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I examine the effects of the U.S. Greenhouse Gas (GHG) Reporting Program, which requires thousands of industrial facilities to measure and report their GHG emissions. I show that facilities reduce their GHG emissions by 7.9% following the disclosure of emissions data. The evidence indicates that benchmarking—whereby facilities use the disclosures of their peers to assess their own relative GHG performance—spurs emission reductions. Firms' concerns about future legislation appear to motivate this behavior and measurement alone (without disclosure) seems not to reduce emissions. My study highlights how mandatory GHG disclosure can create real effects for peers. [ABSTRACT FROM AUTHOR]

Carbon dioxide is the most important greenhouse gas contributing to global warming. To help mitigate increasing CO2 concentrations, we investigate a method of carbon dioxide reduction using high-power electron beams, which can be used on an industrial scale. A series of experiments are conducted in which the reduction of CO2 is measured for different gas compositions and power deposition rates. An electron beam deposition model is applied to compute reduction rates of CO2 and energy cost for breaking a CO2 molecule in flue gas and pure carbon dioxide at atmospheric pressure. For flue gas consisting of 82% N2, 6% O2, and 12% CO2, the calculated energy cost is 85 eV per molecule. In order to dissociate 50% of the CO2 molecules, beam energy density deposition on the order of 20 J/cm³ is required. Electron beam irradiation of 12.6 liter gas volume containing 90% CO2 and 10% CH4 at beam energy density deposition of 4.2 J/cm³, accumulated over 43 shots in a 20 min interval, reduced the CO2 concentration to 78%. Analogous experiments with a gas mixture containing 11.5% CO2, 11.5% CH4, and balance of Ar, reduced the CO2 concentration to below 11% with energy deposition 0.71 J/cm³, accumulated over 10 shots in a 5 min interval. The experimental data and the theoretical predictions of CO2 reduction using pulsed electron beams are in agreement within the experimental error. Other techniques to enhance the removal of CO2 with pulsed electron beams are also explored, yielding new possible avenues of research. [ABSTRACT FROM AUTHOR]

On 29 October 2018 at 13:08 Japanese Standard Time was successfully launched the Greenhouse gas Observing SATellite (GOSAT-2) from the JAXA Tanegashima Space Center. Piggypack with the GOSAT-2 satellite in a circular (623 km), polar synchronous orbit was launched the 22 kilogram mass satellite Ten-Koh (http://kit-okuyama-lab.com/en/ten-koh/), developed in Kyushu Institute of Technology by Prof. K. Okuyama, Chief Scientist of the Spacecraft. Ten-Koh satellite is observing low Earth environment (LEO). The primary purpose is to provide valuable data for future development of satellites or operation. Ten-Koh's primary science instrument is the Charged Particle Detector (CPD) developed at the Prairie View A&M University, and NASA Johnson's Space Center of Houston, TX, USA. Principal Scientist of this payload is Prof. P. Saganti (https://www.pvamu.edu/raise/space-payload/charged-particle-detector-2018/). Principal Engineer of the CPD project is S. D. Holland (formerly with NASA-JSC and currently with Holland-Space LLC, Houston, TX, USA). IKIT-BAS received a request from Prof. Saganti to develop a Liulin type instrument to be part of the CPD payload. Scientists from IKTI's Solar-Terrestrial Physics Department have developed and handed three units per the request (engineering, flight, and operational models) of the instrument named "Liulin Ten-Koh". These instruments are similar to the RADOM instrument, which worked in 2008-2009 on the Indian moon satellite Chadrayaan-1 [12]. This paper describes the flight model, "Liulin Ten-Koh Saganti" instrument and the standard sources radiation tests, which were performed during the calibrations in the laboratory of IKIT-BAS. As of this writing, Ten-Koh spacecraft is making polar orbit passes as expected at about 623 km altitude and at 98 degree inclination with very healthy telemetry data as received by several ground stations across the world. The first received data from "Liulin Ten-Koh Saganti" instrument of the Ten-Koh spacecraft are presented. The available at this moment galactic cosmic rays (GCR) L-value profiles of the dose rate and the dose to flux ratio (D/F) from 11 December 2018 are compared with the R3DE profile at ISS. In addition, the integral "Liulin Ten-Koh Saganti" instrument LET spectrum from 11 December 2018 is compared with spectra from other instruments, measured in and out of the Earth magnetosphere. [ABSTRACT FROM AUTHOR]

The competitive and cooperative reactions between the intramolecular primary and secondary amino groups in CO 2 absorption have been investigated in this work. N -Methylethylenediamine (MEDA) and N -methylpropane-1,3-diamine (MAPA) were studied with various CO 2 loadings at 25 °C. The 13 C NMR technology was employed to obtain accurate 13 C peak areas and chemical shifts for determining the concentration of each species in both of the diamine-CO 2 H 2 O systems. The results showed that the relative amounts of the species is primary-carbamate >> secondary-carbamate >  di-carbamate in the CO 2 absorption process. Moreover, the relative hydrolysis order of the carbamates is di-carbamate > secondary-carbamate > primary-carbamate. The competitive and cooperative reaction mechanism was then proposed based on these results. Finally, it was found that in both the MEDA and the MAPA ternary systems, the whole CO 2 absorption process can be divided into three stages: competitive stage, buffer stage and hydrolysis stage, each of which showed a different trend in the amount of each species as well as in the pH value. [ABSTRACT FROM AUTHOR]

Due to the increasing global warming in the world, analyzing greenhouse gas emissions is a crucial issue. This study has examined greenhouse gas emissions in Turkey according to energy sector, industrial processes sector, agriculture sector and waste sector. Then, time series analysis models are used to estimate greenhouse gas emissions based on sectors. Models' performances are tested using mean error, mean absolute error and root mean square error. The results show that forecasting models have a good potential to estimate the national greenhouse gas emissions for different sector within a reasonable error. The study results will help organize and estimate the national greenhouse gas emissions inventory. [ABSTRACT FROM PUBLISHER]

Carbon dioxide (CO 2 ) enhanced oil recovery (EOR) will likely be the primary means of geologic CO 2 storage during the early stages of commercial-scale carbon capture and storage (CCS) because of the inherent economic incentives as well as the abundant experience and demonstrated success in the United States, where CO 2 EOR has been employed since 1974. The work presented here estimates CO 2 storage efficiency factors in CO 2 EOR operations using a unique industry database of CO 2 EOR sites and 12 different reservoir simulation models. The simulation models encompass fluvial clastic and shallow shelf carbonate depositional environments for reservoir depths of 1219 and 2438 m (4000 and 8000 feet) and 7.6-, 20-, and 64-m (25-, 66-, and 209-foot)-thick pay zones. A novel statistical modeling technique incorporating the Michaelis–Menten function is used to generate empirical percentile estimates of CO 2 storage efficiency factors. West Texas San Andres dolomite water alternating gas (WAG) CO 2 flood performance data were used to derive P10, P50, and P90 CO 2 storage efficiency factors of 0.76, 1.28, and 1.74 Mscf/STB (stock tank barrel) of original oil in place. Median CO 2 storage efficiency factors from continuous CO 2 injection following conventional waterflood varied from 15% to 61% and 8% to 40% for fluvial clastic and shallow shelf carbonate simulation models, respectively, while those from WAG injection varied from 14% to 42% and 8% to 31%, respectively. Variation in the CO 2 storage efficiency factors was largely attributable to reservoir depth (a surrogate for reservoir pressure and temperature) and lithology (clastic versus carbonate). The results of this work provide practical information that can be used to quantify CO 2 storage resource estimates in oil reservoirs during CO 2 EOR operations (as opposed to storage following depletion) and the uncertainty associated with those estimates. [ABSTRACT FROM AUTHOR]

