Full accounting of the greenhouse gas budget in the forestry of China

Forest management to increase carbon (C) sinks and reduce C emissions and forest resource utilization to store C and substitute for fossil fuel have been identified as attractive mitigation strategies. However, the greenhouse gas (GHG) budget of carbon pools and sinks in China are not fully understood, and the forestry net C sink must be determined. The objective of this study was to analyze potential forest management mitigation strategies by evaluating the GHG emissions from forest management and resource utilization and clarify the forestry net C sink, and its driving factors in China via constructing C accounting and net mitigation of forestry methodology. The results indicated that the GHG emissions under forest management and resource utilization were 17.7 Tg Ce/year and offset 8.5% of biomass and products C sink and GHG mitigation from substitution effects from 2000 to 2014, resulting in a net C sink of 189.8 Tg Ce/year. Forest resource utilization contributed the most to the national forestry GHG emissions, whereas the main driving factor underlying regional GHG emissions varied. Afforestation dominated the GHG emissions in the southwest and northwest, whereas resource utilization contributed the most to GHG emissions in the north, northeast, east, and south. Furthermore, decreased wood production, improved product use efficiency, and forests developed for bioenergy represented important mitigation strategies and should be targeted implementation in different regions. Our study provided a forestry C accounting in China and indicated that simulations of these activities could provide novel insights for mitigation strategies and have implications for forest management in other countries.     

Global warming potential factors and warming payback time as climate indicators of forest biomass use

A method is presented for estimating the global warming impact of forest biomass life cycles with respect to their functionally equivalent alternatives based on fossil fuels and non-renewable material sources. In the method, absolute global warming potentials (AGWP) of both the temporary carbon (C) debt of forest biomass stock and the C credit of the biomass use cycle displacing the fossil and non-renewable alternative are estimated as a function of the time frame of climate change mitigation. Dimensionless global warming potential (GWP) factors, GWP_bio and GWP_biouse, are derived. As numerical examples, 1) bioenergy from boreal forest harvest residues to displace fossil fuels and 2) the use of wood for material substitution are considered. The GWP-based indicator leads to longer payback times, i.e. the time frame needed for the biomass option to be superior to its fossil-based alternative, than when just the cumulative balance of biogenic and fossil C stocks is considered. The warming payback time increases substantially with the residue diameter and low displacement factor (DF) of fossil C emissions. For the 35-cm stumps, the payback time appears to be more than 100 years in the climate conditions of Southern Finland when DF is lower than 0.5 in instant use and lower than 0.6 in continuous stump use. Wood use for construction appears to be more beneficial because, in addition to displaced emissions due to by-product bioenergy and material substitution, a significant part of round wood is sequestered into wood products for a long period, and even a zero payback time would be attainable with reasonable DFs.     

National and global greenhouse gas dynamics of different forest management and wood use scenarios: a model-based assessment

An increased use of wood products and an adequate management of forests can help to mitigate climate change. However, planning horizons and response time to changes in forest management are usually long and the respective GHG effects related to the use of wood depend on the availability of harvested wood. Therefore, an integral long-term strategic approach is required to formulate the most effective forest and wood management strategies for mitigating climate change.The greenhouse gas (GHG) dynamics related to the production, use and disposal of wood products are manifold and show a complex time pattern. On the one hand, wood products can be considered as a carbon pool, as is the forest itself. On the other hand, an increased use of wood can lead to the substitution of usually more energy-intense materials and to the substitution of fossil fuels when the thermal energy of wood is recovered. Country-specific import/export flows of wood products and their alternative products as well as their processing stage have to be considered if substitution effects are assessed on a national basis.We present an integral model-based approach to evaluate the GHG impacts of various forest management and wood use scenarios. Our approach allows us to analyse the complex temporal and spatial patterns of GHG emissions and removals including trade-offs of different forest management and wood use strategies. This study shows that the contributions of the forestry and timber sector to mitigate climate change can be optimized with the following key recommendations: (1) the maximum possible, sustainable increment should be generated in the forest, taking into account biodiversity conservation as well as the long-term preservation of soil quality and growth performance; (2) this increment should be harvested continuously; (3) the harvested wood should be processed in accordance with the principle of cascade use, i.e. first be used as a material as long as possible, preferably in structural components; (4) waste wood that is not suitable for further use should be used to generate energy. Political strategies to solely increase the use of wood as a biofuel cannot be considered efficient from a climate perspective; (5) forest management strategies to enhance carbon sinks in forests via reduced harvesting are not only ineffective because of a compensatory increase in fossil fuel consumption for the production of non-wooden products and thermal energy but also because of the Kyoto-“cap” that limits the accountability of GHG removals by sinks under Article 3.3 and 3.4, at least for the first commitment period; (6) the effect of substitution through the material and energy use of wood is more significant and sustained as compared with the stock effects in wood products, which tend towards new steady-state flow equilibria with no further increase of C stocks; (7) from a global perspective, the effect of material substitution exceeds that of energy recovery from wood. In the Swiss context, however, the energy recovery from wood generates a greater substitution effect than material substitution.     

