EM Cheat Sheet: The Biochar Debate

Climate Forests Investments Jan 1, 2001
Avril David

Land-use practices – including forestry and agriculture – are responsible for nearly 40% of all greenhouse gas emissions, which is why accounting for land use, land-use change, and forestry (LULUCF) is a key point of contention in climate-change talks leading up to December’s Conference of the Parties in Copenhagen, Denmark. Ecosystem Marketplace summarizes the latest findings.

17 July 2009 | Thousands of years ago, South Americans of the Amazon Basin began using charred animal waste and wood to make what the Portuguese called “terra preta” (black earth). The terra preta soil they created remains fertile for thousands of years without the use of any fertilizer, thereby increasing agricultural yields and further reducing harmful emissions

Country-Level Initiatives

The International Biochar Initiative has launched nine country initiatives. You can find an overview of these initiatives, as well as contacts and other resources, here.

Below, you will find coverage of other initiatives around the world:

Australia: Turnbull Puts Biochar Front and Center

The leader of the Australian Opposition party, Malcolm Turnbull, has voiced strong support for the inclusion of biochar in an international climate treay and has confirmed that economic incentives for biochar will be central to his negotiations with the Rudd Government on the development of Australia’s emission trading scheme.

Australia: Biochar receives a $1.4-million funding boost from Govt

In May 2009, the Australian Government committed $1.4m in funding for the development of biochar.

DRC: Protect rainforests in Congo

The Congo Basin Forest Fund is an initiative by the British and Norwegian governments, aimed at protecting the unique tropical rain forests of Central Africa and their biodiversity and ecosystem services. The fund recently awarded funding to Belgium’s Biochar Fund and its Congolese partner ADAPEL to implement its biochar concept in 10 villages in the Equateur Province of the Democratic Republic of Congo. The Biochar Fund says the scheme will help address lack of access to clean, renewable energy among poor rural communities while simultaneously cutting emissions from deforestation and forest degradation.

For further coverage of this project, click here.


caused by inefficient farming practices and/or the use of chemical fertilizers.

Today, we call this “biochar” – a highly porous charcoal made from any form of organic waste – ranging from forest to manure – through a process known as pyrolysis, which is when biomass is burned at 400-550 degrees without oxygen.

Due to its high carbon content and porous nature, biochar can help soil retain water and nutrients (it releases them very slowly over time), protect soil microbes, and ultimately increase crop yields in addition to acting as natural carbon sink by sequestering CO2 and storing it in the soil. A World Watch report on Mitigating Climate Change through Food and Land Use estimates that if “biochar additions were applied on just 10 percent of the world’s cropland (160 million hectares), the method could store 29 billion tons of carbon dioxide equivalent, offsetting nearly all the emissions from fossil fuel burning”. According to the report, “initial analyses suggest that planting vegetation for biochar on idle and degraded lands could be quite economical and is thus a promising option for carbon offset payments”.

The Science

Biochar essentially stabilizes soil, thereby allowing it to absorb and store more carbon and enhance its role as a carbon sink.

Left undisturbed or protected, soil serves as a vital carbon sink for the Earth. This function often breaks down, however, when soil is disturbed. Then, it can quickly change from carbon sink to major source of CO2 emissions.

That’s why burying biochar in the soil can improve its carbon sequestration potential just as conservation tilling and grass-planting do.

“The overall natural (carbon) cycle is carbon-neutral,” writes the Illinois Sustainable Technology Center. “In contrast, pyrolysis can lock up this atmospheric carbon as biochar for long periods (e.g., centurial or even millennial time scales)”, which essentially has a carbon-negative effect.

In terms of added agricultural and environmental benefits, the International Biochar Initiative states that, “char-amended soils have shown 50 – 80 percent reductions in nitrous oxide emissions and reduced runoff of phosphorus into surface waters and leaching of nitrogen into groundwater. As a soil amendment, biochar significantly increases the efficiency of and reduces the need for traditional chemical fertilizers, while greatly enhancing crop yields.” In addition, the process used to make biochar (pyrolysis) has useful by-products such as gases that can be converted into electricty, gasoline or industrial chemicals.

Issues and Concerns

During recent climate negotiations in Bonn, Germany, participants of a side event on biochar noted uncertainty around biochar’s ability to sequester carbon, the possibility that biochar might stimulate soil microbes that turn soil carbon into carbon dioxide, and the potential albedo (or reflective) effect of laying charcoal near the soil surface.

Participants also noted that biochar could have multiple unintended social and eco-side effects, for instance, biochar production could lead to the development of biochar plantations that take the place of forests. Negative impacts of plantations can include the appropriation of land from local communities, the loss of rural job opportunities, the loss of biodiversity, and soil degradation.

Furthermore, as according to the Guardian’s George Monbiot, “In some cases charcoal in the soil improves plant growth, in others it suppresses it…in some cases charcoal stimulates bacterial growth, causing carbon emissions from soils to rise.” Not to mention the fact that the process of pyrolosis itself can also be a source of harmful emissions if the gases emitted are not properly managed.

Pilot Projects

While biochar certainly has potential as a climate change mitigation tool in theory, continued research is needed to ensure that it is in fact viable in various soil types and that the potential adverse effects do not outweigh its benefits.

To that end, biochar pilot projects are currently underway in multiple countries.

For instance, at the University of Tarapacá in Chile, researchers are conducting a comprehensive pilot program that utilizes a lab-based pyrolysis unit that produces biochar. The researchers plan to study both availability and applicability of local feedstocks for biochar and will evaluate which feedstocks are the most efficient in producing biochar. After the initial phase, the project will be scaled up to increasingly larger farms with larger units and feedstocks. While the University of Tarapaca’ s project will likely yield some important findings for the further development and use of biochar as a carbon sequestration and soil enhancement tool, other biochar projects are focusing on the substance’s ability to supplement existing conservation efforts.

In Cameroon, a project sponsored by Belgium’s Biochar Fund plans to use biochar as a “buffer” to protect pristine rainforests threatened by slash-and-burn farming and increasing populations. The biochar could enable farmers to produce greater yields on existing agricultural lands rather than using the rainforest as a source for new land.

Avril David conducts research on the terrestrial carbon sector for Ecosystem Marketplace’s Forest Carbon Portal. She may be reached at adavid@nullforest-trends.org.

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