Emission Sources Research Articles

Land-free bioenergy from circular agroecology—a diverse option space and trade-offs

Bioenergy from energy crops is a source of negative emissions and carbon-neutral fuels in many 1.5/2 ∘C IPCC pathways. This may compete with other land uses. In contrast, ancillary biomass like by-products and waste is not primarily grown for energy and thus without land/food/feed competition. Here, we examine the availability and environmental impacts of ancillary bioenergy from agricultural sources under 190 circular agroecological strategies using the global food-system model SOLm for the year 2050. We find that there is a diverse option space for the future food and energy system to meet both global warming targets (1.5 ∘C) and food system sustainability (medium to highly organic) – a similar range of ancillary bioenergy global potential (55–65 EJ)from very different food systems (50%–75% organic agriculture and various levels of waste and concentrate feeding reduction). We find three trade-offs between food system sustainability and ancillary bioenergy provision. First, there is a clear trade-off between nutrient recycling and negative emissions potential. 1.4–2.6 GTCO2eq of negative emissions supplied through ancillary bioenergy with carbon capture and storage comes at the cost of nutrient deficits and resulting incompatibility with even a medium degree of organic farming. Second, reducing feed from croplands increases the ancillary bioenergy production with low shares of organic agriculture and reduces it for high shares. Third, food waste reduction reduces ancillary bioenergy provision. Hence, the sustainable transformation of the food system towards a less animal-based diet and waste reduction may conflict with a higher ancillary bioenergy provision, especially when the organic share is high as well. The policy implication of our results is that ancillary bioenergy can provide a similar range of future bioenergy as foreseen in IPCC AR6 illustrative pathways (±10% ) without additional land use or compromising food availability. However, higher ancillary bioenergy provision or additional negative emissions compete with food system sustainability; hence, we recommend policymakers consider aligning energy system planning with the compatibility of sustainable food systems simultaneously.

The impact of different transportation infrastructures on urban carbon emissions: Evidence from China

Transport infrastructure is an important source of carbon emissions, and different transport infrastructure have varying impacts on urban carbon emissions, which has been lacking in previous research. This study selects 273 cities in China from 2005 to 2020 and applied the spatial Durbin model and mediation effect model to empirically examine the direct impact effects, spatial spillover effects, scale and regional heterogeneity, and indirect pathways of highways, high-speed railways, and urban rail on urban carbon emissions. The results shows that: (1) Overall, high-speed railways have a significant reducing effect on carbon emissions, while highways and urban rail have the opposite effect. (2) Considering spatial spillover effects, highways and high-speed railways can promote carbon emissions reduction in neighboring areas, while urban rail has the opposite effect. (3) For scale heterogeneity, urban rail can reduce carbon emissions in mega-cities, while highways and high-speed railways have the opposite effect. For regional heterogeneity, all three types of transport infrastructure can reduce carbon emissions in western cities, but increase urban carbon emissions in eastern and central regions. (4) Industrial upgrading, technological progress, and population agglomeration are all pathways through which transport infrastructure indirectly affects carbon emissions, but their effects vary for different transport infrastructure.

Targeting methanotrophs and isolation of a novel psychrophilic Methylobacter species from a terrestrial Arctic alkaline methane seep in Lagoon Pingo, Central Spitsbergen (78° N)

The microbial diversity associated with terrestrial groundwater seepage through permafrost soils is tightly coupled to the geochemistry of these fluids. Terrestrial alkaline methane seeps from Lagoon Pingo, Central Spitsbergen (78°N) in Norway, with methane-saturated and oxygen-limited groundwater discharge providing a potential habitat for methanotrophy. Here, we report on the microbial community’s comparative analyses and distribution patterns at two sites close to Lagoon Pingo’s methane emission source. To target methane-oxidizing bacteria from this system, we analysed the microbial community pattern of replicate samples from two sections near the main methane seepage source. DNA extraction, metabarcoding and subsequent sequencing of 16S rRNA genes revealed microbial communities where the major prokaryotic phyla were Pseudomonadota (42–47%), Gemmatimonadota (4–14%) and Actinobacteriota (7–11%). Among the Pseudomonadota, members of the genus Methylobacter were present at relative abundances between 1.6 and 4.7%. Enrichment targeting the methane oxidising bacteria was set up using methane seep sediments as inoculum and methane as the sole carbon and energy source, and this resulted in the isolation of a novel psychrophilic methane oxidizer, LS7-T4AT. The optimum growth temperature for the isolate was 13 °C and the pH optimum was 8.0. The morphology of cells was short rods, and TEM analysis revealed intracytoplasmic membranes arranged in stacks, a distinctive feature for Type I methanotrophs in the family Methylomonadaceae of the class Gammaproteobacteria. The strain belongs to the genus Methylobacter based on high 16S rRNA gene similarity to the psychrophilic species of Methylobacter psychrophilus Z-0021T (98.95%), the psychrophilic strain Methylobacter sp. strain S3L5C (99.00%), and the Arctic mesophilic species of Methylobacter tundripaludum SV96T (99.06%). The genome size of LS7-T4AT was 4,338,157 bp with a G + C content of 47.93%. The average nucleotide identities (ANIb) of strain LS7-T4AT to 10 isolated strains of genus Methylobacter were between 75.54 and 85.51%, lower than the species threshold of 95%. The strain LS7-T4AT represents a novel Arctic species, distinct from other members of the genus Methylobacter, for which the name Methylobacter svalbardensis sp. nov. is proposed. The type of strain is LS7-T4AT (DSMZ:114308, JCM:39463).

