Accounting for Carbon Stocks in Soils and Measuring GHGs Emission Fluxes from Soils: Do We Have the Necessary Standards?

Wastewater treatment plants (WWTPs) using membrane bioreactor (MBR) technology have been considered a significant source of greenhouse gas (GHG) emissions. This study chose a small-scale wastewater treatment plant using MBR technology to estimate its potential for GHG emissions. The total GHG emissions from this wastewater treatment plant ranged from 2,802 to 11,946kg CO2 -eq/month within the 4-year study period, and they were mainly attributable to electricity consumption (79.94%) followed by chemical usages (17.13%) and on-site GHG emissions (2.93%). The on-site GHG emissions varied monthly, but most of them ranged from 80 to 160kg CO2 -eq/month. The aeration tank was an important operating unit for GHG emissions. Off-site GHG emissions mainly came from carbon dioxide (CO2 ) emissions resulting from electricity consumption. The results of this study provide useful information about the potential of GHG emissions from WWTPs using MBR technology and indicate that WWTPs can be sustainably managed. PRACTITIONER POINTS: Wastewater treatment plants have been considered a source of greenhouse gas emissions. Total greenhouse gas emissions from the wastewater treatment plants using membrane bioreactor were mainly attributable to electricity consumption. On-site greenhouse gas emissions were relatively insignificant in this study.

Improving the accuracy of estimating greenhouse gas absorption remains an urgent problem. Identification of the ratio of carbon stocks in soils and stand biomass of young and mid-aged forests will allow clarifying the direction of carbon fluxes in forest ecosystems during the development period most productive for atmospheric decarbonization. Increasing the accuracy of carbon stocks in components of forest ecosystems is necessary to recognize the real absorption capacity of Russian forests at the international level. The purpose of this study was to determine the carbon stocks in stand biomass and soils of young and mid-aged forests in the Republic of Tatarstan, as well as their ratio for forests of different species composition and origin. The studies were conducted on 6 sample plots in the most common forest stands aged 10 to 40 years. Organic carbon stocks in soils, stand biomass and other components of forest ecosystems located on sod-podzolic soils were determined. Total carbon stocks, the share of individual components and the ratio of stocks in stand biomass and soils were calculated. It was found that carbon stocks in the biomass of young stands of natural origin ranged from 8.5 to 50.8 t/ha, while in artificial stands they were 123.0 t/ha, and in mid-aged forests – 102.6–173.4 t/ha. Maximum carbon stocks were found in the biomass of stands of mid-aged birch forest, minimum — in young birch forest. Total organic carbon stocks in the studied ecosystems can vary by up to five times and range from 41.4 t/ha to 208.4 t/ha. The share of stand biomass in the structure of total ecosystem stocks ranged from 20.4 % to 91.4 %. Carbon stocks in sod-podzolic soils of the sample sites varied from 5.5 t/ha to 38.9 t/ha. This was lower than the reference values, but even in this case, soil carbon stocks account for 4.1 % to 73.7 % of the total ecosystem carbon stocks. Clarification of carbon stocks in soils of forested areas should be continued. Perhaps, regional databases on soil carbon stocks should be created, taking into account not only the species and age composition of the forest, but also the taxonomic affiliation of soils. In a 10-year-old birch forest the ratio of carbon stocks in the stand and soil was 3:10, in a 25-year-old birch forest it changed to 11:2, in a young pine forest of natural origin it was about 2:1, in artificial pine plantations of the same age it was 22:1. In natural birch forests, during the transition from young forests of age class I to mid-aged forests, carbon stocks in stand biomass increased by 20.5 times. The results obtained demonstrate the active participation of young and mid-aged natural forests in atmospheric decarbonization, with the main carbon sink at this stage of forest ecosystem development occurring in phytomass. Carbon stocks in soil are more conservative. The ratio of carbon stocks in stand biomass and soils of young aspen and middle-aged oak forests was close to the values for natural forests of other species of the same age. Carbon stocks in stand biomass of artificial pine planting was 2.5 times higher than in natural pine forest of the same age (25 years). Further research is required to draw scientifically grounded conclusions on the contribution of natural and planted forests to carbon sequestration.

