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.     

Accounting for sequestered carbon: the question of permanence

In its attempt to provide quantitative limits on greenhouse gas emissions, the Kyoto protocol accepts the principle that sequestration of carbon in the terrestrial biosphere can be used to offset emissions of carbon from fossil-fuel combustion. Whether or not the Kyoto protocol ever comes into force, it is worthwhile to understand how carbon sequestration might be treated in any mitigation plan that provides a tax or ration on carbon emissions. Emission credits, as proposed for the energy sector, are based on the idea that a prevented emission is prevented forever, and emission credits might be traded among parties. In the event that sequestered carbon is subsequently released to the atmosphere, it would be advantageous to agree what the liability is and who assumes that liability. We describe a system whereby emissions credits could be rented, rather than sold, when carbon is sequestered but permanence of sequestration is either not certain or not desired. Our proposal is similar to that offered by the government of Colombia except that it casts these temporary emissions credits into the traditional concepts of rental agreements and it clarifies the opportunities for secondary transactions. A rental contract for emissions credits would establish continuous responsibility for sequestered carbon; credit would be assigned when carbon is sequestered and debits would accrue when carbon is emitted.     

Carbon storage potential of harvested wood: summary and policy implications

Within national greenhouse gas inventories, many countries now use widely-accepted methodologies to track carbon that continues to be stored in wood products and landfills after its removal from the forest. Beyond simply tracking post-harvest wood carbon, expansion of this pool has further been suggested as a potential climate change mitigation strategy. This paper summarizes data on the fate of carbon through the wood processing chain and on greenhouse gas emissions generated by processing, transport, use and disposal of wood. As a result of wood waste and decomposition, the carbon stored long-term in harvested wood products may be a small proportion of that originally stored in the standing trees—across the United States approximately 1% may remain in products in-use and 13% in landfills at 100 years post-harvest. Related processing and transport emissions may in some cases approach the amount of CO₂e stored in long-lived solid wood products. Policies that promote wood product carbon storage as a climate mitigation strategy must assess full life-cycle impacts, address accounting uncertainties, and balance multiple public values derived from forests.     

Making carbon sequestration a paying proposition

Atmospheric carbon dioxide (CO₂) has increased from a preindustrial concentration of about 280 ppm to about 367 ppm at present. The increase has closely followed the increase in CO₂ emissions from the use of fossil fuels. Global warming caused by increasing amounts of greenhouse gases in the atmosphere is the major environmental challenge for the 21st century. Reducing worldwide emissions of CO₂ requires multiple mitigation pathways, including reductions in energy consumption, more efficient use of available energy, the application of renewable energy sources, and sequestration. Sequestration is a major tool for managing carbon emissions. In a majority of cases CO₂ is viewed as waste to be disposed; however, with advanced technology, carbon sequestration can become a value-added proposition. There are a number of potential opportunities that render sequestration economically viable. In this study, we review these most economically promising opportunities and pathways of carbon sequestration, including reforestation, best agricultural production, housing and furniture, enhanced oil recovery, coalbed methane (CBM), and CO₂ hydrates. Many of these terrestrial and geological sequestration opportunities are expected to provide a direct economic benefit over that obtained by merely reducing the atmospheric CO₂ loading. Sequestration opportunities in 11 states of the Southeast and South Central United States are discussed. Among the most promising methods for the region include reforestation and CBM. The annual forest carbon sink in this region is estimated to be 76 Tg C/year, which would amount to an expenditure of $11.1–13.9 billion/year. Best management practices could enhance carbon sequestration by 53.9 Tg C/year, accounting for 9.3% of current total annual regional greenhouse gas emission in the next 20 years. Annual carbon storage in housing, furniture, and other wood products in 1998 was estimated to be 13.9 Tg C in the region. Other sequestration options, including the direct injection of CO₂ in deep saline aquifers, mineralization, and biomineralization, are not expected to lead to direct economic gain. More detailed studies are needed for assessing the ultimate changes to the environment and the associated indirect cost savings for carbon sequestration.     

