David Beebe said, in a comment here on this previous post:
“Perhaps vested interests aren’t the best sole source for getting to the heart of the science on this matter without at least including contrasting conclusions coming from perhaps more objective sources?
For instance, http://18.104.22.168/90scientistsletter.pdf”
Now I know some but not many of these “vested interests”. In fact, Jim Burchfield has posted on this blog. As far as I know, all scientists have vested interests in getting research funds. And if you know a lot about something, (say a bird species), you tend to think they are pretty important; hence you are never very objective. Maybe we ought to give up the mythology of the objective scientist and just slog through the claims and counterclaims using logic and practitioner knowledge and see how far we get.
So let’s examine the knowledge claims in this letter.
1. Replacement of fossil fuels with bioenergy does not directly stop carbon dioxide emissions from tailpipes or smokestacks. Although fossil fuel emissions are reduced or eliminated, the combustion of biomass replaces fossil emissions with its own emissions (which may even be higher per unit of energy because of the lower energy to carbon ratio of biomass). Agreed.
2. Bioenergy can reduce atmospheric carbon dioxide if land and plants are managed to take up additional carbon dioxide beyond what they would absorb without bioenergy
This isn’t the clearest statement. Plants will grow and absorb carbon. If the previous plants are removed and used for bioenergy, new plants will grow and absorb carbon equivalent to that released when the previous plants are burned. Are we saying the same thing here? Not sure.
3. Alternatively, bioenergy can use some vegetative residues that would otherwise decompose and release carbon to the atmosphere rapidly. I would add possibly “even more rapidly through fires.”
4. Whether land and plants sequester additional carbon to offset emissions from burning the biomass depends on changes both in the rates of plant growth and in the carbon storage in plants and soils. OK.
6. For example, planting fast-growing energy crops on otherwise unproductive land leads to additional carbon absorption by plants that offsets emissions from their use for energy without displacing carbon storage in plants and soils. Agreed but not many acres around that are unproductive but would also grow energy crops.
7. On the other hand, clearing or cutting forests for energy, either to burn trees directly in power plants or to replace forests with bioenergy crops, has the net effect of releasing otherwise sequestered carbon into the atmosphere, just like the extraction and burning of fossil fuels.
The other letter did not talk about replacing forests with bioenergy crops, or clearing forests. If it is thinning, that carbon would be released anyway when the suppressed trees ultimately die. I am not following this logic for thinnings, or for dead trees. If we take dead trees, they are replacing fossil fuels and the place they vacated will be sequestering carbon. By getting the dead guys out, they are also opening places for new plants to re-sequester faster.
These seem to be the main questions:
1. What biomass are you taking off the acres?
2. What would happen to the carbon if you didn’t remove some biomass?
3. What would happen to the carbon if you removed the biomass but didn’t use it for energy?
3. What is the difference if you did use it for bioenergy?
Let’s use an example.
You are doing a thinning in ponderosa pine to “restore to HRV” and/or for fuels reduction.
You can use the trees for energy to replace fossil fuels OR you can put them into wood products OR you can pile them and burn them.
If you put them into wood products, the carbon will be released more slowly than in the woods. But you would be using the gas for heavy equipment and transportation and electricity (coal?) at the mill, more transportation to the Home Depot, etc. However, at the Home Depot it would replace boards from Canada, which might presumably have the same gas to extract from the woods, maybe hydro for western mills (don’t know) and possibly more transportation.
If you put the trees into bioenergy, you would still have to haul somewhere or chip and haul. But should this be compared to, say, extracting natural gas? There seems to be plenty of hauling associated with that, including heavy equipment drilling, compressors, etc. Or our old friend coal. Say, on an open mine there are huge pieces of equipment moving overburden and coal around (see photo above) (compared to how much for a skidder per energy unit) , and it goes on a train to the power plant, if you are in Wyoming, at least.
In fact, the more you think about this (in our region, we are being litigated on both coal and natural gas impacts currently, but not bioenergy) the more it makes sense to not consider carbon any differently from any other environmental impact.
It makes sense to me to line them all up (carbon, particulates, development impacts, etc.) and then make the judgment about what is the best energy source .
A carbon-o-centric view of energy sources might be good for some things (like setting up carbon trading), but not so good for others (deciding on the least expensive, and impactful energy technology that helps put jobs in rural America, and lets us control our own energy destiny).
7 thoughts on “Forest Biomass Carbon- Letter vs. Letter”
For once, I really don’t have anything to add, here! Using the least impactful harvesting methods of today, there ARE solutions to restoration that can improve existing forests without impacting our atmosphere significantly.
Sounds right to me.
This post has a few flawed mental models:
The author said: “If you put them [trees] into wood products, the carbon will be released more slowly than in the woods.” This is not always true. Only a small subset of the tree ends up in wood products and the rest is transferred to the atmosphere more quickly than if the log were left in the woods. OSU forest-carbon expert Mark Harmon says that on balance wood products emit CO2 at about the same rate as dead wood in the forest. The important variable to consider. Large wood is more likely to last longer in the forest than small wood. Wood in the forest is more likely to last longer in cool moist forest types compared to dry forest types with frequent (modern day, not historic) fire return intervals.
The author also said: “…If we take dead trees, … the place they vacated will be sequestering carbon. By getting the dead guys out, they are also opening places for new plants to re-sequester faster.” This is incorrect. It turns out that modifying existing forests so that they “re-sequester faster” necessitates high levels of ecosystem disturbance and carbon removal which results in accelerated transfer of carbon from the forest to the atmosphere. Also, dead trees do not really take up much growing space, and as stated above, dead wood in the forest is not emitting CO2 at any greater rate than wood removed from the forest and turned into wood products. In addition, wood removed form the forest often ends up in landfills where there is a relatively greater risk that it will break down anaerobically and be converted to methane which is far worse than aerobic conversion to CO2.