The study was conducted in the forest concession area of PT. Diamond Raya Timber, Riau Province, Indonesia. Measurement and calculation carbon stocks in soil and vegetation of tropical peat forest should be done accurately to anticipate carbon trading. The objective of the study is to estimate carbon stocks in soil and vegetation in 4 forest conditions. The study found that biomass and carbon stocks in the soil was 8 times higher than in the vegetation in primary forest condition, and 10 times in logged over forest and secondary forest condition. Carbon stocks in vegetation and soil were 189.45 ton C ha -1 and 1537.37 ton C ha -1 in primary forest, 161.76 ton C ha -1 , and 1713.77 ton C ha -1 in logged over area, 139.05 ton C ha -1 and 1486.39 ton C ha -1 in secondary forest, and 43.09 ton C ha -1 and 1205.59 ton C ha -1 in degraded forest. Allocation of carbon stocks in the standing trees in primary forest, logged over area, secondary forest, and degraded forest were 70, 60, 62, and 7% respectively.

Estimation of carbon sequestration in the forest sector should take into consideration changes in carbon stock in all carbon pools, including above-ground and below-ground biomass, litter, deadwood and soil. In this review, we discuss current knowledge of carbon stocks in litter, deadwood and soil in Japan’s forest sector. According to data from published reports and nationwide surveys, the carbon stock in forest litter is less than that indicated in the Intergovernmental Panel on Climate Change (IPCC) guidelines for temperate and cool temperate forests; for example, coniferous species showed 4.4 Mg C ha−1 for Cryptomeria japonica and 3.1 Mg C ha−1 for Chamaecyparis obtusa, and broad-leaved species ranged from 3.5 Mg C ha−1 for Castanopsis spp. to 7.3 Mg C ha−1 for Fagus spp. For deadwood carbon stock, coniferous plantations with a record of non-commercial thinning showed 17.1 Mg C ha−1 and semi-natural broad-leaved forests showed 5.3 Mg C ha−1 on average, although only limited data were available. The black soil group (comparable to Andosols and Andisols) showed large carbon stocks in soil layers 0–30 cm deep (130 Mg C ha−1). The brown forest soil group (Cambisols and Inceptisols), occupying the most dominant area, showed a carbon stock of 87.0 Mg C ha−1 on average, which was similar to the data shown in the IPCC guidelines. In a comparison of land use between the forest sector and the agricultural sector for the same soil group, the carbon stock in the agricultural soil was 21% lower and in the grassland soil it was 18% higher than the stock in the forest soil. In this review, we also discuss issues for improving the estimation method and inventory of carbon stock in litter, deadwood and soil in Japan.

Perennial trees especially fruit trees are considered to be the most competent biological system where atmospheric carbon dioxide is transformed into long-lived soil carbon despite their nutritional and export value. Higher carbon stock helps to sustain production and soil ecosystem services. Better crop nutrition promotes carbon stock. Feasibility of integrated nutrient management in carbon sequestration needs to be evaluated under a subtropical humid condition. An experiment was carried out in randomized block design to study the feasibility of integrated nutrient management for improving soil properties, nutrient availability, fruit yield, and carbon stock in a mango (Mangifera indica L.) (cv. Langra) orchard under a subtropical condition. Various combinations of integrated (farmyard manure, vermicompost, straw mulch, biofertilizers) nutrient management practices were evaluated in two consecutive years in a 30-year-old mango orchard. The results revealed that the organic mulching with straw and conjoint application of farmyard manure and vermicompost improve nutrient availability, microbial activeness (29–44%), and carbon stock (~ 40%) in soil at 0–60 cm soil depth which ultimately improves fruit yield (26–34%). Hence, adoption of integrated nutrient management practices through the application of farmyard manure, vermicompost, and organic mulching with straw would uphold the fruit yield and carbon stock in soil and also promote CO2 sequestration in soil and less greenhouse gas emission, which paved viable economic options to mitigate climate change.

