National Greenhouse Gas Inventory Report Research Articles

Including Methane Emissions from Agricultural Ponds in National Greenhouse Gas Inventories.

Agricultural ponds are a significant source of greenhouse gases, contributing to the ongoing challenge of anthropogenic climate change. Nations are encouraged to account for these emissions in their national greenhouse gas inventory reports. We present a remote sensing approach using open-access satellite imagery to estimate total methane emissions from agricultural ponds that account for (1) monthly fluctuations in the surface area of individual ponds, (2) rates of historical accumulation of agricultural ponds, and (3) the temperature dependence of methane emissions. As a case study, we used this method to inform the 2024 National Greenhouse Gas Inventory reports submitted by the Australian government, in compliance with the Paris Agreement. Total annual methane emissions increased by 58% from 1990 (26 kilotons CH4 year-1) to 2022 (41 kilotons CH4 year-1). This increase is linked to the water surface of agricultural ponds growing by 51% between 1990 (115 kilo hectares; 1,150 km2) and 2022 (173 kilo hectares; 1,730 km2). In Australia, 16,000 new agricultural ponds are built annually, expanding methane-emitting water surfaces by 1,230 ha yearly (12.3 km2 year-1). On average, the methane flux of agricultural ponds in Australia is 0.238 t CH4 ha-1 year-1. These results offer policymakers insights into developing targeted mitigation strategies to curb these specific forms of anthropogenic emissions. For instance, financial incentives, such as carbon or biodiversity credits, can mobilize widespread investments toward reducing greenhouse gas emissions and enhancing the ecological and environmental values of agricultural ponds. Our data and modeling tools are available on a free cloud-based platform for other countries to adopt this approach.

Dead wood volume-to-carbon conversion factors by decay class for ten tree species in Croatia and eight tree genera globally

Dead wood (DW) is an important forest carbon (C) pool for which the reporting of C stock changes within the National Greenhouse Gas Inventory Report (NIR) is mandatory. The use of DW volume-to-carbon conversion factors by decay classes, i.e. DW basic density (DWBD) and C fraction (CF), or C density (CD) as their product, facilitates more accurate estimates of DW C stocks and C stock changes.We present DW conversion factors, namely DWBD, CF, and CD, by decay classes for six broadleaf (Quercus robur L., Carpinus betulus L., Alnus glutinosa Garnet., Fraxinus angustifolia Vahl., Fagus sylvatica L., and Quercus ilex L.) and four conifer (Abies alba Mill., Picea abies (L.) Karst., Pinus nigra Arnold and Pinus pinaster Aiton) tree species from Continental, Alpine and Mediterranean biogeographical regions of Croatia. For each tree species DW logs (diameter from 5 to 30 cm) were visually categorized into four decay classes and nine discs per decay class were sampled. In addition, three healthy trees of each species were felled down at the same location for estimating the basic density of fresh wood (BWD, decay class 0) and calculation of species-specific relative density reduction patterns. In total, 390 discs were sampled and analysed in the laboratory.Our results show that broadleaves, on average, have higher DWBD than conifers (p < 0.05) for decay classes 0–3, but for decay class 4 no difference (p < 0.05) was observed between these two tree species groups. Unlike for DWBD, CF showed no trend with decay class, but a difference (p < 0.05) in the average CF was found between broadleaves and conifers with the mean (s.e.) of 47.65% (0.12%) and 50.67% (0.23%), respectively. The application of decay class-specific CD by forest land use strata used in the Croatian NIR yielded 11.1% − 26.6% lower DW C pool estimates, compared to the current ones calculated using BWDs and default CF.DWBD data from our study was compared with DWBD data from the literature. We observed good agreement between national species-specific DWBD and global genus-specific DWBD for the great majority of investigated tree genera and decay classes. Therefore, we combined our results with the published data to provide a global DWBD meta-means with confidence intervals by decay classes for eight tree genera. Our results suggest that in the absence of local or national DWBD data, the use of genus-specific DWBD meta-means is justified.

