Is Biomass Really Carbon Neutral?

[russ_watters]

I'm going to pick on Germany a bit here, based on something I recently learned in the solar power thread: About 9% of Germany's power is produced by wood biomass burning, second only to wind in their "renewable" sector. Clearly, wood can be "renewable", but to me the more important question is: is it green?

It appears that the EU considers biomass to be "carbon netural" and thus subsidizes it as a clean, renewable energy source. But the situation is not so clear in the US and there is debate about the issue (sources below).

My first pass at the issue is that calling biomass "carbon neutral" and therefore "green" is figuratively and even quite literally missing the forest for the trees. Trees are renewable and carbon neutral in exactly the same way fossil fuels are -- they are, after all, one of the things that generates the "fossils" for fossil fuels. The main difference is the timescale. Trees sequester carbon and if they get buried deep, they sequester carbon for a very long time. Along those lines, an old forest is sequestering more carbon than a young forest and a tree that has been installed in support of a house is sequestering carbon for decades or even centuries longer instead of putting it immediatly back in circulation by burning it.

So to me, while it is true that when viewed from a conservation of mass standpoint and only considering the power plant use in isolation that biomass is carbon neutral, the other ways to use trees are carbon negative or carbon sequestering. So the change of use is therefore carbon positive.

Thoughts?

https://en.wikipedia.org/wiki/Electricity_sector_in_Germany

US policy discussion by a biomass advocacy group:
http://www.afandpa.org/issues/issues-group/carbon-neutrality-of-biomass

EU and biomass:
https://www.chathamhouse.org/expert/comment/wood-not-carbon-neutral-energy-source

 

[Bandersnatch]

It seems pretty clear-cut to me: as an energy source biomass farming is carbon-neutral. As a sequestration device it's carbon-negative (tautologically). The point is, you need to get energy from somewhere, so whether you use biomass or e.g. solar panels, doesn't matter.
Whether you then separately support sequestration initiatives is a completely separate issue. Using the sequestration argument against biomass can just as well be used against solar, and makes as much sense - after all, you could have planted vegetation on the site of your solar plant.

This is assuming that net biomass consumed/replanted by the energy production process remains 0. If you start burning existing forests and not replacing them one for one (as the last article suggests happens), then you're doing the whole concept of renewable wrong.

 

[russ_watters]

It seems pretty clear-cut to me:

Pun intended?

...as an energy source biomass farming is carbon-neutral.

Yes[edit]
By time I finished writing this post, I no longer believe that. I believe it is presented as carbon neutral on the basis of false and red herring assumptions.
[/edit], and I asked the question in the OP knowing the obvious answer because that's how (in my limited research) I see the question presented. My thought path to this thread was essentially:
Wow, Germany uses a lot of biomass!
Why do they do that?
Because it is carbon neutral.
Oh, ok, great...
...er, wait, what? What does that really mean? Is that really all there is? Is it really good/green?

As a sequestration device it's carbon-negative (tautologically).

Is it? I guess it depends on where you set your baseline.

The point is, you need to get energy from somewhere, so whether you use biomass or e.g. solar panels, doesn't matter.

That is indeed the question I'm asking, but I'm struggling with your answer -- which does appear to be the dominant position.

Whether you then separately support sequestration initiatives is a completely separate issue. Using the sequestration argument against biomass can just as well be used against solar, and makes as much sense - after all, you could have planted vegetation on the site of your solar plant.

Again, I suppose it depends on your baseline. Are we starting with an empty field or a forest? If it is an empty field, then either planting trees or putting in solar panels is a positive step. If you start with a forest - and most of Europe was once forest, I think - then you have to weigh the released sequestered CO2 against the benefit of the solar farm, and I don't think that's an easy calculus. Generally, I think environmentalists cite deforestation as being a contributor to global warming.

I think it also depends on what you define as the problem: to me, the problem isn't too much emission of CO2 it is too much CO2 in the atmosphere. Emission of CO2 makes the problem of too much CO2 in the atmosphere worse, but it isn't itself the problem.