There are a number atmospheric gases, in addition to carbon dioxide (CO2), that affect the absorption and emission of infrared radiation throughout the atmosphere, the so-called 'non-CO2 greenhouse gases', and they have a significant impact on climate. In addition, some of these non-CO2 greenhouse gases contain chlorine and/or bromine, and contribute to halogen-catalysed stratospheric ozone depletion. In the mid 1970s, CSIRO at Aspendale became the first southern hemisphere laboratory to initiate research into the atmospheric abundance, trends, sources and sinks of non-CO2 greenhouse gases, and today (2017) is currently observing and modelling the past and present biogeochemical cycling of over eighty of these species, arguably the most comprehensive program of its type globally. The resultant CSIRO data are used to derive global and regional emissions of non-CO2 greenhouse gases and their impact on climate and stratospheric ozone via resultant changes to the planetary radiative budget and the abundance of 'equivalent chlorine' (weighted sum of chlorine and bromine) in the stratosphere. These data and their impacts are reported nationally to relevant Commonwealth and State Departments--environment, energy, industry, agriculture-- and to relevant Australian industries--refrigeration, air-conditioning, aluminium production. They are reported internationally to United Nations agencies responsible for implementing the Vienna Convention for the Protection of the Ozone Layer (1985) and the Framework Convention on Climate Change (1992), who periodically assess the science of climate change and ozone depletion. As the world strives to reduce its greenhouse gas emissions through national, policy-driven, initiatives framed to meet agreed obligations under these international agreements, atmospheric measurement programs, such as those operated by the CSIRO and the Bureau of Meteorology in Australia, are critical in independently verifying the success or otherwise of such endeavours. This paper describes the initial fifteen years (1975-90) of activities in CSIRO that set up the framework for the current, globally significant, CSIRO non-CO2 greenhouse gas research program. [ABSTRACT FROM AUTHOR]

The Greenhouse Gases Observing Satellite (GOSAT) was launched in 2009 to measure global atmospheric CO2 and CH4 concentrations. GOSAT is equipped with two sensors: the thermal and near-infrared sensor for carbon observation (TANSO)-Fourier transform spectrometer (FTS) and TANSO-cloud and aerosol imager (CAI). The presence of clouds in the instantaneous field of view of the FTS leads to incorrect estimates of the concentrations. Thus, the FTS data suspected to have cloud contamination must be identified by a CAI cloud discrimination algorithm and rejected. Conversely, overestimating clouds reduces the amount of FTS data that can be used to estimate greenhouse gases concentrations. This is a serious problem in tropical rainforest regions, such as the Amazon, where the amount of useable FTS data is small because of cloud cover. Preparations are continuing for the launch of the GOSAT-2 in fiscal year 2018. To improve the accuracy of the estimates of greenhouse gases concentrations, we need to refine the existing CAI cloud discrimination algorithm: Cloud and Aerosol Unbiased Decision Intellectual Algorithm (CLAUDIA1). A new cloud discrimination algorithm using a support vector machine (CLAUDIA3) was developed and presented in another paper. Visual inspection can use the locally optimized standards for judging, although CLAUDIA1 and CLAUDIA3 use common thresholds all over the world. Thus, the accuracy of visual inspection is better than that of these algorithms in most regions, with the exception of snow and ice covered surfaces, where there is not enough spectral contrast to distinguish cloud. For the reason visual inspection can be used for the truth metric for the verification exercise. In this study, we compared between CLAUDIA1-CAI and CLAUDIA3-CAI for various land cover types, and evaluated the accuracy of CLAUDIA3-CAI by comparing the both of CLAUDIA1-CAI and CLAUDIA3-CAI against visual inspection of the same CAI images in tropical rainforests. Comparative results between CLAUDIA1-CAI and CLAUDIA3-CAI for various land cover types indicated that CLAUDIA3-CAI had tendency to identify bright surface and optically thin clouds, however, misjudge the edges of clouds as compared with CLAUDIA1-CAI. The accuracy of CLAUDIA3-CAI was approximately 89.5 % in tropical rainforests, which is greater than that of CLAUDIA1-CAI (85.9 %) for the test cases presented here. [ABSTRACT FROM AUTHOR]

The long-term goal of containing average warming below the 2 °C limit requires deep cuts in emissions from all sectors. The fast growing global aviation industry has committed to reduce carbon emissions. Carbon offsetting is an integral element of the sector's strategy. Already, airlines offer voluntary carbon offsetting to those customers who wish to mitigate the impact of their travel. To ensure carbon offsetting can make a meaningful and credible contribution, this paper first discusses the science behind ‘carbon offsetting’, followed by the associated policy perspective. Then, against the context of different aviation emissions pathways, the paper provides empirical evidence of current airline practices in relation to offsetting mechanisms and communication. Building on these insights, the challenges of reducing aviation emissions and using carbon credits to compensate for ongoing growth are discussed. The paper concludes by proposing five principles of best practice for carbon offsetting that airlines can use as a basis to develop credible emissions strategies, and that could inform the sectoral framework currently being developed by leading aviation organisations. [ABSTRACT FROM AUTHOR]

A ground-based high-resolution Fourier transform spectrometer (FTS) station has been established in Hefei, China to remotely measure CO2, CO and other greenhouse gases based on near-infrared solar absorption spectra. Total column measurements of atmospheric CO2 and CO were successfully obtained from July 2014 to April 2016. The spectra collected with an InSb detector in the first year were compared with those collected by an InGaAs detector from July 2015, demonstrating that InGaAs spectra have better signal-to-noise ratios and rms of spectral fitting residuals relative to InSb spectra. Consequently, the measurement precision of the retrieved XCO2 and XCO for InGaAs spectra is superior to InSb spectra, with about 0.04 and 0.09% for XCO2, and 1.07 and 2.00% for XCO within clear-sky days respectively. Daily and monthly averages of columnaveraged dry air mole fraction of CO2 show a clear seasonal cycle, while the daily and monthly averages of XCO displayed no seasonal variation. Also, we analysed the relationship of the anomalies of XCO and XCO2, found that the correlations are only observable for individual days, and the data under different prevailing wind conditions during the observations displayed weak correlation. The observations based on the high-resolution FTS were also compared with the temporally coinciding measurements taken with a low-resolution solar FTS instrument, the EM27/SUN. Ratioing the daily averaged XCO2 of EM27 and FTS gives an overall calibration factor of 0.996±0.001. We also compared ground-based observations from the Tsukuba TCCON station with our observations, the results showing that the variation in phase and seasonal amplitude of XCO2 are similar to our results, but the variation of XCO in Tsukuba is quite different from our data in Hefei. To further evaluate our retrieved data, we made use of satellite measurements. The direct comparison of our observations with the Greenhouse Gases Observing Satellite (GOSAT) data shows good agreement of daily median XCO2, with a bias of -0.52 ppm and standard deviation of 1.63 ppm. The correlation coefficient (R²) is 0.79 for daily median XCO2 between our FTS and GOSAT observations. Daily median Orbiting Carbon Observatory 2 (OCO-2) data produce a positive bias of 0.81 ppm and standard deviation of 1.73 ppm relative to our ground-based data. Our daily median XCO2 also show strong correlation with OCO-2 data, with correlation coefficient (R²) of 0.83. Although there were a limited number of data during the observations due to instrument downtime and adverse weather, the results confirm the suitability of the observatory for ground-based long-term measurements of greenhouse gases with high precision and accuracy, and fulfil the requirements of the Total Carbon Column Observing Network (TCCON). [ABSTRACT FROM AUTHOR]

