

Some proponents also say biochar has potential toย improve agricultural yields, produceย clean energy,ย andย mitigate climate change by sequestering carbon, killing three birds with one stone. The sales pitch works likeย this:

1) Biochar is a valuableย soil enricherย for agriculture, thus a boon for both small- and large-scaleย agribusiness.

2) Theย โ€bio-gas,โ€ โ€œbio-oil,โ€ orย syngasย produced alongside the biochar is a form of climate-friendly, cleanย fuel.ย 

3) The process is not onlyย carbon neutral, in that it doesn’t add hydrocarbons into the atmosphere when burned,ย but it’s actuallyย carbon negative. That’s because its proponents sayย biocharย effectively sequesters carbon into the soil that would otherwise be emitted into the atmosphere when burned orย decomposed.

4)ย Biochar stovesย can be used both to heat homes and to cook without the burning of fossilย fuels.

Yet translating the successes of ancient farmers to a modern-day industrial scale isn’t so cut and dry, and critics say the Terra Preta of hundreds of years ago is not the biochar ofย today.ย 

That hasn’t stopped promoters from trying to market the product, though. One of the most egregious examples came in the form ofย Mantriaย Corporation,ย indicted in 2015 by the U.S. Department of Justiceย (DOJ)ย for running a biochar ponzi scheme, which recently pled guilty.ย 

โ€œThe scheme alleged in this indictment offered investors the best of both worlds โ€” investing in sustainable and clean energy products while also making a profit,โ€ U.S. Attorney Zane Memeger said in a DOJ news release. โ€œUnfortunately for the investors, it was all a hoax and they lost precious savings. These defendants preyed on the emotions of their victims and sold them aย scam.โ€

Enter Bigย Oil

It may seem odd that there’s a concerted effort to scale up biochar before there’s even a centrally agreed upon definition of what the substance actually is. Couple that with the fact the science is far from sound on biochar’s climate change mitigation potential and it seems odderย still.

That is, until one realizes that some of biochar’s biggest fans are โ€” or are closely tethered to โ€” major oil companies and developers of both Canada’s tar sandsย and North American shale basins, where oil and gas is obtained viaย hydraulic fracturing (โ€œfrackingโ€). Big money rides on profiting off of biochar and greenhouse gas offsetsย markets.ย 

Is biochar the way forward? Or are those with a financial stake in the game jumping on the biochar bandwagon before the technology proves itself? Continue to Part 2 and bookmarkย DeSmog’s investigative series on biochar and climate change.