International Biochar InitiativeI B I

Fossil fuels are carbon-positive – they add more carbon to the air. Ordinary biomass fuels are carbon neutral – the

carbon captured in the biomass by photosynthesis would have eventually returned to the atmosphere through natural processes – burning plants for energy just speeds it up. Bio-char systems can be carbon negative because they retain a substantial portion of the carbon fixed by plants. The result is a net reduction of carbon dioxide in the atmosphere, as il-lustrated below.

How Can Biochar Be Carbon-Negative?

Biochar can sequester or store carbon in the soil for hundreds and even thousands of years. Biochar also

improves soil fertility, stimulating plant growth, which then consumes more CO2 in a feedback effect. And the energy generated as part of biochar production can displace carbon-positive energy from fossil fuels.

Additional effects from adding biochar to soil can further re-duce greenhouse gas emissions and enhance carbon stor-age in soil. These include:

• Biochar reduces the need for fertilizer, resulting in reduced emissions from fertilizer production.• Biochar increases soil microbial life which results in more carbon storage in soil.• Because biochar retains nitrogen, emissions of nitrous oxide (a potent greenhouse gas) may be reduced.• Turning waste biomass into biochar reduces methane (an- other potent greenhouse gas) generated by the natural de- composition of the waste.

IBI has developed a simple model to predict the carbon removing power of sustainable biochar systems. The figures

below show the results of this preliminary model. We expect these answers will change as more is learned about the im-pacts of biochar, but the model gives a sense of what is pos-sible.

How Much Carbon Can BiocharRemove from the Atmosphere?

The figure above shows several scenarios that assume biochar production from waste biomass only, which is a

small fraction of Earth’s annual net primary production (NPP). Counting only the impacts of biochar burial in soil, and without considering the displacement of energy from fossil fuels, we can conservatively offset one quarter of a gigaton of carbon annually by 2030.

Optimistically, we could achieve one gigaton of offsets annu-ally before 2050. In the “Optimistic Plus” scenario, we account for reductions in nitrous oxide emissions and for the feedback effect of increased biochar production that may arise from in-creased plant growth in soils enhanced with biochar.

The figure below shows additional carbon offsets possible if energy from biochar production displaces fossil fuel energy, and if CCS (carbon capture and storage) is used.

Annual contributions of components of sustainable biochar technology to carbon offsets (2050)

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CCS (33% of Maximum Possible)

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Four sustainable scenarios using biochar technology

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Optimistic Plus (3.2% NPP)

Optimistic (3.2% NPP)

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