Burning Wood: Not So Carbon Neutral?
Source: The Ecologist
From Turning our Victorian Terrace into an Eco-Home part seven – Heating by Sue Wheat:
Sue Wheat thought a wood-burning stove was the greenest way to heat her house until a chat with authors, Nick Grant and Alan Clarke, made her think again. The biggest crisis of her eco-refurb so far? You bet it was!
With the cold weather closing in, it was time to think about green ways to heat our home. We chose a Stovax multi-fuel stove, which we were lucky enough to get from friends.
In a city where every other house seems to be having its kitchen or bathroom ripped out, there is vast amounts of burnable scrap wood lying around waiting to go to the dump, which could instead be heating your house. Paying for wood to burn seems positively stupid when you can pick up a week’s supply from neighbours, most of whom are all too willing to let you have it. I can’t see the logic in buying wood that’s been transported hundreds of miles either, so I’ve become something of an eagle-eyed wood-spotting obsessive. We look for wood that’s unvarnished, unpainted and untreated, and either carry it home, or rope in friends with cars or vans to pick it up for us. I’ve also got a few friendly builders who drop off scrap wood to us (thus saving them dumping fees), and a supply of off-cuts from a furniture repair workshop. To build up next year’s wood store, which we made from scrap wooden pallets covered with tarpaulin, we’re planning to buy some logs from a local tree surgeon and season them for a year, by which time the excitement of dragging wood out of skips and yards may well have worn off.
As I basked rather smugly in the warm glow of our pretty, near zero-carbon heating system, for a good few weeks I was unaware that things were about to get tricky. Then with one click on the mouse, I stumbled across a website which catapulted me into my biggest eco-refurbishment crisis yet. It seems, according to some of the eminent researchers at the Association of Environmentally Conscious Builders [AECB] that burning wood is not carbon neutral after all. I was gutted, to say the least. I emailed the AECB in a panic, who put me onto the authors of Biomass: A Burning Issue, Nick Grant and Alan Clarke. Their paper concludes that while it’s true that trees do absorb carbon dioxide when they grow, it doesn’t mean that the best use for the wood biomass is burning it. Burning, say Grant and Clarke, produces more carbon emissions than burning gas. Disaster.
Instead, they argue that timber should be left unburnt, thus imprisoning the carbon, and put to other uses; for example, as structural timber, insulation material or furniture. As owners of low-energy houses fuelled by wood burning stoves, they are both gutted too. ‘We don’t want people to hate us,’ Nick told me. ‘Please don’t shoot the messenger.’ The unfortunate result of assuming that wood-burning is carbon neutral is that it has been promoted by just about everyone, which has meant, as they point out, that wood is now being burnt faster than it’s grown, leading to rising prices and unsustainable burning practices to start.
Read the full article by Sue Wheat, and check out the comments section which has some useful links posted by the author.