Optimal Design of Resilient Carbon Capture, Utilization and Storage (CCUS) Supply Chain Networks under Facility Disruption

In recent years, various kinds of carbon dioxide capture, utilization and storage supply chain network design (CCUS SCND) problems have been extensively studied by scholars from the supply chain management community and other fields. The existing works mainly focus on the various deterministic or uncertainty problems; few works consider the CCUS SCND resilience problem in the context of utilization/storage facility disruptions due to unexpected natural disasters or other geological anomaly events. This paper aims to study the CCUS SCND resilience problem under utilization/storage facility capacity disruption risk. We propose a stochastic mixed-integer linear programming model for the considered problem. In the considered problem, the main decisions related to the following areas are taken into account: supply chain design and planning; facility disruption risk handling, including the optimal determination of facility locations and the matching of carbon dioxide emission sources and utilization/storage facilities; carbon dioxide normal transportation planning; and transshipment planning for various disruption scenarios. Finally, an experimental study comprising a case study from China is conducted to validate the effectiveness and performance of our proposed model. The obtained results show that the supply chain networks for the case study obtained by our proposed model are efficient, cost-effective and resilient in mitigating various kinds of utilization/storage facility disruption scenarios, showing the model can be applied to large-scale CCUS projects to help managers effectively deal with disruption risks. Future research should consider multiple disruption events and propose multiple effective resilience strategies.

Occurrence of N-nitrosamines in the atmosphere and human health risk: A case study in an urban area of Chuncheon, Gangwon State, South Korea

This study aimed to investigate the occurrence of eight nitrosamines (NAs) in particulate (PM2.5) and gaseous phases and assess the human health risk associated with these compounds in an urban area of Chuncheon, Gangwon State, South Korea, across four sampling seasons. The findings revealed that the total concentrations of eight NAs measured during the sampling period exceeded the public health recommendation of 0.3 ng/m3 provided by the Norwegian Institute of Public Health, indicating a potential human health risk from NA exposures. In particular, the average total NA concentration observed in the gaseous samples during the winter of 2021 was 18.1 ± 6.46 ng/m3. The primary emission sources could potentially impact the concentrations of NAs in the atmosphere due to their significant positive correlation with primary emission species such as NO2, CO, and SO2. Moreover, the levels of particulate NAs during the summer were negatively correlated with O3, suggesting that their formation might be influenced by ozonation in the aqueous aerosol phase. In addition, the total NA concentrations measured in the gaseous phase were four to six times higher than those measured in the PM2.5 phase throughout the sampling period. Thus, domestic sources have the potential to impact the pollution levels of the research area more significantly than long-range atmospheric transport. In particular, the highest concentrations of NAs in the gas phase were observed during the winter, while the lowest concentrations were recorded in the summer, possibly influenced by photolysis. Nevertheless, the study suggested that tertiary amines might contribute to the presence of gaseous NAs in sunlight. Consequently, further studies focusing on the occurrence of tertiary amines in the gas phase should be considered. The cumulative lifetime cancer risks estimated from inhalation exposure exceeded the acceptable risk level of 10⁻6 for all age groups across all four seasons. Therefore, it is crucial to implement effective control measures to mitigate potential health risks associated with exposure to NAs.

Deep Paβ Imaging of the Candidate Accreting Protoplanet AB Aur b

Giant planets grow by accreting gas through circumplanetary disks, but little is known about the timescale and mechanisms involved in the planet-assembly process because few accreting protoplanets have been discovered. Recent visible and infrared imaging revealed a potential accreting protoplanet within the transition disk around the young intermediate-mass Herbig Ae star, AB Aurigae (AB Aur). Additional imaging in Hα probed for accretion and found agreement between the line-to-continuum flux ratio of the star and companion, raising the possibility that the emission source could be a compact disk feature seen in scattered starlight. We present new deep Keck/NIRC2 high-contrast imaging of AB Aur to characterize emission in Paβ, another accretion tracer less subject to extinction. Our narrow band observations reach a 5σ contrast of 9.6 mag at 0.″6, but we do not detect significant emission at the expected location of the companion, nor from other any other source in the system. Our upper limit on Paβ emission suggests that if AB Aur b is a protoplanet, it is not heavily accreting or accretion is stochastic and was weak during the observations.

