Carbon-neutral wool farming in south-eastern Australia

The sustainability of farming is important to ensure that natural resources remain available into the future. Ruminant livestock production generates more greenhouse gas emissions than other types of agricultural production and most livestock mitigation options to date have a modest greenhouse gas reduction potential (<20%). Trees and soils, by comparison, can sequester large amounts of carbon depending on the availability of land. Previous studies on carbon neutral livestock production have shown that farms with a stocking rate of 8 dry sheep equivalents (DSE)/ha can be carbon neutral or carbon positive by sequestering more carbon than is emitted from the farm. However, the carbon offsets required by farms with higher stocking rates (>20 DSE/ha) has yet to be studied in Australia. The challenge is to sequester enough carbon to offset the higher level of emissions that these higher stocked farms produce. This study calculated the carbon balance of wool, prime lamb and beef enterprises using a range of stocking rates (6–22 DSE/ha) and levels of tree cover in two agroecological zones. Emissions from livestock, energy and transport were offset by the carbon sequestered in trees and soils. Additionally, the carbon balance was calculated of a case study, Jigsaw Farms, an intensive sheep and beef farm in south-eastern Australia. The methods used to calculate emissions and carbon stocks were from the Australian National Greenhouse Gas Inventory. The majority of stocking rates were carbon positive over a 25-year period when 20% of the sheep or beef enterprises were covered with trees. This study demonstrated that substantial reductions can be made in greenhouse gas emissions through the use of carbon sequestration, particularly in trees. The results showed that from 2000 to 2014 Jigsaw Farms reduced its emissions by 48% by sequestering carbon in trees and soil. The analysis of different stocking rates and tree cover provides an important reference point for farmers, researchers and policy analysts to estimate the carbon balance of wool, prime lamb and beef enterprises based on stocking rate and the area of tree cover.

Nepalese community forests are globally recognized for sustainable forest management and improving the livelihoods of forest-dependent communities, but their contribution to carbon sequestration in trees and soil is rarely studied. This study was performed to understand the effect of management practices on carbon stock of two community forests (CFs) - Taldanda (managed) and Dangdunge (unmanaged) - dominated by Sal (Shorea robusta) in the mid-hills of Nepal. Twenty-one concentric sample plots, each of 250 m2, were laid out in each forest to estimate different carbon pools and a stratified random sampling intensity of 0.5% used to collect data. Results showed significant (p<0.05) differences in above and below-ground biomass and carbon sequestration potential between the two CFs. The managed and unmanaged forests had total carbon stock of 269.3±27.4 and 150.0±22.7 ton/ha, respectively, demonstrating 1.79 times higher carbon stock in the former than the latter. The managed forest had significantly (p<0.05) greater mean soil organic carbon (SOC) stock than the unmanaged forest. The SOC was highest in the upper soil layer (0-10 cm), with a steady decrease as the soil depth increased. All other measured carbon pools values were higher in managed compared to unmanaged forest. The difference in carbon stock was due to the manipulation of different forest management activities, including thinning, timber extraction, fire control, grazing, and fuel wood/fodder extraction. The study suggests that the implementation of proper forest management would be necessary for enhancing carbon stock in forest trees and soils.

La production de bétail fait partie de la culture des peuples et est importante pour la nutrition et le bien-être humain. Cependant, le bétail d'élevage conventionnel est une source de gaz à effet de serre (Ges). La séquestration du carbone dans la végétation et les sols peut être améliorée tandis que les émissions de Ges peuvent diminuer avec le pâturage contrôlé, des espèces fourragères appropriées, et l'utilisation de systèmes sylvopastoraux (Sps) combinant arbres, arbustes et pâturages. En outre, les Sps favorisent l'adaptation au changement climatique avec les effets améliorateurs des arbres sur les températures de l'air qui limitent le dessèchement des pâturages et améliorent le bien-être et la productivité des animaux. Plusieurs types de Sps sont très répandus dans les paysages agricoles de l'Amérique latine. Dans les Sps intensifs (Isps), comprenant des banques de fourrage avec des espèces ligneuses plantées à haute densité, les rendements sont supérieurs à l'élevage conventionnel, en raison d'une plus grande densité de bétail et du gain de poids plus élevé des animaux. Les recherches en Colombie, au Nicaragua et au Costa Rica montrent que les Sps ont plus de carbone dans la biomasse aérienne et dans les sols que dans les pâturages dégradés. Dans les Sps, le bois des arbres fruitiers, plantés ou de régénération naturelle, augmente les stocks de carbone et les taux de séquestration. Les espèces arborées locales peuvent être utilisées dans les Sps avec de bons résultats en termes de productivité, de restauration des sols, de séquestration du carbone et de conservation de la biodiversité. L'utilisation de Sps contribue à la séquestration du carbone dans les arbres et dans les sols, tandis que l'établissement des plantations forestières et la conservation des forêts secondaires augmentent la séquestration et le stockage du carbone à l'échelle du paysage. Les Sps et surtout les Isps peuvent contribuer à atténuer le changement climatique car ils peuvent avoir un bilan Ges positif. En Amérique latine, les Isps aux résultats positifs ont été adaptés à des niveaux régionaux. Des mesures incitatives telles que le paiement des services environnementaux ainsi que l'assistance technique peuvent stimuler l'adoption des Sps contribuant ainsi à l'atténuation du changement climatique tout en préservant les moyens de subsistance en milieu rural.