Comparative Analysis of Greenhouse Gas Emissions from Domestic Wastewater Treatment Processes by Modeling: Existing Estimation Methods vs Modeling

This study examined the existing methodologies and the applicability of process modeling concerning the estimation of nitrous oxide (N&lt;sub&gt;2&lt;/sub&gt;O) emissions from wastewater treatment processes. The method of extimating N&lt;sub&gt;2&lt;/sub&gt;O emissions from wastewater occurring during biological nitrification and denitrification processes can be divided into those before and after legal nitrogen effluent quality enhancement for domestic wastewater treatment plant. Initial IPCC guidelines such as IPCC 1996 GL, GPG 2000, and IPCC 2006 GL, provided methods for estimating N&lt;sub&gt;2&lt;/sub&gt;O emissions throughout domestic wastewater, while the revised version, IPCC 2019 RF, proposed methods for estimating each N&lt;sub&gt;2&lt;/sub&gt;O emission by distinguishing wastewater treatment and effluent after the advancement of wastewater treatment plants. The National Greenhouse Gas Inventory Report (NIR) in Korea adopted the methodology of GPG 2000, and the Emissions Trading System (ETS) applies the estimation method of IPCC 2006 GL in the wastewater treatment plants. This study utilized process modeling to consider the process characteristics and operating conditions of wastewater treatment plants. IPCC, NIR, and ETS estimate N&lt;sub&gt;2&lt;/sub&gt;O emissions based on nitrogen behavior activity data and emissions factors. On the other hand, process modeling estimates N&lt;sub&gt;2&lt;/sub&gt;O emissions in each unit process of the wastewater treatment plant using a 4-step AOB nitrification/4-step denitrification model and a liquid/gas transfer model. The estimation results of N&lt;sub&gt;2&lt;/sub&gt;O emissions from modeling method were compared with the estimation results of IPCC, NIR, and ETS to analyze the suitability of the estimation method. Through this, it was evaluated how appropriate process modeling is for estimating N&lt;sub&gt;2&lt;/sub&gt;O emissions in domestic wastewater treatment plants.

New model for predicting carbon storage dynamics and emissions related to the waste management of wood products: introduction of the HWP-RIAL model

The ability of wood products to store carbon allows for their significant contribution to the climate mitigation efforts and the emission reduction commitments set by the EU. In order to optimise the carbon storage capacity of wood products, it is important to take climate mitigation aspects into consideration as much as possible during their production, use and waste management. The aim of this study was to quantify the effects of product development, recycling, and waste management technologies on carbon storage and emissions. In the frame of the ForestLab project, a new model and decision support tool was developed, which is able to predict the duration of carbon storage of wood products and the evolution of emissions from them. The developed HWP-RIAL model (Harvested Wood Product Recycling, Incineration And Landfill model) uses the methodology of the Intergovernmental Panel on Climate Change (IPCC) to calculate emissions, which is also used in the National Greenhouse Gas Inventory report. It combines the IPCC waste model with equations describing the carbon storage and emissions of wood products, and the model is also supplemented with a self-developed recycling and waste routing module. This paper provides insight into the operation of the model by following the life cycle of 200,000 m3 particle board.

N2O emission factors for organic amendments in Japan from measurement campaign and systematic review

