Wood Substitution Research Articles

Have product substitution carbon benefits been overestimated? A sensitivity analysis of key assumptions

Substitution of wood for more fossil carbon intensive building materials has been projected to result in major climate mitigation benefits often exceeding those of the forests themselves. A reexamination of the fundamental assumptions underlying these projections indicates long-term mitigation benefits related to product substitution may have been overestimated 2- to 100-fold. This suggests that while product substitution has limited climate mitigation benefits, to be effective the value and duration of the fossil carbon displacement, the longevity of buildings, and the nature of the forest supplying building materials must be considered.

Quantifying the climate change mitigation potential of China’s furniture sector: Wood substitution benefits on emission reduction

Abstract Wood and wood-based products have positive effects on climate change mitigation. These products can substitute for energy-intensive products made of conventional materials. The main objective of this study was to quantify substitution benefits of wood furniture for China via national-scale mitigation analyses. We selected a basket of representative furniture and estimated the emission reduction for two functionally equivalent products, which differentiate in wood intensity. The emissions avoided in each type of product were weighted by its share of the furniture market to ensure that the basket can represent the current situation. Then, avoided emissions were estimated for wood commodities contained in the products basket. Results demonstrated that wood materials exerted low environmental impacts. From the less to the more wood intensity products with the equivalent function, the proportion of energy-intensive materials decreased 24% while the proportion of their greenhouse gas (GHG) emissions decreased 34%. The overall displacement factor for the wood material was 2.67 kg CO2eq/kg or 1.46 tC/tC. The findings highlight the importance of material selection in mitigating climate change in the furniture sector. It is urgent to use of the existing timber resources efficiently and pursue alternative schemes for emission reduction to achieve the goal of GHG mitigation.

Life Cycle Impact Assessment of Miscanthus Crop for Sustainable Household Heating in Serbia

This paper investigates the environmental impacts and energy benefits of the cultivation of Miscanthus (Miscanthus × giganteus Greef et Deu.), in order to initiate its use in sustainable household heating in the Republic of Serbia. Based on the analysis of available data regarding the use of agricultural machinery in Serbia, a Miscanthus supply chain is constructed and examined in detail, scrutinizing all relevant operations—from planting of rhizomes to thermal energy production. Results of the life cycle assessment identify the briquetting process as the most environmentally burdensome operation due to high electricity consumption and low productivity. It is concluded that an average yield of 23.5 t dry matter (d.m.) year−1 obtained from 1 ha of chernozem soil would have energy output:energy input (EO:EI) ratio of 51:1, and would release 365.5 gigajoules (GJ) of heat during combustion in a boiler. With this amount of energy, around 383 m2 of a free-standing family house in Serbia can be heated annually. The same amount of energy is obtained by the combustion of 22 t of lignite or 23 t of wood logs. The substitution of lignite and wood with Miscanthus briquettes would lead to significant reduction of CO2 equivalents (eq), SO2 eq, P eq, N eq, 1,4 dichlorobenzene (1,4-DB) eq, Non-methane volatile organic compound (NMVOC), PM10 eq and U235 eq emissions. This designates Miscanthus as a more sustainable energy solution for household heating. In instances where more modern agricultural machinery is used, emission reduction is higher, except for CO2 eq due to higher emission factors predicted for more powerful engines. Depending on Miscanthus’ annual yield, the replacement of set-aside land with Miscanthus plantations result in carbon (C) sequestration from 0.08 t C ha−1 year−1 to 0.91 t C ha−1 year−1. In a modern machinery scenario, C sequestration is only attainable when maximal Miscanthus yield is obtained. The combined use of machinery with different engine power is the best option for Miscanthus cultivation in Serbia.

Estimating the effect of abandoning coppice management on carbon sequestration by oak forests in Turkey with a modeling approach

