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Cities consume large amounts of fossil fuels and this results in significant increase of global anthropogenic greenhouse gases. Using city-level carbon dioxide emission data from Shijiazhuang, a traditional heavy manufacturing city and one of the key cities in Jing-Jin-Ji urban agglomeration in Northern China, this paper employs logarithmic mean Divisia index decomposition method (LMDI) to explore the influence of energy intensity, consumption structure, industry structure, per capita Gross Domestic Product (GDP), and population on Shijiazhuang's total carbon dioxide emissions from 2005 to 2016. The LMDI method is further extended to analyze the impacts of above factors at the industry-segment level. This paper finds that the reduction of energy intensity is the major contributor of decreasing carbon dioxide emissions in Shijiazhuang, whereas the growth of per capita GDP is the main driving force for emission accretion. The dominant industrial segments contributing to increasing emissions in Shijiazhuang City from 2005 to 2016, have changed from CMD (coal mining and dressing), EPSH (electric power, steam and hot water production and supply) to SPFM (smelting and pressing of ferrous metals) and PPC (petroleum processing and coking). The CMD industrial segment shows a significant carbon reducing effort and indicates a strong decoupling status. However, the SPFM and PPC respectively show expansive negative decoupling and weak decoupling status, enlightening a change in the policy focus when Shijiazhuang formulates its emission-reduction plans in the future. This study provides important policy insights for the heavy manufacturing cities in other countries with similar industrial structure, as the industry-based carbon mitigation policies should always be adjusted in different stages of the cities' development according to the change of carbon emission driving industries. [ABSTRACT FROM AUTHOR]

[Display omitted] • Membranes as a promising tool for CO 2 capture. • A perspective on direct air capture (DAC) from atmosphere is given. • Process considerations to make DAC feasible are addressed. • Advantages and drawbacks of membranes over other DAC technologies are provided. • An outlook of DAC using membranes is elucidated. Since carbon dioxide (CO 2) is the primary greenhouse gas emitted into the atmosphere due to human activities, strong research efforts have been developed towards capturing and decreasing its production. Unfortunately, specific processes and activities make it impossible to avoid CO 2 emissions. Among the different strategies scientists propose for CO 2 reduction, direct CO 2 capture from the atmosphere, also known as direct air capture (DAC), represents a promising alternative in which sorbents have been mainly used. Recently, gas separation membranes have also been speculated to carry out such a separation, thanks to their smaller footprint and simpler setup and operation; however, their application remains a proposition in the field. This paper gives a perspective of the ongoing research and attempts of DAC applications via membrane separation and introduces the main membrane materials and types used for CO 2 separation. Finally, the process considerations for DAC using membranes are stated to guide the new researchers in the field. [ABSTRACT FROM AUTHOR]

Hydropower, which contributes to around 16% of global electricity and more than 72% of renewable electricity, is expected to play an important role in the deep decarbonization of the energy sector. However, the idea that hydropower is a carbon-neutral energy alternative on par with solar and wind is controversial. Research, mainly from limnology and climate modeling, shows that depending on the characteristics of the hydro project, it could be a significant source of GHG emissions. This aspect has been ignored in most life cycle assessment (LCA) studies, affecting the effective use of LCA results, especially in comparative assessments. This paper aims to provide a comprehensive and critical review on this topic by conducting a systematic literature review on hydropower LCA studies published since 2010. We found that there is inconsistency in how LCA is used for hydropower projects. While the emissions associated with the engineering work are well addressed, efforts to accurately estimate and model reservoir GHG emissions are constrained by limited data availability, difficulties in accurately quantifying highly variable carbon fluxes, and inconsistent modeling approaches. A huge range of emissions values is reported in the reviewed literature, from 1.5 to 3747.8 g CO 2 eq per kWh. Reservoir-based hydropower shows high variability, which is mainly dictated by reservoir-related GHG emissions. Reservoir GHG emissions could be more than 90% of the life cycle emissions, especially for hydropower in a tropical region. The regionalized aspect is a key factor to be considered in extrapolating reservoir GHG emissions. • There is inconsistency in how LCA is used for hydropower projects. • A wide range of emission intensities has been reported (1.5–3747.8 g CO 2 eq/kWh). • The high variability in the emissions is due to major differences in key reservoir characteristics. • Data limitations are the main cause for over- or underestimation of hydropower emissions. • Harmonization of data is vital to effectively conduct LCA and to generate useful results. [ABSTRACT FROM AUTHOR]

• The tailored methodology accounts for changes in CO 2 density and sediment behavior. • The calculator accounts for unique offshore features (i.e., water depths). • Domain storage estimates ranged from 0.5 to 10,000 Gigatons of CO 2. • Saline efficiency was a significant factor when calculating storage capacity. • The methodology and calculator are applicable at multiple geographic scales. The world produces approximately 50 billion tonnes of greenhouse gases annually. This is measured in CO 2 -equivalents, and geologic CO 2 storage has the potential to advance decarbonization and mitigate greenhouse gas emissions. New technologies to assess offshore carbon storage are needed to address resource, regulatory, and commercial needs. Although most efforts to assess storage resources focus on onshore criteria, offshore reservoirs offer significant storage potential and distinct development challenges. Potential advantages of offshore carbon storage include being further from human population centers and less potential to interact with groundwater. The U.S. Department of Energy's method for evaluating storage capacity in non-oil-bearing saline reservoirs has been enhanced to support assessments for offshore environments in the Offshore CO 2 Saline Storage methodology (OCSS). This methodology applies data-driven capabilities to estimate saline storage capacity while accounting for features specific to offshore reservoirs. Features include changes in CO 2 density and sedimentary differences that impact estimates of permanence and capacity. The Offshore CO 2 Saline Storage Calculator mechanizes OCSS to estimate storage capacity. This paper presents the methodology and estimates for 18 geologic domains in the Gulf of Mexico. Potential storage distributions, sensitivity analyses, and the incorporation of spatial data and tools to support safe site selection are also discussed. [ABSTRACT FROM AUTHOR]

