A comparative study of floor construction on sloping sites: an analysis of cumulative energy demand and greenhouse gas emissions

Cattle production is a large source of greenhouse gas (GHG) emissions from the Canadian livestock sector. Efforts to reduce CH4 emissions from enteric fermentation have led to modifications of diet composition for livestock, resulting in a corresponding change in manure properties. We studied the effect of applying manure from cattle fed a barley-based diet with and without the methane inhibitor supplement, 3-nitrooxypropanol (3-NOP), on soil GHG emissions. Three soils common to Alberta, Canada, were used: a Black Chernozem, a Dark Brown Chernozem, and a Gray Luvisol. We compared the supplemented (3-NOPM) and non-supplemented manure (BM) amendments to a composted 3-NOPM (3-NOPC) amendment and a control with no manure amendment (CK). In an 84-day laboratory incubation experiment, 3-NOPM had significantly lower cumulative CO2 emissions compared to BM in both the Black Chernozem and Gray Luvisol. The cumulative N2O emissions were lowest for 3-NOPC and CK and highest for 3-NOPM across all soil types. Cumulative CH4 emissions were only affected by soil type, with a net positive flux from the fine-textured Gray Luvisol and Dark Brown Chernozem and a net negative flux from the coarse-textured Black Chernozem. Cumulative anthropogenic GHG emissions (CO2-equivalent) from soil amended with 3-NOPM were significantly higher than those for both BM and CK amendments in the Black Chernozem, while the cumulative anthropogenic GHG emissions from the 3-NOPC treatment were similar to or significantly lower than those for the BM and CK treatments across all soil types. We conclude that soil GHG emissions resulting from the 3-NOPM amendment are dependent on soil type and 3-NOPM could potentially increase soil GHG emissions compared to BM or CK. Although we show that the composting of 3-NOPM prior to soil application can reduce soil GHG emissions, the composting process also releases GHGs, which should also be considered in assessing the life-cycle of manure application. Our results provide a first look at the potential effect of the next stage in the life cycle of 3-NOP on GHG emissions. Further research related to the effect of soil properties, particularly in field studies, is needed to assess the best management practices related to the use of manure from cattle-fed diets supplemented with 3-NOP as a soil amendment.

DPR of Korea ratified the United Nations Framework Convention on Climate Change (UNFCCC) on 5 December 1994, the Kyoto Protocol on 27 April 2005 and the Paris Agreement on 1 August 2016. As a party of the convention on climate change, DPR of Korea submitted the national greenhouse gas (GHG) emissions inventories to the UNFCCC secretariat, respectively. This study aimed at analysing the characterisation of national GHG emissions in DPR of Korea for a 12-year period (1990-2002), conducted according to 2006 IPCC guidelines. The results show that DPR of Korea accounted for 0.5% of the world GHG emissions in 1990, but only 0.2% of the emissions in 2002. The amount of cumulative GHG emissions was approximately 1,503,820 Gg CO2e (CO2 equivalent) in the period 1990-2002, which accounted for 0.3% of the world cumulative GHG emissions. This showed that DPR of Korea definitely contributed to global warming, although the emissions were negligible, compared to the world emissions.

Biochar and its manure-based feedstock have divergent effects on soil organic carbon and greenhouse gas emissions in croplands

Substituting conventional materials with lightweight materials is an effective way to reduce the life cycle greenhouse gas (GHG) emissions from light-duty vehicles. However, estimated GHG emission reductions of lightweighting depend on multiple factors including the vehicle powertrain technology and efficiency, lightweight material employed, and end-of-life material recovery. We developed a fleet-based life cycle model to estimate the GHG emission changes due to lightweighting the U.S. light-duty fleet from 2016 to 2050, using either high strength steel or aluminum as the lightweight material. Our model estimates that implementation of an aggressive lightweighting scenario using aluminum reduces 2016 through 2050 cumulative life cycle GHG emissions from the fleet by 2.9 Gt CO2 eq (5.6%), and annual emissions in 2050 by 11%. Lightweighting has the greatest GHG emission reduction potential when implemented in the near-term, with two times more reduction per kilometer traveled if implemented in 2016 rather than in 2030. Delaying implementation by 15 years sacrifices 72% (2.1 Gt CO2 eq) of the cumulative GHG emissionmitigation potential through 2050. Lightweighting is an effective solution that could provide important near-term GHG emission reductions especially during the next 10-20 years when the fleet is dominated by conventional powertrain vehicles.