A significant area of the oak forests in Turkey has been historically managed by short-rotation coppicing for wood production. Coppice management was almost abandoned in Turkey in 2006 and so investigating its impact on forest carbon (C) sequestration has become an important issue. Therefore, we investigated the net effect of this change in management on C sequestration by oak forests in Turkey using field measurement data and a forest C model (Forest Biomass and Dead organic matter Carbon (FBDC) model). The FBDC model estimated the annual forest C dynamics and considered the effect of the substitution of wood for fossil fuels under two management scenarios over a 100-year period: (1) abandoning coppice (no management) and (2) continuing coppice (20-year-interval harvest). The field measurement data were used to parameterize the FBDC model to the study sites and to verify the simulated C stocks. Continuing coppice management constrained an increase in the C stocks (116.0–140.3 Mg C ha−1) and showed a mean annual C sequestration of 0.6 Mg C ha−1 yr−1 if wood was substituted for fossil fuels. In contrast, abandoning coppicing practices increased the level of forest C stocks (128.1–236.2 Mg C ha−1), enhancing the mean annual C sequestration to 1.1 Mg C ha−1 yr−1. Accordingly, the abandonment of coppice management increased the mean annual C sequestration by 0.5 Mg C ha−1 yr−1 in the long-term. However, sensitivity analysis showed a possibility of a larger difference in C sequestration between the two scenarios due to a decrease in the stand productivity by repeated coppices and a high likelihood of a lower substitution effect. The verification supported the scientific reliability of the simulation results. Our study can provide a scientific basis for enhancing C sequestration in coppice forests.

A Functionality Based Wood Substitutability Index

Recent progress in Life Cycle Impact Assessment highlighted the need to assess the loss of resources’ functional value when assessing the life cycle impacts of resource depletion. To be able to assess the loss of functional value of resources due to scarcity and depletion, there is a need to assess the potential substitutions among different resources to fulfill the same functionality. In this sense, the main objective of this study is the development of a method for obtaining a substitution index (SI) for wood, quantifying to what extent the wood is substitutable by other available resources for the different functions it can fulfill. The aim of our method is to characterize wood through its functions and inherent properties by using following parameters (availability, price, current usage). As a result, we obtained SI for five functions of wood, classified by country and region. The results showed that wood substitution varies between each of its functions and also for each region. In general, replacing wood with other resources is a challenge for most regions and most functions, with SI usually below 0.5 on a scale from 0 to 1, where 0 indicate that there is no substitution and 1 indicate that the resource can be thoroughly replaced.

Applying a systems approach to assess carbon emission reductions from climate change mitigation in Mexico’s forest sector

The Paris Agreement of the United Nation Framework Convention on Climate Change calls for a balance of anthropogenic greenhouse emissions and removals in the latter part of this century. Mexico indicated in its Intended Nationally Determined Contribution and its Climate Change Mid-Century Strategy that the land sector will contribute to meeting GHG emission reduction goals. Since 2012, the Mexican government through its National Forestry Commission, with international financial and technical support, has been developing carbon dynamics models to explore climate change mitigation options in the forest sector. Following a systems approach, here we assess the biophysical mitigation potential of forest ecosystems, harvested wood products and their substitution benefits (i.e. the change in emissions resulting from substitution of wood for more emissions-intensive products and fossil fuels), for policy alternatives considered by the Mexican government, such as a net zero deforestation rate and sustainable forest management. We used available analytical frameworks (Carbon Budget Model of the Canadian Forest Sector and a harvested wood products model), parameterized with local input data in two contrasting Mexican states. Using information from the National Forest Monitoring System (e.g. forest inventories, remote sensing, disturbance data), we demonstrate that activities aimed at reaching a net-zero deforestation rate can yield significant CO2e mitigation benefits by 2030 and 2050 relative to a baseline scenario (‘business as usual’), but if combined with increasing forest harvest to produce long-lived products and substitute more energy-intensive materials, emissions reductions could also provide other co-benefits (e.g. jobs, illegal logging reduction). We concluded that the relative impact of mitigation activities is locally dependent, suggesting that mitigation strategies should be designed and implemented at sub-national scales. We were also encouraged about the ability of the modeling framework to effectively use Mexico’s data, and showed the need to include multiple sectors and types of collaborators (scientific and policy-maker communities) to design more comprehensive portfolios for climate change mitigation.