With increasing attention being paid to greenhouse gas (GHG) emissions, the transportation industry has become an important focus of approaches to reduce GHG emissions, especially carbon dioxide equivalent (CO 2 e ) emissions. In this competitive industry, of course, any new emissions reduction technique must be economically attractive and contribute to good operational performance. In this paper, a continuous-variable feedback control algorithm called GEET (Greening via Energy and Emissions in Transportation) is developed; customer deliveries are assigned to a fleet of vehicles with the objective function of Just-in-Time (JIT) delivery and fuel performance metrics akin to the vehicle routing problem with soft time windows (VRPSTW). GEET simultaneously determines vehicle routing and sets cruising speeds that can be either fixed for the entire trip or varied dynamically based on anticipated performance. Dynamic models for controlling vehicle cruising speed and departure times are proposed, and the impact of cruising speed on JIT performance and fuel performance are evaluated. Allowing GEET to vary cruising speed is found to produce an average of 12.0–16.0% better performance in fuel cost, and −36.0% to +16.0% discrepancy in the overall transportation cost as compared to the Adaptive Large Neighborhood Search (ALNS) heuristic for a set of benchmark problems. GEET offers the advantage of extremely fast computational times, which is a substantial strength, especially in a dynamic transportation environment. [ABSTRACT FROM AUTHOR]

The change of O 2 content in soil caused by aerated irrigation (AI) must inevitably affect the production and emissions of CO 2 and N 2 O from soils. This paper described in-situ observation of CO 2 and N 2 O emissions from AI soils with static chamber-GC technique, in order to reveal the effects of AI on CO 2 and N 2 O emissions from soils of greenhouse tomato fields in autumn-winter season. CO 2 and N 2 O emissions from AI soils mainly concentrated in the blooming and fruit setting period compared to other periods. AI increased cumulative emissions of CO 2 and N 2 O by 11.8% (p = 0.394) and 10.0% (p = 0.480), respectively, compared to the control. The integrative global warming potential of CO 2 and N 2 O on a 100-year horizon for the AI treatment was 6430.60 kg ha −1 , increased by 11.7% compared with that for the control (p = 0.356). Both the emissions of CO 2 and N 2 O from AI soils had the exponential positive correlation with soil water-filled pore space (WFPS). The highest peak of CO 2 and N 2 O fluxes from AI soils was observed at 46.7% and 47.5% WFPS, with WFPS ranging from 43.3% to 51.5% and from 45.6% to 52.3% during the whole growth stage, respectively. In addition, the average yield for the AI treatment (34.52 t ha −1 ) was significantly greater (17.4%) compared with that of the control (p = 0.018). These results suggest that AI do not significantly increase the integrative greenhouse effect caused by CO 2 and N 2 O from soils of greenhouse tomato fields, but significantly increase the tomato yield. The research results provide certain theoretical foundation and scientific basis for accurately evaluating the farmland ecological effect of AI technique. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO 2 ) is a major greenhouse gas, which is considered as a leading contributor to global warming and climate change. Therefore, the detection of CO 2 is highly important and beneficial for many applications. Layered double hydroxide (LDH) is considered as a good adsorbent for CO 2 with high adsorption selectivity and capacity. However, the adsorption capacities of CO 2 on LDH are usually investigated at high temperatures. And CO 2 adsorption is measured with bulky instrumentation, which exist the problems of high cost, long cycle, complicated test processes and unsuitability for real-time measurements of CO 2 gas. Herein, a new approach to rapid CO 2 detection is introduced using a novel HPTS/NiFe-LDH nanocomposite (8-hydroxypyrene-1,3,6-trisulfonicacid trisodium, HPTS) through a facile fluorescence technology at room temperature. In this paper, HPTS/NiFe-LDH nanocomposite was firstly synthesized through a facile one-step hydrothermal method. The HPTS/NiFe-LDH nanocomposite had no fluorescence with anionic dye HPTS intercalated into the cationic interlayer of NiFe-LDH. When CO 2 gas was gradually bubbled into the above system, CO 3 2− ions were then intercalated into the interlayer of NiFe-LDH and anionic dye was released from NiFe-LDH, thereby leading to the fluorescence recovery of HPTS. The results indicated that fluorescence intensity was linearly related to the bubbling volumes of CO 2 , suggesting that the HPTS/NiFe-LDH nanocomposite can be used as a sensor to selectively discriminate CO 2 gas, which provided not only a new route to rapidly detection of CO 2 but also a new application field of the hybrid LDH composites. [ABSTRACT FROM AUTHOR]

Implementing renewable generation becomes one of the most practical approaches to reduce greenhouse gas emissions for the power sector. A microgrid, with its flexible scale and structure, can be a good platform to integrate distributed conventional and renewable generation resources. In this paper, a stochastic operation scheduling scheme is proposed to cooptimize carbon emissions and generation fuel costs while mitigating the impact of the intermittence of renewable energy. Two different stochastic approaches based on sample average approximation and probabilistic constrained stochastic programming are formulated. Corresponding solution methods are developed and implemented in an experimental microgrid to illustrate and compare the effectiveness of different stochastic models for the intended applications. [ABSTRACT FROM AUTHOR]

Geothermal heat pumps have several advantages over conventional heating and cooling systems. They can operate in both winter and summer, have high efficiencies, and do not directly emit any greenhouse gases during operation. Investors (in developing countries) can use Clean Development Mechanism as a source of financing for new or existing renewable energy facilities by selling Certified Emission Reductions credits (CERs), which represent the amount of CO2 emission (1 CER¼1 tCO2eq) that is avoided using renewable energy. The aim of this paper is to analyze the possibility of CO2 reduction by using geothermal heat pumps for fossil fuel displacement with applying Clean Development Mechanism. Results have shown that by using geothermal heat pumps during a 7-year crediting period, the estimated emission reduction would be 79.45 tCO2 (equal to 80 CERs), enabling the investor to achieve profit from selling 80 CERs and thus helping to fund the proposed project activity. Three main factors which influence the amount of CO2 reduction have been identified: carbon-dioxide emission factor for electricity source, efficiency of technology used for baseline scenario, and coefficient of performance (COP) of heat pumps. [ABSTRACT FROM AUTHOR]