Climate change mitigation strategies in the forest sector: biophysical impacts and economic implications in British Columbia,Canada

Managing forests to increase carbon sequestration or reduce carbon emissions and using wood products and bioenergy to store carbon and substitute for other emission-intensive products and fossil fuel energy have been considered effective ways to tackle climate change in many countries and regions. The objective of this study is to examine the climate change mitigation potential of the forest sector by developing and assessing potential mitigation strategies and portfolios with various goals in British Columbia (BC), Canada. From a systems perspective, mitigation potentials of five individual strategies and their combinations were examined with regionally differentiated implementations of changes. We also calculated cost curves for the strategies and explored socio-economic impacts using an input-output model. Our results showed a wide range of mitigation potentials and that both the magnitude and the timing of mitigation varied across strategies. The greatest mitigation potential was achieved by improving the harvest utilization, shifting the commodity mix to longer-lived wood products, and using harvest residues for bioenergy. The highest cumulative mitigation of 421 MtCO₂e for BC was estimated when employing the strategy portfolio that maximized domestic mitigation during 2017–2050, and this would contribute 35% of BC’s greenhouse gas emission reduction target by 2050 at less than $100/tCO₂e and provide additional socio-economic benefits. This case study demonstrated the application of an integrated systems approach that tracks carbon stock changes and emissions in forest ecosystems, harvested wood products (HWPs), and the avoidance of emissions through the use of HWPs and is therefore applicable to other countries and regions.     

Carbon accounting of material substitution with biomass: Case studies for Austria investigated with IPCC default and alternative approaches

There is evidence that the replacement of carbon-intensive products with bio-based substitutes (‘material substitution with biomass’) can be highly efficient in reducing greenhouse gas (GHG) emissions. Based on two case studies (CS1/2) for Austria, potential benefits of material substitution in comparison to fuel substitution are analysed. GHG savings are calculated according to default IPCC approaches (Tier 2 method assuming first-order decay) and with more realistic approaches based on distribution functions. In CS1, high savings are achieved by using wood residues for the production of insulating boards instead of energy. The superiority of material substitution is due to the establishment of a long-term carbon storage, the high emission factor of wood in comparison to natural gas and higher efficiencies of gas-fired facilities.The biomass feedstock in CS2 is lignocellulosic ethanol being used for bio-ethylene production (material substitution) or replacing gasoline (fuel substitution). GHG savings are mainly due to lower production emissions of bio-ethylene in comparison to conventional ethylene and significantly lower than in CS1 (per unit of biomass consumed). While CS1 is highly robust to parameter variation, the long-term projections in CS2 are quite speculative.To create adequate incentives for including material substitution in national climate strategies, shortcomings of current default accounting methods must be addressed. Under current methods the GHG savings in both case studies would not (fully) materialize in the national GHG inventory. The main reason is that accounting of wood products is confined to the proportion derived from domestic harvest, whereas imported biomass used for energy is treated as carbon-neutral. Further inadequacies of IPCC default accounting methods include the assumption of exponential decay and the disregard of advanced bio-based products.     

