TODAY’S STUDY: BIOMASS AND GREENHOUSE GAS EMISSIONS, A MAGNIFICENT ADVENTURE OR SIMPLY WHAT CAN BE DONE

A fundamental debate among some fervent environmentalists amounts to a Hamlet-like dilemma: To burn or not to burn? But is that the question? Is there any kind of justifiable burning to generate energy?

Forests must be managed. The idealism of purists who oppose forest management is admirable but humans have encroached too far into natural habitats to leave forest management to natural forces and cycles. That is just the way it is.

Does the intelligent, eco-sensitive management of forests open an opportunity for practical uses of biomass?

The jury is largely still out on the question, according to the report highlighted below.

There is probably not the kind of resource and opportunity that would support the building of a whole new biofuels or biomass infrastructure. To do so would support the initiation of a very dangerous chain of events beginning with pilot biofuel and biomass projects and culminating in a ravenous hunger for raw materials that could consume forest ecology and agricultural capability in the name of economic development.

But many studies suggest there is environmental benefit in wisely managing forests and harvesting the biomass waste for useful purposes.

Those useful purposes begin with the sequestration of carbon-based waste and, without adding burning into the process, capturing the resultant biogas for electricity generation.

Research has turned up ways to turn forest waste into biofuels with a net emissions reduction.

And thorough life-cycle assessments (LCAs) suggest harvested wood and wood-waste products may be substituted for emissions-intensive materials like steel and plastic in everyday products like furniture at a net emissions savings.

The greatest value in the study below is its apparent even-handedness. It notes where existing research “findings are robust” and it is straightforward about research “where uncertainties may be large enough to question key assumptions” and it limits its conclusions to areas where there is solid evidence and strong agreement.

Not everybody will appreciate this observation but it seems like purity and idealism have limited applicability except as treasured signposts in this compromised world. Opportunities for progress must be seized where they exist because the enemies of progress are many and seize their opportunities uninhibitedly.

Ultimately, the goal is a New Energy economy based on this good earth's sun, wind, deep heat and flowing waters. Bridges to that goal should be studied for their sturdiness.

This week at NewEnergyNews began with the blind, deaf and undaunted Helen Keller’s famous observation that nothing in this life is without risk and therefore “life is either a magnificent adventure or nothing.”

The authors of the paper on biomass risk looking at the dangerous idea of burning to obtain useable energy in the hope of discovering something practical. They do not leave behind their critical judgment.

Why take the risk? Because, as Helen Keller also observed, “I cannot do everything, but I can do something. I must not fail to do the something that I can do.”

Life cycle impacts of forest management and wood utilization on carbon mitigation: knowns and unknowns
Bruce Lippke, Elaine Oneil, Rob Harrison, Kenneth Skog, Leif Gustavsson and Roger Sathre, August 2011 (Carbon Management/Future Science Group)

Abstract

This review on research on life cycle carbon accounting examines the complexities in accounting for carbon emissions given the many different ways that wood is used. Recent objectives to increase the use of renewable fuels have raised policy questions, with respect to the sustainability of managing our forests as well as the impacts of how best to use wood from our forests. There has been general support for the benefits of sustainably managing forests for carbon mitigation as expressed by the Intergovernmental Panel on Climate Change in 2007. However, there are many integrated carbon pools involved, which have led to conflicting implications for best practices and policy. In particular, sustainable management of forests for products produces substantially different impacts than a focus on a single stand or on specific carbon pools with each contributing to different policy implications. In this article, we review many recent research findings on carbon impacts across all stages of processing from cradle-to-grave, based on life cycle accounting, which is necessary to understand the carbon interactions across many different carbon pools. The focus is on where findings are robust and where uncertainties may be large enough to question key assumptions that impact carbon in the forest and its many uses. Many opportunities for reducing carbon emissions are identified along with unintended consequences of proposed policies.

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Executive Summary

Objectives & methods: the global carbon cycle & life cycle data

ƒ. The goal of reducing GHGs suggests displacing the one-way flow of GHGs from fossil fuel-intensive products with forest products and biofuels from carbon-neutral forests.

ƒ. While afforestation provides a one-time increase in forest carbon, life cycle analysis of all processes where wood displaces non-wood identifies many more opportunities to sustainably reduce emissions.

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Carbon in the forest & the impact from many different uses of wood

ƒ. Life cycle research demonstrates that the emissions from sustainably produced products or biomass for energy are being offset by the forest carbon removed from the atmosphere.