Gas injection process for more oil recovery and in particular CO 2 injection is well-established method to increment oil recovery from underground oil reservoirs. CO 2 sequestration which takes place during this enhanced oil recovery (EOR) method has positive impact on reducing the greenhouse gas emission which causes global warming. Direct gas injection into depleted oil reservoirs, encounters several shortcomings such as low volumetric sweep efficiency, early breakthrough (BT) and high risk of gas leakage in naturally fractured carbonate oil reservoirs. Carbonated water injection (CWI) has been recently proposed as an alternative method to alleviate the problems associated with gas injection. In this paper, the results of extensive experimental tests of ultimate oil recovery efficiency as both secondary and tertiary CWI tests and their CO 2 storage capacity for an Iranian carbonate reservoir are presented. Besides, the CWI recovery efficiencies are compared with traditional water flooding (WF) test. The results showed that higher ultimate oil recovery is achieved when carbonated water is injected as secondary technique compared to tertiary process. The results showed 40.54% and 56.74% more oil recovery during tertiary carbonated water injection (TCWI) and secondary water injection (SCWI) compared to the corresponding water flooding, respectively. However, the CO 2 storage capacities for both TCWI and SCWI cases were almost the same, as it was measured to be more than half of the total delivered CO 2 . [ABSTRACT FROM AUTHOR]

With the growing concern for environmental protection, many countries commit to mitigate the climate change and to reduce the global warming associated with carbon dioxide emissions. Global efforts to reduce greenhouse gas (GHG) emissions have led to the adoption of a series of climate protection programs. In Europe an integrated policy on climate protection has been structured in conformity with the guidelines of the Plan 20 20 20, contained in Directive 2009/29/EC. Specifically, as emerged from the fifth Assessment Report of the International Panel for Climate Change (1PCC), a strong contribution on greenhouse gas emissions results from cities. In this regard, the European Parliament Resolution OJ 2010/C349E/16 promotes initiatives based on energy efficiency and renewable sources, as well as smart distribution networks in urban areas. A detailed knowledge of the urban energy demand plays an important role in order to develop strategies for the implementation of efficient energy management plans. For this purpose, the proposed paper aims at developing a mathematical model derived from the complex network theory and able to represent the energy demand of an urban area. Moreover, the structural properties of the obtained network are highlighted through the degree centrality measure. [ABSTRACT FROM AUTHOR]

Continuous evolution of biogeochemical models developed in the past decades makes possible the more and more accurate estimation of trace and greenhouse gas fluxes of soils. Due to the detailed meteorological, soil, biological and chemical processes the modeled fluxes are getting closer and closer to the real values. For appropriate evaluation models need large amount of input data. In this paper we have investigated how to build an easily accessible meteorological input data source for biogeochemical models, as it is one of the most important input data sets that is either missing or difficult to get from meteorological networks. The DNDC ecological model was used for testing the WRF numerical weather prediction system as a potential data source. The reference dataset was built by numerical interpolation based on measured data. The average differences between the modeled output data using WRF and observed meteorological data in 2009 and 2010 are less than 3.98 ± 1.6; 8.68 ± 6.72 and 6.5 ± 2.17 per cent for CO 2 , N 2 O and CH 4 , respectively, for the test years. Generalization of the results for other regions is restricted, however this work encourages others to examine the applicability of WRF data instead of observed climate parameters. [ABSTRACT FROM AUTHOR]

Recently, many environmental problems have emerged in Egypt. The increase in human activities, technological progress, population density and fossil fuel burning, are known to increase harmful emissions and oxides within densely populated urban areas are considered the main pollutants. These factors lead to an unhealthy environment and the phenomenon of heat island and negatively affect the overall health of the human beings, which in turn, reduce the production efficiency. Hence, it is so important to find the most efficient strategies that can be followed to decrease oxides and harmful emissions. This paper focuses on the role of the green component of plants and trees in the reduction of carbon dioxide emissions, reduce greenhouse gases and improve air quality is studied. The microclimate simulation software “Envimet” is used for calculating the amount of carbon dioxide emissions within the area of “Alsayed Elbadawi”, an ancient area in Tanta, Egypt. The simulation is performed to the current situation of that urban space and after improving it, which comprising this area by planting the green elements and trees. This will manifest the role of the afforestation in improving air quality and reducing oxides concentrations within the area to achieve a clean urban for sustainability. [ABSTRACT FROM AUTHOR]

Russia is the fifth highest emitter of carbon dioxide, having been in the top five for at least six decades. However, thus far no in-depth study has estimated Russia's cumulative emissions in the context of the global 2°C constraint. This is despite the IPCC reiterating the importance of cumulative emissions. Translating the global 2°C temperature commitment into a meaningful national context, this paper derives and evaluates 2°C-compatible carbon budgets for Russia, based on a range of apportionments. The work contributes to the debate by providing a deeper analysis of the principles of allocating carbon emissions to Russia. This analysis demonstrates how, if Russia is to make a fair contribution to global emission reductions in line with 2°C, its 2011–2100 cumulative emissions should stay within 20-26 Gt CO2, commensurate with a 37–52% probability of exceeding 2°C. If Russia continues to emit carbon dioxide at current annual levels, this budget will be “spent” by the mid-2020s. The carbon budget estimated here for Russia appears technically feasible, if extremely challenging. Despite continuing to assert itself as a fossil fuel superpower, Russia has a wealth of opportunities for full and early decarbonization, including the potential to become a net exporter of renewable energy. [ABSTRACT FROM AUTHOR]

