Good Carbon

The Biochar Debate: Charcoal's Potential to Reverse Climate Change and Build Soil Fertility, James Bruges, White River Junction, Vermont: Chelsea Green Publishing, 2010, 128 pages.

In spite of being packed with interesting examples and information, the book occasionally fractures into subtopics, subjecting the reader to rapid-fire asides of marginal relevance. These range from rebuilding aging UK infrastructure to animal cruelty, cap-and-trade strategies and global climate change, none of which receive suitable exploration in the 128-page text. By doing so, Bruges sacrifices precious space that could instead have been devoted to his central focus.Charcoal is produced when organic material, usually wood, is healed at high temperatures in the absence of oxygen. The process produces waste heat, gas and char, which has traditionally been used as a fuel. Biochar is made using a similar process, however the source material ranges from crop residues to animal manure rather than wood. When the final product is crushed into a fine powder and added to soil, it is reported to increase water retention, soil pH and fertility. And because it doesn't break down in soil, it is also touted as a way to build up the carbon content of earth, making it a sink for carbon dioxide, the most prevalent greenhouse gas. As a result, biochar production has been dubbed "coal mining in reverse" and has potential as a biofuel.The Biochar Debate is a bit like having a conversation with a good friend who has just had a new child and is enthusiastically trying to describe all the great things about parenthood--with the important difference that biochar is new to most of us.Reviewed by Jeri ParrentThe "debate" in Bruges' briefing lies primarily in his concerns about carbon-credit schemes for biochar, and the role of large agribusiness in generating biochar for fuel. He argues that such approaches favour large business interests, allowing them to buy carbon credits while continuing to emit greenhouse gases. He suggests that biochar production may divert arable land from food to fuel production, thereby raising food prices and chasing small farmers from their land.The Biochar Debate's most interesting ingredients are a number of case studies. They describe how farmers, who range from those producing chickens to others who grow bananas, are generating biochar from their agricultural waste streams and applying it to their land, thereby reducing irrigation and fertilization needs.Although the book is intended for a general audience, a far better description of the science and biochar's potential uses in combating climate change can be found at the International Biochar Initiative's website (biochar-internalional.org), in language that a non-expert can easily understand.Jeri Parrent, an ecologist gardener and craft cider maker, studies the repercussions of global environmental change on plants and their associated soil biota.Most humans are familiar with charcoal, having depended upon these inky fists of carbon as a primary source of fuel, or as fodder for grilling favourite foods during summer celebrations. Biochar, however, seems much more exotic, novel and environmentally sound than its cousin.

Reviewed by Jeri Parrent