ƒ. Non-wood products can replace every wood product, but most are fossil fuel emission intensive. Meta-data from substitution studies averages 3.9 KgCO2 reduced per Kg of wood used.

ƒ. Using sustainably grown wood in the Pacific Northwest to substitute for fossil-intensive products results in a total carbon trend increase of 4.2 tC/h/y; increasing to 9.7 tC/h/y for direct wood versus steel joist substitution; or 2.9 tC/h/y when wood is used exclusively as a biofuel, the lowest leverage yet still effective use.

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Forest residuals & fire reduction carbon-mitigation opportunities

ƒ. Accessibility studies show that as much as 24% of aboveground carbon could be accessible for biofuel feedstock; four-times the bioenergy currently being used in processing mills.

ƒ. Scandinavian countries with carbon taxes are far ahead in utilizing forest residuals.

ƒ. Using forest residual biomass as feedstock for utilities produces only 4% of the emissions from coal.

ƒ. A continuation of recent US public forest fire rates will result in carbon emissions from unmanaged and overly dense forests. Thinning treatments can restore forest health and double carbon stores.

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Data gaps & uncertainties

ƒ. Landfill carbon stores, while uncertain, are projected to increase with little impact on management and wood-use strategy, except to motivate increased recycling and energy recapture.

ƒ. Soil carbon changes little under sustainable rotations, however increased fertilization to reduce nutrient deficiencies increases above and belowground carbon consistent with commercial management objectives.

Consequential life cycle analysis

ƒ. Attributional life cycle data can be collected down to the individual component level identifying opportunities for improvement in material selection design and processing methods.

ƒ. General equilibrium economic models can estimate consequential life cycle impacts including indirect impacts but only for broad sectorial changes of limited value in design and product selection.

ƒ. Increasing carbon values may encourage conversion from no-management to short rotations raising the opportunity cost to maintain old forest sensitive habitat provided on public lands.

ƒ. Carbon exchanges, regulations and incentives differ across countries but frequently ignore interactions across carbon pools resulting in many unintended and counterproductive impacts.

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Comparisons across international research

ƒ. There are similarities in research methods and findings across the globe in spite of substantial variability in forests, cultural use patterns and economic conditions.

ƒ. Many studies have concluded that the largest single mechanism for reducing carbon emissions is substitution of renewable wood resources for fossil-intensive products.

ƒ. European carbon tax methods are contributing to increased use of forest residuals for biofuels reducing emissions and fossil fuel dependence, while also contributing to substitution in construction materials.

ƒ. In Sweden, fertilization, use of residuals for biofuels and stem wood for construction materials avoided 3.7 tC/h/y carbon emissions, five-times higher than traditional management using stem wood for biofuel.

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Science-based conclusions & limitations

ƒ. There are many opportunities to reduce carbon emissions. Forests provide low cost carbon capture and displacement of fossil emissions if and when carbon values or fossil fuel costs increase

ƒ. Tracking carbon across every stage of processing can avoid counterproductive policies and support incentives that increase the cost of products proportional to their carbon emissions

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Science-based conclusions & limitations

As demonstrated previously, there are many options available to reduce carbon emissions both in the way we manage the forest and the way we use products and biofuels. In this article, there are many complexities in attempting to determine best practices and supportive policies for reducing carbon emissions. While there are similarities in impacts across many developed country forests, there are substantial differences in situations across the globe. While afforestation provides a one-time opportunity to increase the carbon stored in forests, sustainably managing forests provides many opportunities to reduce carbon emissions by using wood as a carbon store, while at the same time displacing fossil intensive products and fuels. Many studies have concluded that the largest single mechanism for reducing carbon emissions is substitution, which depends upon how the wood is used [66,69–71]. Situations are substantially different in many developing countries where the infrastructure to use wood structurally may be lacking and most wood is used for heat with the land base competing for food production. While life cycle methods may be appropriate for developing countries, life cycle data are lacking both as they relates to wood processing and forest management and forest structure in most developing countries. Results from developed countries are supported by many requirements to measure and track the impact of forest uses on carbon across every stage of processing. Conclusions including key limitations in data quality include the following.

