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Introducing Biochar: Climate Change Solution or Greenwash Nightmare?

After years of investigating biochar, which promoters have touted as a potential climate change fix, DeSmog is releasing its findings on the science, claims, and controversy surrounding this approach to sequestering carbon.

Biochar is the product of plant or animal products (biomass) undergoing pyrolysis, a high-heat chemical reaction, to convert the carbon-containing biomass to a stable, non-decomposing form of charcoal. Introduced to mainstream audiences in a Time Magazine article from December 2008, biochar as a climate geoengineering technology has hit a number of peaks and valleys since then. In that time, its best chances at reaching commercial scales so far have failed, according to a new DeSmog report, Biochar: Climate Change Solution or False Hope?

Biochar’s failure to date is due to a number of reasons, such as the lack of scientific consensus surrounding its ability to sequester carbon indefinitely, the vast amounts of land needed to produce biochar at a large enough scale to affect the climate, and the lack of legislative or regulatory frameworks required for investment in commercial-level production.

While some big money is pouring into biochar, particularly via the start-up Cool Planet Energy Solutions, the efforts to market the product as a climate solution appear stronger than the current scientific evidence on its CO2 sequestration capabilities. In fact, when the American Carbon Registry, which exists to promote carbon trading markets, analyzed the nascent biochar industry’s business protocol for scaling up, the registry rejected the plan due to lack of scientific support surrounding its claims.

Released in March 2015, the registry’s protocol review concluded that “the scientific literature does not provide sufficient evidence of the stability of soil carbon sequestration in fields.” A 2011 U.S. Government Accountability Office (GAO) report also poured cold water over the technological feasibility of scaling up biochar production.

Led by the trade association and lobbying group, the International Biochar Initiative (IBI), biochar has faded into the background in the two years since that report came out, and IBI‘s budget has plummeted.

The new DeSmog report shows that among the most enthusiastic supporters of biochar have been the oil and gas industry, which sees biochar as a tool to “offset” its fossil fuel emissions, particularly in North America.

For example, in Alberta, Canada, the biochar industry and the tar sands industry have attempted to team up to create a carbon offset scheme through the Alberta Offset System. IBI also led a lobbying effort to insert biochar into the American Clean Energy and Security Act in 2009 (best known as the Waxman-Markey carbon offsets bill), and into another stand-alone bill called the WECHAR Act.

Cool Planet’s business plan, meanwhile, appears to be the biochar industry’s best hope of scaling up in the U.S. However, its science remains unproven, lacks the scientific standard of peer review, and is considered proprietary business information.

The other major effort to scale up biochar in the U.S., led by the company Mantria, ended in a major federal fraud lawsuit. The U.S. Department of Justice charged the company’s executives with promulgating what has been described as the “biggest green scam to date in the United States.”

These details and much more can be found in DeSmog’s new six-part report on biochar:

1.) Biochar 101: Climate Savior or False Hope?

2.) Is Deploying Biochar as a Climate Geoengineering Tool Scientifically Premature?

3.) Biochar Lobby’s Protocol Receives Blistering Peer Review, Casts Doubts on Serving as Climate Solution

4.) How the Biochar Lobby Pushed for Offsets, Tar Sands, and Fracking Reclamation Using Unsettled Science

5.) Cool Planet: The Biochar Big Leagues and ‘Shoddy Science’

6.) Biochar: A Geoengineering ‘Shock Doctrine’

Momentum on biochar as a climate salvation, for now, has reached a relative standstill. But the industry has already written the playbook for pushing its product, and should that momentum turn around in the months and years ahead, the biggest question will be: Can research confirm biochar’s potential as a climate change solution, or is it just another form of greenwashing?

Find out in the DeSmog biochar report.

By Steve Horn

Main image credit: K.salo.85, Wikimedia Commons

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Rick Engebretson's picture
Rick Engebretson on Mar 28, 2017 4:40 pm GMT

Right now I’m sweaty after putting lime around shrubs and trees. I put down 10-10-10 fertilizer last week. I’ll put down biochar derived “black dirt” in a few weeks.