The contribution of the paper cycle to global warming

Worldwide, paper production is a major industry that contributes about 3 percent of Gross World Product. The paper cycle involves a broad range of natural resource and environmental impacts because fiber supply relies on trees, paper manufacturing requires fuel inputs, and paper waste disposal can contribute to emissions of the potent greenhouse gas (GHG), methane (CH₄). In some countries, the paper cycle may be seen as a net sink for GHG because of reliance on renewable wood by-products and the maintenance of forest plantations. On a worldwide basis, however, this study demonstrates that the paper cycle is a significant contributor to GHG emissions, adding emissions at least comparable in magnitude to that of Australia each year. The estimated global warming contribution of paper in landfills is estimated to be similar to that of paper manufacturing processes, on a heating-equivalent basis. In some temperate regions, original old-growth forests are still harvested to supply pulpwood, resulting in a significant loss of carbon (C) storage. In theory, the paper cycle holds the promise of achieving zero net emissions if pulpwood production, consumption and disposal are carefully managed. In practice, even stabilization of emissions at current levels would be challenging and entail changes comparable to a 20 percent reduction in CH₄ generation from landfilled paper, and a 2.5 percent annual increase in plantation establishment would be needed to offset the projected increase in emissions from paper manufacturing.     

Wood products: potential carbon sequestration and impact on net carbon emissions of industrialized countries

Carbon stocks in the wood products pool are considered to be increasing globally. Simplified methods for estimating the fate of carbon in wood products need to be prepared to allow estimation at the national level. Since current methods cause some problems when dealing with specific countries, we try to improve the current methods. We discuss the potential carbon sequestration in wood products and the impacts of three accounting approaches (IPCC default, stock-change and atmospheric-flow) on net carbon emissions of 16 industrialized countries. We draw the following conclusions: (1) we improved the current methods for estimating the fate of carbon by considering the recycling of paper and the use of other fiber pulp, but further improvement need to be made; (2) the annual carbon sequestrations in wood products during 1990–1999 correspond to a few to 10% of 1990 base-year emissions from fossil fuels and cement production, depending on country and year. For the analyzed countries as a whole, the annual carbon sequestration was around 2%; (3) the impact of the accounting approaches on net carbon emissions at the national level is significant. Therefore, policy implications must be carefully considered when one of these approaches is adopted.     

Impacts of international trade on carbon flows of forest industry in Finland

Finland is a forested country with a large export oriented forest industry. In addition to domestic forest extraction, roundwood is imported, thus displacing the environmental impacts of harvests. In this paper, we analyse the international carbon flows of forest industries in Finland from a consumption-based perspective. Quantitative analyses are available on trade embedded emissions of CO₂ from fossil fuel combustion, and here we address in a similar way the impact of trade on the carbon budget of the forest products sector in Finland. Carbon flows through the forest industry system increased substantially between 1991 and 2005. We show that the annual carbon balance related to forests and forest industry system in Finland functioned as a sink in 1991, whereas in 2005 the system was a sink on a national level, but not on a global level. Through calculating the carbon content in traded forest industry products and emissions embodied in forest industry activities, we further show that the direct impacts of the forest industry in Finland are only a minor fraction of the total CO₂ emissions related to Finnish production. Nearly all of the emissions were caused due to production of exports. Yet, direct carbon dioxide emissions of the industrial production are reported to Finland in the production based inventories.     

Prospects for carbon-neutral housing: the influence of greater wood use on the carbon footprint of a single-family residence