Forest carbon accounting methods and the consequences of forest bioenergy for national greenhouse gas emissions inventories

While bioenergy plays a key role in strategies for increasing renewable energy deployment, studies assessing greenhouse gas (GHG) emissions from forest bioenergy systems have identified a potential trade-off of the system with forest carbon stocks. Of particular importance to national GHG inventories is how trade-offs between forest carbon stocks and bioenergy production are accounted for within the Agriculture, Forestry and Other Land Use (AFOLU) sector under current and future international climate change mitigation agreements. Through a case study of electricity produced using wood pellets from harvested forest stands in Ontario, Canada, this study assesses the implications of forest carbon accounting approaches on net emissions attributable to pellets produced for domestic use or export. Particular emphasis is placed on the forest management reference level (FMRL) method, as it will be employed by most Annex I nations in the next Kyoto Protocol Commitment Period. While bioenergy production is found to reduce forest carbon sequestration, under the FMRL approach this trade-off may not be accounted for and thus not incur an accountable AFOLU-related emission, provided that total forest harvest remains at or below that defined under the FMRL baseline. In contrast, accounting for forest carbon trade-offs associated with harvest for bioenergy results in an increase in net GHG emissions (AFOLU and life cycle emissions) lasting 37 or 90 years (if displacing coal or natural gas combined cycle generation, respectively). AFOLU emissions calculated using the Gross-Net approach are dominated by legacy effects of past management and natural disturbance, indicating near-term net forest carbon increase but longer-term reduction in forest carbon stocks. Export of wood pellets to EU markets does not greatly affect the total life cycle GHG emissions of wood pellets. However, pellet exporting countries risk creating a considerable GHG emissions burden, as they are responsible for AFOLU and bioenergy production emissions but do not receive credit for pellets displacing fossil fuel-related GHG emissions. Countries producing bioenergy from forest biomass, whether for domestic use or for export, should carefully consider potential implications of alternate forest carbon accounting methods to ensure that potential bioenergy pathways can contribute to GHG emissions reduction targets.     

A distributed approach to accounting for carbon in wood products

With an evolving political environment of commitments to limit emissions of greenhouse gases, and of markets to trade in emissions permits, there is growing scientific, political, and economic need to accurately evaluate carbon (C) stocks and flows—especially those related to human activities. One component of the global carbon cycle that has been contentious is the stock of carbon that is physically held in harvested wood products. The carbon stored in wood products has been sometimes overlooked, but the amount of carbon contained in wood products is not trivial, it is increasing with time, and it is significant to some Parties. This paper is concerned with accurate treatment of harvested wood products in inventories of CO₂ emissions to the atmosphere. The methodologies outlined demonstrate a flexible way to expand current methods beyond the assumption of a simple, first-order decay to include the use of more accurate and detailed data while retaining the simplicity of simple formulas. The paper demonstrates that a more accurate representation of decay time can have significant economic implications in a system where emissions are taxed or emissions permits are traded. The method can be easily applied using only data on annual production of wood products and two parameters to characterize their expected lifetime. These methods are not specific to wood products but can be applied to long-lived, carbon-containing products from sources other than wood, e.g. long-lived petrochemical products. A single unifying approach that is both simple and flexible has the potential to be both more accurate in its results, more efficient in its implementation, and economically important to some Parties.     

Forests in climate policy: technical,institutional and economic issues in measurement and monitoring

Despite the economic and environmental significance of the world’s forests, we have limited data about them. Estimates of deforestation in tropical countries and rates of reforestation or afforestation in boreal and temperate countries are inconsistent. Accordingly, estimates of emissions released in deforestation vary widely and range from 7% to 17% of all sources of greenhouse gas (GHG) emissions. The lack of good data severely hampers efforts to shape climate policy because it is difficult to model the role of forests both in the physical global carbon (C) cycle and in cost-effective regimes to abate GHG. Data limits strain the capacity of even the best models to estimate marginal cost functions for forest carbon (C) sequestration. It is technically possible to obtain better information, but for institutional and economic reasons these technologies have not yet been fully deployed. The emergence of carbon (C) trading or tax policy in which forest carbon (C) storage becomes valued would strengthen incentives to supply better data, as would nonmarket regulation if it elicited a shadow value of forest carbon (C) in substituting for reductions in greenhouse gas emissions. “Geo-wiki” may provide a short-term solution to at least part of the data problem. The ultimate solution is the development of a comprehensive forest monitoring system involving remote sensing and on-the-ground truthing. This paper briefly discusses the role of forests in climate policy and then describes data gaps, the capability of technology to fill them, the limits of institutions and budgets in realizing this capability, and possible near-term solutions.     

