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Nitrogen losses to the environment following food-based digestate and compost applications to agricultural land
2017
Nicholson, Fiona | Bhogal, Anne | Cardenas, L. (Laura) | Chadwick, Dave | Misselbrook, T. (Tom) | Rollett, A. (Alison) | Taylor, Matt | Thorman, Rachel | Williams, John
The anaerobic digestion of food waste for energy recovery produces a nutrient-rich digestate which is a valuable source of crop available nitrogen (N). As with any ‘new’ material being recycled to agricultural land it is important to develop best management practices that maximise crop available N supply, whilst minimising emissions to the environment. In this study, ammonia (NH3) and nitrous oxide (N2O) emissions to air and nitrate (NO3−) leaching losses to water following digestate, compost and livestock manure applications to agricultural land were measured at 3 sites in England and Wales. Ammonia emissions were greater from applications of food-based digestate (c.40% of total N applied) than from livestock slurry (c.30% of total N applied) due to its higher ammonium-N content (mean 5.6 kg/t compared with 1–2 kg/t for slurry) and elevated pH (mean 8.3 compared with 7.7 for slurry). Whilst bandspreading was effective at reducing NH3 emissions from slurry compared with surface broadcasting it was not found to be an effective mitigation option for food-based digestate in this study. The majority of the NH3 losses occurred within 6 h of spreading highlighting the importance of rapid soil incorporation as a method for reducing NH3 emissions. Nitrous oxide losses from food-based digestates were low, with emission factors all less than the IPCC default value of 1% (mean 0.45± 0.15%). Overwinter NO3− leaching losses from food-based digestate were similar to those from pig slurry, but much greater than from pig farmyard manure or compost. Both gaseous N losses and NO3− leaching from green and green/food composts were low, indicating that in these terms compost can be considered as an ‘environmentally benign’ material. These findings have been used in the development of best practice guidelines which provide a framework for the responsible use of digestates and composts in agriculture.
Show more [+] Less [-]CO2 emissions from the 2010 Russian wildfires using GOSAT data
2017
Guo, Meng | Li, Jing | Xu, Jiawei | Wang, Xiufeng | He, Hongshi | Wu, Li
In the summer of 2010, more than 6 hundred wildfires broke out in western Russia because of an unprecedented intense heat wave that resulted from strong atmospheric blocking. The present study evaluated the CO2 emissions using GOSAT (Greenhouse gases Observing SATellite) data from July 23 to August 18, 2010 for western Russia. The results demonstrated that the GOSAT CAI (Cloud and Aerosol Imager) was well-suited for the identification of smoke plumes and that the GOSAT FTS (Fourier-Transform Spectrometer) TIR (Thermal InfraRed) could be used to calculate the height of the plumes at approximately 800 hPa (1.58 km). Using GOSAT data, we estimated that the 2010 fires in western Russia emitted 255.76 Tg CO2. We also calculated the CO2 emissions by employing the Biomass Burning Model (BBM) for the same study site and obtained a similar result of 261.82–302.48 Tg CO2. The present study proposes a new method for the evaluation of CO2 emissions from a wildfire using remote sensing data, which could be used to improve the knowledge of the burning of biomass at a regional or a continental scale, to reduce the uncertainties in modeling greenhouse gases emissions, and to further understand how wildfires impact the atmospheric carbon cycle and global warming.