Integrated steelworks are a significant source of anthropogenic CO 2 emissions. In integrated steelworks, which are large stationary plants suitable for application of carbon capture processes, a large fraction of total CO 2 is emitted from the power plant, where carbon-rich blast furnace gas (BFG) and other steel mill off-gases are burned to produce electricity by means of a steam cycle or a gas-steam combined cycle. One option to considerably reduce CO 2 emission from integrated steelworks without affecting the main iron and steel manufacturing process is hence to apply carbon capture and storage (CCS) technologies on the power plant section either in pre-combustion or in post-combustion configurations. The aim of the present paper is to assess the potential of Sorption Enhanced Water Gas Shift (SEWGS) process for pre-combustion CO 2 capture from steel mill off-gas fed to the power plant. The application of the SEWGS process on steel mill off-gas is here investigated and compared to reference monoetanolamine (MEA) and methyldiethanolamine (MDEA) based post-combustion and pre-combustion absorption processes. Different configurations, both for SEWGS and MEA-based cases, have been evaluated and compared from the energy and the environmental point of view. Technical issues associated to the use of the unconventional fuels in state-of-the-art turbines and the effects of steel mill gas blending with natural gas are also discussed. From the mass and energy balances, results show that the MDEA and SEWGS-based plants allow achieving high CO 2 capture efficiencies (of the order of 85–90%), while MEA-based plants need a significant additional heat input through natural gas blending to achieve high capture levels. In terms of efficiency and specific primary energy consumption for CO 2 avoided (SPECCA), the SEWGS technology with the most advanced sorbent developed allows achieving the highest efficiencies (about 37.7%) and the lowest SPECCA (around 2.2   MJ / kg CO 2 ) among the cases assessed. [ABSTRACT FROM AUTHOR]

This paper presents a transportable instrument that simultaneously measures the CO 2 and (relative) O 2 concentration of the atmosphere with the purpose to aid in the detection of CO 2 leaks from CCS sites. CO 2 and O 2 are coupled in most processes on earth (e.g., photosynthesis, respiration and fossil fuel burning), but not in the case of a leak from a CCS site. Whereas a natural increase of the CO 2 concentration is accompanied by a drop in the O 2 concentration, an increase in the CO 2 concentration caused by a leak from a CCS site does not have any effect on the O 2 concentration. The transportable instrument we present here shows an excellent precision for the CO 2 measurements; for O 2 the transportable and flexible design of our system compromised the precision somewhat. The precision in both CO 2 and O 2 determines the detection limit of the system for leaks of CO 2 . The principle of CO 2 leak detection is illustrated by several CO 2 release experiments in which CO 2 was released at a small distance from the air inlet of the measurement system. We present two strategies that can be used to analyze a dataset to find a leak of CO 2 . The detection limit of our instrument is estimated to be around 6 ppm. If a transportable design would not be necessary, the precision for the O 2 measurements can be improved such that the ultimate detection limit of this method is estimated to be around 3 ppm, which would correspond to distances up to 500 m for a leak of 1000 ton CO 2 year −1 (32 g s −1 ) provided favorable atmospheric conditions (wind direction and atmospheric stability) exist. This implies that monitoring time should be long enough to ensure that these conditions occur. [ABSTRACT FROM AUTHOR]

The potassium carbonate (PC) solution is an important chemical solvent to reduce CO 2 emissions due to its advantages of low cost, little toxicity, ease of regeneration, slow corrosiveness, low degradation, and its high stability as well as CO 2 absorption capacity. As a result, the PC process has been applied in more than 700 plants worldwide for CO 2 and hydrogen sulphide removal from streams like ammonia synthesis gas, crude hydrogen, natural gas, and town gas. This paper provides a state-of-the-art review on the research works on CO 2 capture using the PC solution. The studies related to the PC solution comprise three main areas: process, thermodynamics, and kinetics. Important experimental studies as well as modeling and simulation studies are reviewed. Future research directions on CO 2 absorption by aqueous PC solution are highlighted and discussed. [ABSTRACT FROM AUTHOR]

Several carbon capture and storage (CCS) projects around the world were cancelled, delayed or are on hold due to different types of barriers, such as: economic, legal, social and technical. Previous works treat these barriers as independent factors, ignoring potential interactions and possibly providing wrong information. This paper presents the findings of a survey in which experts evaluate the main barriers hampering the deployment of the ROAD project, in the Netherlands. Using the Analytic Hierarchy Process (AHP) and the Decision Making Trial and Evaluation Laboratory (DEMATEL) methods, we have concluded that: (i) CCS barriers are highly interconnected; (ii) “CO 2 price” and “financial incentives” are the most important barriers and should be priorities for investments; (iii) “CO 2 price” highly influences other barriers; (iv) “financial incentives” is very much influenced by them; (v) policy recommendations should take into consideration how these barriers influence each other. Our study recommends caution to policy-makers using the results from previous works, once that they may not reproduce correctly the ranking of the barriers, which may lead to incorrect analysis and conclusions. [ABSTRACT FROM AUTHOR]

To guarantee the safety of CO 2 storage operations, to meet regulatory requirements and thus to be accepted by the public, the operator of a CO 2 storage site has to demonstrate that the risks are adequately managed, which includes the treatment of potential irregularities. This paper proposes a methodology to choose a corrective measure and to optimize its sizing in case of leakage from a CO 2 geological storage through a semi-pervious caprock, a fault, a fractured zone or any other leakage pathway on which it is difficult to directly act. The corrective measures considered in our work are limited to fluid and pressure management practices implemented for controlling the plume migration and eventually for extracting the leaking fluid. The methodology is based on the use of the Multi-Attribute Utility Theory (MAUT) which enables multi-criteria analysis over a continuous set of alternatives. The implementation on a case study illustrates the methodology applicability. The influence of the main assumptions and uncertainties are addressed through a sensitivity analysis. [ABSTRACT FROM AUTHOR]