What contribution can tree plantations make towards meeting Australia’s commitments under the Kyoto Protocol?

The Kyoto Protocol has been drafted to bring about an overall reduction in net emissions of greenhouse gases to the atmosphere. Australia has agreed to limit its increase of net greenhouse gas emissions to 8% between 1990 and 2010. While this target is not as tight as that of other parties to the Protocol, it nonetheless constitutes a significant reduction of net emissions below business-as-usual projections, and it will require significant policy initiatives to achieve this reduction. The Kyoto Protocol allows some carbon sequestration by vegetation sinks to be offset against CO₂ emissions from the burning of fossil fuels. This paper aims to estimate the contribution that forestation projects could make towards meeting Australia’s commitments under the Kyoto Protocol. It concludes that new plantations could sequester between 0.6 and 7 MtC yr⁻¹ over the commitment period (2008–2012) and offset between about 0.5 and 6% of Australia’s 1990 greenhouse gas emissions. The different estimates depend on the area of eligible plantations that will be established from 1999 onwards and whether plantations will be allowed to grow through to the end of the commitment period or will be in short-rotation stands that may be harvested before 2012. The maximum emission offset can only be achieved if new plantations are established at a rate of 100,000 ha yr⁻¹, which is equivalent to the Australian Government’s target under the 2020 vision. It is likely that sufficient suitable land would be available in Australia to achieve the required establishment rates. However, while such a contribution by vegetation sinks would be helpful, it would not, on its own, be sufficient for Australia to meet its required greenhouse gas emission target.     

<Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> stump feature based methodology for <Emphasis Type="Italic">in situ</Emphasis> forest degradation assessment

Initiatives for reducing anthropogenic greenhouse gas emissions from deforestation and degradation require transparent and robust methodologies for the estimation of emissions reduction or removal. Although carbon (C) stock change in degradation and devegetation by remote sensing are becoming increasingly powerful, the drivers of degradation, wood collection and harvest dynamics, cannot be understood without “on the ground” sampling. A methodological tool for the quantitative and qualitative analysis of forest degradation is proposed as developed based on a research on the stump history in the black locust degrading stands sampled in southwest Romania. Based on the survey of stumps, the cutting regime and wood extraction is determined over a past period of some 15 years. Stump age classification comprises multiple qualitative criteria (i.e. bark features; adherence of sprouts; cut edge features; etc.). The method allows for a quantitative assessment of wood removal over time, and is suitable for the development of a dynamic baseline and monitoring of degradation avoidance activities.     

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.     

Integrated scenario modelling of energy,greenhouse gas emissions and forestry

Preventing dangerous climate change requires actions on several sectors. Mitigation strategies have focused primarily on energy, because fossil fuels are the main source of global anthropogenic greenhouse gas emissions. Another important sector recently gaining more attention is the forest sector. Deforestation is responsible for approximately one fifth of the global emissions, while growing forests sequester and store significant amounts of carbon. Because energy and forest sectors and climate change are highly interlinked, their interactions need to be analysed in an integrated framework in order to better understand the consequences of different actions and policies, and find the most effective means to reduce emissions. This paper presents a model, which integrates energy use, forests and greenhouse gas emissions and describes the most important linkages between them. The model is applied for the case of Finland, where integrated analyses are of particular importance due to the abundant forest resources, major forest carbon sink and strong linkage with the energy sector. However, the results and their implications are discussed in a broader perspective. The results demonstrate how full integration of all net emissions into climate policy could increase the economic efficiency of climate change mitigation. Our numerical scenarios showed that enhancing forest carbon sinks would be a more cost-efficient mitigation strategy than using forests for bioenergy production, which would imply a lower sink. However, as forest carbon stock projections involve large uncertainties, their full integration to emission targets can introduce new and notable risks for mitigation strategies.     