That’s the difference. You will have a forgotten worthless web article, and I will have birds, flowers, biodiversity, and productive soil. Talking science and doing science have different results.

Roger Arnold's picture
Roger Arnold on Mar 29, 2017 9:07 pm GMT

I haven’t read the 6 parts of the full report referenced above, so commenting may be premature. However, if this summary is an accurate reflection of the full report, then I have to say I’m surprised.

Biochar is controversial, certainly, but I did not think that the controversy touched on its residence time in soil. Everything I’ve read about it, pro and con, seems agreed on that issue. It’s a “highly recalcitrant” form of soil carbon that persists in the soil more or less indefinitely — so long as the soil in which it resides isn’t washed or blown away. There are no soil organisms that digest or decompose it, and no regular physical / chemical processes that oxidize it.

The “lack of scientific evidence”, AFAIK, is about efficacy, no persistence. Biochar is not a fertilizer, and those who expect it to work like one will be disappointed. It’s a soil amendment and buffering agent. It alters the physical and chemical properties of the soil into which it’s mixed — generally for the better, but that depends on the starting properties of the soil to which it’s added. In general, it increases soil porosity, permeability, and water retention. It aids retention of nutrients and reduces loss of soluble nutrients to runoff. But it doesn’t create nutrients, just buffers them. It holds on to them until they are taken up by plants and organisms living in the soil.

The most effective way to employ biochar, as I understand it, is to include some amount of it with the organic material put into a compost pile. Its physical properties facilitate the composting and the biochar becomes “charged” with nutrients released in the composting process. The finished compost + biochar is then a more effective fertilizer than the finished compost alone.

The problem is that this amounts to a “hobby” use by a relative handful of organic gardeners. At that level, it can never be a significant for carbon sequestration. And while it could be employed in industrial farming to reduce fertilizer runoff and water consumption, the economic case for it is hard to make. The timescale for economic return is well beyond what’s of interest to agricultural corporations.

Engineer- Poet's picture
Engineer- Poet on Mar 30, 2017 2:38 am GMT

IIRC, there is/was a company working on a biochar-bound urea fertilizer which would have been much more commercial than anything based on compost.  I just wish I could remember the name.

If this was drilled into soil (rather than spread on where it could blow or wash away), the char would be permanently incorporated.

Nathan Wilson's picture
Nathan Wilson on Mar 30, 2017 3:28 am GMT

Agreed, making biochar and dumping it into/onto the ground seems like a lousy way to “offset” taking fossil fuel out of the ground (and burning it). Perhaps it is being oversold by some.

We environmentalist all pretty much agree that the first steps to a climate change solution are discontinuing the use of fossil fuel for electricity generation, and expanding electricity use into other areas currently served by fossil fuel.

But many climate scientists (including those at the IPCC) are saying that our children might need to take the further step of deploying technology which removes CO2 from the air and sequesters it in multi-Giga-ton quantities.

There are only a few ways to achieve atmospheric CO2 removal:
– sprinkling CO2-absorbing chemicals on the Earth’s surface, covering an area similar to all forest cover (and hope for no bad side-effects).
– capturing CO2 from biomass combustion, and pumping it under-ground as a high pressure liquid (good luck verifying that the vendor really put it there, and good luck having it stay there).
– making bio-char from biomass, and storing it underground (good reason to believe it will stay there, and easy to monitor production/delivery/movement of the stuff).

So there are reasonable arguments that we should investigate the concept further. Also, some big name scientists are supporting it, such as astrophysicist Frank Shu, with his portable supertorrefaction system, which he hopes will use biomass to co-produce hydrocarbon fuel and sequesterable biochar.

Rick Engebretson's picture
Rick Engebretson on Mar 30, 2017 9:46 am GMT

Any flower store will sell most potted plants in a clay pot, with sand/gravel drainage on the bottom, and the roots in “biochar” and/or peat blended and/or nutrient blended “potting” soil.

