Why wood burning is not carbon neutral

When politicians and advertisers and propagandists want to do something to persuade us that a policy or product or idea is something new, because the old policy, product or idea has failed, they re-invent vocabulary and assign new meanings to words in the hope of fooling us into thinking that the policies, products and ideas are new, whereas it is only the words that are new or used in a different context.

So instead of a settlement negotiation we have a “road map”. A “problem” becomes “an issue”. It has always been thus: Voltaire pointed out that the Holy Roman Empire was neither holy, nor Roman, nor an Empire.

In environmental matters words are abused as much as energy is, to hide their real meanings and persuade us that there are easy options. We have “zero carbon homes” which produce carbon, and “a low carbon building programme” which is neither low carbon, nor is it a building programme and we have carbon offsetting, which does not offset carbon, merely slings a few ounces in one side of the balance when there are pounds in the other side. Worse of all, we have the concept of “carbon neutral”.

A forum at the Burning Issue website points out that “carbon neutral” cannot apply to any carbon based fuel. It can only apply to energy sources that do not in their fuel, create carbon – such as solar, nuclear and wind energy. You can read more about this at http://burningissues.org/forum/phpBB2/viewtopic.php?t=668 and I recommend that you do.

The burning issues website is concerned with air pollution caused by burning. My concern with this subject (and an article I wrote about this) led a UK trade association to write to me to ask me to stop criticising other renewable technologies.

I cannot do that. I cannot subscribe to the concept that all renewable technologies are equal. Some are better than others. Some are better in some locations than others. You would not put solar panels on a house that is in the middle of a shady forest and you shouldn’t put wood burning furnaces in apartment buildings in the middle of London (although the latter has happened, believe it or not!).

The good people at the Burning Issues website have calculated that to offset the carbon produced by a very small home fuelled by wood burning needs around 63 acres of land to plant trees on, cutting down two acres each year for fuel and replanting as they go. After 30 years the process restarts.

I have not tested their calculations but it is clear to me that to offset the carbon emitted by wood burning needs far more tree planting than we are doing as a planet. It may be in some communities in places where the population is small and the woodland extensive this may happen, but it does not count for much if we burn more wood than we grow each year.

Although we are not planting as many trees as we have to plant (and somehow I doubt if we ever will) out in Australia farmers are looking to store or sequestrate carbon in the soil.

Ever since Australia was colonised at the expense of its aboriginal people, the colonists have farmed sheep. They were encouraged to clear the land of trees – they would cut down a tree to make room for a sheep. Intensive grazing by sheep led to soil degradation and when the soil was degraded sufficiently the farmers move on to new land and started the process again there.

That process meant that the land was leached of its stored carbon. Currently Australian soils store little carbon but a new movement there is leading to carbon gradually being replaced in soils by farmers who farm in ways that enable the soil to hold as much carbon as possible and retain it.

In essence they want to ensure that the carbon in decomposing matter that once lived is pushed into the soil by roots of foliage and held there as humus. Depending on what you grow, the soil can either release carbon or store it and the Australian soil carbon farmers seek to retain as much carbon in the soil as possible.

Now this is real carbon sequestration; the soils of the planet already hold more carbon than the atmosphere and vegetation combined, according to the UN Food and Agriculture Organisation.

There is plenty of land to store carbon; the Australian colonial farmers were not exceptional – mostly farming has released carbon from the soil. When a forest is cleared in, say, Ecuador, for farming the clearing of the wood and its burning releases carbon and then when the soil is tilled and ploughed and worked more and more carbon is also released.

It seems fairly obvious that we should not burn wood, except perhaps waste wood from households that we cannot recycle, and that we should leave the forests undisturbed so that they can sequester carbon by allowing the vegetation to rot into peat. We should study the methods of the Australian soil carbon farmers and implement their ideas into farms everywhere.

It also seems obvious that the techniques of political or commercial persuasion by renaming things ultimately never work, because people realise eventually that the thing is still the “same old, same old” thing. They will realise it when they cough their way through wood smoke as the intensity of particulates and the measurements of atmospheric carbon dioxide continues to increase and with it changing the climate, despite all the so called carbon neutrality.

 

18 Responses

  1. I must say, I can not agree with you in 100%, but it’s just my IMHO, which indeed could be very wrong.
    p.s. You have a very good template for your blog. Where did you find it?

  2. This is misleading.

    Natural gas – 117.6 lbs/MMBTU
    Wood – using the wood fired boiler (industrial sized) factor – 195 lbs/MMBTU
    Using the factor for a wood pellet (home unit) stove – 185 lbs/MMBTU
    Fuel Oils
    Kerosene – 159.3 lbs/MMBTU
    #2 oil – 159.3 lbs/MMBTU
    #6 oil (high sulfur) – 162.7 lbs/MMBTU
    Anthracite Coal – 230 lbs/MMBTU

    These are nice figures, and good to have, but the numbers are somewhat deceiving. The fossil fuels that “burn cleaner” are taking carbon that is ALREADY SEQUESTERED and putting it BACK into the atmosphere after it’s been in the ground for millions of years.