In the present paper, a “light-up” chemsensor with a high specificity for carbon dioxide detection using a pyrimido[1,2-a]benzimidazole derivative (P1H) in liquid media has been developed. The results show that P1H reacts with carbon dioxide activated by a basic ion to form a carboxylic acid compound (P1-COOH). These results also provide a possible method for carboxylation reactions of P1H using carbon dioxide based on a vinyl carbanion. The complete reaction mechanism cycle was also described using DFT calculations. [ABSTRACT FROM AUTHOR]

Tillage intensity may differently impact gaseous losses of C and N to the atmosphere, but data from long-term experiments are relatively few. Yet, this information is needed to better understand C and N losses and gains in agricultural systems. The objective of this study was to determine how tillage intensity affects soil greenhouse gas (GHG) fluxes (CO 2 , N 2 O, and CH 4) by comparing experimental data from moldboard plow (MP), chisel plow (CP), double disk (DD), and no-till (NT) soils after 38–40 yr of management in a rainfed corn (Zea mays L.)- soybean (Glycine max (L.) Merr) cropping system. We also reviewed global literature to evaluate the impacts of tillage on soil GHG emissions. After 38–40 yr of management, CO 2 fluxes decreased in this order: MP > CP ≈ DD > NT, indicating that as tillage intensity decreased, CO 2 fluxes decreased. Indeed, daily CO 2 fluxes were typically lower under NT than under MP and CP. Similarly, the overall cumulative CO 2 fluxes across 26-mo of measurement were 1.4–1.8 times lower with NT than MP, CP, and DD soils. Also, MP soils had 1.3 times higher CO 2 fluxes than CP and DD soils. These results are similar to those from our global literature review of 60 studies on CO 2 fluxes. The reduction in CO 2 fluxes in NT was likely due to a combination of increased residue cover, reduced soil temperature (r = 0.71; n = 12; p < 0.001), and increased water content (r = −0.75; n = 12; p < 0.001). Daily N 2 O and CH 4 fluxes were highly variable; and cumulative fluxes across the 26-mo study were unaffected by tillage, mirroring findings of our literature review of 37 papers on N 2 O fluxes and 24 on CH 4 fluxes. Overall, based on the data from both the long-term experiment and literature review, NT appears to be the best option to reduce losses of CO 2 followed by reduced till (DD), but N 2 O and CH 4 fluxes do not generally differ with tillage intensity. • Tillage reduced CO 2 fluxes as: moldboard >chisel =double disk>no-till after 40 yr. • Fluxes of CO 2 decreased as tillage intensity decreased. • Tillage systems had minimal effects on N 2 O and CH 4 fluxes. • No-till farming is the top option to mitigate soil C losses as CO 2. [ABSTRACT FROM AUTHOR]

There are growing concerns in the food industry about how supply chains can be managed in a more sustainable way. When distribution activities are outsourced to a logistics service provider (LSP), shippers need to evaluate the LSPs they may (potentially) engage in order to ensure that supply chain sustainability goals are met. In this paper, we present a methodology for LSP evaluation and focus on the ecological dimension of sustainability. We examine how the network carbon footprint of a real-world distribution system is affected by the LSP network that is chosen to forward goods from production facilities to customers. To do this, we analyze the shipment data of an existing Fast Moving Consumer Goods (FMCG) manufacturer. A quantitative distribution network model is set up to study the network carbon footprint of 125 scenarios. Real-world shipments are forwarded via five generic, idealized types of LSP networks. In total, 625 network carbon footprints, specified by three distribution logistics variables and the structure of the LSP network, have been calculated. The results show that LSP structures practicing a geographically decentralized consolidation of shipments are most efficient in reducing of greenhouse gas (GHG) emissions. Furthermore, the effects of changing the manufacturer's and the LSP's strategies for deciding on the tonnage to be forwarded via the LSP network or moved by direct transports are quantified. Finally, we estimate the GHG effect of improving the capacity utilization of the vehicles that move the products. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions in China have been increasing in line with its energy consumption and economic growth. Major means for energy-related greenhouse gases mitigation in the foreseeable future are transition to less carbon intensive energy supplies and structural changes in energy consumption. In this paper, a bottom-up model is built to examine typical projected scenarios for energy supply and demand, with which trends of energy-related carbon dioxide emissions by 2050 can be analyzed. Results show that low-carbon technologies remain essential contributors to reducing emissions and altering emissions trends up to 2050. By pushing the limit of current practicality, emissions reduction can reach 20 to 28 percent and the advent of carbon peaking could shift from 2040 to 2030. In addition, the effect of electrification at end-use sectors is studied. Results show that electrifying transport could reduce emissions and bring the advent of carbon peaking forward, but the effect is less significant compared with low-carbon technologies. Moreover, it implies the importance of decarbonizing power supply before electrifying end-use sectors. [ABSTRACT FROM AUTHOR]

Climatologies, or long-term averages, of essential climate variables are useful for evaluating models and providing a baseline for studying anomalies. The Surface Ocean CO2 Atlas (SOCAT) has made millions of global underway sea surface measurements of CO2 publicly available, all in a uniform format and presented as fugacity, fCO2. As fCO2 is highly sensitive to temperature, the measurements are only valid for the instantaneous sea surface temperature (SST) that is measured concurrently with the in-water CO2 measurement. To create a climatology of fCO2 data suitable for calculating air-sea CO2 fluxes, it is therefore desirable to calculate fCO2 valid for a more consistent and averaged SST. This paper presents the OceanFlux Greenhouse Gases methodology for creating such a climatology. We recomputed SOCAT's fCO2 values for their respective measurement month and year using monthly composite SST data on a 1° x 1° grid from satellite Earth observation and then extrapolated the resulting fCO2 values to reference year 2010. The data were then spatially interpolated onto a 1° x 1° grid of the global oceans to produce 12 monthly fCO2 distributions for 2010, including the prediction errors of fCO2 produced by the spatial interpolation technique. The partial pressure of CO2 (pCO2) is also provided for those who prefer to use pCO2. The CO2 concentration difference between ocean and atmosphere is the thermodynamic driving force of the air-sea CO2 flux, and hence the presented fCO2 distributions can be used in air-sea gas flux calculations together with climatologies of other climate variables. [ABSTRACT FROM AUTHOR]

