Carbon-storing charcoal

Scientists are developing a type of charcoal that can be used to store carbon instead of being burned for fuel.

Researchers at the UK Biochar Research Centre - recently launched at the School of GeoSciences at Edinburgh University - will produce the charcoal from materials such as dead trees, food waste and crop residues. The materials would otherwise produce CO₂ and methane as they decayed.

The biochar itself is produced by decomposing waste using heat in a low-oxygen environment, without burning. This produces dark-grey grains of carbon.

Scientists say that the biochar could lock carbon away for hundreds or even thousands of years, preventing the release of CO₂ into the atmosphere.

Unlike ordinary charcoal, it is not intended for use as fuel. The charcoal is intended to be added to soil, where it could also potentially improve crop yields.

Its use by farmers, foresters and local governments could help reduce overall CO₂ emissions. It could also save money by reducing the need for plant fertilisers.

'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,' said Dr Simon Shackley, a lecturer at the university.