And then also it depends on how you frame the question. Too often questions like this are framed as yes-or-nos or either-or...and worse, the either-or is often presented wrong. We've had this issue in discussions of nuclear power where people will incorrectly claim saying no no nuclear power wasn't in the past saying yes to coal. It gets a little more complicated here:

If we start with a forest and use it to power a biomass electric plant and shut down a coal plant, that's definitely in the long run a positive step: the loss of sequestration will be offset in probably a pretty short period of time by the savings in coal power. If we start with a field and plant a forest to use for biomass, we get sequestration and coal offset. Of course, if we plant trees on most of it and use a small amount for a solar farm, that would be even better (since solar uses less land per kWh). But then again, if we built a nuclear plant on the land, that would be the best possible carbon offsetting use of the land.

I think therefore the question may hinge on whether existing or new forests are being used. The 3rd link in my OP says it is mostly existing forests, which means it is mostly releasing sequestered carbon. And due to the long time (many decades) it takes a tree to re-grow, that's a pretty significant step in the wrong direction in my view. Natural gas is being touted as a stop-gap solution to help us get off coal. To me, biomass still seems like it's the opposite: it would help some (versus coal) in the long run but hurt in the short run. Which to me still makes it a bad idea.

...still struggling with this though. Incidentally, I just checked Greenpeace's website to see their opinion on the matter, and they agree with me -- which is just about enough to convince me I'm wrong! A more respectable source says scientists are divided:
http://www.sciencemag.org/news/2017/01/wood-green-source-energy-scientists-are-divided

At the very least, the claim of being carbon neutral should require a clear-cut (there it is again!) accounting that the forest is, in fact, being re-grown. It appears from the Science article that it isn't being done that way: the power is designated as carbon neutral without regard to where the wood came from or if new trees are being planted in their place.

 

[TeethWhitener]

It's an interesting question, and a lot of what I read in your links is surprising. Simply for economic sustainability, you'd expect energy generating companies to favor fast-growing biomass (like bamboo or other grasses) over old-growth forests. It looks like at least a few companies are trying to capitalize off agricultural and timber waste, but I'm not sure how big an operation you can run with only those types of biomass sources. With regard to carbon neutrality, I suppose you could make the argument that a source remains carbon neutral if the total biosphere can efficiently soak up the increased carbon emissions from it, but that seems kind of weak in the absence of pretty extensive modeling.

 

[anorlunda]

An IRS auditor once gave me this advice. "Never ever try to apply logic when dealing with the IRS." I say the same to you Russ when dealing with all things "green." It's 95% political and only 5% rational.

 

[russ_watters]

An IRS auditor once gave me this advice. "Never ever try to apply logic when dealing with the IRS." I say the same to you Russ when dealing with all things "green." It's 95% political and only 5% rational.

You are right of course, but I'm not wondering why others support it but rather whether or not I should...based on its merit.

 

[RonL]

You are right of course, but I'm not wondering why others support it but rather whether or not I should...based on its merit.

My take on it is, if we all get on board with the effort to stop (or even slow) global warming, it will be much like each and every person signing a blank bank note and letting politicians fill in the amount, as they throw money at some crazy ideas in (what I think would be futile) attempts to make a difference.
I won't live long enough to be affected, so I will link to what I believe is a possible solution that has some history and with some out of the box thinking will perform well enough to be part of the future solution.

https://en.wikipedia.org/wiki/Compressed_air_energy_storage

History[edit]
Transmission[edit]

It has been suggested that this section be split out into another article titled History of pneumatic power. (Discuss) (November 2015)
Citywide compressed air energy systems have been built since 1870.[15] Cities such as Paris, France; Birmingham, England; Dresden, Rixdorf and Offenbach, Germany and Buenos Aires, Argentina installed such systems. https://en.wikipedia.org/w/index.php?title=Victor_Popp&action=edit&redlink=1 constructed the first systems to power clocks by sending a pulse of air every minute to change their pointer arms. They quickly evolved to deliver power to homes and industry.[16] As of 1896, the Paris system had 2.2 MW of generation distributed at 550 kPa in 50 km of air pipes for motors in light and heavy industry. Usage was measured by meters.[15] The systems were the main source of house-delivered energy in those days and also powered the machines of dentists, seamstresses, printing facilities and bakeries.