Does replacing coal with wood lower CO2 emissions? Dynamic lifecycle analysis of wood bioenergy

Bioenergy is booming as nations seek to cut their greenhouse gas emissions. The European Union declared biofuels to be carbon-neutral, triggering a surge in wood use. But do biofuels actually reduce emissions? A molecule of CO2 emitted today has the same impact on radiative forcing whether it comes from coal or biomass. Biofuels can only reduce atmospheric CO2 over time through post-harvest increases in net primary production (NPP). The climate impact of biofuels therefore depends on CO2 emissions from combustion of biofuels versus fossil fuels, the fate of the harvested land and dynamics of NPP. Here we develop a model for dynamic bioenergy lifecycle analysis. The model tracks carbon stocks and fluxes among the atmosphere, biomass, and soils, is extensible to multiple land types and regions, and runs in ≈1s, enabling rapid, interactive policy design and sensitivity testing. We simulate substitution of wood for coal in power generation, estimating the parameters governing NPP and other fluxes using data for forests in the eastern US and using published estimates for supply chain emissions. Because combustion and processing efficiencies for wood are less than coal, the immediate impact of substituting wood for coal is an increase in atmospheric CO2 relative to coal. The payback time for this carbon debt ranges from 44–104 years after clearcut, depending on forest type—assuming the land remains forest. Surprisingly, replanting hardwood forests with fast-growing pine plantations raises the CO2 impact of wood because the equilibrium carbon density of plantations is lower than natural forests. Further, projected growth in wood harvest for bioenergy would increase atmospheric CO2 for at least a century because new carbon debt continuously exceeds NPP. Assuming biofuels are carbon neutral may worsen irreversible impacts of climate change before benefits accrue. Instead, explicit dynamic models should be used to assess the climate impacts of biofuels.

Review of carbon storage function of harvested wood products and the potential of wood substitution in greenhouse gas mitigation

Global forests have the potential to significantly increase or reduce atmospheric greenhouse gas (GHG) concentration. Harvested wood products (HWP) are an important part of the forest-atmosphere carbon cycle. On the one hand, HWP can retain the carbon for various periods of time, depending on the end uses. On the other hand, using HWP in place of more GHG-intensive materials and using wood bioenergy to substitute for fossil fuels result in reduced fossil fuel emissions. However, critical methodological differences exist in existing literature in assessing the GHG effects of HWP and wood bioenergy substitution, and large diversity in system boundary, substitution scenario, study period, and reference baseline results in large difference in reported GHG effects of wood substitution. In the present study, we conducted a comprehensive literature review to (a) clarify the methodological issues in GHG effects assessments of HWP and wood bioenergy substitution, (b) summarize and compare the reported GHG effects, and (c) identify knowledge gaps to inform future research. We support the conclusion that to accurately assess the GHG effects, HWP and wood bioenergy life-cycle carbon analysis needs to be integrated with forest carbon balance analysis. Substituting HWP for non-wood materials appears to be more effective in reducing GHG emissions than substituting wood for fossil fuels. The time required to obtain net emission reduction for wood bioenergy in place of fossil fuels can be 0years, decades or more than a century, depending on forest biomass sources (e.g., harvest residue, standing live trees) and fossil fuels displaced. For HWP used to replace non-wood material, however, the time required to obtain net emission reduction largely remains a future research need. Overall, HWP and wood bioenergy originated from sustainably managed forests can significantly contribute to GHG emissions reduction in the long term.

Greenhouse gas reduction and cost efficiency of using wood flooring as an alternative to ceramic tile: A case study in China

Chinese wood flooring and ceramic tile are the research objects in this study. Their energy consumption, the greenhouse gas emissions over their life cycles, and the cost of avoided emissions are analyzed. When wood flooring is used as an alternative to ceramic tile, a total of 0.16–2.85 t CO2 eq/m3 is avoided. The cost of GHG emission reduction is −3.42 to 82.28 RMB/kg CO2 eq (−0.51 to 12.34 USD/kg CO2 eq). The GHG emission reduction from the substitution increases and the cost of emission reduction decreases when the carbon stock in wood flooring is included (1a), the flooring is burned with energy recovery after replacement (2b), and the price of ceramic tile increases (4b). To achieve carbon emission reduction and obtain economic benefit from wood substitution, a reasonable approach for dealing with waste, prolonging the life span of wood flooring, and reducing cost should be considered.

