Burning Wood May Do More Harm Than Good

Image credit: Dan Pfiffer

Of all the sources of renewable energy, one type invariably dredges up more debate than any other—biomass. Granted, the term biomass does cover a lot of topics and a lot of different controversies—from food versus fuel to the unintended consequences of anaerobic digestion. But perhaps the most enduring of all the biomass conundrums is this one—to burn wood or not to burn wood. Now Rob Hopkins, founder of the Transition Movement, is igniting the debate once more. And he's rethinking the installation of a stove at his house. This isn't a new topic here on TreeHugger. Daniel has already written about one study claiming that burning biomass may be worse than coal (although this was hotly disputed by the biomass energy industry), and John has written about the astounding amount of wood it takes to heat a home. But in general it's long been somewhat assumed by most greens that burning wood to heat your home, as long as you do it efficiently, has got to be greener than using fossil fuels. After all, trees are only releasing the carbon that they absorb when they grow—so the net input of CO2 into the atmosphere is negligible. Right?

Sadly, assumptions can be a dangerous thing. Rob Hopkins, who I previously interviewed about the birth of the Transition Movement, reports that he had only been weeks away from installing a wood burning stove on his home in Totnes, in the South West of England when he read a study published by the Association for Environmentally Conscious Builders called Biomass: A Burning Issue.

In it, the studies authors (Nick Grant and Alan Clarke, both of whom heat their homes with wood) set out to explore whether wood can really be considered a sensible, sustainable approach to heating homes. Among their findings are that while wood does indeed only release CO2 that it has recently sequestered, "recently" is still a relative term. Pointing out that we need to cut CO2 emissions now, not in 30 years, the authors argue that burning wood directly undermines more beneficial uses for it that keep that carbon locked up for centuries—whether that be building with it, making furniture, or presumably even burying it in the ground. Instead, they argue, we would be better placed burning natural gas efficiently, and letting our woodlands act as a buffer to absorb the carbon that is released.

The authors also tackle another major argument often given for wood burning–namely that it offers a degree of energy security. This, they say, is a myth. If the burning of wood for heat were to be scaled up to any degree, then "peak wood" would hit much faster than peak gas or peak oil. (Of course on an individual level, one could argue that wood does offer some security—wood being a relatively easy resource to harvest and process.)

Ultimately, as usual, the argument circles back to energy efficiency first and foremost. Just as Lloyd has argued against expensive heat pumps, and in favor of some serious insulation, so too Rob was prompted by this paper to reconsider his investment in a wood stove:

"In my own home, this paper has prompted a rethink. Rather than installing a woodstove, would that money be better spent on maximising energy efficiency throughout the building? What else could we do? I am getting quotes for a range of things and will lay my dilemmas out in front of you all soon for your thoughts.... but there is, as they say, no such thing as a free lunch."

Good for Rob for continuing to ask the tough questions, and for listening to the tough answers. I hope he doesn't miss out too much on gathering around that cozy hearth though. I can't help but feel that this guy deserves it more than most...

More on Burning Wood for Heat
Ask TreeHugger: Wood vs Pellet Stoves
4600 Square Miles of Forests Needed to Supply 120 Planned Wood-Fired Power Plants
How Much Wood Would a TreeHugger Burn if a TreeHugger Could Burn Wood?

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