Storage[edit]

• 1978 – The first utility-scale compressed air energy storage project was the 290 megawatt Huntorf plant in Germany using a salt dome.
• 1991 – A 110 megawatt plant with a capacity of 26 hours was built in McIntosh, Alabama (1991). The Alabama facility's $65 million cost works out to $590 per kW of generation capacity and about $23 per kW-hr of storage capacity, using a 19 million cubic foot solution mined salt cavern to store air at up to 1100 psi. Although the compression phase is approximately 82% efficient, the expansion phase requires combustion of natural gas at one third the rate of a gas turbine producing the same amount of electricity.[17][18][19]
• December, 2012 – General Compression completes construction of a 2 MW near-isothermal CAES project in Gaines, TX; the world's third CAES project. The project uses no fuel.[20]

 

[mheslep]

... If you start burning existing forests and not replacing them one for one (as the last article suggests happens), then you're doing the whole concept of renewable wrong.

To do wood for fuel above a couple percent of load is to inevitably to do it wrong. It's a return to the 18th century, where the countryside was denuded of trees for 50 miles around Boston.

Wood chip exports to eu doubling yearly

 

[Bandersnatch]

Yeah, but I don't see anyone advocating using biomass to cover for all the energy needs of modern societies.

 

[mheslep]

Yeah, but I don't see anyone advocating using biomass to cover for all the energy needs of modern societies.

*All* is impossible, but ~1/5 could done for awhile, which would be a disaster in my view. Germany as Russ noted is near 10% biofuel.

 

[zbikraw]

Ex definitione biomass burning should be carbon neutral, but in modern practice - it isn't. I didn't hear about biomass technology wchich gives even chance to be C - neutral (see below). In my opinion it goes from political history of bimass use as climate change remediation. The idea of substituting fossil fuels by biomass exploitation goes from science with some examples of tricky and effective technologies. Then it was elaborated by politicians, statemans and various lobbies, and appears as a law without technological directives. Biomass programs were dedicated to agriculture, forestry and energy sectors, without imposing use of dedicated tchnologies and equipment for low - energy and low - fuel use operation. In reality, all these sectors are public - donation thirsty and technically conservative. All are operated by profit maximization.
So biomass enters existing fossil - fuel consuming factories and technologies without changes, read ineffectively. Co-burning of a woody biomass with fossil fuels in large electricity stations is an example of technical idiotism. To operate, such installation must burn fossil fuel, what means high temperature operation (coal to 1000 deg C, some fuels much more). Minor biomass burned separately gave exhaust gases with temperatures about 500 deg C. Burned with fossil fuels, wood loses competition for limited amount of oxygen and undergoes thermal degradation (similar to "dry distillation process"). Its gaseous products are oxygenates, so they burns in moderate temperatures, lowering thermal output of burning. Condensed products, similar to tar and coke, mainly resists burning in a limited time of appearance in the burning zone. They ends in trash and no one is interested in their content, rich of cancer - causing policyclic aromatic compounds. Low biomass content in fuel gave only donations for electricity stations, higher content would lower thermal output (and energy yield, see Carnot cycle). Burning dedicated to the biomass should give fossil fuel unchanged. Additionally, biomass contains NaCl and other highly corrosive salts and harms much of existing power plants.
In my country (Poland) first bill introducing biofuel defined it as made from food-quality crops and imposing use of nutrients, pesticides, etc. same as for edible crops. Of course, ruling farmer's party wanted to enlarge crop prices, but after many years without peysans in power this didn't change. Now we have EU regulations, a bit more sustainable, but allowing many of such anti - social practices. Existing production and market systems are dedicated to maximization of scale, so the scale of biomass transport is also maximized (use of quality fuels for moving low energy - content biomass should be abolished).
Even the biomass wonder - microalgae, can be planted in climate - harming way. The first such station in Poland was operated under constant all-day artificial light (to overcome solar instability). Taking photosynthesis yield as 8%, LED lamp effectivity as 50% and average power plant effectivity as 33%, one can obtain rather strange example of CO2 emission lowering. Another generally unsolved problem with biomass burning is drying and preservation from moisture. In agricultural practice it's strongly fossil fuel consuming.
Assuming change of political decisions as improbable, one can preserve the climate in many more effective ways. Relatively unexplored are optimization of electromechanical sets performance, change of existing AC grid for DC one, and transforming rubbish into fuel and/or energy. Remember that in 2015 an UN report stated that possibilities of improvement of energy efficiency are in order of 50%.
Greetings for everybody,
Zbikraw

 

[mfb]

Permanent carbon sequestration in forests (carbon that would end up in fossil fuels) is negligible on land, especially in countries like Germany where all the area is managed somehow. All carbon that is bound is released again over years to decades.

