Articles | Biochar - the future is black

Written by Craig Sams | Posted on 11/09/2009 | Category: The Pioneers

“Our soils have become totally degraded after a century of careless farming with tractors and fertilisers. I was born in a farm in Nebraska and when my great-grandfather ploughed virgin prairie lands they held 40 tonnes of carbon per hectare of soil. That’s now down to 5 tonnes - the rest went up in the air as carbon dioxide. This makes agriculture responsible for half of all greenhouse gas emissions up to 1980. My question has always been: how can we put this carbon back into the soil and make it stay there?
 
Since the 1960s I have been involved in the production of organic food. I had an organic bakery in Portobello Road and then Green & Blacks Chocolate. But it was when I launched the first organic wholegrain cornflakes that I realised, thanks to a study by the Carbon Neutral Company, that the carbon footprint of this food was very low. This is because organic farmers increase the amount of carbon in their soils through the use of compost and manures every year. It means less carbon dioxide goes into the atmosphere and, because they’re not using nitrate fertilisers, much less nitrous oxide, another greenhouse gas. I realised that farming itself could sequester carbon back into the soil and mitigate climate change rather than cause it.
 
But the light bulb really came on for me when I was reading a book called ‘1491’ about the Americas in the year before Columbus arrived. It’s a great book! It describes how indigenous civilisations in the Amazon were able to prosper on poor quality jungle soils. They smouldered agricultural, food and other waste to make a crude form of charcoal which they mixed into the soil to improve fertility. This ‘terra preta’ or ‘black earth’ is wonderful stuff because it has a huge surface area which holds waters, nutrients and the beneficial bacteria and fungi normally found in healthy soils. People in Brazil are still digging it up 500 to 2000 years later and selling it to farmers who need to build fertility of their land. It still makes for fertile soil.
 
It seemed to me that using ‘black earth’, or ‘biochar’ as we call it, is a quicker way to get carbon back into the soil than organic farming on its own. Of course organic farming is beneficial, but it’s a slower process. Biochar production is also a way of using up all the agricultural and forestry products that are currently left to rot or burnt. In Mediterranean countries for example, there are huge areas of citrus, olive or nut growing where farmers cut their trees and burn the prunings. If you add up all of these small fires, millions of tones of carbon dioxide are emitted every year. Because the photosynthesis of plant material is the only way to get carbon out of the atmosphere, it’s crazy to put it straight back by burning it. So this is why we set up Carbon Gold: to develop a simple, low cost technology that transforms the carbon in plant waste into biochar with very low greenhouse gas emissions.

At Carbon Gold we are not interested in producing biochar for fuel. We are producing it not to burn but to put back into the soil. Our technology is for small farmers across the world who can use it to improve fertility and lock carbon into their soil for hundreds of years. As well as the agricultural benefits, it gives them an opportunity for additional income from carbon credits for removal of carbon dioxide from the atmosphere. We’ve developed a drum kiln that is made from old oil drums and costs less than $100. It makes 40 kilos of biochar at a time. It’s perfect for allotments and small farmers in remote areas, so it really is a case of ‘small is beautiful’ rather than shiny machines with knobs and dials. We’re currently working on simple technology suitable for a spectrum of different situations, from subsistence farmers in Mozambique to apple producers in the UK.
 
I believe that biochar which is sustainably produced by small farmers and put back into the soil can make a huge contribution to mitigating climate change. That is why we are lobbying for it to be included in any future carbon reduction regime along with things like solar, wind and tidal power. I have three grandchildren and I am doing it to build a future for them. We have limited time to act, probably five years, and the thought that this technology could make a difference is what really inspires me. It’s easy to feel helpless because on an individual level there is only so that much one can do. So this is my way of taking the bull by the horns. It will take time to reduce emissions of greenhouse gases so it makes sense to me to work on taking out carbon we’ve already put in.
 
www.carbongold.com
 

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