Show more [+] Less [-]Effects of simulated acid rain on soil fauna community composition and their ecological niches
2017
Wei, Hui | Liu, Wen | Zhang, Jiaen | Qin, Zhong
Acid rain is one of the severest environmental issues globally. Relative to other global changes (e.g., warming, elevated atmospheric [CO2], and nitrogen deposition), however, acid rain has received less attention than its due. Soil fauna play important roles in multiple ecological processes, but how soil fauna community responds to acid rain remains less studied. This microcosm experiment was conducted using latosol with simulated acid rain (SAR) manipulations to observe potential changes in soil fauna community under acid rain stress. Four pH levels, i.e., pH 2.5, 3.5, 4.5, and 5.5, and a neutral control of pH 7.0 were set according to the current pH condition and acidification trend of precipitation in southern China. As expected, we observed that the SAR treatments induced changes in soil fauna community composition and their ecological niches in the tested soil; the treatment effects tended to increase as acidity increased. This could be attributable to the environmental stresses (such as acidity, porosity and oxygen supply) induced by the SAR treatments. In addition to direct acidity effect, we propose that potential changes in permeability and movability of water and oxygen in soils induced by acid rain could also give rise to the observed shifts in soil fauna community composition. These are most likely indirect pathways of acid rain to affect belowground community. Moreover, we found that nematodes, the dominating soil fauna group in this study, moved downwards to mitigate the stress of acid rain. This is probably detrimental to soil fauna in the long term, due to the relatively severer soil conditions in the deep than surface soil layer. Our results suggest that acid rain could change soil fauna community and the vertical distribution of soil fauna groups, consequently changing the underground ecosystem functions such as organic matter decomposition and greenhouse gas emissions.
Show more [+] Less [-]Does the New European Driving Cycle (NEDC) really fail to capture the NOX emissions of diesel cars in Europe?
2017
Degraeuwe, Bart | Weiss, Martin
Tests with Portable Emissions Measurement Systems (PEMS) have demonstrated that diesel cars emit several times more NOX on the road than during certification on the New European Driving Cycle (NEDC). Policy makers and scientists have attributed the discrepancy to the unrealistically low dynamics and the narrow temperature range of NEDC testing. Although widely accepted, this assumption was never been put under scientific scrutiny. Here, we demonstrate that the narrow NEDC test conditions explain only a small part of the elevated on-road NOX emissions of diesel cars. For seven Euro 4–6 diesel cars, we filter from on-road driving those events that match the NEDC conditions in instantaneous speed, acceleration, CO2 emissions, and ambient temperature. The resulting on-road NOX emissions exceed by 206% (median) those measured on the NEDC, whereas the NOX emissions of all unfiltered on-road measurements exceed the NEDC emissions by 266% (median). Moreover, when applying the same filtering of on-road data to two other driving cycles (WLTP and CADC), the resulting on-road NOX emissions exceed by only 13% (median) those measured over the respective cycles. This result demonstrates that our filtering method is accurate and robust. If neither the low dynamics nor the limited temperature range of NEDC testing can explain the elevated NOX emissions of diesel cars, emissions control strategies used during NEDC testing must be inactive or modulated on the road, even if vehicles are driven under certification-like conditions. This points to defeat strategies that warrant further investigations by type-approval authorities and, in turn, limitations in the enforcement of the European vehicle emissions legislation by EU Member States. We suggest applying our method as a simple yet effective tool to screen and select vehicles for in-depth analysis by the competent certification authorities.
Show more [+] Less [-]Statistical polarization in greenhouse gas emissions: Theory and evidence
2017
Remuzgo, Lorena | Trueba, Carmen
The current debate on climate change is over whether global warming can be limited in order to lessen its impacts. In this sense, evidence of a decrease in the statistical polarization in greenhouse gas (GHG) emissions could encourage countries to establish a stronger multilateral climate change agreement. Based on the interregional and intraregional components of the multivariate generalised entropy measures (Maasoumi, 1986), Gigliarano and Mosler (2009) proposed to study the statistical polarization concept from a multivariate view. In this paper, we apply this approach to study the evolution of such phenomenon in the global distribution of the main GHGs. The empirical analysis has been carried out for the time period 1990–2011, considering an endogenous grouping of countries (Aghevli and Mehran, 1981; Davies and Shorrocks, 1989). Most of the statistical polarization indices showed a slightly increasing pattern that was similar regardless of the number of groups considered. Finally, some policy implications are commented.