Some part of the biomass is just waste from agriculture - that is certainly carbon neutral.
Some parts are from agriculture, where the fields are designed to produce as much biomass as possible - also carbon neutral, but a questionable land use.
Concerning forests: The total area of forests in Germany is roughly constant. 2012 it was 32.0% of the area, 2002 it was 31.9%. That number doesn't take into account how much carbon is bound per area, but there is clearly no large-scale deforestation ongoing.

Most biomass is (a) converted to gas and burned separately, (b) wood, and burned separately (for heating for example), or (c) converted to liquid hydrocarbons and added to fuel. That works reasonably well and saves some petroleum (not much, however).

 

[zbikraw]

Permanent carbon sequestration in forests is a small part of large carbon flux in land. Anhropogenic emissions and diminishing of natural sequestration account for less than 20% of "natural" fluxes on Earth and are partially compensated by elasticity of natural processes. Danger for climate resulting from excess emission is that emissions to atmosphere enlarges natural feedback of heat flux regulation. From a tiny inequilibria in atmospheric composition we obtain the large changes in heat and matter fluxes. The main effect of CO2 content change is a large shift in water liquid-vapor equilibria, and water vapour is the real agent of Earth greenhouse effect.
Most of carbon fluxes in Nature are poorly investigated, which results in large error margin in climatic computing. Climatologists rely on atmospheric measurements and phenomenological coefficients of feedbacks. These can give large errors, as biological feedbacks are nonlinear and changes its chemical mechanisms after passing relatively unknown ambient condition barriers (temperature, pH, etc).
The most of known to me investigations of C content associated with agriculture and forestry gives C content in visible plants significantlty lower than in ambient soil (especially in microorganisms). These latter can change drastically after rain, fertilizer or pesticide application, and its dynamics is hours and days timescale. This relatively unknown research area must be filled by investigation, but these needs many years and we have no time for reconsidering climate policy assumptions. To save our civilization we must act NOW.

 

[rootone]

Other than general reforestation being a good idea, surely somebody must have researched plant species which are particularly efficient for carbon sequestration?
In other threads people are talking about colonies on Mars, and that will need those kind of plants.

 

[zbikraw]

Other than general reforestation being a good idea, surely somebody must have researched plant species which are particularly efficient for carbon sequestration?
In other threads people are talking about colonies on Mars, and that will need those kind of plants.

For every environment there exists many "relatively optimal" sets of plants and accompanying soil microorganisms. "Non-optimal" means non-stable, non-resilient or non-sustainable. There is no sense in planting other sets of organisms. One can choose the set optimal to his purposes. From the point of view of climate protection, CO2 assimilation from air is important criterion, but there exists another ones. The plant can be burned, substituting fossil fuels, and there are huge differences in various plant value as the fuels. The plants can be sources of construction materials, pharmaceuticals and chemicals otherwise produced with large expenses of fossil fuels. Of course, there are many examples of using synthetic ones because there are cheaper or easier to manufacture than "natural" ones.
Any ecosystem has a range of possible effectiveness as "carbon trap", and position in these ranges occupied by given ecosystem depends on many factors dependent on humans (mainly the choice of plants, planting eucalyptuses in tropical jungle is a good choice, in tundra its a catastrophe), or relatively independent (climate during first month of growth, presence of generally unknown organism in a given soil, etc). Generally, we evan don't know many important factors, as this part of agroecology is developed mainly in some rich countries with strong science. So in a huge majority of the lands we have to rely on experience and intuition, not the science.