Organic amendments are important sources of nitrous oxide (N2O) emissions from agricultural soils. In 2020, the total amount of N in organic amendments applied to Japanese agricultural soils (440 ktN) was larger than that of synthetic fertilizer (374 ktN). However, N2O emissions from organic amendments were estimated by using the country-specific N2O emission factor (EF) for synthetic fertilizer (0.31 % for rice paddy, 2.9 % for tea, and 0.62 % for other crops) in the National Greenhouse Gas Inventory Report of Japan. Thus, we conducted a N2O flux measurement campaign at 12 different experimental sites across Japan to estimate fertilizer-induced N2O EFs for major organic amendments in Japan, that is, poultry manure compost, swine manure compost, cattle manure compost, and organic fertilizer pellets. In addition, we conducted systematic review of N2O emissions and EFs for organic amendments, including data from our measurement campaign and published data from peer-reviewed papers in Japan. The final dataset, including the field measurement campaign and published data, resulted in 404 observations (including synthetic fertilizer and zero-N control) in 29 sites. Results showed that soil type affected EFs, that is, the mean EF of Andosols was lower than that of non-Andosols, which is similar to the case of EFs for synthetic fertilizer. Mean EFs for poultry manure compost, swine manure compost, cattle manure (compost and slurry), and non-animal manure organic fertilizers were 0.83 % (uncertainty range of 2.5th and 97.5th percentile: 0.09 % to 3.46 %), 0.70 % (0.02 % to 2.45 %), 0.39 % (0.00 % to 1.62 %), and 1.16 % (0.41 % to 3.03 %), respectively, when weighted by area of soil types. The mean EF of all organic amendments was 0.84 % (0.00 % to 2.91 %), when the area of soil type and amount of organic amendment used in Japan were considered. Our study provides country-specific EFs to estimate N2O emission from organic amendments in Japan.

Soil carbon and nitrogen stock of the Japanese agricultural land estimated by the national soil monitoring database (2015–2018)

ABSTRACT Estimation of the soil organic carbon (SOC) stock based on the monitoring data is important to validate the carbon model estimates and provide the initial values of SOC stock to the model. The Japanese National Greenhouse Gas Inventory Report (NIR) has applied the RothC model since 2015 to report changes in SOC in agricultural land. This study estimated soil carbon and nitrogen stocks and C:N ratio of top 30 cm arable land in Japan using the 2015–2018 database of the national soil monitoring project. Estimates based on the stationary monitoring data from the top 30 cm of the soil layer arethe first public release. We modified categorization of the soil temperature regime and soil-type classification for estimation, expecting to mitigate the underestimation and overestimation of SOC stock in the areas of soil temperature 15–17°C and more than 17°C, respectively, and to optimize the soil classification to 16 fewer types to allow an appropriate estimation even in the current situation of decreasing number of survey sites. Statistical analysis to see the effects of land use and soil temperature on SOC stock, TN stock, and C:N ratio showed that soil types other than Andosols had an inverse temperature-dependent trend for all variables, while Andosols had an unclear trend in soil temperature, supporting existing studies. Also, when Lowland soils (Fluvisols or Anthrosols in the World Reference Base) were surrounded by Andosols, redeposition of volcanic ash could affect the temperature trend in SOC stock for Lowland soils. The distribution map of the SOC stock and C:N ratio across Japan visually showed a high value in the Andosols distribution areas and a temperature-dependent trend at the distribution areas of the other soil types. The total SOC stock estimated in this study was 176±12.8 TgC in paddy field, 100±8.6 TgC in upland field, 25±1.7 TgC in orchard, 78±8.9 TgC in grassland, and 379±17.9 TgC in total, the standard deviations of which were much smaller than those of the mean values for each land use calculated by the simple average method.

Assessing the Carbon Storage of Soil and Litter from National Forest Inventory Data in South Korea

Research Highlights: The estimation of soil and litter carbon stocks by the Land Use, Land-Use Changes, and Forestry (LULUCF) sectors has the potential to improve reports on national greenhouse gas (GHG) inventories. Background and Objectives: Forests are carbon sinks in the LULUCF sectors and therefore can be a comparatively cost-effective means and method of GHG mitigation. Materials and Methods: This study was conducted to assess soil at 0–30 cm and litter carbon stocks using the National Forest Inventory (NFI) data and random forest (RF) models, mapping their carbon stocks. The three main types of forest in South Kora were studied, namely, coniferous, deciduous, and mixed. Results: The litter carbon stocks (t C ha−1) were 4.63 ± 0.18 for coniferous, 3.98 ± 0.15 for mixed, and 3.28 ± 0.13 for deciduous. The soil carbon stocks (t C ha−1) were 44.11 ± 1.54 for deciduous, 35.75 ± 1.60 for mixed, and 33.96 ± 1.62 for coniferous. Coniferous forests had higher litter carbon stocks while deciduous forests contained higher soil carbon stocks. The carbon storage in the soil and litter layer increased as the forest grew older; however, a significant difference was found in several age classes. For mapping the soil and litter carbon stocks, we used four random forest models, namely RF1 to RF4, and the best performing model was RF2 (root mean square error (RMSE) (t C ha−1) = 1.67 in soil carbon stocks, 1.49 in soil and litter carbon stocks). Our study indicated that elevation, accessibility class, slope, diameter at breast height, height, and growing stock are important predictors of carbon stock. Soil and litter carbon stock maps were produced using the RF2 models. Almost all prediction values were appropriated to soil and litter carbon stocks. Conclusions: Estimating and mapping the carbon stocks in the soil and litter layer using the NFI data and random forest models could be used in future national GHG inventory reports. Additionally, the data and models can estimate all carbon pools to achieve an accurate and complete national GHG inventory report.

