Monday, 3 December 2012

Are Wood Burning Stoves the Answer?

There is a lively debate within my local Greening group about the merits of wood as fuel. I have heard convincing arguments on both sides and am not entirely sure where I stand, but I certainly have my reservations.

I have heard wood fuel talked of as if it is the ideal sustainable fuel and also as helpful in reducing our carbon emissions.Yet, when you burn wood it does release carbon dioxide.

If you plant one tree in the place of each tree you burn, it will in time absorb an equivalent amount of carbon, but it will need time to grow. A well managed woodland with trees at many stages of development will get round this problem to some extent. This is because if the woodland is managed well you won't chop down a large wooded area all at once and then replant it, so that there are a number of years before the same amount of carbon is being absorbed as there was by the trees you originally chopped down. However, if you chop just one tree down, it will still take time for a new tree planted in its place to reach the same size.

So, it seems to me that there is a reduction in the amount of carbon absorbed and an increase in the carbon dioxide released into the atmosphere whenever a tree is cut down and burnt, even if it is only for a short while. Planting new trees in the place of each one felled merely limits the shortfall in carbon absorption, but does not stop it entirely.
Ash tree
Nationally we have recently learned that it is important to only plant locally grown saplings grown from native tree seeds, yet the more we need to replant I suspect the temptation is greater to import saplings from abroad especially when they are being sold at a cheaper price than native trees.

You may wonder if you can argue with a woodland being 'well-managed', but what this seems to mean is a way to make a woodland profitable while ensuring that enough of it remains to allow most of the wildlife that inhabits it to survive. However, there is also merit in an unmanaged woodland where trees have fallen down due to old age or the effects of strong winds and have been left to rot and so become a habitat for mosses, lichens and all manner of insect life, which in turn will feed many birds and other animals.

We must remember that a woodland is not just a collection of trees, but also a complex habitat for numerous and diverse plant-life and creatures great and small. The longer the woodland has been undisturbed the greater the biodiversity.

If you like the idea of living as naturally as possible or think our ancestors ways were often better than the way we live today this does not necessarily mean that wood fires are a good idea in modern Britain.

If a few people burn branches that have fallen from trees in their local woods along with the occasional tree that has fallen down in high winds, this will release a minimal overall amount of carbon dioxide into the air, the CO2 emitted during transport will also be minimal and the woodland will have suffered minimal damage, but the more people do even this and we shall increase the amount of CO2 released into the atmosphere.

If we need to transport the wood even a few miles the C02 emissions are likely to rise substantially. The more people who wish to use wood the more damage will be done to the woodlands as there will not be enough fallen wood to cope with demand. Coppicing is one way to ensure large trees are not felled, but a coppiced tree produces spindly growth to begin with, so will still have less capacity to absorb and store carbon than it did before it was coppiced.

If you want to burn wood, do make sure it comes from a sustainable source, as locally as possible, but I can't see this being the answer to our fuel problems as a nation.

Once upon a time Britain was covered in forests and woodlands, but even in the Iron Age large scale felling started to reduce our woodlands substantially. Under Henry VIII a large boat-building programme helped to hasten the progress and all the while wood had been used to build houses, churches, cathedrals, barns and stables etc. Come the industrial revolution and even more wood was needed to create charcoal for the greedy furnaces. Even the great Caledonian Forest is a shadow of its former self. Surrey is the most wooded counties in England, but it cannot even supply all its residents if they all wanted to feed wood burning stoves - thankfully not everyone can or wants to do so.

If Britain does have wood to burn it might be more efficient to burn it in a power station rather than in individual wood burning stoves and then everyone could benefit. Although I won't deny there's nothing so cosy as a roaring fire in the grate on a cold day if you are lucky enough to have a fireplace and chimney. Perhaps this would be best as an occasional treat, however?

Now I don't pretend to be an expert on these matters and they do say a little knowledge can be a dangerous thing, so if you are an expert or can point me in the direction of articles written by experts I would be very interested to hear your views. If you are not an expert I should still be interested in what you think about all this.

This is an article by the Carbon Trust advising how carbon savings can be made by using biomass as opposed to conventional fuels.

There is a diagram on page 2 entitled 'Biomass and the Carbon Cycle'. It makes the point that because new trees are planted to absorb some of the carbon dioxide released into the air by burning wood, it is better than burning coal or oil, which cannot be replaced like trees.

I've also found something about wood fuel on the Permaculture UK Forum. Permaculture is about living as sustainably as possible.  While one contributor called JohnB acknowledges it can be a sustainable source of fuel for some people he suggests that individuals consider their own circumstances and needs in order to decide on the best fuel sources and that other measures such as insulation and dressing warmly in cold weather are also important.

My suspicions are that for most people insulation and choosing more sustainable forms of electricity and gas could be the way forward. However, I await an overwhelming argument in favour of wood fuel to convince me otherwise.


  1. Deciding what to use is so hard. The good thing about a wood burner is it wastes less heat than an open fire. I was helping a friend prune her pear orchard (which is big) and was amazed by how much wood "waste" was created. I guess this is the answer for those with land/some neighbours. Until then hope you find a way to stop your Greening friends falling out! Nicola

  2. Thanks for that, Nicola. What do you think about the carbon emission side of things in such a case? Or perhaps too few people would be able to do this for it to make much difference?

  3. I would say theres nothing wrong with using wood burning as a fuel, because the only greener you can get from there is to cook using a solar oven and not everyone has the money for those, they are expensive now-a-days. So I am for wood burning, if nothing else is available. Can't always be the absolute best.

    -Samudaworth Tree Service

    1. Thanks for dropping by Tree Service. You will have a lot more forests in the USA than we do here in the UK. Does it not depend on the source of the wood? Isn't green electricity from wind, wave or solar power more sustainable as it produces less CO2?

  4. On Facebook, Rae wrote:

    Your blog conclusion seems good to me - biomass is fine in certain situations and up to a certain level of consumption. Lots of wood stoves in cities however would add to the problems from particulate emissions, so it's not just about CO2.

    Electric heat pumps will probably be the main low carbon heat solution for most homes in the UK.

  5. We had our wood burner installed earlier this year & feel for us it is a far better way to keep warm than using the oil central heating. We work for a friend, who instead of paying us, gives us a truck full of eco logs, which are made from wood waste. We collect driftwood on the beach & any fallen branches we come across. Sime also makes paper logs from newspaper we pick up from the holiday lets we look after. We cook on the stove & dry our clothes next to it, so we make the most of it. We live in a rural place, where most people still use coal... Growing up in & around Stoke-on-Trent, where coal mines were still in operation until the late 80s, we can remember the smog, fires produced. Wood is definitely cleaner, but in a city or large town situation green electricity would be the ideal - though how will this progress if peak oil happens? We prefer to think that if electricity ever fails, then at least we have an alternative way to heat & eat.

    K&S :)

    1. Having a wood-burning stove could be an insurance against power failure, but if it were a long-term one wood could become scarce. For now, it probably is an environmentally-friendly option if you live near a good source of firewood and if that wood is cheap or free it makes even better economic sense.

      As you say, though, for the rest of us green electricity is probably the best way to heat our homes and cook if we want to have as small a carbon footprint as possible.


All relevant comments to this post are welcome, so feel free to have your say.