I rarely cut a living tree down, but it goes on the mill if I do. Elsewise we get plenty of firewood cleaning up dead and dying trees. Large dead trees are great on the mill if I get them before they rot. Why won't the local mill take birch logs? I've been curious about milling a few myself.We have a considerable number of biomass power plants in the area. All of them burn waste residues from forestry operations. Here in lies a crucial difference, these residues exist anyway as a by-product of lumber, OSB and pulp making processes. Instead of burning them or landfilling these residues it makes sense to create another product in the form of electricity, the leftover heat from electricity generation is then used in one case for the lumber kilns, another for steam in the pulping process, and another to heat the OSB presses and chip dryers.
Cutting trees specifically for energy is a foolish endeavor. I believe most of us here don't even cut healthy green trees for firewood, I know I cut already dead trees, or ones that have to come down for another reason, or birch that is cut and left for us firewood collectors by the loggers as the local mills can't process birch.
I don't think there is a logical comparison between fossil fuels and wood burning in these cases, cutting dead standing trees opens up the canopy and allows the next generation to grow faster, removing carbon from the atmosphere sooner. It also really depends on the areas trees are cut from, in some areas we have very sandy soils where no organic matter seems to last more than a few years, it rots quickly and is gone. We have other areas of Muskeg (peat bogs) where dozens of feet of organic matter can accumulate, where carbon from a fallen tree would be stored for hundreds but likely many thousands of years. For firewood collection it is much easier to collect from sandy soils, which doesn't store carbon as readily anyway, traversing the Muskeg areas is quite difficult. The exception being to loggers in winter while the muskeg is frozen, and even in these cases the roots are still left behind for their carbon to be stored long term.
We don't have a whole lot of Birch around here, at least any that reaches a reasonable size, a 12" diameter Birch is very large for this area. Even if it does reach that size its often rotten on the inside, with staining that doesn't produce marketable wood.I rarely cut a living tree down, but it goes on the mill if I do. Elsewise we get plenty of firewood cleaning up dead and dying trees. Large dead trees are great on the mill if I get them before they rot. Why won't the local mill take birch logs? I've been curious about milling a few myself.
Our part of Maine is not so different from where you are and there are a ton of birch forests and now I know why. I personally love it as firewood, but you can't give it away here due to large quantities of maple available. Our property unfortunately has little in the way of birch or maple, but we do have a lot of really nice spruce and fir trees that produce excellent boards. I try to keep it under one cord an acre for these really nice 16-24" trees. Anything over that I leave in place since it's too big for my mill and I can't bring myself to cut one down. So far I haven't felled a single living deciduous tree.We don't have a whole lot of Birch around here, at least any that reaches a reasonable size, a 12" diameter Birch is very large for this area. Even if it does reach that size its often rotten on the inside, with staining that doesn't produce marketable wood.
We have 2 sawmills, both are setup for softwood, spruce and pine. Our pulp mill is also setup for softwood, it uses the chips from the 2 sawmills as well as from other mills within a 5 hour radius. We also have an OSB mill that uses poplar, mostly trembling aspen and some balsam poplar as feedstock, they can take some birch but have to limit its quantity.
All logging here is done on public (crown) lands. Both sawmills and the OSB mill have certain areas they have logging rights to (forest tenures), the pulp mill doesn't own any of these so buys chips/pulp logs from the others. Usually if one company cuts a species of timber another mill can use they arrange to have it shipped to that mill for use. In the case of Birch the softwood mills try to leave it standing, as its of no use to them and the OSB mill really doesn't want it either, in the event of it having to be cut it is usually just piled up so firewood gatherers can come get. Its not much waste, in a reasonable sized cutblock with a high fraction of birch there might be 10-20 cords of birch logs left behind. There is starting to become a market for the birch firewood here, as such some logging companies are hauling the birch out to split and sell as firewood, great for reducing waste, no so great for people like me that enjoy free easy firewood.
Our climate is generally a bit colder. We don't have any maple around here. My brother lives in the Annapolis Valley in Nova Scotia, if your weather is similar it's definitely milder than we get.Our part of Maine is not so different from where you are and there are a ton of birch forests and now I know why. I personally love it as firewood, but you can't give it away here due to large quantities of maple available. Our property unfortunately has little in the way of birch or maple, but we do have a lot of really nice spruce and fir trees that produce excellent boards. I try to keep it under one cord an acre for these really nice 16-24" trees. Anything over that I leave in place since it's too big for my mill and I can't bring myself to cut one down. So far I haven't felled a single living deciduous tree.
I don't think there are any operational mills left in our county, but there is a biomass chip plant just outside of town that is always on the verge of being operational.
Now that's an analysis of the preprint that I can agree with - as a physics PhD as well.I took a look at the preprint. Happer is a retired physics prof down the road at Princeton, a member of the NAS and a JASON (an elite post-war science advisory panel). I feel qualified to review the paper because I have a physics PhD, I was offered a job in that dept (which I declined), taught Optics at CalTech (yes, I'm Sheldon), have several older colleagues in the NAS who ask me to review their papers (a PITA) and did my undergrad research for a (different) JASON, who was a lovable, if cranky old bastage. I've never met Happer (maybe he saw my job talk, LOL), but I'm getting a vibe about how he thinks about things.