Global climate change is a major problem generated by increasing concentration of carbon dioxide in the atmosphere. Forests and their soils are major sink of carbon and thus constitute an effective role in the global carbon cycle. Present study was conducted to quantify and compare the amount of carbon stock in litterfall, fine root and soil between Tarai Sal forest and Hill Sal forest of eastern Nepal. Carbon stock in litter and fine root was estimated by ash content method and in soil by multiplying the value of soil organic carbon, bulk density and soil depth. Carbon stock in litterfall was higher (3.94 Mg ha-1) in TSF than HSF (3.26 Mg ha-1) and in fine root (0-5 mm size) in 0-30 cm soil depth it was higher in HSF (2.76 Mg ha-1) than TSF (2.19 Mg ha-1). In soil (0-30 cm depth) the value was higher in HSF (58.23 Mg ha-1) than TSF (50.81Mg ha-1). Tarai Sal forest accumulated higher carbon stock in the litterfall and lower in fine root than Hill Sal forest which was mainly attributed to the amount of litterfall and fine root biomass rather than organic carbon concentration. In Tarai Sal forest the carbon stock in soil was relatively low than Hill Sal forest that may be due to the higher net uptake and mineralization of carbon in the situation of higher growth rate of plant. These outcomes verified that the forest plays important role for mitigation of global warming by storing the atmospheric carbon dioxide in plant parts and the soil. So, it concludes that conserving the considerable quantity of carbon in forests is inevitable for proper forest management.

<strong class="journal-contentHeaderColor">Abstract.</strong> The combustion of woodfuel for residential use is often not considered to be a source of greenhouse gas (GHG) emissions in households since emissions from woodfuel combustion can be offset by the CO2 absorbed by the growth of the forest as a carbon sink (IPCC, 2006). However, this only applies to wood that is harvested in a renewable way, i.e., at a rate not exceeding the regrowth rate of the forest from which it is harvested (Drigo et al., 2002). This paper estimates the share of GHG emissions attributable to non-renewable woodfuel harvesting for use in residential food activities. It adds to a growing research base estimating GHG emissions from across the entire agri-food value chain, from the manufacture of farm inputs, through food supply chains, and finally to waste disposal (Tubiello et al., 2021). Country-level information is generated from United Nations Statistics Division (UNSD) and International Energy Agency (IEA) data on woodfuel use in households. We find that, in 2019, annual emissions from non-renewable woodfuel use in household food consumption were about 745 million tonnes (Mt&thinsp;CO2eq&thinsp;yr^&minus;1), with uncertainty ranging from &minus;20&thinsp;% to + 22&thinsp;%, having increased 6 % from 1990. Overall, global trends were a result of counterbalancing effects: the emission increases were largely fuelled from countries in Sub-Saharan Africa, Southern Asia, and Latin America while significant decreases were seen in countries in Eastern Asia and South-eastern Asia. The Food and Agriculture Organisation of the United Nations (FAO) has developed and regularly maintains a database covering GHG emissions from the various components of the agri-food sector, including pre- and post-production activities, by country and world regions. The dataset is developed according to International Panel on Climate Change guidelines (IPCC, 2006), which avoids overlaps across AFOLU and energy components. It relies mainly on UNSD Energy Statistics data, which are used as activity data for the calculation of the GHG emissions (Tubiello et al., 2022). The information used in this work is available as open data with DOI <a href="https://doi.org/10.5281/zenodo.7310932" target="_blank" rel="noopener">https://doi.org/10.5281/zenodo.7310932</a> (Flammini et al., 2022).