This paper examines the energy and carbon balance of two residential house alternatives; a typical wood frame home using more conventional materials (brick cladding, vinyl windows, asphalt shingles, and fibreglass insulation) and a similar wood frame house that also maximizes wood use throughout (cedar shingles and siding, wood windows, and cellulose insulation) in place of the more typical materials used – a wood-intensive house. Carbon emission and fossil fuel consumption balances were established for the two homes based on the cumulative total of three subsystems: (1) forest harvesting and regeneration; (2) cradle-to-gate product manufacturing, construction, and replacement effects over a 100-year service life; and (3) end-of-life effects – landfilling with methane capture and combustion or recovery of biomass for energy production.The net carbon balance of the wood-intensive house showed a complete offset of the manufacturing emissions by the credit given to the system for forest re-growth. Including landfill methane emissions, the wood-intensive life cycle yielded 20 tons of CO₂e emissions compared to 72 tons for the typical house. The wood-intensive home's life cycle also consumed only 45% of the fossil fuels used in the typical house.Diverting wood materials from the landfill at the end of life improved the life cycle balances of both the typical and wood-intensive houses. The carbon balance of the wood-intensive house was 5.2 tons of CO₂e permanently removed from the atmosphere (a net carbon sink) as compared to 63.4 of total CO₂e emissions for the typical house. Substitution of wood fuel for natural gas and coal in electricity production led to a net energy balance of the wood-intensive house that was nearly neutral, 87.1 GJ energy use, 88% lower than the scenario in which the materials were landfilled.Allocating biomass generation and carbon sequestration in the forest on an economic basis as opposed to a mass basis significantly improves the life cycle balances of both houses. Employing an economic allocation method to the forest leads to 3–5 times greater carbon sequestration and fossil fuel substitution attributable to the house, which is doubled in forestry regimes that remove stumps and slash as fuel. Thus, wood use has the potential to create a significantly negative carbon footprint for a house up to the point of occupancy and even offset a portion of heating and cooling energy use and carbon emissions; the wood-intensive house is energy and carbon neutral for 34–68 years in Ottawa and has the potential to be a net carbon sink and energy producer in a more temperate climate like San Francisco.     

Greenhouse gas mitigation with scarce land: The potential contribution of increased nitrogen input

Agricultural lands have been identified to mitigate greenhouse gas (GHG) emissions primarily by production of energy crops and substituting fossil energy resources and through carbon sequestration in soils. Increased fertilizer input resulting in increased yields may reduce the area needed for crop production. The surplus area could be used for energy production without affecting the land use necessary for food and feed production. We built a model to investigate the effect of changing nitrogen (N) fertilizer rates on cropping area required for a given amount of crops. We found that an increase in nitrogen fertilizer supply is only justified if GHG mitigation with additional land is higher than 9–15 t carbon dioxide equivalents per hectare (CO₂-eq._./ha). The mitigation potential of bioenergy production from energy crops is most often not in this range. Hence, from a GHG abatement point of view land should rather be used to produce crops at moderate fertilizer rate than to produce energy crops. This may change if farmers are forced to reduce their N input due to taxes or governmental regulations as it is the case in Denmark. However, with a fertilizer rate 10 % below the economical optimum a reduction of N input is still more effective than the production of bioenergy unless mitigation effect of the bioenergy production exceeds 7 t carbon dioxide (CO₂)-eq._./ha. An intensification of land use in terms of N supply to provide more land for bioenergy production can only in exceptional cases be justified to mitigate GHG emissions with bioenergy under current frame conditions in Germany and Denmark.     

Effect of age and disturbance on decadal changes in carbon stocks in managed forest landscapes in central Canada

Forests have the potential to be a sink in the global carbon (C) budget and thus play an important role in mitigating climate change. However, large-scale management of forests to their sink potential requires understanding of factors responsible for changes in forest C stocks. In this paper, we quantify the effects of initial forest landscape condition and disturbance rates on landscape-level changes in forest C stocks using predictions for managed forests in Ontario, Canada. Ten-year changes in C stocks in public forests managed for wood fibre production were simulated under four scenarios reflecting the range of volume harvested between 1998 and 2007. Changes in forest C stocks varied across Ontario and with harvest rate, resulting in the forest ranging from being a source of 0.767 tC ha^-1 year^?1 to a sink of 0.656 tC ha^?1 year^?1. Simulation results were used to develop a predictive equation explaining over 93 % of the variation in forest C stocks. Variables included in the equation, in descending order of their effect on changes in forest C stocks, were relative harvest rate, forest growth rate, natural disturbance rate, and initial forest C stocks. A reduced equation, including only the first three variables, explained nearly 89 % of the variation in forest C stocks. The results indicate that short-term changes in C stocks depend on initial forest condition and that there are limits to how much these changes can be manipulated by altering harvest and disturbance rates.     