 

[BillTre]

Forest management will influence the answer:
Oregon has http://www.oregonloggers.org/Forest_facts_SimpleFacts.aspx after harvesting timber:

"Strict forest laws assure trees are planted and growing to replace timber harvested. Oregon has the highest private land reforestation compliance rate in the nation -- averaging 97%. For example, Oregon's landowners planted trees on a total of 150,879 acres in 1996 -- over half of this reforestation was done by private owners. More than 40 million seedlings were planted. That's 12 seedlings for every Oregonian."​

This should in the long run (hundreds of years for old growth forests) bring it toward carbon neutrality. I don't know if that was one of the reasons for the Oregon law (it was enacted before I moved to the state). Other possible reasons might be reducing erosion (Oregon has its hilly parts) or some other reason.

Most of the timber harvested will be turned into lumber for building and similar purposes. Thus it will largely remain sequestered for a while (decades maybe, in a house or whatever).
That which is not could be burned but that would be a fraction of the whole.

The immediacy of sequestration returns would also be affected by how old the trees are and when in their lives do they sequester the most carbon dioxide (old trees sequester more seems to be the answer).

A question I have is what happens to the carbon when the trees die or parts fall off (how much becomes carbon dioxide and how much gets trapped in the ground or other growing plants or fungi, how long will it stay there).
For example, this horizontal non-log in this picture from the Olympic Peninsula:

 

[CWatters]

A question I have is what happens to the carbon when the trees die or parts fall off (how much becomes carbon dioxide and how much gets trapped in the ground or other growing plants or fungi, how long will it stay there).

As I understand it small branches generate methane when they rot so burning them is carbon negative. However whole trees release their carbon much more slowly and if you include emissions from transportation they end up carbon positive when burnt. I'm sure it's not that simple though.

 

[PAllen]

I'm going to pick on Germany a bit here, based on something I recently learned in the solar power thread: About 9% of Germany's power is produced by wood biomass burning, second only to wind in their "renewable" sector. Clearly, wood can be "renewable", but to me the more important question is: is it green?

It appears that the EU considers biomass to be "carbon netural" and thus subsidizes it as a clean, renewable energy source. But the situation is not so clear in the US and there is debate about the issue (sources below).

My first pass at the issue is that calling biomass "carbon neutral" and therefore "green" is figuratively and even quite literally missing the forest for the trees. Trees are renewable and carbon neutral in exactly the same way fossil fuels are -- they are, after all, one of the things that generates the "fossils" for fossil fuels. The main difference is the timescale. Trees sequester carbon and if they get buried deep, they sequester carbon for a very long time. Along those lines, an old forest is sequestering more carbon than a young forest and a tree that has been installed in support of a house is sequestering carbon for decades or even centuries longer instead of putting it immediatly back in circulation by burning it.

So to me, while it is true that when viewed from a conservation of mass standpoint and only considering the power plant use in isolation that biomass is carbon neutral, the other ways to use trees are carbon negative or carbon sequestering. So the change of use is therefore carbon positive.

Thoughts?

https://en.wikipedia.org/wiki/Electricity_sector_in_Germany

US policy discussion by a biomass advocacy group:
http://www.afandpa.org/issues/issues-group/carbon-neutrality-of-biomass

EU and biomass:
https://www.chathamhouse.org/expert/comment/wood-not-carbon-neutral-energy-source

I agree with you, and further think a similar case corn based ethanol. Here, while there is not other use that carbon negative, the tradeoff is making a crucial food staple more expensive. I personally don't think either of these should be pursued much as part of the (unmentionable on PF) solution.

 

[Rive]

Thoughts?

Some wood can be extracted from a forest without severely damaging it. With this the sum of biomass will drop compared to the untouched forest (this part of the business releases carbon), but on long term the annually extracted wood is actually 'free carbon' (since it is no longer compared to an untouched, but to an used forest).

The carbon neutrality of this 'free carbon' depends on the circumstances. How far is it transported, what it is used for.
For example to import wood chips (which is actually not by- but main product in this regard) from Canada to Europe - well, is that even a question?
Was it ever a question?

About plants used as energy source: this is the same system which is used for food production, and THAT just turns fuel to food, with pretty bad efficiency (energy wise). To turn it back to fuel/energy - quite bad deal.

About byproducts of food or other production: again, this depends on the circumstances, and cannot be discussed without details.