Study of Composites Produced with Recovered Polypropylene and Piassava Fiber

This work addresses the use of piassava fibers (PF) as reinforcement for recovered polypropylene (PPr) in the manufacturing of composites. The composites were molded with variable amounts of PF (10, 20 and 30 wt%), with and without maleic anhydride functionalized polypropylene (MAPP) (10 wt%) as compatibilizer. The composites were characterized using mechanical tests (flexural, tensile, impact and hardness), thermal analyses (thermogravimetric analysis and differential scanning calorimetry), along with evaluations of heat deflection temperature, melting flow index, density and morphology. Tensile and flexural strength of composites increased with PF content, but impact strength decreased, since the material became stiffer. The use of MAPP in the formulations yielded superior properties, showing good fiber/matrix interaction. In all, the use of PF as reinforcement in PPr was considered an interesting way of reducing solid waste and to reinforce plastics, being a possible alternative for the substitution of wood in WPC composites.

Responses to stimulate substitution and cascade use of wood within a wood use system: Experience from Bavaria, Germany

The ideas of cascade use within the wood use system and innovation of new wood-based materials and applications to substitute for other materials have recently gained new impulse within Germany since they have been declared to be priorities within the German government's climate change related policies. This paper explores responses to government policies for a sustainability transition through more intensive and efficient use of wood among Bavarian enterprises. It is based upon interviews with architects, officials, and enterprise owners and managers conducted in 2015 and 2016. The research identifies the opportunities for and barriers to substitution and cascade use of wood as perceived by managers of enterprises embedded in the wood use system. The paper assesses whether the enterprises studied are ready to be change agents in the envisioned sustainability transition. It also maps out the complex Bavarian institutional context within which innovative uses of wood are taking place.

Estimating product and energy substitution benefits in national‐scale mitigation analyses for Canada

AbstractThe potential of forests and the forest sector to mitigate greenhouse gas (GHG) emissions is widely recognized, but challenging to quantify at a national scale. Mitigation benefits through the use of forest products are affected by product life cycles, which determine the duration of carbon storage in wood products and substitution benefits where emissions are avoided using wood products instead of other emissions‐intensive building products and energy fuels. Here we determined displacement factors for wood substitution in the built environment and bioenergy at the national level in Canada. For solid wood products, we compiled a basket of end‐use products and determined the reduction in emissions for two functionally equivalent products: a more wood‐intensive product vs. a less wood‐intensive one. Avoided emissions for end‐use products basket were weighted by Canadian consumption statistics to reflect national wood uses, and avoided emissions were further partitioned into displacement factors for sawnwood and panels. We also examined two bioenergy feedstock scenarios (constant supplyandconstrained supply) to estimate displacement factors for bioenergy using an optimized selection of bioenergy facilities which maximized avoided emissions from fossil fuels. Results demonstrated that the average displacement factors were found to be similar: product displacement factors were 0.54 tCdisplaced pertCof used for sawnwood and 0.45 tC tC−1for panels; energy displacement factors for the two feedstock scenarios were 0.47 tC tC−1for theconstant supplyand 0.89 tC tC−1for theconstrained supply. However, there was a wide range of substitution impacts. The greatest avoided emissions occurred when wood was substituted for steel and concrete in buildings, and when bioenergy from heat facilities and/or combined heat and power facilities was substituted for energy from high‐emissions fossil fuels. We conclude that (1) national‐level substitution benefits need to be considered within a systems perspective on climate change mitigation to avoid the development of policies that deliver no net benefits to the atmosphere, (2) the use of long‐lived wood products in buildings to displace steel and concrete reducesGHGemissions, (3) the greatest bioenergy substitution benefits are achieved using a mix of facility types and capacities to displace emissions‐intensive fossil fuels.

Recycle, Bury, or Burn Wood Waste Biomass?: LCA Answer Depends on Carbon Accounting, Emissions Controls, Displaced Fuels, and Impact Costs

SummaryThis study extends existing life cycle assessment (LCA) literature by assessing seven environmental burdens and an overall monetized environmental score for eight recycle, bury, or burn options to manage clean wood wastes generated at construction and demolition activity sites. The study assesses direct environmental impacts along with substitution effects from displacing fossil fuels and managed forest wood sourcing activities. Follow‐on effects on forest carbon stocks, land use, and fuel markets are not assessed. Sensitivity analysis addresses landfill carbon storage and biodegradation rates, atmospheric emissions controls, displaced fuel types, and two alternative carbon accounting methods commonly used for waste management LCAs. Base‐case carbon accounting considers emissions and uptakes of all biogenic and fossil carbon compounds, including biogenic carbon dioxide. Base‐case results show that recycling options (recycling into reconstituted wood products or into wood pulp for papermaking) rank better than all burning or burying options for overall monetized score as well as for climate impacts, except that wood substitution for coal in industrial boilers is slightly better than recycling for the climate. Wood substitution for natural gas boiler fuel has the highest environmental impacts. Sensitivity analysis shows the overall monetized score rankings for recycling options to be robust except for the carbon accounting method, for which all options are highly sensitive. Under one of the alternative methods, wood substitution for coal boiler fuel and landfill options with high methane capture efficiency are the best for the overall score; recycling options are next to the worst. Under the other accounting alternative, wood substitution for coal and waste‐to‐energy are the best, followed by recycling options.

