Improving soil health and mitigating climate change: is biochar part of the solution?


Biochar is a form of charcoal produced from burning organic material at high temperatures with little to no oxygen availability. The potential of utilizing biochar to sequester carbon in the soil and improve soil health has received considerable attention in recent years, and a webinar series was dedicated to this promising technology by the Global Bioenergy Partnership (GBEP).

The first webinar, entitled ‘Biochar systems for sustainable agriculture’ was presented on 7 May 2020 by Prof. David Chiaramonti, Professor of Systems for Energy and Environment at Polytechnic University of Turin. It focused on different production technologies and how biochar characteristics depend on the types of feedstock. The webinar also highlighted the interesting synergies between biochar systems and biogas produced from the anaerobic digestion of organic matter. Biochar can be used to improve a biogas system, for example, by co-composting biochar with digestate (the by-product of biogas production) to significantly improve increase the fertilizer it eventually produces.

The second webinar, presented on 11 June 2020 by Prof. Johannes Lehmann, Professor of Soil Biogeochemistry and Soil Fertility Management at Cornell University, focused on the agronomic aspects of biochar. It illustrated how crop yields can increase when biochar is applied to different soils. It also discussed the effectiveness of biochar application in sequestering carbon and the questions that surround this.

Biochar for carbon sequestration

Biochar has an important carbon sequestration potential due to it is high stability and resistance to decomposition in the soil. Both Prof. Chiaramonti and Prof. Lehmann cited the recent IPCC report: Climate Change and Land, published in 2019, which specifically addresses the GHG mitigation potential of biochar, and includes GHG savings from biochar in carbon accounting. It is an option to be considered given that it can be deployed on a large scale at low cost, and has been usually found to also promote more sustainable agriculture and climate change adaptation.  

However, Prof. Lehmann cautioned that location is important for drawing benefits from biochar and that it may not be an appropriate practice in all cases. He noted  differences in responses to biochar application depending on various factors, for example soil type and pH as well as costs and soil carbon sequestration potential .

Technology readiness for different applications and scales, as well as high costs and possible risks of soil contamination, are  constraints that currently prevent biochar market penetration. Methodologies for evidence-based economic recognition of carbon sequestration through certification could improve the economic competitiveness of biochar. Robust certification schemes of this type could create a market for carbon offset through payment for biochar application. 

Missed the webinars?

If you missed the webinars but are interested in these topics, the recordings are available on the GBEP website.

The Global Bioenergy Partnership secretariat is hosted at FAO Headquarters in Rome, and has been supported by Italy with funding from FAO, Brazil, Germany, the Netherlands, Sweden, the United Kingdom and the United States.