Mangroves, as part of the blue carbon ecosystem, are considered a cost-effective nature-based solution pathway to help mitigate climate change and achieve the Paris Agreement’s aim to limit warming to 1.5˚C. The accurate quantification of greenhouse gas (GHG) emissions and carbon accounting has become a key challenge for policymakers and scientists addressing climate change.  Globally, Indonesia emits the highest potential CO2 emissions from soils in the mangrove ecosystems because of its high rates of mangrove losses in recent decades. Unfortunately, there are limited studies on carbon and GHG emissions from Indonesian mangroves. This study aims to quantify carbon loss due to mangrove conversion due to aquaculture development by combining carbon stocks and GHG emissions data located in Tabalar Muara Village, Berau, East Kalimantan, Indonesia. We collected data from aboveground (vegetation, downwood) and belowground (roots and soil) carbon stocks in five and three transects of mangrove forests and aquaculture ponds, respectively. Soil bulk density and carbon concentration in various soil depth intervals were also analyzed. In addition, we conducted three consecutive days of regular monthly monitoring of CO2 and CH4 fluxes associated with soil physicochemical properties in mangrove forests and aquaculture ponds from January – December 2023. Total ecosystem carbon stocks in mangrove forests and aquaculture ponds were 926 ± 20 and 658 ± 45 Mg C ha−1, respectively. Thus, it implies 984 Mg CO2 ha−1 of potential carbon loss during mangrove forest conversion to aquaculture ponds. Soil carbon stocks between 0 and 300 cm depth varied significantly, where carbon stock in aquaculture ponds (658 Mg C ha−1) was 18% lower than in mangrove forests (777 Mg C ha−1). Soil carbon dominates total ecosystem carbon stocks by up to 88% in mangrove forests.  For GHG fluxes, mangrove forests have six times higher heterotrophic CO2 emissions (79.44 ± 4.47 Mg CO2 ha-1 yr-1) compared to that from the aquaculture ponds (13.88 ± 0.88 Mg CO2 ha-1 yr-1). The annual total CH4 flux was 17 times higher in mangrove forests (7.72 ± 0.50 Mg CO2e ha-1 yr-1) than in aquaculture ponds  (0.46 ± 0.04 Mg CO2e ha-1 yr-1). The results of this research are useful to refine GHG emissions accounting on mangroves by providing higher Tier of emission factors to fulfill Indonesia’s Enhanced Nationally Determined Contributions.