    Burning wood is re-releasing carbon that was only recently fixed. If you calculate that into the equation, plus the energy required to get and refine the fossil fuels, wood burning is MUCH better. It’s not carbon-neutral, but it’s one hell of a lot closer than any other power generation method that requires burning.

    If people consistently plant trees to replace the onces they burn, their carbon output from that will be minimal, though not non-existent.

    You’re right in your general point, about rood burning not being “green”, but it’s much greener than using coal or oil based energy.

  3. Hello Robert,

    Some interesting points in your article – not least the way that certain people are hijacking environmental terminology disingenuously for their own agendas.

    I’m not challenging that we may not be planting enough replacement trees for the ones we’re burning but I would make a couple of points.

    1) It is easier to plant 1,000 extra trees than to obtain a few millions tons of carboniferous matter, sequester it under a mile or so of geological crushing power and wait a few million years for it to become coal / oil gas.

    2) It is younger trees that do all the C02 absorbing and 02 ‘exhaling’. Older trees make little difference to net C02 absorption. The case is therefore for properly managed forests. That’s not to say that we should start cutting down old trees, but we should support responsibly managed forests.

    There are pros and cons everywhere – wind & tidal stations almost always involve huge quantities of concrete – a material with a massive carbon footprint. Solar panels use huge quantities of plastic and, unless you’re powering directly and only in daylight then you’re into the realms of batteries with acid and nickel and lead and God only knows what else vile chemicals.

    You seem to be advocating natural gas – I can only wonder what the inhabitants of Ukraine and Eastern Europe would make of that viewpoint after recent events. We’ve seen so many wars over fossil fuels, anyone ever seen a war over trees?

    But these are the kinds of points that are seized upon by the selfish and the truly irresponsible. They grab the headline “Why burning wood ain’t so wonderful after all” and use it as an excuse for why there’s no point in them giving up their SUV’s or turning down their fossil fuel central heating. You mentioned Voltaire’s observation on The Holy Roman Empire. Are you also familiar with Churchill’s observation on Democracy?

    The long term (if we have one) will involve a package of environmentally better energy production measures than we have now. Properly managed wood burning will need to be a piece of that puzzle, the same as wind, tidal, solar etc.

  4. Michael

    I think you have hit the nail on the head, Some of the previous responders to this post seem to think that it’s a simple eaquation – carbon in and carbon out. You have shown that even on this basis there is more carbon out than carbon in when burning wood but have pointed out the time differences when carbon is held in the air.

    I’ll clarify my thinking on this and post about it later.
    Robert

  5. There are a number of reassons why buring wood is not “carbon neutral”. These include:

    The assumption that all of the carbon in the wood will be released to the atmosphere thereby meaning that when you burn wood, you are just releasiong what will be released anyway. this is not true. In the northern boreal forsst, +/- 80% of the carbon mass is in the soil. In southern forests this is less but still significant. Therefore, when you burn wood, you release CO2 which would not otherwise be released causing a net increase in the atmoshphere.

    The other issue is rate of carbon release compared to rate of carbon sequestration. When you burn a log that took 10 to 20 years to grow in one or two hours, you are buring it faster than the trees can sequester the carbon released by the burning. Even if you burn just dead wood that has already fallen from the trees, you will burn a piece of wood in two hours what may take 10 to 15 years for it to degrade.

    You can not get trees to sequester carbon as quickly as you release it by burning so therefore, you case a net increase in CO2 because dsequestration can never keep up with the release rate. (I suppose if you had 50 or 60 acres you could by careful pruning or other management techniques for at least a time cause the trees to grow more mass each year than you burn but with billions of people om the earth, is there enough land for each person to manage many acres of woodlands?

    It is just a fantasy to think that we can be “carbon neutral” if we get energy by burning things. The following table compares CO2 released per btu by energy source. Wood doesn’t compare too favorably to natutal gas expecially if you consider the other materials released by burning wood including polynuclear aromatic hydrofcarbons, particulates, NOX and SOX, etc. Gas is a lot cleaner.

    Natural gas – 117.6 lbs/MMBTU
    Wood – using the wood fired boiler (industrial sized) factor – 195 lbs/MMBTU
    Using the factor for a wood pellet (home unit) stove – 185 lbs/MMBTU
    Fuel Oils
    Kerosene – 159.3 lbs/MMBTU
    #2 oil – 159.3 lbs/MMBTU
    #6 oil (high sulfur) – 162.7 lbs/MMBTU
    Anthracite Coal – 230 lbs/MMBTU

    WE NEED WIND AND SOLAR AND TIDAL ETC

  6. Setting the carbon neutral issue aside the a moment I must agree with you comment about the way that politicians “re-invent vocabulary and assign new meanings to words in the hope of fooling us into thinking that the policies, products and ideas are new” We must always be vigilant in our thinking and look for the real meaning in what we are being told.

Leave a Reply