Stop burning wood to generate electricity

A recent article describes the shipment of wood pellets from the USA to Europe and, soon, to Asia.

My initial reaction, echoed in many comments by others following the article, was; How can cutting trees in the US, turning them into pellets, shipping them to Europe and burning them to produce “carbon neutral” electricity make any sense? That’s the initial 1bio story: Burning trees to produce electricity makes no sense!

Let’s look more closely:

We cut a 25 year old tree, and plant a seedling at (A), turn the tree into pellets and burn it to generate electricity at (F).  Over 25 (+) years the seedling extracts carbon from the air (H), but the excess carbon released up front (G) hangs around for the full 25 years. [See Note 1 for more detail on the diagram.] The idea is more forcefully explained in a letter from 500+ scientists to the leaders of the USA, EU, Japan and South Korea sent in February 2021. [Note 2 for excerpt]

It’s a bad deal. It’s like saying; ‘Give me a thousand dollars today, if all goes well I’ll pay you back, at zero interest, over 25 years”.

If it’s such a bad deal why is it happening? Why are European countries subsidizing pellet burning power plants, with Japan and South Korea planning to follow suit? How can this be termed carbon neutral when greenhouse gases are expended at every point of the cycle?

It’s an “accounting error”The Kyoto Protocol of 1997 was a major achievement of international cooperation, but still a political exercise.  The counting of greenhouse gas emission and capture in the protocol is subject to intricate rules. The accounting reference manual itself is a 130 page book. In effect none of the emissions (B, C, D, E) count against any country’s total. Logging and pellet manufacture (B and C) are largely covered by “forest management” exemptions. Shipping emissions are lost in the complexities of ownership, registration and so forth. 

The major emissions, when the pellets are turned into electricity (E), are carbon neutral on the basis of good forestry practice in the supplying countries.  That means a country can burn wood, instead of coal, oil or gas, and claim emission reductions, when it is really adding large amounts of greenhouse gases.

Clearly the problem was recognized.  In 2003 IPCC published the Good Practice Guidance for Land Use, Land-Use Change and Forestry [see Note 3 for some thoughts on this document]

In 2009 Timothy Searchinger and others published a key article titled “Fixing a Critical Climate Accounting Error – Rules for applying the Kyoto Protocol and national cap and trade laws contain a major, but fixable, carbon accounting flaw in assessing bioenergy”. One snippet from the paper: “The straightforward solution is to fix the accounting of bioenergy. That means tracing the actual flows of carbon and counting emissions from tailpipes and smokestacks whether from fossil energy or bioenergy.” [Further articles on the issues of biomass burning are at Note 4]

More recent developments are:

The IPCC released “Climate Change and Land. An IPCC Special Report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems” in January 2020 [see Note 5 for some detail and links]

In July of 2020 an advisory board to the Netherlands government warned that burning biomass is not sustainable.  More details are in news reports from Euractiv and Dutchnews.  This advice fits with an overall European review of the practice, based on the IPCC special report.  However, ”Whether or not forest biomass will still legally be considered as a carbon neutral and renewable source of energy by then [when the review is complete and EU laws altered] remains to be seen.”

In summary then; it makes no sense to use trees to generate electricity! BUT – despite all this data, analysis and eloquent advocacy it is likely that the opposite will happen. More countries will use pellets, with subsequent higher demand for the fuel, because wood pellets do make excellent sense to many people; 

  • National policymakers who are faced with a requirement to lower emissions and stay within a budget see the “carbon neutral” burning of biomass as a way to achieve both.  They rely on the suppliers of the fuel to ensure carbon neutrality.
  • The lumber industry sees an income, or at least an eliminated cost, when they can dispose of “waste”, such as dead trees, sawdust, offcuts and branches.
  • Landowners see opportunities, beyond dimensional lumber, in forest maintenance paid for by selling low value trees and understory and/or in conversion of low value land to higher value timber stands
  • Some environmentalists are in support of clearing the “trash” from the forest floor to prevent a buildup of flammable material and so reduce the incidence and severity of wildfires, which cause much more damage than responsible management activities.
  • The pellet manufacturers point to jobs and community support (plus profits of course).
  • The shippers are happy that investments in ships and port facilities give a good return..
  • Local politicians are content because the industry pays taxes, creates jobs and keeps the community alive.