全球气候变化下中国林产品的减排贡献：基于木质林产品固碳功能核算

森林及其产品的固碳功能对减缓气候变化具有重要作用。木质林产品（下简称HWP）的碳储存是全球气候变化的重要议题,研究HWP碳储量并对其进行功能管理,对我国政府提高温室气体减排潜力并参与气候谈判、提交国家温室气体排放清单具有重要的现实意义。论文依据政府间气候变化专门委员会（IPCC）建议的HWP碳量核算模型,研究了1961—2011年中国HWP的固碳功能,继而比较分析了中国HWP碳储量的减排潜力。研究表明：从总量看,储量变化法、大气流动法基础上核算的中国2011 年度碳储量值分别为6.76×10⁸ t 碳和2.58×10⁸ t 碳;从年增长量看,储量变化法、大气流动法基础核算的中国HWP碳储量增长平均值为1 063×10⁴ t 碳和262×10⁴ t 碳。基于中国是世界HWP进口大国,储量变化法的选择应用将对我国有利。HWP碳储量减排贡献的研究发现：中国HWP碳储量为森林立木总量的4.75%~8.42%,平均约为6%;对比中国能源消费的年碳排放量值,中国HWP的年碳储量可以减排约1.6%,中国HWP具有显著的碳汇功能及进一步提升的减排潜力。     

Wood-based building materials and atmospheric carbon emissions

This study investigates the global impact of wood as a building material by considering emissions of carbon dioxide to the atmosphere. Wood is compared with other materials in terms of stored carbon and emissions of carbon dioxide from fossil fuel energy used in manufacturing. An analysis of typical forms of building construction shows that wood buildings require much lower process energy and result in lower carbon emissions than buildings of other materials such as brick, aluminium, steel and concrete. If a shift is made towards greater use of wood in buildings, the low fossil fuel requirement for manufacturing wood compared with other materials is much more significant in the long term than the carbon stored in the wood building products.As a corollary, a shift from wood to non-wood materials would result in an increase in energy requirements and carbon emissions.The results presented in this paper show that a 17% increase in wood usage in the New Zealand building industry could result in a 20% reduction in carbon emissions from the manufacture of all building materials, being a reduction of about 1.5% of New Zealand’s total emissions. The reduction in emissions is mainly a result of using wood in place of brick and aluminium, and to a lesser extent steel and concrete, all of which require much more process energy than wood. There would be a corresponding decrease of about 1.5% in total national fossil fuel consumption. These figures have implications for the global forestry and building industries. Any increases in wood use must be accompanied by corresponding increases in areas of forest being managed for long term sustained yield production.     

生物炭添加对土壤温室气体排放影响的长短期效应研究进展

人类活动引起的大气温室气体浓度增加是气候变暖的主要原因,全球变暖已经成为了当今人类社会所面临的严峻挑战,应对气候变暖的关键是减少温室气体排放和增加生态系统碳汇,由于生物炭特有的理化和生物学特性,将其施入土壤被认为是一种有前景的减排增汇措施.因此进行生物炭对土壤温室气体排放的影响研究对于减缓温室效应和实现“碳中和”具有重要意义.通过综述生物炭对土壤温室气体排放影响的长短期效应及其影响机制,发现生物炭添加对土壤温室气体排放的影响因生物炭原料类型、热解温度、添加量、土壤和植被类型的不同而不同.此外,因老化时间、老化方式和培养方法的不同,老化生物炭对土壤温室气体的减排效应可能增强或减弱甚至消失.同时,在总结现有研究不足的基础上,对未来生物炭影响土壤温室气体排放研究的方向和重点进行了分析和展望,提出了今后应加强CO₂、 N₂O和CH₄排放影响的同步研究、减排与固碳效应的同步研究、不同老化方式生物炭和不同培养方法的联合研究和利用¹³C和¹⁵N示踪技术从过程层次上揭示影响机制.     