ƒ. Necessity of tracking carbon impacts across all linked stages of processing
The goal of reducing GHGs suggests decreasing the use of fossil fuel-intensive products and fuels that provide a one-way flow of GHGs to the atmosphere and increasing carbon storage in other pools, such as growing forests and using forest products and biofuels that displace the use of fossil fuels and fossil-intensive products. Understanding the direct and indirect substitution impacts between fossil fuels and forests is essential to ensure that policy decisions do not result in unintended consequences, such as reducing forest growth or failing to use forest products and biofuels that substitute for fossil-intensive products and fuels. This requires a science-based method to track the carbon through forest regeneration and management and each successive processing stage through product use, and ultimately end-of-life management. Comparing the life cycle inputs and outputs across all stages of processing for an array of alternative forest treatments, processing methods, material/product selection and building design alternatives provides quantifiable measures of performance-improvement opportunities supporting better investments and policies.

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ƒ. Sustainably managed forests provide the opportunity to sustain a maximum rate of
carbon absorption
The utilization of wood from the forest determines the leverage by which forest carbon can displace fossil emissions. While maximizing forest growth contributes more wood to utilize, the dominant source of carbon mitigation comes from sustainably displacing fossil emissions through the use of wood since the carbon stored in the forest is a one-time creation and can only contribute to sustainably reducing carbon emissions by harvesting the wood to substitute for other materials.

ƒ. Sustainably managed forests are essentially carbon neutral
The life cycle research results accumulated over the last decade does not lead one to assume forest carbon neutrality, rather it demonstrates that the emissions from burning biomass for energy and the products produced from forest removals are being offset by the sustained growth in forest carbon removed from the atmosphere even after deducting any emissions from unused dead wood left in the forest. Sustainable management is a key element in any ‘forest certification’.

ƒ. Peer-reviewed LCI/LCA data are available
Life cycle inventory data have been collected and reviewed and are available, such as the US DOE NREL LCI database for both forests and mill processing as well as for fossil fuels and fossil-intensive products. LCA comparisons to alternative fossil-intensive uses demonstrate how to achieve improved environmental performance with reduced GHG emissions. Life cycle data also provide measures of the alternative/substitute materials that are displaced, including the volume of renewable biofuel produced that displaces non-renewable fossil fuels and their emissions.

ƒ. Counterproductive incentives/carbon exchanges
Carbon exchanges, regulations and incentives differ across countries but frequently reward one or more carbon pools independently resulting in counterproductive impacts on carbon emissions from other pools.

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Obvious examples include:

ƒ. Carbon exchanges that incentivize not harvesting, which can contribute to greater emissions from using more fossil fuels than can be offset by increasing forest carbon stores;

ƒ. Ignoring substitution of wood for fossil fuel intensive products since it is difficult to measure even though it has the highest potential leverage in reducing emissions;

ƒ. Incentivizing low valued fuel substitutes such as ethanol that will divert feedstock from higher leverage displacement options such as composite wood products;

ƒ. Regulations that do not properly distinguish processing differences such as considering biogenic boiler emissions no different than fossil emissions ignoring that biomass carbon was being absorbed by the forest at the same rate as it was being burnt for energy;

ƒ. Renewable fuel requirements for utilities that divert feedstock from higher leverage uses.

ƒ. There are many options to reduce carbon emissions

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Carbon-storage options include:

ƒ. Storing carbon in the forest, knowing that ultimately, the rate that carbon is removed from the atmosphere through net new growth will slow down, and in the event of a disturbance may emit more carbon than if harvested;

ƒ. Sustainably harvesting wood from the forest before growth slows down and storing the carbon in wood products while offsetting fossil fuel consumption;

ƒ. Reducing fire risks in unmanaged forests by thinning, while also producing biofuels and carbon stored in wood products, which also avoids many costs incurred in fighting fires and rehabilitating the land;

ƒ. Investing in shorter rotation and higher yielding crops as well as developing lower cost collection technologies to collect and process smaller trees and forest residuals.

Processing options include:

ƒ. Using more renewable fuels;

ƒ. Increased recycling and collection of wastes for at least their fuel value;

ƒ. Reallocation strategies that target reductions in the highest fossil emission intensive products. End-of-life options include recycling and recapturing the energy value in wood products to replace fossil energy;

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Construction and design options include:

ƒ. Codes that are based on integrated life cycle impacts;

ƒ. Using products and processes that produce the least amount of carbon emissions;

ƒ. Incentives that increase the cost of every product proportional to its carbon emission intensity can motivate the efficient use of every grade of wood fiber where it can have the greatest impact.