Decisions about our biosphere are never easy.  At least we can still make them.  As time goes by we will have less choices and these decisions will only become more disruptive, more expensive, more gut wrenching. (see The challenging politics of climate change)

Just based on the facts above we should stop the large scale use of wood to generate electricity.  And we have not even taken into account other biosphere concerns such as biodiversity (see my previous post on the Dasgupta review), ecosystems, monocultures, habitats, water conservation or local pollution.

However we live in an imperfect world; rules will be bent, loopholes explored, laws not enforced. 

Accountants will move accounts and lawyers will argue law.  The biosphere does not care about any of that; we need to play by its rules not ours.

The overview so far leaves a lot of questions unanswered [Some are in Note 10]. But that’s OK. I hope I have left a sufficiently solid trace to explore both the pro and con sides of this industry.  I do think there is room for wood pellets in private use or in situations where carbon neutrality is more evident and controllable [Note 11].

The 1bio story becomes: Burning trees to produce electricity makes no sense! Stop!

To reiterate the 1bio story is not intended to repeat the data gathering, analysis and reporting already done.  It is meant to be a “meta narrative” [Note 9] with a short headline, a few paragraphs of background and then a trail of evidence to support the story [Note 6].

Bottom line: I believe the evidence strongly supports the story.  As always I will appreciate thoughts on how to make that support line stronger and easier to develop.


Notes

NOTE 1:

More Detail On The Initial Diagram

We cut a 25 year old tree and plant a new seedling at the same time (A) [In the USA this is likely to be a loblolly pine – see Note 7 below], logging operations and transport (B) generate emissions, as does the manufacture of the pellets ( C). Transport overseas creates more emissions (D). The pellets are then burned (E) and electricity finally distributed (F). That electricity is termed to be “Carbon Neutral”.  The red stepped line shows the increasing emissions of greenhouse gases.

Let’s say it takes a year for that cycle. The seedling we planted at (A) has started to capture CO2 from the air, but very little – it’s only 1year old..  But all the CO2 from its 25 year old, very much larger, predecessor is in the air.  Let’s now draw a 25 year picture in the lower part of the diagram.  The year (A to F) is compressed to the start. The red area (G) is the CO2 emitted, the green area (H) is CO2 captured.

So, we’re all good, the carbon got recaptured, it’s carbon neutral.  What’s the problem?  The problem is that for those 24 years after the major emission (E) the excess CO2 has been hanging around contributing to global warming

Anyone studying the diagram will point out some major ERRORS – which I will try and explain (or excuse?) briefly:

  • 25 year old trees don’t get cut for biomass, they get used for dimensioned lumber! Yes, in most cases. However as demand for biomass increases cutting of mature trees will happen.  If not in the US or western Europe, then in less regulated countries.  Also the scale of the diagram does not matter; if we cut 10 year old trees, then the regrow time will be 10 years (plus – see next point)
  • The regrow time is too short, the emissions generated by felling, transport and processing are not included! Yes, that’s a mistake.  I tried back of envelope calculation but rather than guess I left them out.  Anyone have numbers?
  • The slope of the carbon capture line is all wrong! Young trees absorb carbon faster than old ones and very old trees take up practically no carbon! Not so. Young trees absorb a higher percentage in carbon (much like young animals grow very fast) but as the tree matures the absolute amount of carbon stored each year increases.  For one data point see this practical study.
  • In practice we plant much more than one seedling to replace a mature tree.  We then cut some of those new trees when semi-mature for biofuel while leaving others to grow to full “commercial lumber” size.  So the payback time is much shorter than your 25 years! I don’t have enough knowledge to counter that claim. If correct, and carried out under careful forest management, it will shorten the carbon recapture time.  But there will still be a time lag and for that time the free atmospheric carbon will do damage. I suspect that this point has been analysed somewhere in the mountains of studies I mention. Any input?

NOTE 2:

500 Scientist Letter: The following excerpt is from the February 2021 letter from 500+ scientists to US, EU, Japan and South Korean leaders: “The result of this additional wood harvest is a large initial increase in carbon emissions, creating a “carbon debt,” which increases over time as more trees are harvested for continuing bioenergy use. Regrowing trees and displacement of fossil fuels may eventually pay off this carbon debt, but regrowth takes time the world does not have to solve climate change. As numerous studies have shown, this burning of wood will increase warming for decades to centuries. That is true even when the wood replaces coal, oil or natural gas. The reasons are fundamental. Forests store carbon – approximately half the weight of dry wood is carbon. When wood is harvested and burned, half or more of the live wood in trees harvested is typically lost in harvesting and processing before it can supply energy, adding carbon to the atmosphere without replacing fossil fuels. Burning wood is also carbon-inefficient, so the wood burned for energy emits more carbon up smokestacks than using fossil fuels. Overall, for each kilowatt hour of heat or electricity produced, using wood initially is likely to add two to three times as much carbon to the air as using fossil fuels.