Abstract. To track progress towards keeping global warming well below 2 ∘C or even 1.5 ∘C, as agreed in the Paris Agreement, comprehensive up-to-date and reliable information on anthropogenic emissions and removals of greenhouse gas (GHG) emissions is required. Here we compile a new synthetic dataset on anthropogenic GHG emissions for 1970–2018 with a fast-track extension to 2019. Our dataset is global in coverage and includes CO2 emissions, CH4 emissions, N2O emissions, as well as those from fluorinated gases (F-gases: HFCs, PFCs, SF6, NF3) and provides country and sector details. We build this dataset from the version 6 release of the Emissions Database for Global Atmospheric Research (EDGAR v6) and three bookkeeping models for CO2 emissions from land use, land-use change, and forestry (LULUCF). We assess the uncertainties of global greenhouse gases at the 90 % confidence interval (5th–95th percentile range) by combining statistical analysis and comparisons of global emissions inventories and top-down atmospheric measurements with an expert judgement informed by the relevant scientific literature. We identify important data gaps for F-gas emissions. The agreement between our bottom-up inventory estimates and top-down atmospheric-based emissions estimates is relatively close for some F-gas species (∼ 10 % or less), but estimates can differ by an order of magnitude or more for others. Our aggregated F-gas estimate is about 10 % lower than top-down estimates in recent years. However, emissions from excluded F-gas species such as chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs) are cumulatively larger than the sum of the reported species. Using global warming potential values with a 100-year time horizon from the Sixth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC), global GHG emissions in 2018 amounted to 58 ± 6.1 GtCO2 eq. consisting of CO2 from fossil fuel combustion and industry (FFI) 38 ± 3.0 GtCO2, CO2-LULUCF 5.7 ± 4.0 GtCO2, CH4 10 ± 3.1 GtCO2 eq., N2O 2.6 ± 1.6 GtCO2 eq., and F-gases 1.3 ± 0.40 GtCO2 eq. Initial estimates suggest further growth of 1.3 GtCO2 eq. in GHG emissions to reach 59 ± 6.6 GtCO2 eq. by 2019. Our analysis of global trends in anthropogenic GHG emissions over the past 5 decades (1970–2018) highlights a pattern of varied but sustained emissions growth. There is high confidence that global anthropogenic GHG emissions have increased every decade, and emissions growth has been persistent across the different (groups of) gases. There is also high confidence that global anthropogenic GHG emissions levels were higher in 2009–2018 than in any previous decade and that GHG emissions levels grew throughout the most recent decade. While the average annual GHG emissions growth rate slowed between 2009 and 2018 (1.2 % yr−1) compared to 2000–2009 (2.4 % yr−1), the absolute increase in average annual GHG emissions by decade was never larger than between 2000–2009 and 2009–2018. Our analysis further reveals that there are no global sectors that show sustained reductions in GHG emissions. There are a number of countries that have reduced GHG emissions over the past decade, but these reductions are comparatively modest and outgrown by much larger emissions growth in some developing countries such as China, India, and Indonesia. There is a need to further develop independent, robust, and timely emissions estimates across all gases. As such, tracking progress in climate policy requires substantial investments in independent GHG emissions accounting and monitoring as well as in national and international statistical infrastructures. The data associated with this article (Minx et al., 2021) can be found at https://doi.org/10.5281/zenodo.5566761.

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.

Drained peatlands in temperate Europe are a globally important source of greenhouse gas (GHG) emissions. This article outlines a methodology to assess emissions and emission reductions from peatland rewetting projects using vegetation as a proxy. Vegetation seems well qualified for indicating GHG fluxes from peat soils as it reflects long-term water level, affects GHG emissions via assimilate supply and aerenchyma and allows fine-scaled mapping. The methodology includes mapping of vegetation types characterised by the presence and absence of species groups indicative for specific water level classes. GHG flux values are assigned to the vegetation types following a standardized protocol and using published emission values from plots with similar vegetation and water level in regions with similar climate and flora. Carbon sequestration in trees is accounted for by estimating the annual sequestration in tree biomass from forest inventory data. The method follows the criteria of the Voluntary Carbon Standard and is illustrated using the example of two Belarusian peatlands.

The decrease in the level of greenhouse gas (GHG) emissions from industry and agriculture is one of the biggest challenges that European Union (EU) countries have to face. Their economic development should occur under the conditions of limiting the pressure on the environment. The agricultural and industrial sectors play a key role in ensuring food security, technological progress, job security, social well-being, economic competitiveness, and sustainable development. The main purpose of this article was to identify and compare the level, trends, and variability in greenhouse gas emissions from industry and agriculture in EU countries in 2010–2019, to create classes of countries with similar gas emissions, and to analyze the average values of their economic conditions. The original contribution to the article was to investigate whether there is a relationship between the level of greenhouse gas emissions and the economic development of countries and other economic indicators characterizing the sectors of industry and agriculture. Empirical data were obtained from the Eurostat and Ilostat databases. Basic descriptive statistics, classification methods, multiple regression, and correlation methods were used in the study. The industrial and agricultural sectors in EU countries emit similar amounts of greenhouse gases into the environment. In the years 2010–2019, the percentage share of emissions from these sectors in total gas emissions was growing dynamically, but no evidence was found indicating that those countries that emitted the most greenhouse gases significantly reduced their emissions in the decade under review. Moreover, EU countries are still significantly and invariably differentiated in this respect. Greenhouse gas emissions from industry and agriculture are influenced by the economic characteristics of these sectors, such as the level of GDP per capita, the scale of investment by enterprises, the expenditure on research and development, as well as employment in these sectors. The findings of this study show that total greenhouse gas emissions from all sources increase with countries’ economic growth, while a higher level of support of EU countries for research and development, and a greater share of employment in both industry and agriculture, translate into higher greenhouse gas emissions from these sectors. These conclusions may be useful for decision makers in developed and developing countries, as well as those in the industrial and agricultural sectors, in controlling and verifying the possible causes of greenhouse gas emissions in terms of the need to reduce their negative role on the environment and human health.

