Mary Appelhof's Worms Eat My Garbage is one of my all-time favorite gardening books. Not only does it contain the first principles of worm composting; not only is written in an engaging, warm and yet practical voice; it's one of those special books that says a lot about the person who displays it on his or her bookshelf, a freak flag representing all sorts of affiliations, opinions and predilections. I was thinking about Mary after I read a strange tidbit about worm composting in today's Wall Street Journal Informed Reader blog. It linked to an article in Britain's Daily Telegraph called "Wormeries 'may add to greenhouse gases.'" Hmmm.
In fact, the greenhouse gases emitted by a large commercial worm composting plant may be comparable to the global warming potential of a landfill site of the same scale, according to the Open University. This is because worms used in composting emit nitrous oxide — a greenhouse gas 296 times more powerful, molecule for molecule, than carbon dioxide. Landfill sites produce methane which is 23 times more powerful a greenhouse gas than carbon dioxide.
What is this Open University? (Apparently, it is a "distance learning" program in the UK). And how much nitrous oxide do worms emit as they consume garbage? Is it comparable to the amount that the garbage would emit if it sat in a landfill? Is it less? More?(Mary's website? www.wormwoman.com, naturally.)