 

[Ken Fabos]

Depending on how well it's managed burning biomass looks, in climate terms, to be at best "less bad" than fossil fuels, but for many environmentalists - them being a very diverse lot with varied priorities - the maximising of biodiversity values of land use may take precedence over biomass use displacing fossil fuels; I seriously doubt that it's hard core political environmentalism's choice to use forests that way, it is more likely that biomass burning is commercial forestry's choice. That would be choices made by interests other than "green" ones, in response to the broad challenges the climate problem present.

Can forests sequester more than got released in the prior deforestation? I'm doubtful. Even when it's sequestered as wood products that won't be a permanent sink except by total mass of wood products constantly rising. Some rebound from more extreme deforestation practices of the past will only give an unsustainable illusion of dealing with emissions from ongoing burning of fossil fuels.

Whilst the fundamental problem is an unparalleled environmental one, in human terms it's also an unparalled problem affecting long term economic prosperity and security; we shouldn't blame environmentalism for mainstream politics' inability to grasp with the issues effectively nor for the broad willingness to choose gestures over substance, nor blame them for the choices commercial interests have taken in response to the inadequate and compromised emissions policies that conflicted politics has produced. We certainly should not blame them for GHG emissions considerations making their inconvenient way into energy and other policy choices, no matter how we may disagree with those policies; science based knowledge independent of any political environmentalist agenda did that.

 

[Buzz Bloom]

The systems were the main source of house-delivered energy in those days

Hi Ron:

I am confused about why a compressed air system is relevant to the topic of "carbon neutral"? Is electricity carbon neutral? It seems to me that both compressed air and electricity are means of transferring energy from one place to another. What seems relevant is how energy is created rather than how it is transmitted.

I suppose that compressed air can be compared with electricity with respect to the efficiency of transmission, that is, the fraction of energy loss by the transmission process. Do you have any data sources on hat? Being more efficient with transmission is no doubt a benefit, bit I don't see that it is a carbon neutral issue.

Regards,
Buzz

 

[Buzz Bloom]

As I understand it small branches generate methane when they rot so burning them is carbon negative.

Hi CWatters:

I confess I do not understand this point. From what you said, It seems that burning the small branches produces CO2 while letting them rot produces CH4. That appears to break even with respect to carbon. In addition, CH4 in the atmosphere raises temperature more effectively per molecule than CO2. Therefore burning would seem to be a better choice in reducing climate effects than rotting.

Regards,
Buzz

 

[Kevin McHugh]

By that logic, coal which is derived from biomass should be carbon neutral too. The only difference a time lag in utilization.

Apologies Russ, after further review I see you made the same point.

 

[Dale]

The main difference is the timescale.

That is a really interesting point that I had not considered before. There is only a certain amount of carbon on the planet, so in that sense everything is necessarily carbon neutral. The question is how long has the carbon been out of the atmosphere. Instead of talking about tons of CO2 emitted, they should talk about the "age" of the released carbon. Algae and grass (incl. corn) would be months, trees would be decades, and fossil fuels would be eons.

Carbon sequestration could be described in similar terms.

 

[PAllen]

That is a really interesting point that I had not considered before. There is only a certain amount of carbon on the planet, so in that sense everything is necessarily carbon neutral. The question is how long has the carbon been out of the atmosphere. Instead of talking about tons of CO2 emitted, they should talk about the "age" of the released carbon. Algae and grass (incl. corn) would be months, trees would be decades, and fossil fuels would be eons.

Carbon sequestration could be described in similar terms.

The last time the carbon in fossil fuels was in circulation was the coal age, which had much less land mass, more ocean, and very hot weather world wide. Clearly, the planet could survive this, as could people. The big question is the cost (all senses) of avoidance versus adaptation.

 

[CWatters]

Hi CWatters:

I confess I do not understand this point. From what you said, It seems that burning the small branches produces CO2 while letting them rot produces CH4. That appears to break even with respect to carbon. In addition, CH4 in the atmosphere raises temperature more effectively per molecule than CO2. Therefore burning would seem to be a better choice in reducing climate effects than rotting.

Regards,
Buzz

Yes from what I read burning some wood is a good idea BUT it depends on the wood and where it comes from. There are probably better articles but this refers to UK government data..

https://www.carbonbrief.org/is-burning-wood-for-energy-worse-for-the-climate-than-coal

Good..

