Bio-char: a Carbon Negative Way to Improve our Food Supply
Bio-char is a finely-grained charcoal-like substance made from plant waste. It is highly resistant to decomposition and produced via the carbon neutral process of pyrolysis or carbonisation, which is the ancient technique used to produce charcoal – the modern version heats organic waste airtight metal vessel to reduce pollution and condense volatile by-products like gases which would otherwise escape into the atmosphere, and the bio-energy produced can be converted to electricity, as well as producing and conserving ethanol and methanol.
Overall, the bio-char process is carbon negative because it produces both bio-energy (in the form of usable gases) and a form of fertiliser that stores the carbon produced by agricultural waste – which means there is a reduction of carbon dioxide (CO2) in the atmosphere.
Because bio-char is both stable and inert, it can store the carbon it sequesters for centuries – and as the char improves soil fertility by adding valuable trace elements, improving drainage and amending and improving exhausted soils. Terra Prata soils, which are found on highly fertile islands in the Amazon Basin, were created naturally, through a unique combination of climatic and environmental conditions, but bio-char aims to use the same process on a speeded up and industrial scale to create highly fertile and long-lasting soil additives that can improve crop yield and end the reliance on high-input and imported fertilisers and soil amenders.
At present, there is an American research programme that makes grants to bio-char initiatives and both Australia and New Zealand have bio-char initiatives listed in their climate change action plans, but there are no large-scale bio-char projects being run on an international basis. Since the bio-fuels initiative had its rocky start, with high hopes being somewhat dashed by evidence that the diversion of grains and oils from traditional uses to creating bio-fuel has worsened poverty and damaged environments in some areas, bio-char pioneers are revisiting their projections to ensure that the development of bio-char programmes won’t cause inadvertent harm to other environmental projects.
One problem with all these projects is that they tend to be ‘silo’ programmes, with dedicated experts who have spent many years working on a specific environmental programme but with little or no interdisciplinary relationship with other programmes that are often considering use of the same resource material for differing aims. This can mean that projects that become viable at similar times discover that they are competing not only for the same funding, but also for the same source material – leading to the kinds of environmental conflicts that have been seen around bio-fuels in the last twelve months.