Co-effects of salinity and moisture on CO2 and N2O emissions of laboratory-incubated salt-affected soils from different vegetation types

Adding Corbicula fluminea altered the effect of plant species diversity on greenhouse gas emissions and nitrogen removal from constructed wetlands in the low-temperature season

The investigative material 3-nitrooxypropanol (3-NOP) can reduce enteric methane emissions from beef cattle. North American beef cattle are often supplemented the drug monensin to improve feed digestibility. Residual and confounding effects of these additives on manure greenhouse gas (GHG) emissions are unknown. This research tested whether manure carbon and nitrogen, and GHG and ammonia emissions, differed from cattle fed a typical finishing diet and 3-NOP [125–200 mg kg−1 dry matter (DM) feed], or both 3-NOP (125–200 mg kg−1 DM) and monensin (33 mg kg−1 DM) together, compared to a control (no supplements) when manure was stockpiled or composted for 202 days. Consistent with other studies, cumulative GHGs (except nitrous oxide) and ammonia emissions were higher from composted compared to stockpiled manure (all P < 0.01). Dry matter, total carbon and total nitrogen mass balance estimates, and cumulative GHG and ammonia emissions, from stored manure were not affected by 3-NOP or monensin. During the current experiment, supplementing beef cattle with 3-NOP did not significantly affect manure GHG or NH3 emissions during storage under the tested management conditions, suggesting supplementing cattle with 3-NOP does not have residual effects on manure decomposition as estimated using total carbon and nitrogen losses and GHG emissions.

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Agricultural soils are responsible for a majority of human caused greenhouse gas (GHG) production, such as N₂O and carbon dioxide (CO₂). Nitrous oxide is a potent GHG that stays in the atmosphere for at least 100 years. It is also an ozone-depleting gas. Carbon dioxide is problematic due to its abundance in the atmosphere. These GHGs, along with methane, have had a significant impact on climate change. Claypan soils are characterized as having a significantly higher clay content deeper in the soil profile compared to the layers directly above it. The goal of this research was to investigate the impact N fertilizer placement has on GHG emissions and corn growth. The specific research objectives were to determine the effects of urea fertilizer placement with and without a nitrification inhibitor (NI) on cumulative soil GHG emissions (N₂O and CO₂) and to assess the effects of urea fertilizer placement with and without a NI on plant N uptake, N use efficiency (NUE), and corn (Zea mays L.) production, on a poorly drained claypan soil in Northeastern Missouri. A NI helps reduce the amount of nitrous oxide produced. Field studies were conducted in 2014 and 2015. Soil greenhouse gas emissions were measured frequently throughout the growing season to determine flux and cumulative N₂O and CO₂ emissions. Soil water content and soil temperature were also assessed at each gas sampling event. Rainfall was higher than the 10-year average over the growing season for both 2014 and 2015 and possibly resulted in increased environmental N loss. Soil N₂O and CO₂ emissions were higher during the 2015 growing season. The UDB treatment produced the greatest amount of cumulative soil N₂O emissions during both growth seasons at 100 and 354 g N₂O-N ha⁻¹. Deep banded urea without a NI resulted in the highest soil CO₂ production in 2014 and UAA had the greatest cumulative CO₂ emissions in 2015 at approximately 11 and 17 kg CO₂-C ha⁻¹, respectively. Incorporating urea to a depth of 8 cm, deep banding urea, and deep banding urea with a NI all resulted in significantly higher yields of corn by as much as much as 10%. Deep banding urea with a NI provided as high as a 48% increase in grain yield compared to other treatments in 2015. The highest yields occurred in 2014 when there were lower N₂O emissions. In 2015, there were higher N₂O emissions and lower yields. This research suggests that urea fertilizer placement has an impact on GHG emissions and corn growth and this information should be provided to farmers who are interested in producing more corn and losing less N. The amount of rainfall during the growing season may also influence soil GHG emissions and corn growth. More research should be conducted to understand to what extent climatic variability impacts GHG and crop production.

Evaluating long-term greenhouse gas mitigation opportunities through carbon capture, utilization, and storage in the oil sands