If Drax is burning wood residues like twigs, small branches or sawdust that would otherwise have been burnt as waste, then the emissions will be below 100 kilograms per megawatt hour, or at least ten times lower than burning coal.

Burning wood residues instead of leaving them in the forest to rot is also generally low carbon. Increasing plantation yields with fertiliser or better management also yields climate-friendly biomass, as long as the rate of harvest does not increase.

Bad..

Not all types of biomass are good for the climate. In the cold northern forests of Canada it is usually lower carbon to leave coarse forest residue or trees killed by beetles to rot, because this happens slowly. Biomass from sources like this produces emissions higher than natural gas, though still lower than coal.

Reducing the rotation rate of trees to boost forest output is also generally a bad idea for the climate and can lead to the production of biomass that’s higher carbon than coal. Several other DECC scenarios also show that burning wood in UK power plants can be worse than coal. This includes harvesting wood from naturally regenerating forest, with emissions of up to 5,174 kilograms per megawatt hour – a staggering five times that of coal.

 

[Rive]

Burning wood residues instead of leaving them in the forest to rot is also generally low carbon.

Side effect is, that on long term it sterilising the forest. Making it a vulnerable, fragile ecosystem.
Guess that's not a big problem for the author, since not too far on this track

Increasing plantation yields with fertiliser

coming the hydroponic forest.

 

[Buckleymanor]

That is a really interesting point that I had not considered before. There is only a certain amount of carbon on the planet, so in that sense everything is necessarily carbon neutral. The question is how long has the carbon been out of the atmosphere. Instead of talking about tons of CO2 emitted, they should talk about the "age" of the released carbon. Algae and grass (incl. corn) would be months, trees would be decades, and fossil fuels would be eons.

Carbon sequestration could be described in similar terms.

I reckon that is why they call it Biomass and not fossil fuel.
Strictly speaking fossil fuels are part of the biological mass that contains captured carbon but the time scale is what is important as far unacceptable warming to the atmosphere.
If you were to release all the carbon that has been out of the atmosphere then there would be problems with temperature however more recently produced biomass burning will probably produce a negative or neutral effect with regards warming.

 

[Dr Transport]

Interesting thread, enjoying every bit of the discussion here.

Some wood can be extracted from a forest without severely damaging it. ...

Yes, absolutely true, when I lived at home with my parents, dad and I installed a word burner to heat the house. We only cut up dead trees and went through our 20 acre plot to look for diseased trees to remove. The area actually became healthier and the forest more efficient over a decade. I'm not for clear cutting but for selective removal, you keep the forest going without lags in productivity when you have to wait decades for seedlings to mature so that you can cut them down for fuel.

 

[Greg Bernhardt]

We only cut up dead trees and went through our 20 acre plot to look for diseased trees to remove.

In a way though, isn't keeping the dead trees where they are part of the natural process? When you remove decaying matter you remove important biodiversity?

 

[Dr Transport]

In a way though, isn't keeping the dead trees where they are part of the natural process? When you remove decaying matter you remove important biodiversity?

It does, but in a forest where insects are the culprit in propagating a disease, it also reduces the spread of the devastation.

 

[RonL]

Hi Ron:

I am confused about why a compressed air system is relevant to the topic of "carbon neutral"? Is electricity carbon neutral? It seems to me that both compressed air and electricity are means of transferring energy from one place to another. What seems relevant is how energy is created rather than how it is transmitted.

I suppose that compressed air can be compared with electricity with respect to the efficiency of transmission, that is, the fraction of energy loss by the transmission process. Do you have any data sources on hat? Being more efficient with transmission is no doubt a benefit, bit I don't see that it is a carbon neutral issue.

Regards,
Buzz

I have a hard time using relevance to tie my thought process together one topic to another, "carbon-neutral" registered more than "bio-mass" and I thought of compressed air, which to me is different from electricity by the fact it performs not only because of pressure but by the heat it carries or is exposed to and the variation of such adjustments. Electricity is pretty cut and dried watt for watt.
It might be off topic enough to require it's own discussion thread,

 

[Dr. Courtney]

When I was a farmer in Ohio for a decade, I sold firewood on the side which made up about 20% of the farm business income. But the firewood production was always secondary to another operation, usually the sale of standing timber to be made into furniture. We'd sell a stand of timber to some Amish timber guys who would drop the trees and haul the marketable timber (big logs) out with horses to be sold to the mills to be cut and go into the furniture pipeline. Then me and my guys would go in behind the timber guys and make the "slash" into firewood. These are the limbs and branches that are too small (or poorly formed) to be made into marketable lumber. At least where I was in Ohio, about 80% of the wood mass ended up on the trucks headed for the mills, and about 20% ended up as "slash" which was what we made into firewood and sold as such.

