A recent article in Nature (see http://www.nature.com/news/agriculture-state-of-the-art-soil-1.16699) suggests that interest in biochar is also growing among scientists, who are quickly ramping up studies to test its potential. They are particularly interested in how the chemical and physical properties of biochar particles affect water moving through soil, remove pollutants, alter microbial communities and reduce emissions of greenhouse gases (N2O). The other hope is that biochar can help farmers around the world, particularly those in Africa and other developing regions, who often struggle with poor soils. That all sounds good and appears to have many benefits.

However, the process of producing biochar – or charcoal, as it was once known – from wood etc., is a low temperature, low oxygen conversion step. This step itself produces greenhouse gases (CO2) and can produce carcinogenic by-products called tars. So whilst there are benefits these need to be wejosired against the dis-benefits. What we need is an LCA here to assess whether there is real merit in this process before we export it to the developing world. We would not want to improve crop growth with no greenhouse gas reduction benefit nor added to this, cause health issues and a rise in deforestation.