Our Earth has a razor thin 2 miles of sustaining atmosphere, and a patchwork of 10 inches of topsoil. The last 100 years has seen unprecedented changes in population, atmosphere, and topsoil. Water and general ecosystems are also rapidly changing.

I really didn’t like the article’s snarky first sentence;
“biochar, which promoters have touted as a potential climate change fix.” I just need healthy productive soil and don’t know a better option.

Rex Berglund's picture
Rex Berglund on Mar 30, 2017 12:48 pm GMT

I did not think that the controversy touched on its residence time in soil.

Nor did I, apparently an absence of evidence is portrayed as an evidence of absence.

The position of the NAS probably influenced this POV. When the National Academies published their Carbon Dioxide Removal results, they relied heavily on a paper by Gurwick for their biochar conclusion. Gurwick’s paper had hundreds of references, most of which did not support the long term residence of biochar in soil. This led the Academies to assert that “The residence time of biochar in situ is not well established (Gurwick et al., 2013). Although there has been research associated with the role biochar could play on carbon and nitrogen dynamics, the literature is still limited, and the impacts of utilization on net greenhouse gas emissions are not well defined (Gurwick et al., 2013).”

The paper’s references are not unanimously negative, I looked at the summaries of the first 20 or so and found some that were more positive on biochar’s potential.

I wrote to the IBI asking for comment, and received the following from Thayer Tomlinson, essentially claiming that their experimental methodologies rendered long term field studies unnecessary:

We had written a response when the Gurwick paper was first published which I copy below:

IBI and some external expert reviewers have reviewed this paper in detail. We would like to point out that the authors did not fully understand the experimental designs necessary to estimate biochar carbon stability (that is, the mean residence time, or MRT, of biochars in soils).

Of the seven studies identified in the paper, four of those cannot be used to estimate biochar mineralization (transformation of organic carbon to CO2) rates because: (1) they either do not distinguish between possible losses due to physical processes (e.g., erosion, leaching) and actual mineralization; or (2) they are not able to distinguish between native soil organic carbon and biochar carbon and thus cannot be used to make any inferences about MRT of biochar. The three other studies in the table did utilize methodologies that are suitable for calculating MRT. Those three studies reported MRTs of 173, 293 and 600 years, when adjusted to the average global land surface temperature of 10 C.

More field studies will absolutely help to further demonstrate the persistence of biochar carbon in situ. However, we disagree strenuously (as do independent experts) with the premise of the paper that only field studies can be used to calculate biochar MRT in soils.

On the contrary, laboratory incubation studies are widely acknowledged in the scientific community to be reliable methods to understand mechanisms for biochar mineralization and make predictions about persistence in the soil. Lab experiments apply harsh moisture and temperature conditions to maximize mineralization.
In the field, frequent lack of moisture or excess moisture and temperatures outside the optimum range will reduce mineralization. For this reason, lab experiments, when maximizing for high rates of mineralization, can be considered conservative estimates.

This holds true in principle when considering well-known variations in decomposition of uncharred litter in the field. So variations will depend on field and lab conditions. It is invalid to assume that field conditions will show faster mineralization rates than lab studies.

Rick Engebretson's picture
Rick Engebretson on Mar 30, 2017 2:07 pm GMT

Thanks, Rex. My wife and I have some experience with this. We’ve added at least 80 cubic yards of “black dirt” from different suppliers, and seen over a decade of results.

First, there is no single chemical entity identified as “biochar.” Trees have different lignin content, as well as other resins. Hay crops also differ in cellulose proportion. Different processing also produces different product.

Biochar black dirt blenders often use silt washed off crushed rock sold for concrete. Some add cow manure and sand. This is all very much a learning process for everybody, so I don’t understand all this conclusive data.

We have also blended rotten hay, chopped or baled or disced, and sawdust wood chips by the truckload. We have a healthy worm and vole population to help.

The soil will retain the favored properties until it is disced and exposed to intense sunlight. Then you quickly get dust and dead dirt again.

What I and others can certify, there is no comparison to un-enhanced soil productivity. When the Amish move into a farm community, they bring their manure and black dirt with them.

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