Inclusion of nitrate (NO3-) in ruminant diets is a means of increasing non-protein nitrogen intake while at the same time reducing emissions of enteric methane (CH4) and, in Australia, gaining carbon credits. Rumen microorganisms contain intracellular enzymes that use hydrogen (H2) released during fermentation to reduce NO3- to nitrite (NO2), and then reduce the resulting NO2- to ammonia or gaseous intermediates such as nitrous oxide (N2O) and nitric oxide (NO). This diversion of H2 reduces CH4 formation in the rumen. If NO2- accumulates in the rumen, it may inhibit growth of methanogens and other microorganisms and this may further reduce CH4 production, but also lower feed digestibility. If NO2- is absorbed and enters red blood cells, methaemoglobin is formed and this lowers the oxygen-carrying capacity of the blood. Nitric oxide produced from absorbed NO2- reduces blood pressure, which, together with the effects of methaemoglobin, can, at times, lead to extreme hypoxia and death. Nitric oxide, which can be formed in the gut as well as in tissues, has a variety of physiological effects, e.g. it reduces primary rumen contractions and slows passage of digesta, potentially limiting feed intake. It is important to find management strategies that minimise the accumulation of NO2-: these include slowing the rate of presentation of NO3- to rumen microbes or increasing the rate of removal of NO2-, or both. The rate of reduction of NO3- to NO2- depends on the level of NO3- in feed and its ingestion rate, which is related to the animal's feeding behaviour. After NO3- is ingested, its peak concentration in the rumen depends on its rate of solubilisation. Once in solution, NO3- is imported by bacteria and protozoa and quickly reduced to NO2-. One management option is to encapsulate the NO3- supplement to lower its solubility. Acclimating animals to NO3- is an established management strategy that appears to limit NO2- accumulation in the rumen by increasing microbial nitrite reductase activity more than nitrate reductase activity; however, it does not guarantee complete protection from NO2- poisoning. Adding concentrates into nitrate-containing diets also helps reduce the risk of poisoning and inclusion of microbial cultures with enhanced NO2--reducing properties is another potential management option. A further possibility is to inhibit NO2- absorption. Animals differ in their tolerance to NO3- supplementation, so there may be opportunities for breeding animals more tolerant of dietary NO3-. Our review aims to integrate current knowledge of microbial processes responsible for accumulation of NO2- in rumen fluid and to identify management options that could minimise the risks of NO2- poisoning while reducing methane emissions and maintaining or enhancing livestock production. [ABSTRACT FROM AUTHOR]

Understanding feedback responses of greenhouse gas (GHG) emissions to future climate projections is critical for the effective development of mitigation and adaptation strategies. It is proposed that effects of elevated carbon dioxide (CO 2 ) and temperature can have differential effects on GHG fluxes but the magnitude and direction of such impact is not fully known, especially in dryland ecosystems, which are typically water and nutrient limited. We examined individual and interactive impacts of elevated CO 2 (400 ppm vs. 600 ppm) and elevated temperature (ambient vs. +3 °C increase) treatments on GHG fluxes, in three Australian dryland soils. Firstly, we quantified the individual and interactive effects of elevated CO 2 and temperature on CO 2 , methane (CH 4 ) and nitrous oxide (N 2 O) fluxes and the corresponding soil net global warming potential (GWP). Secondly, biotic and abiotic drivers of GHG emissions were identified by exploring the relationship between CO 2 , CH 4 and N 2 O fluxes with the abundance of bacteria, methanotrophs and N 2 O-reducing bacteria as well as soil abiotic characteristics. Our results show that soil CO 2 emissions and CH 4 uptake respond mainly to elevated temperature in all dryland soils tested, with interactive treatment effects showing a less than additive trend on soil net GWP. Nitrous oxide emissions responded less to climate change treatments, and these were site-specific. Soil site characteristics were the main determinant of all GHG emissions; however, the abundance of total bacteria and N 2 O-reducing bacteria significantly explained CO 2 and N 2 O fluxes, respectively. This study shows that dryland soils respond to climate change with an offset under interactive climate treatments. Our findings suggest that future studies on GHG feedback responses should explicitly consider both biotic and abiotic soil characteristics in order to provide a better mechanistic understanding for the development of future mitigation strategies. [ABSTRACT FROM AUTHOR]

There is growing international concern about the increasing levels of greenhouse gases in the atmosphere, particularly CO2and methane. The emissions of methane derived from human activities are associated with large flows and very low concentrations, such as those emitted from landfills and wastewater treatment plants, among others. The present work was focused on the biological methane degradation at diffuse concentrations (0.2% vv−1) in a conventional biofilter using a mixture of compost, perlite and bark chips as carrier. An extensive characterization of the process was carried out at long-term operation (250 days) in a fully monitored pilot plant, achieving stable conditions during the entire period. Operational parameters such as waterings, nitrogen addition and inlet loads and contact time influences were evaluated. Obtained results indicate that empty bed residence times within 4–8 min are crucial to maximize elimination rates. Waterings and the type of nitrogen supplied in the nutrient solution (ammonia or nitrate) have a strong impact on the biofilter performance. The better results compatible with a stable operation were achieved using nitrate, with elimination capacities up to 7.6 ± 1.1 g CH4 m−3 h−1. The operation at low inlet concentrations (IC) implied that removal rates obtained were quite limited (ranging 3–8 g CH4 m−3 h−1); however, these results could be significantly increased (up to 20.6 g CH4 m−3 h−1) at higher IC, which indicates that the mass transfer from the gas to the liquid layer surrounding the biofilm is a key limitation of the process. [ABSTRACT FROM PUBLISHER]

RATIONALE: The isotopic composition of greenhouse gases helps to constrain global budgets and to study sink and source processes. We present a new system for high-precision stable isotope measurements of carbon, hydrogen and oxygen in atmospheric methane and carbon dioxide. The design is intended for analyzing flask air samples from existing sampling programs without the need for extra sample air for methane analysis. METHODS: CO2 and CH4 isotopes are measured simultaneously using two isotope ratio mass spectrometers, one for the analysis of δ13C and δ18O values and the second one for δ²H values. The inlet carousel delivers air from 16 sample positions (glass flasks 1-5 L and high-pressure cylinders). Three 10-port valves take aliquots from the sample stream. CH4 from 100-mL air aliquots is preconcentrated in 0.8-mL sample loops using a new cryo-trap system. A precisely calibrated working reference air is used in parallel with the sample according to the Principle of Identical Treatment. RESULTS: It takes about 36 hours for a fully calibrated analysis of a complete carousel including extractions of four working reference and one quality control reference air. Long-term precision values, as obtained from the quality control reference gas since 2012, account for 0.04‰ (δ13C values of CO2), 0.07‰ (δ18O values of CO2), 0.11‰ (δ13C values of CH4) and 1.0‰ (δ²H values of CH4). Within a single day, the system exhibits a typical methane δ13C standard deviation (1σ) of 0.06‰ for 10 repeated measurements. CONCLUSIONS: The system has been in routine operation at the MPI-BGC since 2012. Consistency of the data and compatibility with results from other laboratories at a high precision level are of utmost importance. A high sample throughput and reliability of operation are important achievements of the presented system to cope with the large number of air samples to be analyzed. [ABSTRACT FROM AUTHOR]