Different accounting approaches to harvested wood products in national greenhouse gas inventories: their incentives to achievement of major policy goals

The 2006 IPCC Guidelines for National Greenhouse Gas Inventories provide four accounting approaches to harvested wood products (HWP). These differ in the way they define system boundaries. Therefore, reported national carbon emissions differ according to the accounting approach used, and the implications of each accounting approach differ for different countries. This paper investigates four IPCC accounting approaches, as well as the 1996 IPCC default approach, to determine whether they provide incentives to achievement of major policy goals related to climate, forest, trade, and waste, taking into account indirect effects of wood use change (i.e., the effects on forest carbon stocks and on carbon emissions from the use of other fuels and materials). Conclusions are as follows: (1) The analyses produced many different results from those of previous studies. These differences appear to be attributable to whether or not the indirect effects of wood use change are taken into account and the reference scenarios that are assumed; (2) The best approaches for achieving each policy goal differ, and the best approaches for particular policy goals might pose problems for other policy goals; (3) Overall, the IPCC default approach is the best accounting approach from the viewpoint of greater compatibility with, or integration across, the array of policy goals, although it does not address the issue of an increasing global carbon stock in HWP.     

Greenhouse gas emissions,life-cycle inventory and cost-efficiency of using laminated wood instead of steel construction.: Case: beams at Gardermoen airport

This article compares the use of glulam beams at the new airport outside Oslo with an alternative solution in steel in order to (1) make an inventory of greenhouse gas (GHG) emissions and energy use over the life cycle of glulam and of steel, (2) calculate the avoided GHG emissions and the cost of the substitution, and (3) analyse which factors have the strongest influence on the results. Compared to previous analyses of substitution between steel and glulam related to greenhouse gas emissions, this article brings in three new methodological elements: combining traditional life-cycle analysis with economic costs, considering explicitly the emissions’ points in time, and using discounted global warming potential (DGWP).The total energy consumption in manufacturing of steel beams is two to three times higher and the use of fossil fuel 6–12 times higher than in the manufacturing of glulam beams. Manufacturing of steel in the most likely scenario gives five times higher GHG emissions compared to manufacturing of glulam beams. Waste handling of glulam can either be very favourable or unfavourable compared to steel depending on the glulam being landfilled or used for energy production. Other assumptions that substantially affect the results over the life cycle are carbon fixation on the forest land that is regenerated after harvesting, whether the steel production is scrap-based or ore-based, and which energy sources are used for producing the electricity used by the steel industry. The uncertainty in the inventory data for glulam do not influence the results much compared to changes in these main assumptions. The glulam construction cannot be more than 1–6% more expensive than steel before the price per ton avoided greenhouse gas emissions becomes high compared to the present Norwegian CO₂-tax on gasoline. In the most likely scenario, and not including carbon fixation on forest land, 0.24–0.31 tons of CO₂-equivalents per cubic metre input of sawn wood in glulam production is avoided by using glulam instead of steel, whereas this figure increases to 0.40–0.97 t/m³ if carbon fixation on forest land is included. Using DGWP does not influence the results of the analysis significantly.     

Carbon sequestration in wood products: a method for attribution to multiple parties

When forest is harvested some of the forest carbon ends up in wood products. If the forest is managed so that the standing stock of the forest remains constant over time, and the stock of wood products is increasing, then carbon dioxide is being removed from the atmosphere in net and this should be reflected in accounting for greenhouse gas emissions. We suggest that carbon sequestration in wood products requires cooperation of multiple parties; from the forest owner to the product manufacturer to the product user, and perhaps others. Credit for sequestering carbon away from the atmosphere could acknowledge the contributions of these multiple parties. Accounting under a cap-and-trade or tax system is not necessarily an inventory system, it is a system designed to motivate and/or reward an environmental objective. We describe a system of attribution whereby credits for carbon sequestration would be shared among multiple, contributing parties. It is hoped that the methodology outlined herein proves attractive enough to parties concerned to spur them to address the details of such a system. The system of incentives one would choose for limiting or controlling greenhouse gas emissions could be quite different, depending on how the attribution for emissions and sequestration is chosen.     

Forest Management for Mitigation of CO2 Emissions: How Much Mitigation and Who Gets the Credits?

