Why biochar?

In the quest to reduce green house gas emissions biochar has caught the interest for some very important reasons.

A study performed by Johannes Lehmanns group at Cornell Univesity estimated that "up to 12% of the total anthropogenic C emissions by land use change (0.21 Pg C) can be off-set
annually in soil, if slash-and-burn is replaced by slash-and-char." - Lehman et al 2006

Slash-and-char is the most commonly used method for clearing forests into use for agricultural purposes. In the proces only 3% of the biomass bound coal is harvested and returned to the soil. The ash produced from burning also is prone to leaching especially in areas with heavy seasonal rainfalls such as the Amazon or central Africa.

Biochar is a very sturdy material. In contrast to ash, biochar will degrade at a much slower pace so that after 100 yrs more than 40% of the initial carbon sequestered will still be burried in the ground.

Plants also benefit from the addition of biochar. Water retention capability alongside with cation exchange capacity and other trates makes biochar a good soil amendment and has been reported to increase biomass production thereby sequestering even more atmospheric carbon.

In nature biomass slowly degrades and is used again by plants as sources of minerals and nutrients. The degradation is performed by microbes, fungi and insects. Especially microbes produce methane in the process. Methane is even more potent a green house gas than CO2. In the process of making biochar by pyrolysis, virtually all methane is consumed and doesn't end up in the atmosphere. For example GASEK Oy has constructed a small power plant that uses the methane from wood gasification.

There are plenty more reasons for producing biochar and they will be covered further on as well as in depth discussions of previously mentioned reasons.