Warm mix asphalt (WMA) describes various technologies that allow asphalt mixtures to be produced at lower temperatures as compared with hot mix asphalt (HMA). WMA technologies also offer improvements in workability, cost, and environmental sustainability, such as reduced fuel usage, greenhouse gas emissions, and wear and tear at plants, while enhancing worker health and safety conditions. The objective of this study was to quantify the laboratory performance of field-produced mixtures that utilize WMA technologies and to evaluate the influence of lowering the production temperature on the mixture properties in the field. To achieve this objective, three field projects across Louisiana were selected to provide eight mixtures for the evaluation of WMA technologies. Plant-produced mixtures were sampled and the laboratory performance of WMA mixtures and conventional HMAwas evaluated. Further, the characteristics of WMA mixtures were compared with conventional HMA mixtures during production and construction. Based on the results of the experimental program, it was concluded that there was no difference in the rutting performance of WMA compared with HMA. In addition, the use of WMA technologies improved asphalt mixture fracture resistance. With respect to moisture susceptibility, the tensile strength ratio (TSR) of the WMA mixtures was comparable to the conventional HMA in two projects; however, it was lower than the TSR criterion of 80% in the third project. During production, while the moisture content in WMA was slightly higher than the conventional mixtures, both mixture types met Louisiana's specifications (with moisture content less than 0.3%). Further, asphalt absorption was not statistically different between HMA and WMA. During paving, the temperature of the mat was distinctly lower for WMA than for HMA.With respect to the compaction effort, there seemed to be no discernible difference in the compaction effort required for HMA and WMA. In addition, the WMA mixtures were able to meet the minimum specification requirement of 92% density in most of the cases. [ABSTRACT FROM AUTHOR]

Switchgrass-derived ethanol has been proposed as an alternative to fossil fuels to improve sustainability of the US energy sector. In this study, life cycle analysis ( LCA) was used to estimate the environmental benefits of this fuel. To better define the LCA environmental impacts associated with fertilization rates and farm-landscape topography, results from a controlled experiment were analyzed. Data from switchgrass plots planted in 2008, consistently managed with three nitrogen rates (0, 56, and 112 kg N ha−1), two landscape positions (shoulder and footslope), and harvested annually (starting in 2009, the year after planting) through 2014 were used as input into the Greenhouse gases, Regulated Emissions and Energy use in transportation ( GREET) model. Simulations determined nitrogen (N) rate and landscape impacts on the life cycle energy and emissions from switchgrass ethanol used in a passenger car as ethanol-gasoline blends (10% ethanol:E10, 85% ethanol:E85s). Results indicated that E85s may lead to lower fossil fuels use (58 to 77%), greenhouse gas ( GHG) emissions (33 to 82%), and particulate matter ( PM2.5) emissions (15 to 54%) in comparison with gasoline. However, volatile organic compounds ( VOCs) and other criteria pollutants such as nitrogen oxides ( NOx), particulate matter ( PM10), and sulfur dioxides ( SOx) were higher for E85s than those from gasoline. Nitrogen rate above 56 kg N ha−1 yielded no increased biomass production benefits; but did increase (up to twofold) GHG, VOCs, and criteria pollutants. Lower blend (E10) results were closely similar to those from gasoline. The landscape topography also influenced life cycle impacts. Biomass grown at the footslope of fertilized plots led to higher switchgrass biomass yield, lower GHG, VOCs, and criteria pollutants in comparison with those at the shoulder position. Results also showed that replacing switchgrass before maximum stand life (10-20 years.) can further reduce the energy and emissions reduction benefits. [ABSTRACT FROM AUTHOR]

The paper considers the status and trends of greenhouse gas (GHG) emissions from Metallurgical and Mining Industry in Ukraine to fulfill target of the United Nations' Framework Convention on Climate Change (UNFCCC) and to mitigate climate change (CC). The paper collected current status in Ukraine to dynamics of GHG emissions from metallurgical and mining industry based on data of National GHG inventories. [ABSTRACT FROM AUTHOR]

N2O, CO2, and CH4 are important greenhouse gases (GHGs) in paddy fields, and rice plants play an important role in GHG emissions in paddy fields. However, the relationship between light and rice plant GHG emissions is unclear. In this study, we monitored N2O, CO2, and CH4 emissions of mature aging rice under different light qualities and intensities. The results showed that (i) under natural sunlight, the rice phyllosphere N2O emission rate was 22.94 μg pot-1 h-1, accounting for 60% of the whole rice plant total N2O-N evaporation loss. The CO2 emission rates from the phyllosphere and the root system were 27.82 mg pot-1 h-1 and 8.02 mg pot-1 h-1, respectively. However, no CH4 net emission effects were observed. (ii) Under a constant LED monocolor light intensity (1600 Lux), red, blue, and white light can inhibit N2O and CO2 emissions from the rice phyllosphere, resulting in lower emissions than yellow light. White light can also inhibit N2O and CO2 emissions from rice roots. (iii) Within the range of 0-6000 Lux, increases in light intensity can reduce rice phyllosphere CO2 emissions, but such increases also promote N2O emissions from the rice phyllosphere and the roots. In contrast, natural sunlight can promote rice phyllosphere N2O and CO2 emissions and can inhibit root N2O emissions. The measure of light control may be the key to low-carbon technology for GHG emission reductions in mature paddy ecosystems. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

In Northern China, vegetables are usually grown in solar greenhouses using intensive fertilization and cultivation, which produces significant greenhouse gas (GHG) emissions to the atmosphere. In this study, the nitrous oxide (N2O) emissions from 12 solar greenhouses with different fertilization practices (without manure application (SG); with chicken (SG-CM) or swine (SG-SM) manure application) were measured in the southern Loess Plateau of China during the summer fallow (35-61 days) in 2013 and 2014. The daily N2O fluxes varied over the ranges of 0.002-0.041, 0.014-12.58, and 0.005-8.41 mg N m−2 h−1 with averages of 0.037, 0.81, and 1.70 mg N m−2 h−1 in the SG, SG-CM, and SG-SM greenhouses, respectively, and the total N2O emissions were 1.17, 12.0, and 16.0 kg N ha−1, respectively. Significantly high peak N2O emissions were observed at the beginning of the summer fallow and after manure application, accounting for more than 80% of the total N2O emissions. The management practices of polythene removal, greenhouse enclosure for a week, and tillage also significantly increased the N2O daily fluxes and total emissions. Linear regression analyses showed that soil moisture and manure application were the main factors controlling the N2O emissions during summer fallow, followed by the residual mineral N in the soil. The results indicated that solar greenhouses cause high N2O emissions during summer fallow and farmers should use appropriate measures to mitigate these emissions. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