Show more [+] Less [-]Modelling carbon dioxide emissions from agricultural soils in Canada
2017
Yadav, Dhananjay | Wang, Junye
Agricultural soils are a leading source of atmospheric greenhouse gas (GHG) emissions and are major contributors to global climate change. Carbon dioxide (CO2) makes up 20% of the total GHG emitted from agricultural soil. Therefore, an evaluation of CO2 emissions from agricultural soil is necessary in order to make mitigation strategies for environmental efficiency and economic planning possible. However, quantification of CO2 emissions through experimental methods is constrained due to the large time and labour requirements for analysis. Therefore, a modelling approach is needed to achieve this objective. In this paper, the DeNitrification-DeComposition (DNDC), a process-based model, was modified to predict CO2 emissions for Canada from regional conditions. The modified DNDC model was applied at three experimental sites in the province of Saskatchewan. The results indicate that the simulations of the modified DNDC model are in good agreement with observations. The agricultural management of fertilization and irrigation were evaluated using scenario analysis. The simulated total annual CO2 flux changed on average by ±13% and ±1% following a ±50% variance of the total amount of N applied by fertilising and the total amount of water through irrigation applications, respectively. Therefore, careful management of irrigation and applications of fertiliser can help to reduce CO2 emissions from the agricultural sector.
Show more [+] Less [-]Greenhouse gas emission accounting at urban level: A case study of the city of Wroclaw (Poland)
2017
Sówka, Izabela | Bezyk, Yaroslav
The paper analyses the building process of a GHG emissions inventory, which would likely enable more strongly cities to manage their efforts and set realistic targets for emission reduction. The work includes the determination of GHG emission estimation tools and approaches used for estimation of key sources of these emissions at the local level. The actual task is the determination of major GHG emitting sectors including the key characteristics of these emissions sources at the local level, establishing targets for emissions reductions at Wroclaw urban area, Poland. The sectoral GHG emission trends in the selected urban area including a comparison of carbon dioxide (CO2) emission level with national inventory data are presented. The total GHG emissions from Wroclaw municipality in 2013 were 7.2 percent lower than those in 1990. Energy consumption is a major contributor of emissions responsible for 63% of citywide CO2 through the consumption of electricity and district and individual heating using coal and natural gas energy sources. The proposed data structure is connected in an informative Sankey diagram for all anthropogenic GHG emissions occurred in Wroclaw municipality in 2013. In order to determine the City progress towards urban carbon neutrality, reducing emissions 25% by 2020 and 80% by 2050, as well as the future risks and impacts of GHG emissions on climate change the ‘business as usual’ final energy consumption and emission scenarios are provided.
Show more [+] Less [-]Reduction of CO2 emissions with automatic mooring systems. The case of the port of Santander
2017
Ortega Piris, Andrés | Díaz-Ruiz-Navamuel, Emma | Pérez-Labajos, Carlos A. | Oria Chaveli, Jesús
The revolutions in the maritime industry resulting from the implementation of integrated transport systems (bulk) and containerization (regular lines) at first had little effect on traditional mooring systems for ships in port. However, the research into innovation in automated mooring systems with increasingly advanced technologies carried on regardless.The so-called “Automatic Mooring Systems” (AMS), automatic systems that allow vessels to be moored without ropes, are being increasingly implemented in numerous ports in many different countries in the world, particularly in those whose traffic volumes have allowed the threshold of profitability of these infrastructures to be reached. But besides the financial benefits, the implantation of the AMS is having positive effects on the environment by reducing CO2 emissions in many commercial ports.The present work aims to measure for the first time the reduction in the CO2 emissions of merchant vessels as a consequence of the substitution of traditional mooring systems with the new automatic systems, continuing along the lines of previous works in the field of the reduction in CO2 emissions in ports.The estimation is made by applying the EPA and ENTEC “bottom-up” methodologies to the traffic in the port of Santander (Spain) in the year 2014.The implementation of the AMS, when compared to the traditional mooring systems, leads to a reduction in CO2 emissions of 76.78% calculated using the EPA method and 76.63% using the ENTEC method. Hence, the Port Authorities in their long-term planning decisions should promote the introduction of automatic mooring systems wherever the profitability thresholds of traffic allow it, as this will lead to significant environmental benefits by substantially reducing CO2 emissions during the maneuvers of merchant ships in maritime commercial ports.