I'm not exactly sure the time scale of the sequestration of the 80% that went to the mills, but the part that made it into furniture got sequestered for a long time. The trimmings and sawdust ends up in various applications with shorter sequestration times: paper, pencils, fiberboard, and pressed wood pellets for wood stoves (same heating application as firewood).

Since firewood (and pellets) and the other shorter sequestration uses are all much less valuable than lumber in most markets, I would reckon that there are very few wood markets where 100% of the wood production gets burned within a year or two of harvest. A sensible discussion needs to quantify how much of the biomass production of the wood ends up in long sequestration applications (homes, furniture) and how much ends up in short sequestration applications (fuel, paper, pencils, etc.)

At least in Ohio, the slash that becomes firewood would just sit in the woods rotting with a comparable sequestration time if it is not picked up and sold in the fuel markets. Due to the cost of labor, a lot of slash from timber harvests is not used for fuel.

 

[Ken Fabos]

Seems like there is a lot of room for continuing use of biomass for energy beyond and apart from simple local use of firewood (because it's there) for cooking and heating - but I think at larger scale it will mostly be as an adjunct to other activities, such as dealing with waste streams from sawmilling (because it's there) or perhaps, in places of high fire hazard (like where I live), harvesting and gasifying flammable plant materials in place of hazard reduction burning around the interfaces between rural and urban (because it's going to be burned anyway). I would be interested to see more development of small scale gasification for rural households - astonishing amounts of highly flammable material get raked into piles and burned or burned in situ each year around rural and forest/park edge households simply to reduce bushfire risks. It's not going to be 100% carbon neutral but it can still reduce emissions by it's participation in the fast carbon cycle. The slow carbon cycle includes mineral weathering, laying down and natural release of fossil carbon via coal and oil - it's the fast carbon cycle, between vegetation, soils, soils atmosphere and oceans that is relevant here and now.
There isn't going to be one ideal forest management regime - we can manage to maximise timber production, manage to reduce wildfire hazard, manage to preserve local natural ecosystems and biodiversity, manage to deal with immediate problems like weeds, pests and diseases as well as deal with long term ones like achieving those aims with expectations of changing climates and shifting land use priorities. The removal of all dead wood for example, will have impacts on nutrient cycling and availability of habitat for wildlife.

 

[Rive]

A sensible discussion needs to quantify how much of the biomass production of the wood ends up in long sequestration applications (homes, furniture) and how much ends up in short sequestration applications (fuel, paper, pencils, etc.)

The very first thing would be to ask about forest from somebody who has the qualifications to manage a forest. A cycle length for forest management is 30-100 years: even for the less valuable forests it is longer than the whole environmentalism in whole.

That's what pissing me off about these kind of discussions (especially the ones where the topic is narrowed down to short term carbon management -> thus rendered completely useless).

There isn't going to be one ideal forest management regime - we can manage to maximise timber production, manage to reduce wildfire hazard, manage to preserve local natural ecosystems and biodiversity, manage to deal with immediate problems like weeds, pests and diseases as well as deal with long term ones like achieving those aims with expectations of changing climates and shifting land use priorities. The removal of all dead wood for example, will have impacts on nutrient cycling and availability of habitat for wildlife.

I don't know how this work for other countries, but here (Hungary) the starting line is that there is a given percent of wood mass what should remain in the forest, regardless of its quality.
The actual topic in forest management is the application of a kind of 'rolling cut' instead of regular 'clear cut', so in any area the trees would be with mixed age.
This one is so 'hot' topic that during the next 30-50 years the whole industry is expected to apply it.

Now, tell me something in environmentalism what could be planned for even just a decade.

...

...Sorry, had to vent some steam.