<strong class="journal-contentHeaderColor">Abstract.</strong> The combustion of woodfuel for residential use is often not considered to be a source of greenhouse gas (GHG) emissions in households since emissions from woodfuel combustion can be offset by the CO2 absorbed by the growth of the forest as a carbon sink (IPCC, 2006). However, this only applies to wood that is harvested in a renewable way, i.e., at a rate not exceeding the regrowth rate of the forest from which it is harvested (Drigo et al., 2002). This paper estimates the share of GHG emissions attributable to non-renewable woodfuel harvesting for use in residential food activities. It adds to a growing research base estimating GHG emissions from across the entire agri-food value chain, from the manufacture of farm inputs, through food supply chains, and finally to waste disposal (Tubiello et al., 2021). Country-level information is generated from United Nations Statistics Division (UNSD) and International Energy Agency (IEA) data on woodfuel use in households. We find that, in 2019, annual emissions from non-renewable woodfuel use in household food consumption were about 745 million tonnes (Mt&thinsp;CO2eq&thinsp;yr^&minus;1), with uncertainty ranging from &minus;20&thinsp;% to + 22&thinsp;%, having increased 6 % from 1990. Overall, global trends were a result of counterbalancing effects: the emission increases were largely fuelled from countries in Sub-Saharan Africa, Southern Asia, and Latin America while significant decreases were seen in countries in Eastern Asia and South-eastern Asia. The Food and Agriculture Organisation of the United Nations (FAO) has developed and regularly maintains a database covering GHG emissions from the various components of the agri-food sector, including pre- and post-production activities, by country and world regions. The dataset is developed according to International Panel on Climate Change guidelines (IPCC, 2006), which avoids overlaps across AFOLU and energy components. It relies mainly on UNSD Energy Statistics data, which are used as activity data for the calculation of the GHG emissions (Tubiello et al., 2022). The information used in this work is available as open data with DOI <a href="https://doi.org/10.5281/zenodo.7310932" target="_blank" rel="noopener">https://doi.org/10.5281/zenodo.7310932</a> (Flammini et al., 2022).

<strong class="journal-contentHeaderColor">Abstract.</strong> The combustion of woodfuel for residential use is often not considered to be a source of greenhouse gas (GHG) emissions in households since emissions from woodfuel combustion can be offset by the CO2 absorbed by the growth of the forest as a carbon sink (IPCC, 2006). However, this only applies to wood that is harvested in a renewable way, i.e., at a rate not exceeding the regrowth rate of the forest from which it is harvested (Drigo et al., 2002). This paper estimates the share of GHG emissions attributable to non-renewable woodfuel harvesting for use in residential food activities. It adds to a growing research base estimating GHG emissions from across the entire agri-food value chain, from the manufacture of farm inputs, through food supply chains, and finally to waste disposal (Tubiello et al., 2021). Country-level information is generated from United Nations Statistics Division (UNSD) and International Energy Agency (IEA) data on woodfuel use in households. We find that, in 2019, annual emissions from non-renewable woodfuel use in household food consumption were about 745 million tonnes (Mt&thinsp;CO2eq&thinsp;yr^&minus;1), with uncertainty ranging from &minus;20&thinsp;% to + 22&thinsp;%, having increased 6 % from 1990. Overall, global trends were a result of counterbalancing effects: the emission increases were largely fuelled from countries in Sub-Saharan Africa, Southern Asia, and Latin America while significant decreases were seen in countries in Eastern Asia and South-eastern Asia. The Food and Agriculture Organisation of the United Nations (FAO) has developed and regularly maintains a database covering GHG emissions from the various components of the agri-food sector, including pre- and post-production activities, by country and world regions. The dataset is developed according to International Panel on Climate Change guidelines (IPCC, 2006), which avoids overlaps across AFOLU and energy components. It relies mainly on UNSD Energy Statistics data, which are used as activity data for the calculation of the GHG emissions (Tubiello et al., 2022). The information used in this work is available as open data with DOI <a href="https://doi.org/10.5281/zenodo.7310932" target="_blank" rel="noopener">https://doi.org/10.5281/zenodo.7310932</a> (Flammini et al., 2022).