Forestry projects can mitigate the net flux of carbon (C) to the atmosphere in four ways: (1) C is stored in forest biomass—trees, litter and soil, (2) C is stored in durable wood products, (3) biomass fuels displace consumption of fossil fuels, and (4) wood products often require less fossil-fuel energy for their production and use than do alternate products that provide the same service. We use a mathematical model of C stocks and flows (GORCAM) to illustrate the inter-relationships among these impacts on the C cycle and the changing C balance over time. The model suggests that sustainable management for the harvest of forest products will yield more net C offset than will forest protection when forest productivity is high, forest products are produced and used efficiently, and longer time periods are considered. Yet it is very difficult to attribute all of the C offsets to the forestry projects. It is, at least in concept, straightforward to measure, verify, and attribute the C stored in the forests and in wood products. It is more challenging to measure the amount of fossil fuel saved directly because of the use of biomass fuels and to give proper attribution to a mitigation project. The amount of fossil fuel saved indirectly because biomass provides materials and services that are used in place of other materials and services may be very difficult to estimate and impossible to allocate to any project. Nonetheless, over the long run, these two aspects of fossil fuel saved may be the largest impacts of forestry projects on the global C cycle.     

杉木人工林碳收获预估技术研究

从收获预估的角度确定森林碳收获大小与林分之间的关系,定义了碳收获和碳收获表的概念.采用二次正交旋转设计设置杉木(Cunninghamia lanceolata)人工林典型标准地,调查测定获取典型样地杉木人工林样木各器官碳含量及碳贮量基本数据,基于相对生长方程以单株胸径、树高、材积为自变量建立杉木人工林单木碳收获量模型,以林分平均胸径、平均树高、密度指数和蓄积量为自变量建立杉木人工林林分碳收获量模型并编制其可变密度碳收获量表.经检验,所建立杉木人工林单木各器官碳收获量模型和林分碳收获量模型预估精度均达95%以上,且模型充分考虑了单株材积和林分蓄积量对碳收获量的影响,具有较强的兼容性和可操作性,在森林碳汇估测中具有应用价值.将所建立杉木人工林碳收获量模型应用于杉木人工林单木碳收获量及林分碳收获量预估,实例计算表明其预估精度较高,单木碳收获模型的相对误差仅为4.70 %,说明所建立杉木人工林碳收获量模型可应用于福建省杉木人工林单木和林分碳储量估计,从而丰富了森林资源动态预测内容,并可为森林资源监测及其相关研究提供基础数据.     

深圳市温室气体排放清单研究

根据深圳市相关统计资料收集到的活动水平数据,参照《2006年IPCC国家温室气体清单指南》温室气体核算方法,建立了深圳市温室气体排放清单,并且与其他城市的温室气体排放水平进行了对比. 结果表明:2008年深圳市温室气体总排放量(以CO₂排放当量计)为6 569.4×104 t,能源部门的温室气体排放量占总排放量的比例最大,达80.8%;工业过程、废物处理处置部门和农林和其他土地利用(AFOLU)部门排放所占比例分别为16.5%、5.1%和-2.4%. 深圳市温室气体人均排放量为7.49 t/人,单位GDP的温室气体排放量为0.84 t/104元,二者均低于北京、上海、天津和无锡的平均排放水平,但高于重庆市.      