Trees are more valuable alive than dead both for climate and for biodiversity. To meet future net zero emission goals, your governments should work to preserve and restore forests and not to burn them”. [my bolding]

NOTE 3:

Comment On IPCC Best Practice Guide: Intergovernmental Panel on Climate Change Good Practice Guidance for Land Use, Land-Use Change and Forestry [This guide contains 590 pages, including 4 pages of reviewers, typically government scientific organizations and one person from the World Wildlife Fund.  I am curious why there were no reviewers from other organizations, like the Nature Conservancy, Rainforest Alliance, Greenpeace, Native Forest Foundation, Natural Resources Defence Council and so forth?]

NOTE 4:

Further Reading On Biomass Burning : A number of articles about biomass burning are presented on Mongabay.com. Also, “Carbon debt and payback time – Lost in the forest?” is available through sciencedirect.com. A telling sentence from the abstract is: “Narrative reviews demonstrate that the payback time of apparently comparable forest bioenergy supply scenarios vary by up to 200 years allowing ample room for confusion and dispute …”

[BTW: As an independent viewer, without the backing of an academic organization or commercial corporation I find the costs for reading full articles like this one a major impediment.  I could spend hundreds of dollars chasing just one fact through the mesh of publications.  Just another reason why I hope 1biosphere.net will, one day, in some form, take on a more organizational shape].

NOTE 5:

IPCC Special Report, Climate Change and Land (SRCCL): The summary of this report is 41 pages. Chapter 4 of the report on Land Degradation is 186 pages.

An excerpt (from page 66 of Chapter 4) reads: “Moreover, assessments of climate benefits of any mitigation action must also consider the time dynamics of atmospheric impacts as some actions will have immediate benefits (e.g. avoided deforestation) while others may not achieve net atmospheric benefits for decades or centuries.  For example, the climate benefits of woody biomass use for bioenergy depend on several factors such as the source and alternate fate of the biomass, the energy type it substitutes and the rates of regrowth of the harvested forest (Laganière et al. 2017; Ter-Mikaelian et al. 2014; Smyth et al. 2017).  Conversion of primary forests in regions of very low stand replacing disturbances to short-rotation plantations where the harvested wood is used for short-lived products with low displacement factors will increase emissions. In general, greater mitigation benefits are achieved if harvested wood products are used for products with long carbon retention time and high displacement factors.” [My bolding]

NOTE 6:

The Iceberg Diagram: The key to the 1bio story lies in the 3 step trace; Verify, Publish, Annotate.  

  • The “Verify” stage is complex.  To dig through the data would take a big team and time.  That is why I come back to the question; can this be done at least semi-automatically by tracing references to basic research and comparing economic factors?
  • After that it is relatively easy (not trivial by any means) to “Publish” 
  • I see “Annotations” as asking some of the meta-questions [😉] raised by the story.  What do we really want to/need to do and what are the alternatives?

NOTE 7:

Loblolly Pine: The most likely tree to be felled for wood chips in the US is the Loblolly Pine. It is the second-most common tree in the United States and is regarded as the most commercially important tree in the Southeastern U.S. “Left to grow, this tree can reach 100 or more feet and over 4 feet in diameter. The largest was found in Georgia – 185 feet tall and 11 feet across! Sadly, it was cut down 35 years ago.” [1985?]  

Photo: Woodlot, CC BY-SA 3.0

NOTE 8:

Albedo: is a measure of surface reflectivity.  A darker, less reflective, surface (lower albedo) means more heating and worsens the climate change problem.  Pine trees are typically darker and so absorb more sunlight, while hardwoods tend to reflect more sunlight. The differences are small but significant.  In winter pines stay dark green, while hardwoods lose their leaves.  In areas where it snows the albedo will be higher in deciduous forests (hardwood) because more snow will be visible through the naked branches. Admittedly snow is rare in the SE USA regions mentioned in the news report (NYT) that triggered this post.

NOTE 9:

Meta-Narrative: I came across this term in “The Listening Society: A Metamodern Guide to Politics, Book One (Metamodern Guides 1)” by Hanzi Freinacht.  Much as I am suspicious of any phrase starting with “meta” I do think “meta-narrative”, a story about a story, does fit 1bio.  I will hold off any comment on the book as a whole until I finish it.