Fluctuations in gross volume increment estimated by the Lithuanian National Forest Inventory compared with annual variations in single tree increment

There are significant inter-annual fluctuations of growing stock volume changes of living trees estimated by the Lithuanian National Forest Inventory (NFI). In the current study, we compared two sources of information on forest productivity: conventional NFI data and dendrochronological data based on tree cores collected in parallel with the measurements of the fourth Lithuanian NFI cycle during 2013–2017 on the same permanent plots (total number of cores was 4967). The main finding is that the dendrochronological basal area increment data confirmed the depression of gross stand volume increment around 2006–2007 (based on Lithuanian NFI measurements in 2008–2009), followed by a steep increase during 2008–2011 (NFI from 2010–2013). The findings explain the differences between projected growing stock volume change, which have been used for forest reference level estimation according to land use, land-use change and forestry sector regulation, and the one recently provided in National Greenhouse Gas Inventory Reports.&#x0D; Key words: Growing stock volume change, basal area increment, forest reference level, greenhouse gas reporting

Greenhouse gas emissions trend in old landfill, Malaysia

According to Malaysia National Greenhouse Gas Inventory report, a total of 67,532 Gg CO2eq of methane was emitted in year 2011. The highest methane emission was from the solid waste disposal sites, which accounted for about 46 % from the total which remained the largest source throughout the time series period. Proper gas monitoring was not done in most landfills which the emission trend, pattern and impact remains untold. Understanding methane and carbon dioxide concentration trends will positively help in spatial variation of landfill emissions in Malaysia. Therefore, this research highlighted two objectives. First, to test feasibility of prototype sampling tube to collect gas samples. Second, to analyze gas samples using micro gas chromatography and evaluate emission trend in Taman Beringin Closed Landfill. Using proper technique, the sampling tube was employed manually at the gas well which located at the highest point of the hill. Three samples collected everyday between 12 to 2 p.m. for 1 mth. Result shows an interesting trend recorded for methane and carbon dioxide. Though the concentrations vary for each day, it highlighted certain range in the graph. Methane ranging between 550,000 ppm to 850,000 ppm and carbon dioxide ranging between 400,000 ppm to 620,000 ppm. It is high concentration emitted everyday considering maximum recommended safe methane concentration for workers during an 8-h period is 1,000 ppm (0.1 %) as stated by National Institute for Occupational Safety and Health's (NIOSH) and Occupational Safety and Health Administration (OSHA) has set a Permissible Exposure Limit (PEL) for carbon dioxide of 5,000 ppm by volume (0.5 % concentration). In addition, T-test was done to statistically shows the significant different between samples collected and the permissible standard. Result shows significant high concentration emitted compared to the safe level allowable in ambient air. This study helps addressing gap in landfills greenhouse emission monitoring in Malaysia.