ƒ. Landfill emissions are a waste management problem that can be improved
While the data quality for landfill emissions is poor and not well linked to the time that waste is deposited in the landfill, the substantial emissions of methane from oxygen constrained decay in the landfill can offset carbon stores from biomass waste. While recapture of methane released from landfill for its energy value is improving, biomass waste recapture for energy or product recycling is also improving reducing the need for landfill. Best forest and product management choices for carbon mitigation do not depend upon the carbon stored in the landfill except perhaps to increase recycling.

ƒ. Soil carbon & biomass growth productivity can be increased
While there is little evidence of a loss in soil carbon for different sustainably managed forest rotations, where there are nutrient deficiencies fertilization can increase both aboveground and belowground productivity, thus reducing net carbon emissions by increasing carbon stock in standing biomass and forest soils, as well as increasing the supply rate of biomass for material and fuel substitution.

ƒ. The energy required & emissions produced to collect biomass currently left in the forest is low
Removal of merchantable wood contributes only approximately 7% to processing energy requirements, and their carbon equivalent emissions as little as 1% of the total carbon stored in the wood removed. Similar results can be expected for the collection of low-grade forest residuals and other wastes when carbon values are high enough to offset the collection costs, which will also produce new rural economic activity. European experience shows that fossil fuel energy inputs for recovering and transporting harvest residues are approximately 3–5% of the available energy in the recovered biomass. The carbon emissions from biofuel-collection activities will only be a small percentage of the fossil emissions displaced. However, the low cost of fossil fuels minimizes the opportunities to economically collect biofuels, especially in North America in the absence of internalizing a cost of carbon emissions.

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ƒ. Supply responses with higher carbon values
Forest supplies can increase substantially with low cost incentives and have already increased through improved forest regeneration technology on industrial lands. It is the comparatively low cost of fossil fuels that limits the collection of forest residuals or other wood wastes that could be used for energy. If price changes or other incentives result in supply responses that go beyond this low cost supply source and compete with resources serving other sectors there may be partially offsetting carbon emissions, such as producing agricultural products from less productive land, and almost certainly from exporting carbon and economic activity across borders where symmetry in incentives or carbon taxes is not achieved.

ƒ. Supply responses that convert unmanaged forestland to managed forestland
While many forests are underutilized, conversion of some unmanaged lands that provide old forest habitat that has been declining may warrant increased valuations and incentives to maintain old forest habitat as increasing carbon values are competitive with old-forest habitat. However, it is less costly to manage lands to produce old forest habitat than to depend upon no management. In dry forest areas in particular, historic habitat has been substantially diminished as a consequence of a century of fire suppression resulting in overly dense stands supporting different species. In this case, thinning stands to reduce fire risks will also reduce carbon emissions and restore historic habitat, a unique situation
where carbon emission reduction and restoring habitat are complementary.

ƒ. Forest productivity varies substantially across regions
While there are substantial differences in forests across the globe, the findings from life cycle studies on softwood-growing regions remain quite similar with the high leverage opportunities to use more wood where it can displace the most fossil intensive products. More detailed regional analysis will be required to support the best uses of biomass in each region.

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Future perspective

Better policies will be instituted and contribute to carbon mitigation as the benefits of LCI/LCA are more broadly recognized and LCAs more frequently used. Substitution provides the highest leverage, suggesting research on improved products, designs and materials use are good investments for the future. Sustainably managed forests currently provide low cost carbon capture and storage that can be substantially increased. However, prices and/or incentives will have to increase in order to support investments responsive to aggressive mitigation and energy independence objectives. The increased use of renewable resources to reach these objectives will not be achieved, so long as the low cost of fossil emitting alternatives are embedded in current market costs. Natural variations across forests are large, as are cultural differences across countries requiring more regional and site-specific analyses for credibility and efficient implementation. More effective education on the many unintended consequences flowing from current policy and on the many opportunities that can improve environmental performance will be critical. Efficiency in carbon mitigation and reducing the hidden tax from energy dependence depends heavily on the ability of policy changes to induce higher costs proportional to carbon emission intensity in product uses that will induce improvements in product selection, processes, design, use of residuals and waste, and forest management. Markets will ultimately acknowledge the importance of carbon mitigation through better education on life cycle impacts, resulting in increasing demand for products that improve carbon mitigation.