NOTE 10:

Unanswered Questions: As I was writing this post a number of questions came to mind. Some have been answered, or at least approached an answer, within the post. Some are open  The devil, as always, is in the details and those are hard to find. 

  • Does the carbon neutrality definition take time into account?  We burn the pellet product now, but how long will it take the newly planted tree to reabsorb the released carbon? 20 years? 40?  Longer?  Will we pass a trigger point that starts a carbon feedback loop within that time? [Answered, I think; it depends on the age of the base fuel e.g. a ten year old tree will have a 10 year grow back time PLUS the pay-back time for the emissions during transport and processing.]
  • How much of this process is accounting and legal argument versus actual reduction in emissions?  The pellet producers can claim their industry creates minimal carbon output in the US, because the Europeans do the burning.  A very similar argument is used by Australian coal exporters; how can they be held accountable for carbon emissions, when it is India and China who burn the coal? (Just a reminder: the biosphere has no borders nor does it do accounting) [Answered, I think]
  • Under the laws of most countries can there be or should there be control over logging on private land? Is it legal, ethical and practical to even ask that question? The treatment of contracts between owners and commercial or governmental entities is a separate, but equally valid, concern.
  • Should dead trees and undergrowth remain, at least in part, to provide animal habitat?
  • What are the effects on the soil of removing the “trash” rather than having it rot into the ground? Two articles give some background: Can Soil Help Combat Climate Change? and The Effects of Forest Management on Erosion and Soil Productivity
  • Are new plantations diverse or monoculture?
  • Will planting pines versus hardwoods change the albedo significantly? (see short explanation in Note 8 above)
  • What is the political will to verify compliance to the terms of the various contracts?  That question applies at both ends.  What is the mechanism for the European users to verify what happens at the US (or other suppliers!) end?  Equally, how much supervision is there on the supply end, especially at the local level, where both the benefits (jobs, income, taxes) and risks (pollution, environmental damage, health effects) occur?
  • Can we define small scale biofuel users based on size, proximity of fuel to user and genuine, verifiable, forest management?  Can we then differentiate between small scale use and large scale use for electricity generation and apply different measures to each?

NOTE 11:

Personal Experience – admittedly very slight;  

Customers in more remote parts of New Jersey, where there are no gas lines, were unanimous in praise of their pellet burners; inexpensive fuel, easy to maintain and giving comfortable heat.  But they were rare in comparison to users of oil or propane fuel.

The photos below show a biofuel plant owned by a Bavarian abbey.  It supplies heat to the abbey itself, plus accommodation buildings, a butcher’s shop and restaurant.  In addition there is high pressure steam for the abbey’s brewing and distilling operations. It is fuelled by wood chips from their own forest and has been in operation since 2005.  Although it is a carbon emitter the claims for environmental neutrality are somewhat more convincing.  The forest supplying the material is owned by the abbey, is close by, and has been under their stewardship since 1119.  It is unlikely to be clear-felled or damaged while the abbey retains that control. The abbey also uses extensive photovoltaic areas to supplement their electricity use. 

(Photos above and the translated excerpt below are from the web site of the Benedictine Abbey at Scheyern, Germany)

“In contrast to the combustion of fossil fuels, biomass plants do not cause any additional pollution, but are considered environmentally neutral. When wood is burned, only the substances bound during growth are released again. They form the basis for the growth of other trees and plants. The biological cycle can begin again. Therefore this process is CO2 neutral. The balance of carbon dioxide savings of 2,751 tons per year compared to a conventional oil-fired system should also be emphasized” 

I do think there is a case for biofuels in personal and limited examples like this. However given the content and direction of this post I can only attest that the restaurant was warm and the beer good.

One thought on “Stop burning wood to generate electricity

  1. Update – from ‘Enough with the burning’: EU executive accused of sacrificing forests

    “Lina Burnelius, project leader at Protect the Forest Sweden, said the commission had failed to address one of the key drivers of forest degradation – counting forest biomass as renewable energy. “Fit for 55 is harmful to forests and insufficient to tackle climate change. We are in desperate need of honest policies that include all our emissions in the statistics.”
    The European Commission had chosen “to sacrifice forests rather than admit that current EU bioenergy policy is making the climate crisis worse”, she said. “Enough with the burning. We cannot just switch from burning one climate disastrous fuel to another”.
    Burning wood for electricity releases more carbon into the atmosphere than gas or coal, and many scientists are sceptical that planting trees to repay the “carbon debt” squares with commitments under the Paris climate agreement.”

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