Down scaling to regional assessment of greenhouse gas emissions to enable consistency in accounting for emissions reduction projects and national inventory accounts for northern beef production in Australia

This paper explores the effect of using regional data for livestock attributes on estimation of greenhouse gas (GHG) emissions for the northern beef industry in Australia, compared with using state/territory-wide values, as currently used in Australia’s national GHG inventory report. Regional GHG emissions associated with beef production are reported for 21 defined agricultural statistical regions within state/territory jurisdictions. A management scenario for reduced emissions that could qualify as an Emissions Reduction Fund (ERF) project was used to illustrate the effect of regional level model parameters on estimated abatement levels. Using regional parameters, instead of state level parameters, for liveweight (LW), LW gain and proportion of cows lactating and an expanded number of livestock classes, gives a 5.2% reduction in estimated emissions (range +12% to –34% across regions). Estimated GHG emissions intensity (emissions per kilogram of LW sold) varied across the regions by up to 2.5-fold, ranging from 10.5 kg CO2-e kg–1 LW sold for Darling Downs, Queensland, through to 25.8 kg CO2-e kg–1 LW sold for the Pindan and North Kimberley, Western Australia. This range was driven by differences in production efficiency, reproduction rate, growth rate and survival. This suggests that some regions in northern Australia are likely to have substantial opportunities for GHG abatement and higher livestock income. However, this must be coupled with the availability of management activities that can be implemented to improve production efficiency; wet season phosphorus (P) supplementation being one such practice. An ERF case study comparison showed that P supplementation of a typical-sized herd produced an estimated reduction of 622 t CO2-e year–1, or 7%, compared with a non-P supplemented herd. However, the different model parameters used by the National Inventory Report and ERF project means that there was an anomaly between the herd emissions for project cattle excised from the national accounts (13 479 t CO2-e year–1) and the baseline herd emissions estimated for the ERF project (8 896 t CO2-e year–1) before P supplementation was implemented. Regionalising livestock model parameters in both ERF projects and the national accounts offers the attraction of being able to more easily and accurately reflect emissions savings from this type of emissions reduction project in Australia’s national GHG accounts.

'탄소발자국' 개념의 발전 과정과 농림 부문에서의 활용 전망

The concept of 'carbon footprint' has been developed as a means of quantifying the specific emissions of the greenhouse gases (GHGs) that cause global warming. Although there are still neither clear definitions of the term nor rules for units or the scope of its estimation, it is broadly accepted that the carbon footprint is the total amount of GHGs, expressed as equivalents, emitted into the atmosphere directly or indirectly at all processes of the production by an individual or organization. According to the ISO/TS 14067, the carbon footprint of a product is calculated by multiplying the units of activity of processes that emit GHGs by emission factor of the processes, and by summing them up. Based on this, 'carbon labelling' system has been implemented in various ways over the world to provide consumers the opportunities of comparison and choice, and to encourage voluntary activities of producers to reduce GHG emissions. In the agricultural sector, as a judgment basis to help purchaser with ethical consumption, 'low-carbon agricultural and livestock products certification' system is expected to have more utilization value. In this process, the 'cradle to gate' approach (which excludes stages for usage and disposal) is mainly used to set the boundaries of the life cycle assessment for agricultural products. The estimation of carbon footprint for the entire agricultural and forestry sector should take both removals and emissions into account in the National Greenhouse Gas Inventory Report. The carbon accumulation in the biomass of perennial trees in cropland should be considered also to reduce the total GHG emissions. In order to accomplish this, tower-based flux measurements can be used, which provide a direct quantification of exchange during the entire life cycle. Carbon footprint information can be combined with other indicators to develop more holistic assessment indicators for sustainable agricultural and forestry ecosystems.

국내 습지(침수지) 온실가스 배출량 산정

This study was reviewed the national greenhouse gas inventory report (NIR) of Annex I countries and estimated national greenhouse gas inventory on wetlands in Korea. Annex I countries submitted National Inventory Report which are focused on land converted to wetlands category and wetland remaining wetland (mainly peat lands) because IPCC did not suggest a formal methodology on flooded land. So we conducted a study on estimating of national greenhouse gas inventory in wetland (flooded land). The total annual <TEX>$CO_2-eq.$</TEX> emission of wetland remaining wetland (flooded land) was ranged from 99.9 Gg <TEX>$CO_2-eq.$</TEX> to 237.1 Gg <TEX>$CO_2-eq.$</TEX> from 1990 to 2012. The <TEX>$CO_2-eq.$</TEX> emissions was declined after peaking in 1995, however, it slightly increasing in recently years. The latest total <TEX>$CO_2-eq.$</TEX> emission from flooded land was 117.7 Gg <TEX>$CO_2-eq.$</TEX> in 2012 which was covered only 0.00002% of national GHG inventory. This means that flooded land is not key-category in Korea. We will consider an improvement for emissions of flooded land, if IPCC suggest formal or complementary methodology.