Assessment of greenhouse gas emission from A/O and SBR wastewater treatment plants in Beijing, China

Soil is a key compartment for climate regulation as a source of greenhouse gases (GHGs) emissions and as a sink of carbon. Thus, soil carbon sequestration strategies should be considered alongside reduction strategies for other greenhouse gas emissions. Taking this into account, several international and European policies on climate change are now acknowledging the importance of soils, which means that proper, comparable and reliable information is needed to report on carbon stocks and GHGs emissions from soil. It also implies a need for consensus on the adoption and verification of mitigation options that soil can provide. Where consensus is a key aspect, formal standards and guidelines come into play. This paper describes the existing ISO soil quality standards that can be used in this context, and calls for new ones to be developed through (international) collaboration. Available standards cover the relevant basic soil parameters including carbon and nitrogen content but do not yet consider the dynamics of those elements. Such methods have to be developed together with guidelines consistent with the scale to be investigated and the specific use of the collected data. We argue that this standardization strategy will improve the reliability of the reporting procedures and results of the different climate models that rely on soil quality data.

<p>Accurately representing historical soil and vegetation carbon stocks in land data systems is important when evaluating outcomes of land use change decisions (e.g. land use change emissions). Moreover, carbon stocks (especially soil carbon stocks) are subject to uncertainty and vary significantly based on assumptions used by different data sets. For this reason, when representing carbon stocks in data systems, it is important to present a range of values based on the distribution of carbon stock observations for a given unit (region/country/basin) at the grid cell level.</p><p>We updated the moirai land data system (LDS) to generate historical estimates of soil carbon stocks (at a depth of 0-30 cms) and vegetation carbon stocks (broken down into above ground and below ground biomass) at the sub-national (basin) level based on global fine resolution raster input data. The LDS has also been programmed to calculate soil carbon stock values based on multiple data sets (such as SoilGrids database maintained by the ISRIC and the harmonized world soil database maintained by the FAO) to enable efficient comparisons of carbon stock estimates by end users between data sets. Moreover, to account for uncertainty, carbon stocks are calculated for 6 “states” based on 5 arcmin grid cell level observations of carbon stocks (The states are -weighted average, median, minimum, maximum, quartile 1 and quartile 3).  This provides a robust representation of soil and vegetation carbon stocks at the sub-national level which are differentiated by data sources and the above-mentioned states, which can be used to represent more realistic outcomes from land use change decisions. To demonstrate the utility of this data, we also implemented the same in the land module of a multi sector dynamics model, Global Change Analysis Model (GCAM) to observe the impacts on land use change decision outcomes with different initializations of carbon stock data.   </p>

Animal production is a significant source of greenhouse gas (GHG) emissions. One of the major challenges in sustainable management is to mitigate the effects of climate change by reducing GHG emissions. The diversity of animal production systems and accompanying diversification of technological processes, mean that specific production effects can be obtained at different levels of GHG emissions. The aim of the study was to determine the carbon footprint (CF) of beef cattle grown in a conventional system (i.e. indoor confinement). The research was carried out on the beef cattle farm belonging to a large-area enterprise, Długie Stare Ltd. The beef cattle production system consisted of the following subsystems: a basic breeding herd (consisting of suckler cows, replacement heifers and calves up to 6.5 months), breeding heifers, breeding bulls and fattening bulls. The method of life cycle analysis (LCA) in the stages from "cradle-to-farmgate" was used to assess the GHG emissions associated with the production of beef cattle. The average CF in the entire beef cattle production system was 25.43 kg of CO2 kg-1 of live weight of marketed cattle, while in the individual subsystems of basic breeding herd, breeding heifers, breeding bulls and fattening bulls, the CF (after GHG allocation) was: 11.0 kg CO2 eq., 34.30 kg CO2 eq., 27.32 and 25.40 kg CO2 eq., respectively. GHG emissions associated with young calves staying in the cow-calf pairs until weaning (in the period from 0-6.5 months), had a decisive influence on the final CF in each of the subsystems of beef cattle production. The second important factor directly affecting the CF was GHG emissions related to methane (CH4) enteric fermentation and manure management. Knowledge of factors affecting the CF structure allows better identification of critical areas in production processes with high GHG emission potential. Information on the CF of beef cattle and beef meat responds to a wider societal demand for the ecological characteristics of market products, which ultimately contributes to improving their market competitiveness.

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

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.

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.