An upscaling method such as renormalization converts a detailed geological model to a coarse one. Although flow equations can be solved faster on a coarse model, its results have more errors. Numerical dispersion, heterogeneity loss, and connectivity misrepresentation are the factors responsible for errors. Connectivity has a great effect on the fluid distribution and leakage pathways in EOR processes or CO2 storage. This paper deals with the description and quantification of connectivity misrepresentation in the upscaling process. For detection of high-flow regions, the flow equations are solved under simplified single-phase conditions. These regions are recognized as the cells whose fluxes are greater than a cut-off. The connectivity is investigated by checking whether the high-flux region forms a spanning cluster across the model. An indicator called the flux connectivity distortion is defined to measure the connectivity misrepresentation of coarse grids. This indicator is shown to have a strong correlation with the oil saturation error. For renormalization method, this relation helps to propose an upper limit of coarsening beyond which the coarse model results are not reliable. Once the proper sizes of coarse blocks are determined, flow behavior can be simulated accurately in a project of CO2-EOR or CO2 sequestration. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Purpose: Australia is the largest supplier of high-quality wool in the world. The environmental burden of sheep production must be shared between wool and meat. We examine different methods to handle these co-products and focus on proportional protein content as a basis for allocation, that is, protein mass allocation (PMA). This is the first comprehensive investigation applying PMA for calculating greenhouse gas (GHG) emissions for Australian sheep production, evaluating the variation in PMA across a large number of farms and locations over 20 years. Materials and methods: Inventory data for two superfine wool Merino farms were obtained from farmer records, interviews and site visits in study 1. Livestock GHG emissions were modelled using Australian National GHG Inventory methods. A comparison was made of mass, protein mass and economic allocation and system expansion methods for handling co-production of wool and sheep meat. In study 2, typical crossbred ewe, Merino ewe and Merino wether flocks in each of the 28 locations in eight climate zones were modelled using the GrassGro/GRAZPLAN simulation model and historical climatic data to examine the variation in PMA values for different enterprise types. Results and discussion: Different methods for handling co-products in study 1 changed allocated GHG emissions more than fourfold, highlighting the sensitivity to method choice. In study 2, enterprise, climate zone and year and their interactions had significant effects on PMA between wool and liveweight (LW) sold. The wool PMA (wool protein as proportion of total protein sold) least square means (LSM) were 0.61 ± 0.003 for wethers, 0.43 ± 0.003 for Merino ewes and 0.27 ± 0.003 for crossbred ewe enterprises. The wool PMA LSM for the main effect of Köppen climate zone varied from 0.39 to 0.46. Two zones (no dry season/warm summer and distinctively dry and hot) had significantly lower wool PMA LSM, of 0.39 and 0.41, respectively, than the four other climate zones. Conclusions: Effects of superfine wool production on GHG emissions differed between regions in response to differences in climate and productivity. Regarding methods for handling co-production, system expansion showed the greatest contrast between the two studied flocks and highlighted the importance of meat from wool production systems. However, we also propose PMA as a simple, easily applied allocation approach for use when attributional life cycle assessment (LCA) is undertaken. [ABSTRACT FROM AUTHOR]

Purpose: The estimations of greenhouse gas (GHG) field emissions from fertilization and soil carbon changes are challenges associated with calculating the carbon footprint (CFP) of agricultural products. At the regional level, the IPCC Guidelines for National Greenhouse Gas Inventories (2006a) Tier 1 approach, based on default emission factors, insufficiently accounts for emission variability resulting from pedo-climatic conditions or management practices. However, Tier 2 and 3 approaches are usually considered too complex to be practicable. In this paper, we discuss different readily available medium-effort methods to improve the accuracy of GHG emission estimates. Methods: We present four case studies-two wheat crops in Germany and two peach orchards in Italy-to test the performance of Tier 1, 2, and 3 methodologies and compare the estimated results with available field measurements. The methodologies selected at Tier 2 and Tier 3 level are characterized by simple implementation and data collection, for which only a medium level of effort for stakeholders is required. The Tier 2 method consists of calculating direct and indirect NO, emissions from fertilization with a multivariate empirical model which accounts for pedo-climatic and crop management conditions. The Tier 3 method entails simulation of soil carbon stock change using the Rothamsted carbon model. Results and discussion: Relevant differences were found among the tested methodologies: in all case studies, the Tier 1 approach exceeded the Tier 2 estimations for fertilizer-induced emissions (up to +50 %) and the measurements. Using this higher Tier approach reduced the estimated CFP calculation of annual crops by 4 and 21 % and that of the perennial crop by 7 %. Removals related to positive soil carbon change calculated using the Tier 1 approach also exceeded the Tier 3 calculations for the studied annual crops (up to +90 %) but considerably underrated the Tier 3 estimations and measurements for perennial crops (−75 %). In this case, the impact of the selected Tier method on the final CFP results was even more relevant: an increase of 194 and 88 % for the studied annual crops and a decrease of 67 % for the perennial crop case study. Conclusions: The use of higher Tiers for the estimation of land-based emissions is strongly recommended to improve the accuracy of the CFP results. The suggested medium-effort methods tested in this study represent a good compromise between complexity reduction and accuracy improvement and can be considered reliable for the assessment of GHG mitigation potentials. [ABSTRACT FROM AUTHOR]

In the context of deadlocked climate change negotiations, and the expectation that legally binding targets may only set in as early as 2020, this paper addresses the question of whether the current economic recession in major economies in the North can help us buy time by reducing the emissions of greenhouse gases (GHGs). This review paper examines the vast literature on the subject to extract eight key trends that are broadly connected to GHG emissions, green economy, climate change policy and public opinion, and the impact on the economies of developing countries. The eight trends amount to two story lines. The first is that the perception of the public during a recession focuses narrowly on recovery and climate change appears framed in their minds as hampering recovery. This leads to reduced societal emphasis on building the green economy both in the North and the South. The counter story that the recovery process following a recession should emphasize restructuring the economy towards a green one appears a more wishful thinking than a fact in the absence of leadership and buy-in from the public. [ABSTRACT FROM PUBLISHER]

During the past decade, significant advances in ionic liquid-based materials for the development of CO2 separation membranes have been accomplished. This review presents a perspective on different strategies that use ionic liquid-based materials as a unique tuneable platform to design task-specific advanced materials for CO2 separation membranes. Based on compilation and analysis of the data hitherto reported, we provide a judicious assessment of the CO2 separation efficiency of different membranes, and highlight breakthroughs and key challenges in this field. In particular, configurations such as supported ionic liquid membranes, polymer/ionic liquid composite membranes, gelled ionic liquid membranes and poly(ionic liquid)-based membranes are detailed, discussed and evaluated in terms of their efficiency, which is attributed to their chemical and structural features. Finally, an integrated perspective on technology, economy and sustainability is provided. [ABSTRACT FROM AUTHOR]

Background: The last decade has seen major development and adoption of bioenergy, particularly in Germany. This has resulted in a scattering of decentralised bioenergy plants across the landscape, due to their dependency on spatially diffuse biomass resources. Regional conditions (e.g., soils, climate, management) influence the environmental burdens resulting from biomass production and thus, also effect the environmental performance of bioenergy production. Therefore, more regionally focused life cycle approaches are required for assessing these bioenergy systems. The aim of this paper is to outline such an approach. 'RELCA', is a regional life cycle inventory for assessing the regional and spatial variation in the environmental performance of bioenergy production within a region. Methods: Five modelling steps are combined to form the RELCA approach in order to determine: (1) regional crop allocation, (2) regional biomass management, (3) representative bioenergy plant models, (4) bioenergy plant catchments, and (5) indirect upstream emissions (non-regional) associated with regional bioenergy production. The challenges and options for each of these five modelling steps are outlined. Additionally, a simple example is provided using greenhouse gases emissions (GHG) to show how RELCA can be used to identify the potential regional distribution of environmental burdens associated with the production of a bioenergy product (e.g. biodiesel) within a region. Results: An approach for combining regionally distributed inventory for biomass production with regionally distributed inventory for bioenergy technologies, through the use of catchment delineation was developed. This enabled the introduction of greater regional details within the life cycle approach. As a first 'proof of concept,' GHG emissions were estimated for a simple example, illustrating how RELCA can identify the potential regional distribution of environmental burdens (direct and indirect) associated with producing a bioenergy product. Conclusions: RELCA (v1.0) is a powerful scoping approach, which is the first to investigate the regional and spatial variation in the environmental performance of bioenergy production within a region through the use of catchment delineation. RELCA (v1.0) is not without its limitations. Despite these, it still provides a good starting point for further discussion, improvements, and modelling developments for assessing the regional and spatial environmental implications of bioenergy production (e.g., such as impacts to soil, water, and biodiversity) for a within regional context . [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O), an increasingly abundant greenhouse gas in the atmosphere, is the most important stratospheric ozone-depleting gas of this century. Natural abundance ratios of isotopocules of N2O, NNO molecules substituted with stable isotopes of nitrogen and oxygen, are a promising index of various sources or production pathways of N2O and of its sink or decomposition pathways. Several automated methods have been reported to improve the analytical precision for the isotopocule ratio of atmospheric N2O and to reduce the labor necessary for complicated sample preparation procedures related to mass spectrometric analysis. However, no method accommodates flask samples with limited volume or pressure. Here we present an automated preconcentration system which offers flexibility with respect to the available gas volume, pressure, and N2O concentration. The shortest processing time for a single analysis of typical atmospheric sample is 40 min. Precision values of isotopocule ratio analysis are < 0.1 ‰ for δ15Nbulk (average abundances of 14N15N16O and 15N14N16O relative to 14N14N16O), < 0.2 ‰ for δ18O (relative abundance of 14N14N18O), and < 0.5 ‰ for site preference (SP; difference between relative abundance of 14N15N16O and 15N14N16O). This precision is comparable to that of other automated systems, but better than that of our previously reported manual measurement system. [ABSTRACT FROM AUTHOR]