A life cycle assessment approach to quantifying greenhouse gas emissions from land-use change for beef production in eastern Australia

In life cycle assessment studies, greenhouse gas (GHG) emissions from direct land-use change have been estimated to make a significant contribution to the global warming potential of agricultural products. However, these estimates have a high uncertainty due to the complexity of data requirements and difficulty in attribution of land-use change. This paper presents estimates of GHG emissions from direct land-use change from native woodland to grazing land for two beef production regions in eastern Australia, which were the subject of a multi-impact life cycle assessment study for premium beef production. Spatially- and temporally consistent datasets were derived for areas of forest cover and biomass carbon stocks using published remotely sensed tree-cover data and regionally applicable allometric equations consistent with Australia’s national GHG inventory report. Standard life cycle assessment methodology was used to estimate GHG emissions and removals from direct land-use change attributed to beef production. For the northern-central New South Wales region of Australia estimates ranged from a net emission of 0.03 t CO2-e ha–1 year–1 to net removal of 0.12 t CO2-e ha–1 year–1 using low and high scenarios, respectively, for sequestration in regrowing forests. For the same period (1990–2010), the study region in southern-central Queensland was estimated to have net emissions from land-use change in the range of 0.45–0.25 t CO2-e ha–1 year–1. The difference between regions reflects continuation of higher rates of deforestation in Queensland until strict regulation in 2006 whereas native vegetation protection laws were introduced earlier in New South Wales. On the basis of liveweight produced at the farm-gate, emissions from direct land-use change for 1990–2010 were comparable in magnitude to those from other on-farm sources, which were dominated by enteric methane. However, calculation of land-use change impacts for the Queensland region for a period starting 2006, gave a range from net emissions of 0.11 t CO2-e ha–1 year–1 to net removals of 0.07 t CO2-e ha–1 year–1. This study demonstrated a method for deriving spatially- and temporally consistent datasets to improve estimates for direct land-use change impacts in life cycle assessment. It identified areas of uncertainty, including rates of sequestration in woody regrowth and impacts of land-use change on soil carbon stocks in grazed woodlands, but also showed the potential for direct land-use change to represent a net sink for GHG.

Comparison of approaches for reporting forest fire-related biomass loss and greenhouse gas emissions in southern Europe

Wildfires are the most common disturbances in Mediterranean forest ecosystems that cause significant emissions of greenhouse gases as a result of biomass burning. Despite this, there is reasonably high uncertainty regarding the actual fraction of burnt biomass and the related CO2 and non-CO2 gas emissions released during forest fires. The aim of this paper is to compare existing methodologies adopted in the National Greenhouse Gas Inventory reports of five of the most fire-affected countries of southern Europe (Italy, Spain, Greece, Portugal, France) with those proposed in the literature, to operationally estimate forest fire emissions, and to discuss current perspectives on reducing uncertainties in reporting activities for the Land Use, Land Use Change and Forestry sector under the United Nations Framework Convention on Climate Change and the Kyoto Protocol. Five selected approaches have been experimentally applied for the estimation of burnt biomass in forest fire events that occurred in Italy in the period 2008–2010. Approaches based on nominal rates of biomass loss can lead to an overly conservative value or, conversely, to underestimation of the fraction of burnt biomass. Uncertainties can be greatly reduced by an operational method able to assess inter-annual and local variability of fire effects on fire-affected forest types.

