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.
Filed under: biofuels, biomass, carbon emissions, carbon offsetting, climate change, energy, global warming, heat, microgeneration, propaganda, renewables, solar, solar energy, solar panels | Tagged: Australia, Burning Issue, carbon neitral, carbon offset of trees, forest clearing in Ecuador, holy roman empire, low carbon building programme, soil carbon. soil carbon farmers, UNFAO, Voltaire, wood burning furnace in London, zero carbon homes
Firstly, let’s be clear that carbon neutral does not mean zero emissions, as the link above claims. It means zero net emissions, that is, any emissions are cancelled out by withdrawals from the atmosphere. This is the case when burning wood from a sustainable source where re-growth replaces harvest. (In the link, definition of “neutral” given is “…no activity or development” ie. no overall change with time, not necessarily no activity.)
Secondly, the numbers regarding amount of land needed to sustain energy harvest are for a semi-natural forest, so are not very applicable. It’s absolutely true that preserving old-growth forests and peatlands is extremely important for global carbon balance, but what about all the marginal lands such as abandoned pasture? Here we have a choice between enhanced permanent sequestration on these lands and cultivation of energy crops to displace fossil fuel energy.
To use an environmental economics argument, conducting a cost-benefit analysis, where all external and tangible costs and benefits are taken into account, to compare the options of enhanced sequestration versus fossil fuel substitution, will hugely favour the latter option - not for the money earned but for the overall value of the project. This is a standard environmental economics technique, and the result here will come from the large net present value of the future emissions avoided by displacing the fossil fuel energy (larger than the net present value of the carbon absorbed in the one-off sequestration event). This result will become stronger the more you care about carbon (and assign a higher value to avoided emissions/sequestration) and the plight of future generations (and assume a low discount rate).
Noel
You make an excellent point but it is difficult if not impossible to measure whether something is genuinely carbon neutral and the phrase is bandied around for every pellet burning stove and even taxi cars, that it risks having no meaning.
I’d like to understand how you measure the overall value of the project in environmental economics. Can you explain further?
Robert
The denotations are taken directly from a dictionary:
Neutral: “no activity or development; not taking part of”
Offset: “anything that balances, counteracts, or compensates”
Here is an analogy: A vehicle transmission has “drive, neutral, and reverse.” You can only be in one of these at a time, in other words, driving forward one kilometer, then driving backward in reverse one kilometer does not equal having been “in neutral” the whole time. Rather, what we have done is “offset” our displacement. “Neutral” is a completely different state: there is no impetus, thus we have not moved the car any distance at all.
People are mistakenly claiming biomass combustion to be “carbon neutral” when it is actually “carbon offset.” The word “offset” fits the term; the word “neutral” does not.
Neither is burning the waste from growing corn used to produce Ethanol, the waste as I have seen in the Philippines is burnt in the farm where the extract the corn Kernels using a thresher machine running from a petrol engine!
In effect something neutral has no effect on the scales; whereas what burning wood for energy claims to do is to put in one balance the same that has bee put into the other.
The biggest problem with Noel’s definition is that there is no evidence that the scales are evenly balanced, so the neutrality (which implies that the scales are 100% balanced) seems to be a very large and very false assumption!
Robert
Woodynet,
I strongly sympathise with your air pollution agenda, however, to restate a point, the inclusion of the word “development” implies no change over time, and not necessarily no “activity”. Think of the word ‘neutralise’, in the way an alkali can neutralise an acid. In addition the common parlance use of ‘carbon neutral’ matches this definition – a ‘carbon neutral’ company is one whose emissions have been offset. Again I sympathise with the air pollution issue, however you are fighting a losing battle against popular, and correct, conception.
Robert,
Try this as a starting point:
http://en.wikipedia.org/wiki/Cost-benefit_analysis
Here are some rough numbers for you:
Firstly note that CBA monetises all costs and benefits to come up with Total Economic Value (TEV), so should definitely include the real money profitability of the two options. Biomass for energy is much more profitable, but I’m even prepared to forego this in the analysis.
So just looking at carbon:
Assumptions:
Biomass yield 10 odt/ha-yr
Calorific Value of biomass: 20GJ/odt
Efficiency of biomass electricity production: 35%
KWh/MJ = 3.6
Coal electricity carbon impact (counterfactual 1) 850gCO2/KWh
Natural Gas electricity carbon impact (counterfactual 2): 530gCO2/KWh
Cost of carbon €30/tonne
Inflation rate for that carbon price: 4%pa
Discount rate to analyse project: 3% (actually a high discount rate for this sort of analysis)
Lifetime of project: 50 years (NB this is a big assumption – the project will continue saving carbon after this point, but the carbon price outlook beyond here is uncertain. So a big, but fair, assumption.)
NPV(versus coal) = €31,000 (approx)
NPV (versus gas) = €20,000 (approx)
For enhanced carbon sequestration, numbers in a paper by Yong Shin (Journal of Environmental Management 82 (2007) 260–276) indicate a very generous assumption of carbon storage possible versus the mean long term carbon storage of the energy crops would be 200 t/ha. So NPV = €6,000
So the larger NPV of the biomass harvest option is demonstrated on conservative assumptions.