The Thermal and Near Infrared Sensor for Carbon Observation (TANSO)--Fourier Transform Spectrometer (FTS) on board the Greenhouse Gases Observing Satellite (GOSAT) has been observing carbon dioxide (CO2) concentrations in several atmospheric layers in the thermal infrared (TIR) band since its launch. This study compared TANSO-FTS TIR version 1 (V1) CO2 data and CO2 data obtained in the Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL) project in the upper troposphere and lower stratosphere (UTLS), where the TIR band of TANSO-FTS is most sensitive to CO2 concentrations, to validate the quality of the TIR V1 UTLS CO2 data from 287 to 162 hPa. We first evaluated the impact of considering TIR CO2 averaging kernel functions on CO2 concentrations using CO2 profile data obtained by the CONTRAIL Continuous CO2 Measuring Equipment (CME), and found that the impact at around the CME level flight altitudes (~11 km) was on average less than 0.5 ppm at low latitudes and less than 1 ppm at middle and high latitudes. From a comparison made during flights between Tokyo and Sydney, the averages of the TIR upper-atmospheric CO2 data were within 0.1% of the averages of the CONTRAIL CME CO2 data with and without TIR CO2 averaging kernels for all seasons in the Southern Hemisphere. The results of comparisons for all of the eight airline routes showed that the agreements of TIR and CME CO2 data were worse in spring and summer than in fall and winter in the Northern Hemisphere in the upper troposphere. While the differences between TIR and CME CO2 data were on average within 1 ppm in fall and winter, TIR CO2 data had a negative bias up to 2.4 ppm against CME CO2 data with TIR CO2 averaging kernels at the northern low and middle latitudes in spring and summer. The negative bias at the northern middle latitudes resulted in the maximum of TIR CO2 concentrations being lower than that of CME CO2 concentrations, which led to an underestimate of the amplitude of CO2 seasonal variation. [ABSTRACT FROM AUTHOR]

An algorithm based on CO2 slicing, which has been used for cirrus cloud detection using thermal infrared data, was developed for high-resolution radiance spectra from satellites. The channels were reconstructed based on sensitivity height information of the original spectral channels to reduce the effects of measurement errors. Selection of the reconstructed channel pairs was optimized for several atmospheric profile patterns using simultaneous studies assuming a cloudy sky. That algorithm was applied to data by the Greenhouse gases Observing SATellite (GOSAT). Results were compared with those obtained from the space-borne lidar instrument on-board Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Monthly mean cloud amounts from the slicing generally agreed with those from CALIPSO observations despite some differences caused by surface temperature biases, optically very thin cirrus, multilayer structures of clouds, extremely low cloud tops, and specific atmospheric conditions. Comparison of coincident data showed good agreement, except for some cases, and revealed that the improved slicing method is more accurate than the traditional slicing method. Results also imply that improved slicing can detect low-level clouds with cloud top heights as low as approximately 1.5 km. [ABSTRACT FROM AUTHOR]

Recently, research has focused on the biofuel production from local industrial wastes due to the risk of greenhouse emissions derived from land-use change (both directly and indirectly) of conventional feedstock and the social concern about the effect of conventional biofuel production on oil prices and its availability (the so-called food vs. fuel debate). Therefore, with the aim to evaluate the use of biofuels derived from wastes from traditional manufacturing industries in Turkey, biodiesel fuels from leather fat, obtained as a by-product in the leather industry, waste anchovy fish oil, derived from the fish-processing industry, and waste frying cottonseed oil achieved from food industry, have been tested in a three-cylinder DI diesel engine at a steady-state condition. In a previous work, the viability of these fuels was evaluated by analyzing measured and estimated properties and indicators for main diesel emissions, and recommendations were made on their alternative use to conventional biodiesels with the benefit of potentially lower life-cycle greenhouse emissions. The experimental results, which were compared with ULSD operation, demonstrated that the engine performance was not significantly affected, while a substantial change in emissions was observed with the use of biofuels. In general, the emission results reported here are in a similar range to those obtained with the use of conventional biodiesel fuels. Nonetheless, the exact magnitude of these changes depended upon the biodiesel origin. Lubricity of alternative biofuels was also tested, revealing an enormous capacity for protecting the fuel system from wear, in line with conventional biodiesel fuels. [ABSTRACT FROM AUTHOR]

What we eat greatly influences our personal health and the environment we all share. Recent analyses have highlighted the likely dual health and environmental benefits of reducing the fraction of animal-sourced foods in our diets. Here, we couple for the first time, to our knowledge, a region-specific global health model based on dietary and weight-related risk factors with emissions accounting and economic valuation modules to quantify the linked health and environmental consequences of dietary changes. We find that the impacts of dietary changes toward less meat and more plant-based diets vary greatly among regions. The largest absolute environmental and health benefits result from diet shifts in developing countries whereas Western high-income and middle-income countries gain most in per capita terms. Transitioning toward more plant-based diets that are in line with standard dietary guidelines could reduce global mortality by 6-10% and food-related greenhouse gas emissions by 29-70% compared with a reference scenario in 2050. We find that the monetized value of the improvements in health would be comparable with, or exceed, the value of the environmental benefits although the exact valuation method used considerably affects the estimated amounts. Overall, we estimate the economic benefits of improving diets to be 1-31 trillion US dollars, which is equivalent to 0.4-13% of global gross domestic product (GDP) in 2050. However, significant changes in the global food system would be necessary for regional diets to match the dietary patterns studied here. [ABSTRACT FROM AUTHOR]

Mode water is a distinct water mass characterized by a near vertical homogeneous layer or low potential vorticity, and is considered essential for understanding ocean climate variability. Based on the output of GFDL CM3, this study investigates the response of eastern subtropical mode water (ESTMW) in the North Pacific to two different single forcings: greenhouse gases (GHGs) and aerosol. Under GHG forcing, ESTMW is produced on lighter isopycnal surfaces and is decreased in volume. Under aerosol forcing, in sharp contrast, it is produced on denser isopycnal surfaces and is increased in volume. The main reason for the opposite response is because surface ocean-to-atmosphere latent heat flux change over the ESTMW formation region shoals the mixed layer and thus weakens the lateral induction under GHG forcing, but deepens the mixed layer and thus strengthens the lateral induction under aerosol forcing. In addition, local wind changes are also favorable to the opposite response of ESTMW production to GHG versus aerosol. [ABSTRACT FROM AUTHOR]