Abstract. The combustion of wood fuel for residential use is often not considered to be a source of greenhouse gas (GHG) emissions from households, as the emissions from wood fuel combustion can be offset by the CO2 absorbed by the growth of the forest (as a carbon sink) (IPCC, 2006). However, this only applies to wood that is harvested in a renewable way, i.e. at a rate not exceeding the regrowth rate of the forest from which it was harvested (Drigo et al., 2002). This paper estimates the share of GHG emissions attributable to non-renewable wood fuel harvesting for use in residential food activities, by country and with global coverage. It adds to a growing research base estimating GHG emissions from across the entire agri-food value chain, from the manufacture of farm inputs, through food supply chains, and finally to waste disposal (Tubiello et al., 2021). Country-level information is generated from United Nations Statistics Division (UNSD) and International Energy Agency (IEA) data on wood fuel use by households. We find that, in 2019, annual emissions from non-renewable wood fuel consumed for household food preparation were about 745×106 t (Mt CO2 eq. yr−1), with an uncertainty ranging from −63 % to +64 %. Overall, global trends were a result of counterbalancing effects: the emission increases were largely fuelled by countries in sub-Saharan Africa, southern Asia, and Latin America, whereas significant decreases were seen in countries in eastern Asia and South-East Asia. The Food and Agriculture Organization of the United Nations (FAO) has developed and regularly maintains a database covering GHG emissions from the various components of the agri-food sector, including pre- and post-production activities, by country and world regions. The dataset has been developed according to the International Panel on Climate Change guidelines (IPCC, 2006), which avoid overlaps between agriculture, forestry, and other land use (AFOLU) and energy components. The aforementioned dataset relies mainly on UNSD Energy Statistics data, which are used as activity data for the calculation of the GHG emissions (Tubiello et al., 2022). The information used in this work is available as open data at https://doi.org/10.5281/zenodo.7310932 (Flammini et al., 2022a).

The combustion of woodfuel for residential use is often not considered to be a source of greenhouse gas (GHG) emissions in households since emissions from woodfuel combustion can be offset by the CO2 absorbed by the growth of the forest as a carbon sink (IPCC, 2006). However, this only applies to wood that is harvested in a renewable way, i.e., at a rate not exceeding the regrowth rate of the forest from which it is harvested (Drigo et al., 2002). This paper estimates the share of GHG emissions attributable to non-renewable woodfuel harvesting for use in residential food activities. It adds to a growing research base estimating GHG emissions from across the entire agri-food value chain, from the manufacture of farm inputs, through food supply chains, and finally to waste disposal (Tubiello et al., 2021). Country-level information is generated from United Nations Statistics Division (UNSD) and International Energy Agency (IEA) data on woodfuel use in households. We find that, in 2019, annual emissions from non-renewable woodfuel use in household food consumption were about 745 million tonnes (Mt CO2eq yr−1), with uncertainty ranging from −20 % to + 22 %, having increased 6 % from 1990. Overall, global trends were a result of counterbalancing effects: the emission increases were largely fuelled from countries in Sub-Saharan Africa, Southern Asia, and Latin America while significant decreases were seen in countries in Eastern Asia and South-eastern Asia. The Food and Agriculture Organisation of the United Nations (FAO) has developed and regularly maintains a database covering GHG emissions from the various components of the agri-food sector, including pre- and post-production activities, by country and world regions. The dataset is developed according to International Panel on Climate Change guidelines (IPCC, 2006), which avoids overlaps across AFOLU and energy components. It relies mainly on UNSD Energy Statistics data, which are used as activity data for the calculation of the GHG emissions (Tubiello et al., 2022). The information used in this work is available as open data with DOI https://doi.org/10.5281/zenodo.7310932 (Flammini et al., 2022).

Aluminum production is a major energy consumer and source of greenhouse gas (GHG) emissions. The regional transfer of the primary aluminum (PA) industry, which mainly consists of the processes of electrolysis and aluminum ingot casting, is currently an important international trend in aluminum industrial development. However, the changes in GHG emissions from aluminum production for such transfers are unclear. This study has established a life cycle assessment model of aluminum industry based on regional transfers in the context of China, determined the GHG emissions of PA and secondary aluminum (SA) production, examined the GHG emission changes of PA production based on regional industry transfer between the years 2007 and 2017, and explored seven driving factors that affect GHG emissions in the aluminum industry. GHG emissions per unit PA and SA production in China decreased by 18.6% and 6.3%, respectively, but the total GHG emissions from aluminum industry still increased by 2.2 times between the years 2007 and 2017. The driving factor analysis showed that the major positive effects of GHG emissions from China's aluminum industry from 2007 to 2017 included the production scale effect of SA and the energy structure effect. Existing regional transfers (between the years 2007 and 2017) did not deliver significant annual GHG emissions reductions. Currently, Xinjiang, Henan, Shandong, and Inner Mongolia are the main PA production provinces in China, although regional transfers have been implemented. This study provides a basis for the improvement and sustainable development of the aluminum industry, suggests policies for regional aluminum development, and proposes a beneficial layout of the aluminum industry.