Carbon storage and sequestration potential of selected tree species in India

A dynamic growth model (CO2FIX) was used for estimating the carbon sequestration potential of sal (Shorea Robusta Gaertn. f.), Eucalyptus (Eucalyptus Tereticornis Sm.), poplar (Populus Deltoides Marsh), and teak (Tectona Grandis Linn. f.) forests in India. The results indicate that long-term total carbon storage ranges from 101 to 156 Mg C?ha^?1, with the largest carbon stock in the living biomass of long rotation sal forests (82 Mg C?ha^?1). The net annual carbon sequestration rates were achieved for fast growing short rotation poplar (8 Mg C?ha^?1?yr^?1) and Eucalyptus (6 Mg C?ha^?1?yr^?1) plantations followed by moderate growing teak forests (2 Mg C?ha^?1?yr^?1) and slow growing long rotation sal forests (1 Mg C?ha^?1?yr^?1). Due to fast growth rate and adaptability to a range of environments, short rotation plantations, in addition to carbon storage rapidly produce biomass for energy and contribute to reduced greenhouse gas emissions. We also used the model to evaluate the effect of changing rotation length and thinning regime on carbon stocks of forest ecosystem (trees?+?soil) and wood products, respectively for sal and teak forests. The carbon stock in soil and products was less sensitive than carbon stock of trees to the change in rotation length. Extending rotation length from the recommended 120 to 150 years increased the average carbon stock of forest ecosystem (trees?+?soil) by 12%. The net primary productivity was highest (3.7 Mg ha^?1?yr^?1) when a 60-year rotation length was applied but decreased with increasing rotation length (e.g., 1.7 Mg ha^?1?yr^?1) at 150 years. Goal of maximum carbon storage and production of more valuable saw logs can be achieved from longer rotation lengths. ‘No thinning’ has the largest biomass, but from an economical perspective, there will be no wood available from thinning operations to replace fossil fuel for bioenergy and to the pulp industry and such patches have high risks of forest fires, insects etc. Extended rotation lengths and reduced thinning intensity could enhance the long-term capacity of forest ecosystems to sequester carbon. While accounting for effects of climate change, a combination of bioenergy and carbon sequestration will be best to mitigation of CO₂ emission in the long term.     

Bioenergy and the forest industry in Finland after the adoption of the Kyoto protocol

In Finland the percentage of biomass fuels of total primary energy supply is relatively high, close to 17%. The share of biomass in the total electricity generation is as much as 10%. This high share in Finland is mainly due to the cogeneration of electricity and heat within forest industry using biomass-based by-products and wastes as fuels. Forest industry is also a large user of fossil-based energy. About 28% of total primary energy consumption in Finland takes place in forest industry, causing about 16% of the total fossil carbon dioxide emissions.The Kyoto protocol limits the fossil CO₂ and other greenhouse gas emissions and provides some incentives to the Finnish forest sector. There are trade-offs among the raw-material, energy and carbon sink uses of the forests. Fossil emissions can be reduced e.g. by using more wood and producing chemical pulp instead of mechanical one. According to the calculation rules of the Kyoto protocol Finnish forests in 2008–2012 are estimated to form a carbon source of 0.36 Tg C a⁻¹ due to land use changes. Factually the forest biomass will still be a net carbon sink between 3.5 and 8.8 Tg C a⁻¹. Because the carbon sinks of existing forests are not counted in the protocol, there is an incentive to increase wood use in those and to decrease the real net carbon sink. Also the criteria for sustainable forestry could still simultaneously be met.     

Life cycle assessment of ACQ-treated lumber with comparison to wood plastic composite decking

A cradle-to-grave life cycle assessment was done to identify the environmental impacts related to alkaline copper quaternary (ACQ)-treated lumber used for decking and to determine how the impacts compare to the primary alternative product, wood plastic composite (WPC) decking. A model of ACQ-treated lumber life cycle stages was created and used to calculate inputs and outputs during the lumber production, treating, use, and disposal stages. Lumber production data are based on published sources. Primary wood preservative treatment data were obtained by surveying wood treatment facilities in the United States. Product use and disposal inventory data are based on published data and professional judgment. Life cycle inventory inputs, outputs, and impact indicators for ACQ-treated lumber were quantified using functional units of 1000 board feet and per representative deck (assumed to be 320 square feet (30 square meters) of surface decking material) per year of use. In a similar manner, an inventory model was developed for the manufacture, use, and disposal of the primary alternative product, WPC. Impact indicator values, including greenhouse gas (GHG) emissions, fossil fuel use, water use, acidification, smog forming potential, ecological toxicity, and eutrophication were quantified for each of the two decking products. National normalization was done to compare the significance of a representative deck surface per year of use to a family’s total annual impact footprint.If an average U.S. family adds or replaces a deck surfaced with ACQ-treated lumber, their impact “footprint” for GHG emissions, fossil fuel use, acidification, smog forming potential, ecological toxicity, and eutrophication releases each is less than one-tenth of a percent of the family’s annual impact. ACQ-treated lumber impacts were fourteen times less for fossil fuel use, almost three times less for GHG emissions, potential smog emissions, and water use, four times less for acidification, and almost half for ecological toxicity than those for WPC decking. Impacts were approximately equal for eutrophication.