Factors affecting methane production and mitigation in ruminants

Methane (CH(4)) is the second most important greenhouse gas (GHG) and that emitted from enteric fermentation in livestock is the single largest source of emissions in Japan. Many factors influence ruminant CH(4) production, including level of intake, type and quality of feeds and environmental temperature. The objectives of this review are to identify the factors affecting CH(4) production in ruminants, to examine technologies for the mitigation of CH(4) emissions from ruminants, and to identify areas requiring further research. The following equation for CH(4) prediction was formulated using only dry matter intake (DMI) and has been adopted in Japan to estimate emissions from ruminant livestock for the National GHG Inventory Report: Y = -17.766 + 42.793X - 0.849X(2), where Y is CH(4) production (L/day) and X is DMI (kg/day). Technologies for the mitigation of CH(4) emissions from ruminants include increasing productivity by improving nutritional management, the manipulation of ruminal fermentation by changing feed composition, the addition of CH(4) inhibitors, and defaunation. Considering the importance of ruminant livestock, it is essential to establish economically feasible ways of reducing ruminant CH(4) production while improving productivity; it is therefore critical to conduct a full system analysis to select the best combination of approaches or new technologies to be applied under long-term field conditions.

Allometric biomass and carbon factors database

Abstract: The “Allometric, Biomass and Carbon factors” database (ABC factors database) was designed to facilitate the estimation of the biomass carbon stocks of forests in order to support the development and the verification of greenhouse gas inventories in the LULUCF sector (Land Use, Land Use Change and Forestry). The database contains several types of expansion, conversion and combined factors, by various tree species or species groups that can be used to calculate biomass or carbon of forests of Eurasian region from proxy variables (e.g., tree volume) that may come from forest inventories. In addition to the factors, and depending on the information that was available in the cited source, the database indicates: (1) the biomass compartments involved when the factor was developed; and (2) the possible applicability of the factor, e.g. by country or by ecological regions. The applicability of the factors is either suggested by the source itself, or the type of source (e.g. National Greenhouse Gas Inventory Report), or was based on the expert judgement by the compilers of the database. Finally, in order to facilitate the selection of the most appropriate of the data, the web-based interface provides the possibility to compare several factors that may come from different sources. The ABC factors database is freely available at web site AFOLU-DATA, funded and hosted by the Joint Research Centre (European Commission, DG-JRC).

Developing a carbon stocks and flows model for Australian wood products

Summary This paper describes the development of a model for estimating Australia's stocks and flows of carbon in harvested wood products, including estimates of atmospheric emissions. The model estimates emissions in various forms, including those from wood products contained in Australia, encompassing both domestically produced (net of exports) and imported wood products. This estimate is the basis of Australia's National Greenhouse Gas Inventory report on wood products. The model can also estimate emissions from all (and only) wood products produced in Australia, and a third variant that presumes emissions from wood products at the time of harvest. The model represents a collaborative effort, involving relevant Commonwealth and state government agencies, industry groups and research bodies. The model uses available statistics on log flows from forest harvest and estimates of the carbon content of the various wood products processed (for example, sawn timber, plywood, pulp and paper and woodchips) to determine carbon inputs to wood products. The model uses estimates of the decay period of various classes of wood product to calculate the pool of carbon in wood products. Crosschecking with independent input data was done wherever possible to test the robustness of various input data used in the model development. The model is built in Microsoft Excel with all rate and age parameters easily accessed and varied for sensitivity testing using the @Risk software. Wood products in use are assigned to young-, medium-and old-age pools. Simulated losses of wood products from their service life occur from each of the young-, medium-and old-age pools. Material leaving service is either transferred to bioenergy, added to landfill, recycled or emitted to the atmosphere. Losses of carbon can also occur from the landfill pool. The recorded imports and exports of wood products are used to calculate emissions under two approaches. The first is from wood products produced in Australia (but not necessarily remaining within Australia), and the second from wood products stored in Australia (wherever they were produced). Further simulations, with and without consideration of storage and emissions from landfill, are then run for each approach. The results show that an accounting approach that presumes emissions from wood products at harvest over-estimates emissions to the atmosphere when compared with approaches that consider the service life of wood products. The storage of wood products in landfill is also significant.