An aqueous ammonia based CO2capture offers several advantages over the conventional monoethanolamine (MEA) solvent, including a high CO2loading capacity, low stripper heat duty, a lower degradation rate of solvent, low equipment corrosion, and the ability to capture multipollutants. However, in order to make an aqueous, ammonia-based CO2capturing process economically feasible, attention must be paid to the following issues: ammonia slip due to the high evaporation rate of ammonia, energy input for CO2regeneration, and CO2removal efficiency improvements. In conventional, aqueous ammonia-based CO2capture, the process either needs to operate at very low temperatures or must include wash-water columns to mitigate ammonia slips, which increase the capital and operational costs of the system. In this paper, a blended solution of 2-amino-2-methyl-1-propanol (AMP) and ammonia was used to analyze the CO2capture efficiency, ammonia slip, and stripper heat duty. Our results show that, using the blended (30 wt.% AMP + 3 wt.% NH3) solution for CO2capture, the ammonia slip was reduced by 64% at a lean CO2loading of 0.07, CO2capture efficiency was increased by 17.2%, and the heat duty requirement for CO2regeneration was reduced by 80% at a stripper inlet temperature of 60°C. Moreover, the loss of AMP due to evaporation was 0.042 kg/day. [ABSTRACT FROM AUTHOR]

Due to the ongoing increase in the number of commercial flights, greenhouse gas emissions from aviation are expected to rise significantly. Balancing the pursuit of productivity growth with environmental-footprint control policies comprises a long-term regulatory challenge. In this light, the main goals of the present paper are: (i) to measure the CO 2 emissions of European airlines from 2000 to 2010, (ii) to compute airlines’ productivity in developing an environmental-sensitive productivity index, (iii) to compare the obtained results with those resulting from a traditional index, and (iv) to identify the drivers affecting productivity changes. Our results show that on average, airlines’ relative CO 2 emissions have decreased. Although the airlines we studied experienced an average productivity increase—both considering and not considering negative externalities production—environmentally sensible productivity growth is lower than traditional productivity growth. Finally, we find that improvements in load factor as well as a combined increase in stage length and aircraft size affect productivity changes positively, while fuel efficiency is significant only in the case of a CO 2 -sensitive measure of productivity. [ABSTRACT FROM AUTHOR]

Growing energy demand coupled with the threat of global warming call for investigating alternative and unconventional energy sources while reducing CO 2 emissions. One of these unconventional fuels is sour gas, which consists of methane, hydrogen sulfide and carbon dioxide. Using this fuel poses many challenges because of the toxic and corrosive nature of its combustion products. A promising technology for utilizing it is oxy-fuel combustion with carbon capture and storage, including the potential of enhanced oil recovery for added economic benefits. Although methane oxy-fuel cycles have been studied in the literature, using sour gas as the fuel has not been investigated or considered. In this paper, water is used as the diluent to control the flame temperature in the combustion process, and the associated cycle type is modeled to examine its performance. As the working fluid condenses, sulfuric acid forms which causes corrosion. Therefore, either expensive acid resistant materials should be used, or a redesign of the cycle is required. These different options are explored. A cost analysis of the proposed systems is also conducted to provide preliminary estimates for the levelized cost of electricity (LCOE). The results show the acid resistance cycle with a 4.5% points increase in net efficiency over the cycle with SO x removal. However there is nearly a 9% decrease in the cycle's LCOE for the latter case. [ABSTRACT FROM AUTHOR]

In this paper, we used a theoretical model for the variation of Eulerian porosity, which takes into account the adsorption process known to be the main mechanism of production or sequestration of gas in many reservoir of coal. This process is classically modeled using Langmuir's isotherm. After implementation in Code_Aster, a fully coupled thermo-hydro-mechanical analysis code for structures calculations, we used numerical simulations to investigate the influence of coal's hydro-mechanical properties (Biot's coefficient, bulk modulus), Langmuir's adsorption parameters, and the initial liquid pressure in rock mass during CO2 injection in coal. These simulations showed that the increase in the values of Langmuir's parameters and Biot's coefficient promotes a reduction in porosity because of the adsorption process when the gas pressure increases. Low values of bulk modulus increase the positive effect (i.e., increase) of hydro-mechanical coupling on the porosity evolution. The presence of high initial liquid pressure in the rock mass prevents the progression of injected gas pressure when CO2 dissolution in water is taken into account. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Spinning reserve (SR) is one of the most important resources used by system operators to respond to unforeseen events. In a low-carbon economy mode, carbon capture plant is an important CO2 abatement option and might constitute a significant proportion of the generation mix. Due to their potential flexibility, such plants might affect the requirement for SR. This paper describes a multi-period optimization model for coordinating the generation, carbon capture and SR provision. In turn, this model is used to optimize the SR requirements, with the objective of minimizing the overall cost. Since this objective function combines the generation production cost, the expected energy not supplied (EENS) cost, SR provision cost and the carbon emission cost, it is better suited to evaluate the SR requirements of power system with carbon capture plants. Numerical results based on a 26-unit test system show that the proposed model is effective and practical. [ABSTRACT FROM PUBLISHER]