Effects of Gamma Radiation on Thermal and Mechanical Properties of Wood-Flour Filled Polybenzoxazines

In this study, the composites for wood substitution made of benzoxazine filled with rubber wood-flour were fabricated. The wood flour contents was varied from 0 to 30 wt%. The effects of gamma radiation on the thermal and mechanical properties of wood-flour filled polybenzoxazine were determined. The different radiation dose (i.e. 0, 10, 20, and 30 kGy) was applied to the fabricated samples. The differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA) were used to evaluate glass transition temperature (Tg) and degradation temperature (Td), respectively. While the flexural strength was determined using Universal Testing Machine (UTM). It could be noted that the increase of radiation dose provided the decrease of Td. Moreover, the values of Tg, flexural strength, and water absorption reveals the similar trend with the maximum point at 20 kGy of radiation dose.

The global potential for carbon capture and storage from forestry.

BackgroundDiscussions about limiting anthropogenic emissions of CO_2 often focus on transition to renewable energy sources and on carbon capture and storage (CCS) of CO_2. The potential contributions from forests, forest products and other low-tech strategies are less frequently discussed. Here we develop a new simulation model to assess the global carbon content in forests and apply the model to study active annual carbon harvest 100 years into the future.ResultsThe numerical experiments show that under a hypothetical scenario of globally sustainable forestry the world’s forests could provide a large carbon sink, about one gigatonne per year, due to enhancement of carbon stock in tree biomass. In addition, a large amount of wood, 11.5 GT of carbon per year, could be extracted for reducing CO_2 emissions by substitution of wood for fossil fuels.ConclusionThe results of this study indicate that carbon harvest from forests and carbon storage in living forests have a significant potential for CCS on a global scale.

Vegetative Growth and Leaf Nutrient Status of ‘Carpino’ Chrysanthemum on a Pecan Wood-amended Commercial Substrate

Commercial production of pecan [Carya illinoinensis (Wangenh.) K. Koch.] generates significant woody biomass from hedge prunings with little economic value. Value-added uses could aid pecan growers, and one possible use is wood chips for potting substrates to lessen dependence on peatmoss, thereby aiding greenhouse growers. We evaluated vegetative growth and leaf nutrient responses of ‘Carpino’ garden chrysanthemum (Dendranthema ×grandiflorum) over a 60-day period. Plants were grown in five pecan wood chip substrate levels that substituted 0%, 25%, 50%, 75%, and 100% of peatmoss by volume. Three water soluble fertilizer (WSF) rates—N at 0, 200, or 400 mg·L−1 (0–N, 200–N, and 400–N, respectively)—were applied with each irrigation and to each of the wood substitution treatments. The WSF and wood substitution treatments interacted strongly. In the presence of wood, (25−100% substitution levels), increasing WSF to 400–N increased cumulative evapotranspiration (ET), crop height, total leaf number and area, total leaf and stem dry weight, and leaf N and P concentrations. However, with 0% wood substitution, 400−N provided little or no such enhancements. With 25% to 50% wood substitution, root dry weight increased by 61% to 91% from 0–N to 200–N, which may be an adaptive response to nutrient-limiting conditions at 200–N. Appearance of a white rot fungal species in and atop pecan wood-supplemented substrate supports the likelihood that microbial activity was, at least in part, responsible for the nutrient limitations. High WSF at 400–N in combination with 25% pecan wood substitution maintained adequate fertility and shoot growth that was comparable to the conventional peat-only substrate at 200–N. With low to moderate amounts of pecan wood, further adjustments to WSF rate and irrigation volume would support sustainable fertigation practices, reduce dependence on peatmoss by greenhouse industry, and provide a value-added recycling option for pecan growers.