The availability of fossil resources is predicted to decrease in the near future: they are a non-renewable source, they cause environmental concerns, and they are subjected to price instability. Utilization of biomass as raw material in a biorefinery is a promising alternative to fossil resources for production of energy carriers and chemicals, as well as for mitigating climate change and enhancing energy security. This paper focuses on a biorefinery concept which produces bioethanol, bioenergy, and biochemicals from switchgrass, a lignocellulosic crop. Results are compared with a fossil reference system producing the same products/services from fossil sources. The biorefinery system is investigated using a Life Cycle Assessment approach, which takes into account all the input and output flows occurring along the production chain. This paper elaborates on methodological key issues like land use change effects and soil N2O emissions, whose influence on final outcomes is weighted in a sensitivity analysis. Since climate change mitigation and energy security are the two most important driving forces for biorefinery development, the assessment has a focus on greenhouse gas (GHG) emissions and cumulative primary energy demand (distinguished into fossil and renewable), but other environmental impact categories (e.g., abiotic depletion, eutrophication, etc.) are assessed as well. The use of switchgrass in a biorefinery offsets GHG emissions and reduces fossil energy demand: GHG emissions are decreased by 79% and about 80% of non-renewable energy is saved. Soil C sequestration is responsible for a large GHG benefit (65 kt CO2-eq/a, for the first 20 years), while switchgrass production is the most important contributor to total GHG emissions of the system. If compared with the fossil reference system, the biorefinery system releases more N2O emissions, while both CO2 and CH4 emissions are reduced. The investigation of the other impact categories revealed that the biorefinery has higher impacts in two categories: acidification and eutrophication. Results are mainly affected by raw material (i.e., switchgrass) production and land use change effects. Steps which mainly influence the production of switchgrass are soil N2O emissions, manufacture of fertilizers (especially those nitrogen-based), processing (i.e., pelletizing and drying), and transport. Even if the biorefinery chain has higher primary energy demand than the fossil reference system, it is mainly based on renewable energy (i.e., the energy content of the feedstock): the provision of biomass with sustainable practices is then a crucial point to ensure a renewable energy supply to biorefineries. This biorefinery system is an effective option for mitigating climate change, reducing dependence on imported fossil fuels, and enhancing cleaner production chains based on local and renewable resources. However, this assessment evidences that determination of the real GHG and energy balance (and all other environmental impacts in general) is complex, and a certain degree of uncertainty is always present in final results. Ranges in final results can be even more widened by applying different combinations of biomass feedstocks, conversion routes, fuels, end-use applications, and methodological assumptions. This study demonstrated that the perennial grass switchgrass enhances carbon sequestration in soils if established on set-aside land, thus, considerably increasing the GHG savings of the system for the first 20 years after crop establishment. Given constraints in land resources and competition with food, feed, and fiber production, high biomass yields are extremely important in achieving high GHG emission savings, although use of chemical fertilizers to enhance plant growth can reduce the savings. Some strategies, aiming at simultaneously maintaining crop yield and reduce N fertilization application through alternative management, can be adopted. However, even if a reduction in GHG emissions is achieved, it should not be disregarded that additional environmental impacts (like acidification and eutrophication) may be caused. This aspect cannot be ignored by policy makers, even if they have climate change mitigation objectives as main goal.

Evaluation of organic waste diversion alternatives for greenhouse gas reduction

Multi-information integration-based life cycle analysis of greenhouse gas emissions for prefabricated construction: A case study of Shenzhen

Greenhouse gas emissions associated with plastics in China from 1950 to 2060

Compost application is commonly considered by winegrape producers to improve soil health while sequestering carbon (C) and mitigating climate change. However, inputs of available C and nitrogen (N) as nutrients can induce emissions of greenhouse gases (GHG) such as carbon dioxide (CO2) and nitrous oxide (N2O). A 2-year field experiment in a Mediterranean vineyard on the California Central Coast was conducted to investigate the short-term effects of compost application at four different rates on soil C dynamics and greenhouse gas emissions. Two years of greenhouse gas sampling were performed using static chambers at vineyard management events in two functional locations (tractor row and under the vines). Soil samples were collected annually in spring at the same locations at 0–15, 15–30 and 30–60 cm depth, and during greenhouse gas sampling at 0–15 cm. The increasing compost application rate did not increase soil C stock, cumulative greenhouse gas emissions and global warming potential. The increase in active soil C observed to the depth of 60 cm suggests that increasing the compost application rate up to the rate of 13.5 Mg ha-1 year-1 can facilitate the early stages of C stabilization and sequestration. Compost application did not have a significant effect on grape yield or cover crop growth during the study. Our results provided important information on the potential environmental tradeoffs as greenhouse gas emissions from compost applications, which should be taken into account when considering the vineyard C budget.

In-field measurements of direct soil greenhouse gas (GHG) emissions provide critical data for quantifying the net energy efficiency and economic feasibility of crop residue-based bioenergy production systems. A major challenge to such assessments has been the paucity of field studies addressing the effects of crop residue removal and associated best practices for soil management (i.e., conservation tillage) on soil emissions of carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). This regional survey summarizes soil GHG emissions from nine maize production systems evaluating different levels of corn stover removal under conventional or conservation tillage management across the US Corn Belt. Cumulative growing season soil emissions of CO2, N2O, and/or CH4 were measured for 2–5 years (2008–2012) at these various sites using a standardized static vented chamber technique as part of the USDA-ARS’s Resilient Economic Agricultural Practices (REAP) regional partnership. Cumulative soil GHG emissions during the growing season varied widely across sites, by management, and by year. Overall, corn stover removal decreased soil total CO2 and N2O emissions by -4 and -7 %, respectively, relative to no removal. No management treatments affected soil CH4 fluxes. When aggregated to total GHG emissions (Mg CO2 eq ha−1) across all sites and years, corn stover removal decreased growing season soil emissions by −5 ± 1 % (mean ± se) and ranged from -36 % to 54 % (n = 50). Lower GHG emissions in stover removal treatments were attributed to decreased C and N inputs into soils, as well as possible microclimatic differences associated with changes in soil cover. High levels of spatial and temporal variabilities in direct GHG emissions highlighted the importance of site-specific management and environmental conditions on the dynamics of GHG emissions from agricultural soils.