In this study, CO2emissions in different sectors in Turkey were examined in order to serve as a foundation for planning future reduction of greenhouse gas emissions. These reductions are being planned in accordance with the Kyoto Protocol, of which Turkey is a signatory, and which was re-examined by the Doha Climate Change Conference in 2009. For this purpose, variation of the total factor efficiencies of CO2emissions per capita for many developed and developing countries including Turkey (35 countries in total) were examined by data envelopment analysis and Malmquist Index approaches. It was aimed to determine the sectors in Turkey that should be the primary foci for reductions of CO2emissions and which actions might be taken before Doha 2020 oriented towards reductions in CO2emissions in these sectors. Meanwhile, current regulations and perspectives for greenhouse gas plans developed within the scope of Vision 2023 were discussed. [ABSTRACT FROM PUBLISHER]

Carbon dioxide (CO2) and ozone (O3) are important greenhouse gases that contribute to global climate change. The effects of elevated CO2 and/or O3 on plants remain unclear. Plant responses to mixtures of the two gases at high concentrations are likely to be complex. Previous studies have shown that the ability to tolerate elevated levels of the two gases varies among plant species; physiological adaptability in the face of changing atmospheric composition also differs among taxa. However, the effects of mixtures of the two greenhouse gases on the growth and physiology of bamboo are largely unexplored, even though bamboos are important vegetation elements throughout tropical and subtropical regions of the planet. In this study, we used open-topped chambers (OTC) to double the concentrations of atmospheric CO2 and O3, and examined changes in membrane lipid peroxidation, photosynthetic physiology, and antioxidase activities in Indocalamus decorus leaves. After 103 days of treatment, elevated O3 depressed net photosynthetic rate (Pn) without changing stomatal function, but caused no significant oxidative damage in the leaves. High levels of antioxidase activities were maintained in the leaves, indicating that this species had a strong tolerance to elevated O3. Decreases in reactive oxygen content and antioxidase activity in the leaves highlighted the significant positive effects of elevated CO2 on photosynthesis in I. decorus. When a mixture of both gases was supplied at high concentrations, we detected no oxidative damage, although photosynthetic capacity was reduced. Negative effects of O3 were very marked during the early part of the treatment period, but the effects of CO2 were positive. CO2 mitigated the oxidative damage caused by O3 and promoted the growth of I. decorus. Thus, I. decorus tolerated the two greenhouse gases, and was able to adapt to elevated CO2 and O3 levels. These findings contribute to the current knowledge base on the response of bamboo to global climate change. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue including impacts of freight transportation in California, environmental implications of energy efficiency developments; and a research on Greenhouse Gas (GHG) emissions of cars in Great Britain.

Buildings account for more than 40 % of the total energy demand in the European Union (EU). The energy sector is responsible for 80 % of the total greenhouse gas emissions in the EU, of which more than a third are emitted as a result of energy use in buildings. Given these numbers and the large potential for energy savings in buildings, the energy and buildings sectors emerged as key contributors to fulfilling the European climate targets. Effective cooperation between these two key sectors can contribute significantly to the efficacy of the European climate strategy. However, there may be factors that negatively impact the relationship between the energy and buildings sectors and put cooperation in climate-friendly developments at risk. Based on 23 semi-structured interviews and a web survey answered by key stakeholders, this paper provides a snapshot of the current level of cooperation between the energy and buildings sectors in Sweden and identifies factors that impact the interdependencies between the two sectors. The findings show that the current business models in energy supply and the regulations in place limit the development of mutually beneficial cases between the energy and buildings sectors. This paper contributes to improved knowledge for policymaking that affects both sectors and highlights issues for further study. [ABSTRACT FROM AUTHOR]

As drivers of climate action, cities are taking measures to reduce greenhouse gas (GHG) emissions, which if left unabated pose a challenge to meeting long-term climate targets. The economics of climate action needs to be at the forefront of climate dialogue to prioritize investments among competing mitigation measures. A marginal abatement cost (MAC) curve is an effective visualization of climate action that initiates a technical and economic discussion of the cost-effectiveness and abatement potential of such actions among local leaders, policy makers, and climate experts. More commonly demonstrated for countries, MAC curves need to be developed for cities because of their heterogeneity, which vary in their urban activities, energy supply, infrastructure stock, and commuting patterns. The methodology for constructing bottom-up MAC curves for cities is presented for technologies that offer fuel switching and/or energy efficiencies, while considering technology lifetimes, city-specific electricity and fuel prices, and emission intensities. Resulting MAC curves are unique to every city, and chart the pathway towards low-carbon growth by prioritizing measures based on cost-effectiveness. A case study of Toronto's climate targets demonstrates the prioritization of select technologies. Leveraging MAC curves to support climate programs enables cities to strategically invest in financing climate action and designing incentives. [ABSTRACT FROM AUTHOR]

Next generation 5G wireless networks envision innovative radio technologies for ultra dense deployment with improved coverage and higher data rates. However, the deployment of ultra dense 5G networks, with relatively smaller cells, raises significant challenges in network energy consumption. Emerging green cloud radio access networks (C-RANs) are providing assurance of energy efficient cellular operations for reduction of both greenhouse emissions and operators’ energy bill. Cellular traffic dynamics play a significant role in efficient network energy management. In this paper, we first identify the complexity of the optimal traffic awareness in 5G C-RAN and design a framework for traffic-aware energy optimization. The virtual base station cluster (VBSC) of C-RAN exploits an information theoretic approach to model and analyze the uncertainty of cellular traffic, captured by remote radio heads (RRH). Subsequently, using an online, stochastic game theoretic algorithm, the VBS instances optimize and learn the cellular traffic patterns. Efficient learning makes the C-RAN aware of the near-future traffic. Traffic awareness helps in selective switching of a subset of RRHs, thus reducing the overall energy consumption. Our VBS prototype implementation, testbed experiments, and simulation results, performed with actual cellular traffic traces, demonstrate that our framework results in almost 25% daily energy savings and 35% increased energy efficiency with a negligible overhead. [ABSTRACT FROM PUBLISHER]

Coal is the most abundant hydrocarbon energy source in the world. It also produces a very high volume of greenhouse gases using the current production technology. It is more difficult to handle and transport than crude oil and natural gas. We face a challenge: how can we access this abundant resource and at the same time mitigate global environmental challenges, in particular, the production of carbon dioxide (CO)? The editors of this special edition journal consider the opportunity to increase the utilization of this globally abundant resource and recover it in an environmentally sustainable manner. Underground coal gasification (UCG) is the recovery of energy from coal by gasifying the coal underground. This process produces a high calorific synthesis gas, which can be applied for electricity generation and/or the production of fuels and chemicals. The carbon dioxide emissions are relatively pure and the surface facilities are limited in their environmental footprint. Unused carbon is readily separated and can be geo-sequester in the resulting cavity. The cavity is also being considered as a potential option to mitigate against change impacts of other sources of carbon dioxide (CO) emissions. These outcomes mean there is an opportunity to provide developing and developed countries a source of low-cost clean energy. Further, the burning of coal in situ means that the traditional dangers of underground mining and extraction are reduced, a higher percentage of the coal is actually recovered and the resulting cavern creates the potential for a long-term storage solution of the gasification wastes. The process is not without challenges. Ground subsidence and groundwater pollution are two potential environmental impacts that need to be averted for this process to be acceptable. It is essential to advance the understanding of this practice and this special edition journal seeks to share the progress that scientists are making in this dynamic field. The technical challenges are being addressed by researchers around the world who work to resolve and understand how burning coal underground impacts the geology, the surface land, and ground water both in the short and the long term. This special issue reviews the process of UCG and considers the opportunities, challenges, risks, competitive analysis and synergies, commercial initiatives and a roadmap to solutions via the modelling and simulation of UCG. Building and then disseminating the fundamental knowledge of UCG will enhance policy development, best practices and processes that reflect the global desires for energy production with reduced environmental impact. [ABSTRACT FROM AUTHOR]