THERMAL STABILITY OF Pinus oocarpa AND MAIZE COB PARTICLEBOARDS

Agricultural waste materials are generated in large quantities in Brazil. These can accumulate and cause serious environmental problems. One of the most commonly generated wastes in the brazilian agricultural culture is the maize cob. Being lignocellulosic in nature, the maize cob can find use as the raw material in the production of particleboards mainly concerned with furniture making. Therefore, studies regarding its thermal stability and fire resistance would be interesting. The aim of this study was to evaluate the combustibility and thermal stability of the particleboards produced from maize cob and Pinus oocarpa wood. The percentages in which maize cob was associated with Pinus oocarpa were 0%, 25%, 50%, 75% and 100%. The panels were produced using 8% urea-formaldehyde and 1% paraffin. The pressing cycle parameters included: temperature 150 °C, pressure of 3.92 MPa during 10 min. The combustibility curve analysis showed that the panels containing 25% content of maize cob had higher resistance to combustion. In general, the thermal stability decreased as the wood substitution by maize cob increased.

Carbon profile of the managed forest sector in Canada in the 20th century: sink or source?

Canada contains 10% of global forests and has been one of the world's largest harvested wood products (HWP) producers. Therefore, Canada's managed forest sector, the managed forest area and HWP, has the potential to significantly increase or reduce atmospheric greenhouse gases. Using the most comprehensive carbon balance analysis to date, this study shows Canada's managed forest area and resulting HWP were a sink of 7510 and 849 teragrams carbon (TgC), respectively, in the period 1901-2010, exceeding Canada's fossil fuel-based emissions over this period (7333 TgC). If Canadian HWP were not produced and used for residential construction, and instead more energy intensive materials were used, there would have been an additional 790 TgC fossil fuel-based emissions. Because the forest carbon increases in the 20th century were mainly due to younger growing forests that resulted from disturbances in the 19th century, and future increases in forest carbon stocks appear uncertain, in coming decades most of the mitigation contribution from Canadian forests will likely accrue from wood substitution that reduces fossil fuel-based emissions and stores carbon, so long as those forests are managed sustainably.

Building professionals’ attitudes towards the use of wood in building design and construction in Taiwan

This study aims to analyse the attitudes of building professionals towards the use of wood in building design and construction in Taiwan, and to investigate how professionals’ backgrounds affect their attitudes upon the wood usage using statistical analysis. 123 valid questionnaires were collected from various building professionals, including architecture students, architects, interior designers and building construction engineers. It has been shown that wood is regarded as the most environmentally-friendly material in building design and construction. ‘Beauty’ and ‘proprietor’ are the most two essential factors identified by professionals that may influence their decisions to use wood, whereas the deconstruction phase and post-use of demolished wood are considered less important. With respect to the wood utilisation in construction, building professionals prefer using wood in the substructure to main structure at present. On the other hand, the differences between professionals’ experience in designing wood houses or wood elements, and their attitudes towards the importance of reasons in using wood are generally insignificant, except for the easy assembly (p = 0.03) and easy disassembly (p = 0.02) of wood construction. Professionals in favour of wood substitution are more likely to choose wood in column, beam, window, outdoor wall and door. Moreover, there are significant differences between professionals’ occupations and their opinions upon the recyclability issues of materials (p = 0.02). In the future, more sufficient communications are required through the design process among various professional groups.

Wood preservation (carbon sequestration) or wood burning (fossil-fuel substitution), which is better for mitigating climate change?

The effective ways of using wood production with a view to mitigating climate change are still disputed. Currently, there are two major opposing conceptions. One proposes to increase the carbon stock in forests, in wood products or in some kind of long-term wood storage, thus giving primacy to carbon sequestration. The other invokes the concept of biomass carbon neutrality to assert that the substitution of wood for fossil fuels avoids carbon emissions. This paper contributes to this debate by comparing carbon footprints of heat generation when choosing wood or other fuels as alternatives. On condition that wood can be preserved with sufficient durability to meet the time frame of the necessary transition towards carbon-free energy resources (decadal to centennial time scales), one can demonstrate that the use of fossil fuels, with the exception of coal, is still preferable. The reasons are that the intrinsic carbon emission factor for wood has the highest value among all fuels in common use and that reference to the concept of wood carbon neutrality neglects the possibility of storing carbon positively in wood for a long time. The conclusion is that to mitigate climate change it is better to store wood than use it as a fuel.