Climate change and global warming as the main human societies’ threats are fundamentally associated with energy consumption and GHG emissions. The residential sector, representing 27% and 17% of global energy consumption and CO 2 emissions, respectively, has a considerable role to mitigate global climate change. Ten countries, including China, the US, India, Russia, Japan, Germany, South Korea, Canada, Iran, and the UK, account for two-thirds of global CO 2 emissions. Thus, these countries’ residential energy consumption and GHG emissions have direct, significant effects on the world environment. The aim of this paper is to review the status and current trends of energy consumption, CO 2 emissions and energy policies in the residential sector, both globally and in those ten countries. It was found that global residential energy consumption grew by 14% from 2000 to 2011. Most of this increase has occurred in developing countries, where population, urbanization and economic growth have been the main driving factors. Among the ten studied countries, all of the developed ones have shown a promising trend of reduction in CO 2 emissions, apart from the US and Japan, which showed a 4% rise. Globally, the residential energy market is dominated by traditional biomass (40% of the total) followed by electricity (21%) and natural gas (20%), but the total proportion of fossil fuels has decreased over the past decade. Energy policy plays a significant role in controlling energy consumption. Different energy policies, such as building energy codes, incentives, energy labels have been employed by countries. Those policies can be successful if they are enhanced by making them mandatory, targeting net-zero energy building, and increasing public awareness about new technologies. However, developing countries, such as China, India and Iran, still encounter with considerable growth in GHG emissions and energy consumption, which are mostly related to the absence of strong, efficient policy. [ABSTRACT FROM AUTHOR]

This study investigates carbon dioxide (CO) and methane (CH) emissions and carbon (C) budgets in a horizontal subsurface flow pilot-plant constructed wetland (CW) with beds vegetated with Cyperus papyrus L., Chrysopogon zizanioides (L.) Roberty, and Mischantus × giganteus Greef et Deu in the Mediterranean basin (Sicily) during the 1st year of plant growing season. At the end of the vegetative season, M. giganteus showed the higher biomass accumulation (7.4 kg m) followed by C. zizanioides (5.3 kg m) and C. papyrus (1.8 kg m). Significantly higher emissions of CO were detected in the summer, while CH emissions were maximum during spring. Cumulative CO emissions by C. papyrus and C. zizanioides during the monitoring period showed similar trends with final values of about 775 and 1,074 g m, respectively, whereas M. giganteus emitted 3,395 g m. Cumulative CH bed emission showed different trends for the three C4 plant species in which total gas release during the study period was for C. papyrus 12.0 g m and ten times higher for M. giganteus, while C. zizanioides bed showed the greatest CH cumulative emission with 240.3 g m. The wastewater organic carbon abatement determined different C flux in the atmosphere. Gas fluxes were influenced both by plant species and monitored months with an average C-emitted-to-C-removed ratio for C. zizanioides, C. papyrus, and M. giganteus of 0.3, 0.5, and 0.9, respectively. The growing season C balances were positive for all vegetated beds with the highest C sequestered in the bed with M. giganteus (4.26 kg m) followed by C. zizanioides (3.78 kg m) and C. papyrus (1.89 kg m). To our knowledge, this is the first paper that presents preliminary results on CO and CH emissions from CWs vegetated with C4 plant species in Mediterranean basin during vegetative growth. [ABSTRACT FROM AUTHOR]

Olefins are important platform chemicals widely used in industry. In terms of the short supply of oil resources, natural gas and coal are two significant alternative feedstocks. In this paper, energy consumption and GHG emissions of olefins production are analysed with life cycle assessment methods. Results showed the energy consumption and GHG emissions of natural gas-to-olefins are roughly equivalent to those of oil-to-olefins, while coal-to-olefins suffers from higher energy consumption and serious GHG emissions, including 5793 kg eq. CO 2 /t olefins of direct emissions and 5714 kg eq. CO 2 /t olefins of indirect emissions. To address the problem, the effect of carbon capture on coal-to-olefins is investigated. In comprehensive consideration of energy utilization, environmental impact, and economic benefit, the coal-to-olefins with 80% CO 2 capture of the direct emissions is found to be an appropriate choice. With this carbon capture configuration, the direct emissions of the coal-to-olefins are reduced to 1161 kg eq. CO 2 /t olefins. However, the indirect emissions are still not captured, which should be strictly monitored and significantly reduced. Finally, a scenario analysis is conducted to estimate resource utilization and GHG emissions of olefins production of China in 2020. Several suggestions are also proposed for policy making on the sustainable development of olefins industry. [ABSTRACT FROM AUTHOR]

The knowledge of Green House Gases GHGs fluxes at the air--sea interface at high resolution is crucial to accurately quantify the role of the ocean in the absorption and emission of GHGs. In this paper we present a novel method to reconstruct maps of surface ocean partial pressure of CO2, pCO2, and air--sea CO2 fluxes at super resolution (4 km) using Sea Surface Temperature (SST) and Ocean Colour (OC) data at this resolution, and CarbonTracker CO2 fluxes data at low resolution (110 km). Inference of super-resolution of pCO2, and air--sea CO2 fluxes is performed using novel nonlinear signal processing methodologies that prove efficient in the context of oceanography. The theoretical background comes from the Microcanonical Multifractal Formalism which unlocks the geometrical determination of cascading properties of physical intensive variables. As a consequence, a multiresolution analysis performed on the signal of the so-called singularity exponents allows the correct and near optimal cross-scale inference of GHGs fluxes, as the inference suits the geometric realization of the cascade. We apply such a methodology to the study offshore of the Benguela area. The inferred representation of oceanic partial pressure of CO2 improves and enhances the description provided by CarbonTracker, capturing the small scale variability. We examine different combinations of Ocean Colour and Sea Surface Temperature products in order to increase the number of valid points and the quality of the inferred pCO2 field. The methodology is validated using in-situ measurements by means of statistical errors. We obtain that mean absolute and relative errors in the inferred values of pCO2 with respect to in-situ measurements are smaller than for CarbonTracker. [ABSTRACT FROM AUTHOR]

Established practice is available as a reference for evaluating sustainable transport and CO2 emissions at national, European and global levels, but comparing corresponding systems at the regional and local levels are more challenging. Therefore, this paper analyses the use of indicators, evaluation methods and data availability at local and regional levels for applied policies and measures in transport planning. Sweden is used as a case study. Available data show that total surveys (e.g., vehicle registry data), sample surveys (e.g., interviews) or modelling can be used to develop transport indicators, and that either generated (volume generated in the area) or performed (volume in the area) traffic and transportation is estimated. However, there are limitations with all methods and the design of evaluations needs careful consideration in order to reflect changes in local and regional transport systems and to relate those changes to specific measures and policies. In most cases, survey methods need to be used in order to follow up the most common indicators. All evaluation methods need to be complemented with analyses of a baseline to determine additionality and also potential rebound effects need to be considered, which requires the application of a wider systems perspective. [ABSTRACT FROM AUTHOR]

