Secrets of the Amazon may help Scotland reduce global warming

Published Date: 01 April 2009
By Jenny Haworth
Environment Correspondent

SCOTS scientists are replicating a technique used by Amazonian tribes to create charcoal that boosts crop growth and locks up carbon dioxide.
They believe "biochar", made from waste plant products, could help tackle climate change by locking away carbon and preventing it escaping into the atmosphere. Instead of being burned, the substance would be spread on fields and remain in the soil for thousands of years.The charcoal has been shown to improve the quality of soil, which could then be sold to farmers and gardeners to reduce the use of fertiliser. The UK Biochar Research Centre launched today at Edinburgh University, will lead the way in the development of the charcoal.Dr Simon Shackley, of the university's School of GeoSciences, told The Scotsman he believed the potential of the process was "enormous".He added: "Biochar offers an achievable, affordable method of storing carbon for hundreds, if not thousands, of years – we have to adopt technologies such as this to reduce carbon emissions in the long term."He said scientists discovered the charcoal when they noticed dark patches of earth in the Amazon that were highly fertile.And he said he believed people living in the rainforest hundreds of years ago had produced the substance by accident when they burned trees and plants after clearing areas of the forest."This created these very dark soils, which were incredibly fertile," Dr Shackley said."From the archaeological evidence, I think they probably discovered it by accident. "They were clearing forest and when they burned large amounts of wood some of it would probably become charcoal."Scientists at Edinburgh University are now exploring the potential of the substance.Dr Shackley believes research could offer a "win-win" opportunity to help farmers improve crop yields, simultaneously storing away carbon that could otherwise add to global warming.Material can be produced from plant matter such as dead trees, food waste, leaves, and crop residues such as rice husks, which would otherwise produce carbon dioxide and methane as they decayed.The waste decomposes under intense heat, in a low-oxygen environment, without burning. This results in dark grey grains of carbon that can be spread on fields.However it is unclear why the charcoal benefits crop yields as this does not introduce any nutrients directly to the soil, but Dr Shackley believes it improved the structure of the soil, and pores in the charcoal could help retain moisture."It seems that when you use chemical fertiliser the char retains some of it, so instead of getting lost by leaching it gets locked up in the charcoal," he said."It is also very good for water retention."His team is now working with an East Lothian farmer to discover more about the impact of biochar on crop growth.They are also building a plant to make biochar and determine which materials are best used to create it.Dr Shackley believes in the future a biochar production industry could spring up in Scotland."Scotland has an 80 per cent carbon reduction target so it will be a useful contributor to that," he said.In developing countries he thinks this could help create a market for carbon, providing income for poor communities. However, he emphasised the importance of ensuring that large areas of rainforest were not cleared just to create the substance.