There's probably no such thing as "clean coal," but a form of charcoal could be of benefit to the environment, and help prevent global warming.
Biochar, first used hundreds of years ago to enrich soil in the Amazon, is a carbon-rich form of charcoal made from burning biological materials. Unlike regular charcoal, biochar is so resistant to degradation, it can be used to "sequester carbon in soils for hundreds to thousands of years," according to research by Christoph Steiner of the University of Georgia.
By adding biochar to the soil, Steiner believes that not only can it improve harvest, it can create a carbon "sink" which will remove carbon dioxide that would normally enter the atmosphere and create global warming.
The biomaterials used to create biochar would normally degrade on the fields, or be burned, which Steiner says creates greenhouse gases. The process to create biochar is reletelivey airtight, so those gases would not be released during its production.
Biochar would also take care of some of the problems inherent with biofuels by returning biomaterials to agricultural fields, where they will enhance the soil like fertilizer.
Expect to hear a lot more about biochar in the next few years. It's a major component of the UN's next climate-change agreement, which would go into effect in 2012.
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