Recent studies have shown that the importance of embodied carbon is growing in relation to assessing the environmental impact of buildings. This paper investigates how designers are looking to tackle this, and the effectiveness of some of the methods chosen. Although a number of commercial and non-commercial organisations are developing in-house tools to calculate embodied carbon, these lack the flexibility to be adopted by a wide range of users as well as the efficiency required to be appealing to designers at the early stages of a design. An alternative to these stand-alone tools is offered through the functionality of Building Information Modelling (BIM) software, which is capable of incorporating embodied carbon assessments as part of the normal design process. The potential of plug-in tools to obtain embodied carbon data from suppliers is an area that remains to be explored further. [ABSTRACT FROM AUTHOR]

The promotion of carbon dioxide (CO 2 ) reduction methods is due to the fact that the CO 2 concentration has been increasing rapidly in 21 st century. In order to prevent further damage of the environment caused by greenhouse gases, CO 2 concentration should be stabilized by increasing CO 2 fixation, which can reduce CO 2 emission into the atmosphere. Mineral carbon sequestration or mineral carbonation is the process of utilizing minerals, mostly rich in calcium and magnesium (Ca/Mg) as the feedstock in reaction with CO 2 to produce stable solid carbonates. Mineral carbonation through indirect pH swing process is a very effective method for producing calcium and magnesium carbonates. The Ca/Mg ions are extracted out of feedstock using suitable solvents at low pH condition and then in the second step the leached Ca/Mg ions are carbonated at elevated pH condition. In this paper the state-of-the-art of the carbonation involving pH swing method is updated. [ABSTRACT FROM AUTHOR]

Planetary boundary layer (PBL) CO2 mole fraction data are needed by transport models and carbon budget models as both input and reference for validation. The height of in situ CO2 mole fraction measurements is usually different from that of the model levels where the data are needed; data from short towers, in particular, are dificult to utilize in atmospheric models that do not simulate the surface layer well. Tall tower CO2 mole fraction measurements observed at heights ranging from to 115ma.g.l. at a rural site in Hungary and regular airborne vertical mole fraction profile measurements (136 vertical profiles) above the tower allowed us to estimate how well a tower of a given height could estimate the CO2 mole fraction above the tower in the PBL. The statistical evaluation of the height-dependent bias between the real PBL CO2 mole fraction profile (measured by the aircraft) and the measurement at a given elevation above the ground was performed separately for the summer and winter half years to take into account the different dynamics of the lower troposphere and the different surface CO2 flux in the dif15 ferent seasons. The paper presents: (1) how accurately the vertical distribution of CO2 in the PBL can be estimated from the measurements on the top of a tower of height H, (2) how tall a tower would be needed for the satisfaction of different requirements on the accuracy of the estimation of the CO2 vertical distribution, (3) how accurate a CO2 vertical distribution estimation can be expected from the existing towers; and (4) how much improvement can be achieved in the accuracy of the estimation of CO2 vertical distribution applying the virtual tall tower concept. [ABSTRACT FROM AUTHOR]

For the greenhouse gas (GHG) emissions in China, little attention has been given to CH 4 emissions and related emission mitigation. This paper presents a detailed bottom-up estimation and comparison analysis of China's CH 4 and CO 2 emissions for the first time. China's CH 4 emissions are shown with comparable importance to the CO 2 emissions at the national and regional levels. The national total CH 4 emission in 2008 amounts to 39 Tg, equivalent to about 1/8, 1/3 and 3/5 of the total CO 2 emission by the 100-year global warming potential (GWP) factor, the 20-year GWP factor and the global thermodynamic potential factor, respectively. Increasing CH 4 emissions could compromise China's efforts to mitigate its GHG emissions. In contrast to energy-dominated emission pattern for CO 2 , the major sources of China's CH 4 emissions are coal mining, enteric fermentation, rice cultivation and waste management. Meanwhile, there exists a large gap between the eastern coastal regions and the western and central inland regions in the emission magnitude and emission intensity for CH 4 and CO 2 , with different mitigation flexibilities. Reducing CH 4 emissions should be integrated into the national and regional policies for GHG emission mitigation. In some central and western regions such as Shanxi, Henan, Sichuan, Guizhou, Qinghai and Tibet, the inclusion of CH 4 emission intensity reduction can be more cost-effective than only setting a target for CO 2 emission intensity to reduce the regional GHG emission intensity. [ABSTRACT FROM AUTHOR]

There is growing interest to constrain and validate greenhouse gas (GHG) emission inventories at urban and intra-urban scales. This contribution reviews methods to identify, quantify and attribute emissions (and sequestration) of carbon dioxide, methane and nitrous oxide in cities using in-situ measurements in the atmosphere. Measurements of GHG mixing ratios and fluxes in cities will allow validation of inventories, identification and quantification of poorly-known sources and accounting for the effects of urban land-cover change. In-situ measurements of GHG emissions (and sequestration) in the urban atmosphere are possible (i) at the micro-scale by capturing GHG plumes of individual sources using mobile platforms and measuring vertical profiles of GHGs in the urban canopy layer, (ii) at the local-scale by direct eddy-covariance flux measurements of GHGs on towers, and, (iii) at the meso-scale by measurements of mixing ratios and isotopologues of GHGs in the urban and rural boundary layer combined with box and inverse models. This paper reviews all approaches and highlights their potential and current limitations. These observational methods combined with models will support future endeavors in fine-scale GHG emission monitoring in cities and allow for validation of upcoming remote-sensing products of urban-scale GHG emissions. [ABSTRACT FROM AUTHOR]