Modeling greenhouse gas emissions from biological wastewater treatment process with experimental verification: A case study of paper mill

The state of Massachusetts (MA) has passed comprehensive climate change legislation and a roadmap of achieving Net Zero emissions in 2050, which includes the protection of environmental resources (e.g., soil) and green space across the state. Soil resources are an integral part of the land cover/land use. They can be a significant source of greenhouse gas (GHG) emissions because of the conversion of “low disturbance” land covers (e.g., evergreen forest, hay/pasture) to “high disturbance” land covers (e.g., low-, medium-, and high-intensity developed land). These often “invisible” GHG emissions can be considered as “negative externalities” and “external costs” because of the difficulty in assigning ownership to the emissions. The combination of remote sensing and soil information data analysis can identify the ownership associated with GHG emissions and therefore expand the range of policy tools for addressing these emissions. This study demonstrates the rapid assessment of the value of regulating ecosystems services (ES) from soil organic carbon (SOC), soil inorganic carbon (SIC), and total soil carbon (TSC) stocks, based on the concept of the avoided social cost of carbon dioxide (CO2) emissions for MA by soil order and county using remote sensing and information from the State Soil Geographic (STATSGO) and Soil Survey Geographic Database (SSURGO) databases. Classified land cover data for 2001 and 2016 were downloaded from the Multi-Resolution Land Characteristics Consortium (MRLC) website. The results provide accurate and quantitative spatio-temporal information about likely GHG emissions, which can be linked to ownership. The state of MA can use these remote sensing tools and publicly available data to quantify and value GHG emissions based on property ownership, therefore “internalizing” the costs of these emissions for a cost-effective climate mitigation policy.

We report carbon stock in biomass, litter and soil estimated for six locations in natural Quercus ilex L. stands of the Middle and High Moroccan Atlas. Twenty trees at each location were selected according to their diameter classes and felled to measure the biomass of trunk, branches, twigs and leaves and determine allometric relationships. Soil was sampled in five depths (0 - 15, 15 - 30, 30 - 50, 50 - 70 and 70 - 100 cm) and litterfall production measured in all tree stands. The total carbon stock in above-ground biomass ranged between 17 Mg&#183ha&#451 in A&#239t Aamar stand (High Atlas) and 91 Mg&#183ha&#451 in Ksiba stand (Middle Atlas). Perennial organs (trunk, branches and twigs) stored over 95% of the tree carbon stock. Soil organic carbon concentrations ranged from 0.01% (in 70 - 100 cm in all stands) to 8.1% (in 0 - 15 cm in the Ajdir stand in Middle Atlas). The total organic carbon stock in the soil ranged between 141.4 t&#183ha&#451 in Ajdir and 24.6 t&#183ha&#451 in Asloul. The litter contained 0.2 Mg C ha&#451 in the clearing (C2) stand of High Atlas and 14.3 Mg C ha&#451 in (Ajdir) of carbon. The best fitted model for predicting carbon stock in tree biomass was obtained by applying the allometric equation Y = aXb for each biomass fraction and stand, where Y is the aboveground biomass (dry weight) and X is the DBH (Mean diameter at breast height, 1.30 m). These previous data obtained in the present study confirm the important function of these natural forests as longterm C sinks, in forest biomass, litter and soil. The potential long term C storage of these systems is moderately high, especially in less-intensively managed forests that include large trees. The established relationship between DBH and carbon stock in different tree organs can be used for forest carbon accounting, and also synthesize available information on oak forest as a sink for atmospheric CO2, and identify the management options that may enhance the capacity for C capture/ storage in forest soils.