A new way of carbon accounting emphasises the crucial role of sustainable timber use for successful carbon mitigation strategies

The roles of forest management and the use of timber for energy in the global carbon cycle are discussed. Recent studies assert that past forest management has been accelerating climate change, for example in Europe. In addition, the increasing tendency to burn timber is an international concern. Here, we show a new way of carbon accounting considering the use of timber as a carbon neutral transfer into a pool of products. This approach underlines the robust, positive carbon mitigation effects of sustainable timber harvesting. Applying this new perspective, sustainable timber use can be interpreted not as a removal but a prevention of carbon being converted within the cycle of growth and respiration. Identifying timber use as a prevention rather than a removal leads to the understanding of timber use as being no source of carbon emissions of forests but as a carbon neutral transfer to the product pool. Subsequently, used timber will then contribute to carbon emissions from the pool of forest products in the future. Therefore, timber use contributes to carbon mitigation by providing a substantial delay of emissions. In a second step, the carbon model is applied to results of a previous study in which different timber price scenarios were used to predict timber harvests in Bavarian forests (Germany). Thus, the influence of the economic dimension “timber price” on the ecological dimension carbon sequestration was derived. It also shows that these effects are stable, even if an increasing tendency of burning timber products for producing energy is simulated. Linking an economic optimization to a biophysical model for carbon mitigation shows how the impact of management decisions on the environment can be derived. Overall, a sustainably managed system of forests and forest products contributes to carbon mitigation in a positive, stable way, even if the prices for (energy) wood rise substantially.     

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.     

A generalised approach of accounting for biospheric carbon stock changes under the Kyoto Protocol

The Kyoto Protocol aims to reduce net emissions of greenhouse gases to the atmosphere by various measures including through management of the biosphere. However, the wording that has been adopted may be difficult and costly to implement, and may ultimately make it impossible to cost-effectively include biosphere management to reduce net greenhouse gas emissions. An alternative scheme is proposed here, especially for the second and subsequent commitment periods, to more effectively deal with the anthropogenic component of carbon stock changes in the biosphere. It would categorise the terrestrial biosphere into different land-use types, with each one having a characteristic average carbon density determined by land-use and environmental factors. Each transition from one land-use type to another, or a change in average carbon density within a specified type due to changed management would be defined as anthropogenic and credited or debited to the responsible nation. To calculate annual credits and/or debits, the change in average carbon stocks must be divided by a time constant which would either be a characteristic of each possible land-use conversion, or applicable to the sum of changes to a nation's biospheric carbon stocks. We believe that this scheme would be simpler and less expensive to implement than one based on the measurement of actual carbon changes from all specified areas of land. It would also avoid undue credits or debits, because they would only accrue as a result of identified anthropogenic components of biospheric carbon changes whereas carbon fluxes that are due to natural variation would not be credited or debited.     

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.     

Developing Canada's National Forest Carbon Monitoring, Accounting and Reporting System to Meet the Reporting Requirements of the Kyoto Protocol

The rate of carbon accumulation in the atmosphere can be reduced by decreasing emissions from the burning of fossil fuels and by increasing the net uptake (or reducing the net loss) of carbon in terrestrial (and aquatic) ecosystems. The Kyoto Protocol addresses both the release and uptake of carbon. Canada is developing a National Forest Carbon Monitoring, Accounting and Reporting System in support of its international obligations to report greenhouse gas sources and sinks. This system employs forest-inventory data, growth and yield information, and statistics on natural disturbances, management actions and land-use change to estimate forest carbon stocks, changes in carbon stocks, and emissions of non-CO₂ greenhouse gases. A key component of the system is the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS). The model is undergoing extensive revisions to enable analyses at four spatial scales (national, provincial, forest management unit and stand) and in annual time steps. The model and the supporting databases can be used to assess carbon-stock changes between 1990 and the present, and to predict future carbon-stock changes based on scenarios of future disturbance rates and management actions.