Underground coal gasification (UCG) is an advancing technology that is receiving considerable global attention as an economic and environmentally friendly alternative for exploitation of coal deposits. UCG has the potential to decrease greenhouse gas emissions (GHG) during the development and utilization of coal resources. In this paper, the life cycle of UCG from in situ coal gasification to utilization for electricity generation is analyzed and compared with coal extraction through conventional coal mining and utilization in power plants. Four life cycle assessment models have been developed and analyzed to compare (greenhouse gas) GHG emissions of coal mining, coal gasification and power generation through conventional pulverized coal fired power plants (PCC), supercritical coal fired (SCPC) power plants, integrated gasification combined cycle plants for coal (Coal-IGCC), and combined cycle gas turbine plants for UCG (UCG-CCGT). The analysis shows that UCG is comparable to these latest technologies and in fact, the GHG emissions from UCG are about 28 % less than the conventional PCC plant. When combined with the economic superiority, UCG has a clear advantage over competing technologies. The comparison also shows that there is considerable reduction in the GHG emissions with the development of technology and improvements in generation efficiencies. [ABSTRACT FROM AUTHOR]

Underground coal gasification (UCG) has been identified as an environmentally friendly technique for gasification of deep un-mineable coal seams in situ. This technology has the potential to be a clean and promising energy provider from coal seams with minimal greenhouse gas emission. The UCG eliminates the presence of coal miners underground hence, it is believed to be a much safer technique compared to the deep coal mining method. The UCG includes drilling injection and production wells into the coal seam, igniting coal, and injecting oxygen-based mix to facilitate coal gasification. Produced syngas is extracted from the production well. Evolution of a cavity created from the gasification process along with high temperature as well as change in pore fluid pressure causes mechanical changes to the coal and surrounding formations. Therefore, simulation of the gasification process alone is not sufficient to represent this complex thermal-hydro-chemical-mechanical process. Instead, a coupled flow and geomechanical modeling can help better represent the process by allowing simultaneous observation of the syngas production, advancement of the gasification chamber, and the cavity growth. Adaptation of such a coupled simulation would aid in optimization of the UCG process while helping controlling and mitigating the environmental risks caused by geomechanical failure and syngas loss to the groundwater. This paper presents results of a sequentially coupled flow-geomechanical simulation of a three-dimensional (3D) UCG example using the numerical methodology devised in this study. The 3D model includes caprock on top, coal seam in the middle, and another layer of rock underneath. Gasification modeling was conducted in the Computer Modelling Group Ltd. (CMG)'s Steam, Thermal, and Advanced processes Reservoir Simulator (STARS). Temperature and fluid pressure of each grid block as well as the cavity geometry, at the timestep level, were passed from the STARS to the geomechanical simulator i.e. the Fast Lagrangian Analysis of Continua in 3 Dimensions (FLAC3D) computer program (from the Itasca Consulting Group Inc.). Key features of the UCG process which were investigated herein include syngas flow rate, cavity growth, temperature and pressure profiles, porosity and permeability changes, and stress and deformation in coal and rock layers. It was observed that the coal matrix deformed towards the cavity, displacement and additional stress happened, and some blocks in the coal and rock layers mechanically failed. [ABSTRACT FROM AUTHOR]

Underground Coal Gasification (UCG) produces less surface impact, atmospheric pollutants and greenhouse gas than traditional surface mining and combustion. Therefore, it may be useful in mitigating global change caused by anthropogenic activities. Careful monitoring of the UCG process is essential in minimizing environmental impact. Here we first summarize monitoring methods that have been used in previous UCG field trials. We then discuss in more detail a number of promising advanced geophysical techniques. These methods - seismic, electromagnetic, and remote sensing techniques - may provide improved and cost-effective ways to image both the subsurface cavity growth and surface subsidence effects. Active and passive seismic data have the promise to monitor the burn front, cavity growth, and observe cavity collapse events. Electrical resistance tomography (ERT) produces near real time tomographic images autonomously, monitors the burn front and images the cavity using low-cost sensors, typically running within boreholes. Interferometric synthetic aperture radar (InSAR) is a remote sensing technique that has the capability to monitor surface subsidence over the wide area of a commercial-scale UCG operation at a low cost. It may be possible to infer cavity geometry from InSAR (or other surface topography) data using geomechanical modeling. The expected signals from these monitoring methods are described along with interpretive modeling for typical UCG cavities. They are illustrated using field results from UCG trials and other relevant subsurface operations. [ABSTRACT FROM AUTHOR]

Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG) emissions and aqueous nutrient releases of the whole anthropogenic municipal water cycle starting from raw water extraction to wastewater treatment and reuse/discharge for five municipal water and wastewater systems. The assessed options included conventional centralized services and four alternative options following the principles of source-separation and water fit-for-purpose. The comparative life cycle assessment identified that centralized drinking water supply coupled with blackwater energy recovery and on-site greywater treatment and reuse was the most energyand carbon-efficient water service system evaluated, while the conventional (drinking water and sewerage) centralized system ranked as the most energy- and carbon-intensive system. The electricity generated from blackwater and food residuals co-digestion was estimated to offset at least 40% of life cycle energy consumption for water/waste services. The dry composting toilet option demonstrated the lowest life cycle eutrophication potential. The nutrients in wastewater effluent are the dominating contributors for the eutrophication potential for the assessed system configurations. Among the parameters for which variability and sensitivity were evaluated, the carbon intensity of the local electricity grid and the efficiency of electricity production by the co-digestion with the energy recovery process were the most important for determining the relative global warming potential results. [ABSTRACT FROM AUTHOR]

In order to reduce its greenhouse gas emissions without drastically changing currently-used processes, the primary aluminum industry will need to consider capturing CO2 released in the electrolytic cells. In order to make the capture more economically attractive to the aluminum industry, the possibility of using a blended amine absorption solution which combines the advantages of two different amines (a fast reactivity from a cyclic polyamine, piperazine (PZ), and a high absorption capacity and low regeneration cost from a sterically-hindered alkanolamine) is considered in this work. Specific to an aluminum plant, not only the costs and benefits of a CO2 capture facility are evaluated, but also the possibility and cost of coupling the capture process with a waste heat recovery strategy. A mixture of 0.08 g/g PZ and 0.32 g/g AMP appears to be the most appropriate, reducing the capital costs by 25 % and operating costs by 29 % compared to the use of MEA (monoethanolamine) solutions. The capture cost is evaluated to be 65.10 $/ton of CO2 avoided (without carbon tax). A thermal integration of the capture plant within the primary aluminum smelter could further reduce the cost to 57.57 $/ton of CO2 avoided, or equivalently, 69.56 $/ton of Al produced (without carbon tax). [ABSTRACT FROM AUTHOR]

New insights into the transformation of ethanol to butadiene over MgO–SiO2 catalysts, prepared by means of the sol–gel technique, have been gained via characterization, catalytic tests, and in situ infrared diffuse reflectance spectroscopy. Catalysts with low Si-content, i.e., with a Mg/Si atomic ratio in the range between 9 and 15, gave superior butadiene yields, because of the proper combination of strong basic sites, required for ethanol activation, and a moderate number of medium-strength acid sites, needed for the dehydration of intermediately formed alkenols to butadiene. A model of the medium-strength, Lewis-type acid sites, consisting of Mg2+ cations with neighbouring Si4+ atoms, has been proposed; these sites are converted into Brønsted sites in the presence of water, a co-product of the multistep transformation of ethanol into C4 molecules. [ABSTRACT FROM AUTHOR]