Everything in the paper looks appropriately done. The authors are looking at a 'one-dimensional' model of the earths atmosphere, with different altitudes exchanging energy with each other radiatively, and those layers of gas then warm up or cool off and expand or contract to reach thermal equilibrium. When the gases expand, this raises their altitude, and allows them to radiate heat more easily. This model is then repeated at different latitudes, and the results averaged.
While setting up such a model is non-trivial, it looks like a couple months work for a graduate student, tops.
There are several 'problem' assumptions with the model:
1. The model assumes that the atmosphere is 'well-mixed'. In practice, human created CO2 is mostly at lower altitudes, and will take decades or centuries to reach the mesosphere. Only the lowest layer (the troposphere) is relatively well mixed, bc it undergoes unstable convection, creating clouds and weather and precipitation. Above the tropopause, the stratosphere and mesosphere are stable, and have very little vertical mixing. This is NOT a quibble, since a lot of the 'saturation' effect they discuss is due to radiative heating and swelling, not of the lower atmosphere, but of the atmosphere on the edge of space. At best this means is that the model is a model for AGW at some far future date (centuries in the future?) where the emitted gases have made it way up there. Does something similar happen when the gases are lower? Happer doesn't compute that or tell us, but since energy flow in the troposphere is mostly non-radiative, it seems unlikely.
2. The model assumes the atmosphere is completely transparent...that is, there are NO clouds. This is not bc it is a good assumption, it is bc there is no easy way to include the effects of cloud formation, evaporation and opacity in the model Happer has formulated. Google seems to think that satellites say that cloud cover of the earth is 67% on a global average, vs Happer's 0% assumption. Clouds would block a lot of the IR that is assumed to be transmitted to the mesosphere, swelling it. I did not see any effort to account for this anywhere, like multiplying the radiative transfer by 0.33 somewhere as a fudge, etc.
These two points make the model hopelessly 'not serious'. That is, this is the sort of model that a scientist would've made in the 1960s (and which could be run on 1960s computers), and which might've been publishable back then. This is of course, Happer's heydey. The actual science of global warming is MUCH more complex than the radiative and ideal gas law physics in this 2020 preprint. It also includes a LOT of cloud physics and optics, and convective transport. Similar 'one-dimensional' models like the preprint, but with some cloud physics included, were the standard 'climate model' popular back in the 1980s. One of my classmates worked on one (he ended up stealing and marrying my prettiest girlfriend), now he is a grey-beard working on climate models at NOAA (and has two very beautiful and smart children).
Those were the 1980s models (more sophisticated than Happer's) which predicted about 2X as much global warming as current models. Improvements in computers (and modeling of cloud physics) have enabled climate models to become higher resolution and three dimensional, and the magnitude of the predicted effect, and I posted originally, has dropped by a bit less than half.
So yeah, bottom line, the preprint is 'not serious' because it literally leaves out all the HARD parts of climate models. It only includes the radiative transfer parts, which have been know since the 1800s. But it does those PERFECTLY.
If I were reviewing the paper, I would also flag several 'fishy' things they did.
3. The comparison to satellite data is qualitative. I couldn't see what they wanted me to see.
4. They describe the magnitude of the saturated global warming effect in very ambiguous ways. They say it is 'four orders of magnitude smaller than the linear term'. This is meaningless. Everyone knows that the forcing is sub-linear in additional CO2. If they are saying that the effect of a new CO2 molecule is 0.0001 relative to the FIRST CO2 molecule added to the atmosphere, that is a ridiculous comparison, and IMO intentionally misleading. They also talk about the change in forcing from doubling CO2 being a 'few percent' of the total. So ambiguous. What does that mean? The default I posted above says doubling CO2 changes the temp 1°C out of 35°C of total greenhouse effect. That is 3%. Is Happer saying he agrees with other climate models? Or does he mean doubling from current levels (quadrupling historical levels) and thus is saying quadrupling CO2 would only give another 1°C warming? Its unintelligible. Why?
5. Their model seems to predict that the saturation effect would be stronger over the poles, and that AGW would be weaker there. Maybe I misread it, but this is contrary to all other (modern) models, which show (along with satellite data) much stronger warming over the poles. He seems to throw this out there without discussing it. This seems fishy....since it is contra actual well-known data that would undermine confidence in his model.
Taken together 1-5 make him look like a crank with an agenda, tbh. Wake me up when the paper gets published in a peer-reviewed journal, rather than posted on a free database (with no peer review) and promulgated on 'wattsupwiththat'.
I'd add that even acceptance in a peer-reviewed journal does not necessarily indicate that the paper is 100% correct in its methods and findings. IMO, publishing means that it's good enough science to share with others while encouraging further scrutiny and ultimately enhancing the respective body of knowledge.Wake me up when the paper gets published in a peer-reviewed journal, rather than posted on a free database (with no peer review) and promulgated on 'wattsupwiththat'.