Show more [+] Less [-]Diurnal variation of CO2, CH4, and N2O emission fluxes continuously monitored in-situ in three environmental habitats in a subtropical estuarine wetland
2017
Yang, Wen-Bin | Yuan, Chung-Shin | Tong, Chuan | Yang, Bin | Yang, Lei | Huang, Bang-Qin
Wetlands play a crucial role in modulating atmospheric concentrations of greenhouse gases (GHGs) such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The key factors controlling GHG emission from subtropical estuarine wetlands were investigated in this study, which continuously monitored the uptake/emission of GHGs (CO2, CH4, and N2O) by/from a subtropical estuarine wetland located in the Minjiang estuary in the coastal region of southeastern China. A self-designed floating chamber was used to collect air samples on-site at three environmental habitats (Phragmites australis marsh, mudflats, and river water). The CO2, CH4, and N2O concentrations were then measured using an automated nondispersive infrared analyzer. The magnitudes of the CO2 and N2O emission fluxes at the three habitats were ordered as river water>P. australis>mudflats. P. australis emitted GHGs through photosynthesis and respiration processes. Emissions of CH4 from P. australis and the mudflats were revealed to be slightly higher than those from the river water. The total GHG emission fluxes at the three environmental habitats were quite similar (4.68–4.78gm−2h−1). However, when the total carbon dioxide equivalent fluxes (CO2-e) were considered, the river water was discovered to emit the most CO2-e compared with P. australis and the mudflats. Based on its potential to increase global warming, N2O was the main contributor to the total GHG emission, with that emitted from the river water being the most considerable. Tidal water carried onto the marsh had its own GHG content and thus has acted as a source or sink of GHGs. However, water quality had a large effect on GHG emissions from the river water whereas the tidal water height did not. Both high salinity and large amounts of sulfates in the wetlands explicitly inhibited the activity of CH4-producing bacteria, particularly at nighttime.
Show more [+] Less [-]Long-term trend analysis of CO in the Yongsan district of Seoul, Korea, between the years 1987 and 2013
2017
ʻAẓmatullah K̲h̲ān̲, | Szulejko, Jan E. | Bae, M.-S. | Shon, Zang Ho | Sohn, Jong-Ryeul | Seo, J.W. | Jeon, E.-C. | Kim, Ki Hyun
In this study, the long-term trend in atmospheric carbon monoxide (CO) concentration was analyzed using the CO levels measured (intermittently) at an air quality monitoring (AQM) station in Seoul, Korea, between the years 1987 and 2013. Temporal trends in CO were analyzed on an annual and seasonal basis in reference to other important air pollutants such as methane (CH4), particulate matter (PM10), sulfur dioxide (SO2), nitrogen monoxide (NO), nitrogen dioxide (NO2), mercury (Hg), and ozone (O3). The annual mean of CO for the entire period was 0.93 ± 0.22 ppm. CO levels were reduced by 83% from 3.25 ± 0.78 ppm (1987) to 0.51 ± 0.31 ppm (2013). Its relative reduction was compared over three periods chosen arbitrarily as period 1 (fast reduction, 1987–1988), period 2 (intermediate reduction, 1999–2000), and period 3 (slow reduction, 2004–2013). The concentrations of CO were strongly correlated with others (e.g., SO2, NO, NO2, O3, and Hg), suggesting the effects of similar source processes (e.g., fuel combustion). The reduction in its level was marginally consistent with the decreasing trend in the total CO column concentration in Seoul by the Measurements of Pollution in the Troposphere (MOPITT) satellite between 2000 and 2013, indicating decreasing anthropogenic CO emissions (despite increasing anthropogenic CO2 emissions). The rapid relative reduction of CO in period 1 and the subsequent slower but moderate reduction thereafter appear to reflect the effects of both enforcement of administrative regulations and advances in emissions control technologies.
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