This will be my last post here as I actually object to the use of strong language backing up what are in fact guesses, as seems to be a bloggers prerogative. For example, it is clearly not “obvious” that sequestration is the right course of action, and in fact there is not “no evidence” regarding the carbon impact of biomass fuel – there’s lots of it. True, the scales you envisage are not perfectly balanced, but nor are they for any sustainable technology (eg. you have to emit carbon to build a solar thermal panel), so I would sum up with the recent research findings of Dr Thornley and Dr Paul Upham from the Tyndall Centre Manchester in conjunction with academics from The University of Ulster and Aston University, “the most comprehensive UK-focused study of biomass electricity generation systems ever conducted”, which concluded that “power generation from biomass is a sustainable energy technology which can contribute to substantial reductions in greenhouse gas emissions.”.
In the literal sense, “wood burning” is in fact carbon neutral.
In the practical sense, biomass power is sustainable technology, and has very low carbon impact.
Noel, you have the definitions backwards. I refer to unambiguous, accurate, and precise denotative definitions of the words “neutral” and “offset,” yet you continue to attempt to twist and distort their meanings. I carefully reread every possible definition of the word “neutral” and the word “offset.” There is nothing in the word “neutral” which refers to a “process of development.” Everywhere is the term “neither” or “nor.” That implies a state of existence: of “neutrality.” Neutrality is NOT a process; it is a state of being, a state of existence. The definition of “offset” does, however, denote a PROCESS and a DEVELOPMENT (look it up)
As an example you gave: “An acid neutralizes a base.” I would counter with “giving neither acidic NOR alkaline reaction.” In electrical work, neutral means “neither positively NOR negatively charged, or uncharged” There’s that word “NOR” again - suggesting a state of being, not a process or activity.
In chemistry, there is a state defined as “neutrality,” where the hydrogen ion concentration equals the hydroxide ion concentration. That is equivalent to what I have referred to in the vehicle analogy, as one of neutrality: It is a STATE of existence. I cannot hold in my hand a vessel (of solid liquid or gaseous carbon fuel) which is “carbon-neutral” because there is no such thing. What exactly is a neutral carbon fuel where carbon is present? This cannot be “neutral,” where the “object of neutrality” is in existence. That’s like saying “It’s there, but it isn’t there. That makes no sense at all! On the other hand, I can hold a beaker of “neutral” pH pure water, or a neutral salt solution, because that is a tangible thing. Neutral a mode of being, not a process.
Your acid-neutralization analogy brings to mind that we cannot justify, for example, the combustion of coal or wood, which both produce organic acids and inorganic acidic anhydrides (SO2, NO2, and CO2) which contaminate the lakes with acid rain. After all, we can offset the low pH with lime. But then, what of the trees and ground water - we cannot practically remove all of that acid. It is not right to pollute the atmosphere in the first place. That is what solid fuel combustion does best: pollute.
One website I’ve researched refers to “carbon-neutral” in it’s correct sense: NOT USING CARBON. (i.e. wind, solar, hydroelectric) Then they go on to address (what they refer to as) “The other carbon-neutral”: (i.e. burning biomass) Why confuse people? Why not call a horse a horse? Why must there be TWO TYPES of carbon-neutral? Why can’t biomass combustion be correctly referred to as what it actually is: “OFFSET?” Why don’t you define for our audience what “carbon-offset” means? Where is that going to take this conversation? (Maybe I should not dare ask)
Why do people misuse words? For example, I often hear people use the term “very unique” (just what does that mean?) Can something be 68.7% unique? 89.4% unique? The point is that the word “unique” cannot be quantified. Something is either unique or not. Calling wood burning “carbon neutral” is as absurd as calling a tomato a vegetable (it is a fruit)
You are trying to forge a denotation out of a connotation. I applaud your efforts, but I could not justify your determined position on these obtuse interpretations of these two words. Are we supposed to adopt an inaccurate word definition into our language, simply because people continue to mindlessly utter it without thinking? I refuse to jump on this bandwagon. We must use words in their proper context, with their real meanings, if we wish to have some semblance of being scientific.
“Carbon-neutral-wood-burning” is not a FACT, simply because you say so. Sorry but I have added this to my list of oxymorons. I don’t care if I were the last man on earth to make this argument, wood burning cannot be carbon neutral, simply by definition. I am not the one fighting a “losing battle.” In fact, I’m not “fighting” anything; the English language is what it is.
“A rose by any other name would smell as sweet” (From Shakespeare’s Romeo and Juliet)
Woodnyet
We are using neutrality in relation to energy.
How about the dictionary?
neutral
adj. impartial, without bias; lacking definition, of no particular kind or character; without intense coloration, matching most colors; neither acidic nor alkaline (Chemistry); neither of a positive charge nor a negative charge (Physics)
I think in practice the term “carbon neutral” is used confusingly to mean
(a) creating energy without producing carbon e.g. a solar panel
(b) creating energy producing carbon but balancing the carbon produced with carbon sequestrated as part of the process e.g. biomass
(c) Carbon offsetting generally e.g. the London Taxi that claims it is carbon neutral.
Taking the dictionary definition it seems to me that the use within the contexts of (b) and (c) are simply marketing phrases and the accurate meaning of the word lies in (a).
Of course there are nuances; on a lifetime basis solar panels are made with carbon but generally after two years or less they save the carbon used in their manufacture and thereafter produce energy without producing carbon. None of this to my mind stops solar panels being carbon neutral.
Woodynet; people misuse words for their own purposes - Orwell’s 1984 shows that when words lose their meaning we lose our freedom.
Robert