Tree- Welcome to our blog! I appreciate your contribution. BTW more sensitive people than I might not like your use of the terms “incorrect” and “flawed”. Our hope for this blog is that we might discuss to learn why you think the way you do and I think the way I do. We tend to use the term “disagree” more on this site (well, there are exceptions).
I think we are talking past each other (so common!) because I have a certain context in mind and your statements are generalizations, possibly about other contexts. I was too general also, in my previous post, thanks for catching that, which is why you think I am incorrect- I should have said that I have a specific situation in mind.
Especially since there are at least two different contexts on public lands..
1. What to do with trees when they need to be removed to reduce hazardous fuels or for other reasons.
2. Removing vs. leaving trees that are thinned when they don’t need to be removed for hazardous fuel reduction.
I am talking about 1- you may be talking about 2.
1. Again, here is the situation: you are thinning living trees anyway for fuels reduction. Your three choices are a) pile and burn, b) wood products, c) bioenergy.
You said that Harmon said that non-board elements of trees would give off carbon faster than if they were left in the woods. I am assuming that they would be lying there giving off carbon, but that’s not what would happen for an effective fuel treatment. They need to be removed, through trucking them off somewhere or by burning in place. Leaving them laying around would not satisfy the purpose and need.
Also, it seems to me that you can’t globally say “the rest is transferred to the atmosphere more quickly than if the log lays in the woods.” Wouldn’t it depend on what that particular mill does with the sawdust, bark, etc.? Conceivably, those products they could be used in a variety of products with different carbon rates. Some mills may use their waste for drying wood, etc., potentially replacing fossil fuels.
Isn’t most of the bole removed used in products? I haven’t been to a sawmill for a long time, but I assume that waste isn’t good for their efficiency (even 20 years ago I remember then using computer based sawing to reduce waste). So wouldn’t it a question of whether (y grams of tree in boards x carbon release rate for boards) is equal to, less than, or greater than (z grams of tree in waste x carbon release rate for whatever they use waste for)?
I wonder if this was what Harmon was thinking.. do you have a cite to a specific paper where he lays out his assumptions?
I was just saying that the NEW PLANTS on the area that the log would have been lying are sequestering faster than if the plants had to wait til the logs break down to become established. I probably wasn’t clear enough in this statement.
Actually, we are not talking about “modifying forests to re-sequester faster,” we are talking about (given that we have a fuels reduction treatment) (should we move and use or burn in place?). You seem to be arguing against managing forests for carbon, which is not at issue here.
In my example, there are no dead trees until they are cut down in the thinning project. So they are laying on the ground, and other plants can’t grow through them.
This doesn’t make sense for the example. We are discussing the pros and cons of burning on site, using in wood products or for bioenergy. Sending to landfills is hopefully not on the table as an alternative. It seems, though, as if bioenergy may produce less methane than natural gas or coal.
Both live and dead fuels add to the fuel loading problems in our National Forests. We are not only overstocked with green trees in many areas, we are also “snag rich” to the point of WAY too many. The belief that more trees and more snags is better is quite flawed, and we are seeing the enhanced mortality and fire intensity from this situation.
If we were to have biomass burners around, no wood would ever again have to go into landfills, causing those methane emissions. Imagine residents taking yard waste and putting it out on the curb to be picked up and paid for by biomass operators. Kind of like recycling bottles and cans are today.
Opponents of biomass subscribe to the slippery slope syndrome. They are saying that millions of acres will be immediately clearcut if biomass subsidies are enacted. They refuse to make comparisons of catastrophic wildfires to biomass burning. They refuse to fairly compare the impacts and benefits of biomass operations to their preferred idea of “letting nature take its course”. They also claim that HUGE biomass plants will be overbuilt, and that too many trees and snags will be cut to feed those plants. These are merely claims and opinions, and not facts, “Chicken Littles”.
Not only do catastrophic wildfires decimate forests, kill animals and people, damage watersheds, destroy cultural resources, raze campgrounds, spew GHG’s and other toxic gases, they also add other GHG sources like fuels for fire engines, crew carriers, helicopters, air tankers. Current eco-comparisons never mention all of the climate impacts of catastrophic wildfires, bark beetles and decomposition of dead trees. In fact, many dead trees in the LA Basin were taken to dumps and burned or buried. I saw loads of cull old growth being transported from LA to the old Standard big log SPI mill in Sonora. Sure, they got the wood for a few bucks per load but, had to transport the logs for about 400 miles, one way. They were able to get some boards out of them, and chipping the rest for “hog fuel”.
Foto- it seems like everyone’s difficulties would be resolved if there were more local “wood dumps” where people could take wood and it could be used for some kind of energy. People imagine a huge industrial plant that needs a long-term source. We need something more opportunistic that can be moved to areas with many dead trees and then hook the electricity into a grid, or a liquid fuel that could run equipment. I would see flocks of these units gathering around beetle outbreaks and then dispersing on to the next, just like crows on a carcass.
Of course, we shouldn’t let fears of replicating the bad things of the past prevent us from dreaming good things for the future.
“It turns out that modifying existing forests so that they “re-sequester faster” necessitates high levels of ecosystem disturbance… ” Who says that forest management HAS to have “high levels of ecosystem disturbance”? Ummmm, with so much forest mortality and wildfires, isn’t the current state of our ecosystems “highly disturbed”? Or, are you saying that our forests are pristine and that any amount of management constitutes “high disturbance”, despite the poor condition of a given ecosystem?
I’d say that catastrophic wildfires that bake the soils constitutes “higher disturbance” than simply thinning stands from below.