Whilst I was away on holiday in the US last week, I had plenty of time to do some reading, and I took the opportunity to work my way through half a dozen recent issues of the New Scientist, as well as read some American house building magazines. I came across some interesting stuff, one of which was an article by Richard Lovett entitled Carbon Lockdown (3 May, page 32 (behind a paywall)), which posited that a good way to reduce CO2 in our atmosphere would be to grow lots of trees for burial, thus sequestering the carbon underground.
Atmospheric scientist Ning Zeng is convinced that if we buried enough trees - where ‘enough’ equals ‘half the trees that grow each year’ - in such a manner that it doesn’t decay, we could offset all our fossil fuel emissions. Other schemes involve burying ‘biochar’, which sounds a lot like charcoal, or hydrothermally carbonised biomatter.
Another tactic is to reinvigorate the wold’s marshes and bogs, which naturally sequester CO2 in plant matter that’s turned into peat. This is already being done in places, not just for carbon sequestration but also as a way to protect and extend endangered habitats.
But here’s a thought or two. Firstly, it’s not an either/or situation - we can probably embark on all sorts of carbon sequestration projects. No one method is going to save the world on its own. Secondly, instead of burying wood, why not just use more of it in building and furniture making?
Wood retains its CO2 content so long as it’s not rotting, which means that wood used in a house is as good as wood buried in an anoxic environment, so why not use more of it? Our forefathers grew wood as a crop, projecting their needs a couple of hundred years into the future and planting trees accordingly. Many forests are now similarly managed, and if we treat wood as valuable crop, instead of as a sacred cow, we can use a lot more of it than we currently do.
I’ve noticed that some environmentalists feel that chopping down trees is the biggest sin we can commit, but we need to draw a very clear line between sustainable and well managed wood resources where trees are planted to replace those cut down, and pristine forests that are being raped and pillaged by ruthless loggers and desperate farmers. We need more crop trees, and we need to go all-out to protect our endangered forest habitats, but we can’t turn our back on all wood and treat every tree as if it’s sacred.
The way I see it, more wooden furniture, more wood used in house-building, and more innovative uses of wood, such as turning it into insulation, could both reinvigorate our forest-based economy and help us sequester carbon. A side effect would also be to provide us with a higher-quality and longer-lasting furniture, for example, or a warmer feel to our car interior finishes - nicer, more enjoyable day-to-day environments.
Burying wood seems like a waste when we can do so much more with it.