A pilot study to capture methane from the exhausted air of dairy cows using a cryogenic approach

In the agricultural sector, ruminants are the largest methane (CH4) emission source and many efforts have been undertaken to reduce these greenhouse gas emissions, while compromising animal health and physiology. On the other hand, ruminal CH4, which is biomethane, is in high demand, especially in its liquid form (LBM) that can be used as high energy density fuel. However, CH4 released from a ruminant is immediately mixed with air and highly diluted (<0.1%), challenging CH4 capture technologies. Here we aimed to construct a cryogenic pilot system to capture and liquefy enteric CH4 released from dairy cows kept in respiration chambers. To approach this aim, the outlet air from the chambers was directed through a two-step cooling trap to capture CO2 (−120 to −130 °C) as a solid in the first and CH4 and O2 as liquids in the second cooler (−160 to −180 °C). Warming the second cooler resulted in the evaporation of O2, thereby separating O2 and CH4. LBM purity was in average 90% and was lowest at warming rates higher than 0.88 °C/min. The mean CH4 capture efficiency was 92% and found to be independent of sequestration time and flow rate. However, an increase in CH4 concentration to 0.6%, as it occurs directly at the muzzle of a cow, reduced the sequestration time for CH4. These results show that cryogenic technology can be used to obtain LBM from the air containing ultra-low CH4 concentrations as it is found in cattle barns with high efficiency and purity.

A comprehensive assessment of ions in snow and ice cores based on global observational data

Snow and ice are important reservoirs of atmospheric ions, yet a comprehensive understanding of ions in snow/ice remains a challenge due to spatiotemporal limitations of field campaigns. To address this issue, mathematical statistics were employed to summarize global observational data from 49 published sources covering 546 snow and 19 ice core sampling sites. The findings show remarkable variability in ion concentrations and compositions in snow, with differences spanning 4 to 6 orders of magnitude. This variation changes with elevation, season and historical development, and differs regionally and within regions. These complex patterns of ion distribution in snow and ice are shaped by a range of factors, including local and remote emission sources, trans-regional transports, atmospheric circulations, natural climate variability, geographical features and environmental factors. This comprehensive global analysis would effectively enhance our understanding of snow and ice chemistry and its significant environmental implications, particularly in the context of a rapid changing global climate.

Performance evaluation of four sampling techniques and source apportionment for the atmospheric deposition fluxes of polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are primarily emitted into the atmosphere through anthropogenic activities and can be transported to receptor sites at varying distances. In this study, the atmospheric PAH deposition was investigated using a dry deposition plate (DDP) with Mylar, a dry deposition disk (DDD) with Velcro, a resin bulk deposition sampler (Resin-BDS), and a water bulk deposition sampler (Water-BDS) in Ulsan, South Korea, during May–October 2013. Additionally, ambient PAH concentrations were monitored using high-volume air samplers. The mean deposition fluxes of Σ13 PAHs were 8.62 ± 1.44, 36.9 ± 6.81, 56.9 ± 9.74, and 63.8 ± 8.04 μg/m2/d for the DDP, DDD, Resin-BDS, and Water-BDS, respectively. The DDD was more effective than the DDP because it could collect high molecular weight (HMW) PAHs from dry deposition, which are more toxic than low molecular weight PAHs. The Water-BDS had the highest fluxes of Σ13 PAHs; however, the Resin-BDS may be more suitable for collecting HMW PAHs from both dry and wet deposition due to relatively constant values for the deposition velocity of PAHs. Furthermore, the PAH fluxes in the Resin-BDS samples were significantly positively correlated with the gaseous and total (gaseous + particulate) concentrations of ambient PAHs. Hence, the fluxes obtained by the Resin-BDS were further used to apply principal component analysis, multiple linear regression, and backward air trajectory simultaneously to identify the emission sources of the deposited PAHs. The results indicate that the combustion of fossil fuels and biomass was the major source. In particular, the industrial complexes using petroleum and coal on the city's east coast and vehicular exhausts were the main local sources. Meanwhile, long-range sources may be forest fires, harbors, and industrial activities in nearby countries. Our study suggests that BDS, considering both dry and wet deposition, can be selectively used for research on PAH deposition.

Defining Detection Limits for Continuous Monitoring Systems for Methane Emissions at Oil and Gas Facilities

Networks of fixed-point continuous monitoring systems are becoming widely used in the detection and quantification of methane emissions from oil and gas facilities in the United States. Regulatory agencies and operators are developing performance metrics for these systems, such as minimum detection limits. Performance characteristics, such as minimum detection limits, would ideally be expressed in emission rate units; however, performance parameters such as detection limits for a continuous monitoring system (CMS) will depend on meteorological conditions, the characteristics of emissions at the site where the CMS is deployed, the positioning of CMS devices in relation to the emission sources, and the amount of time allowed for the CMS to detect an emission source. This means that certifying the performance of a CMS will require test protocols with well-defined emission rates and durations; initial protocols are now being used in field tests. Field testing results will vary, however, depending on meteorological conditions and the time allowed for detection. This work demonstrates methods for evaluating CMS performance characteristics using dispersion modeling and defines an approach for normalizing test results to standard meteorological conditions using dispersion modeling.

Evaluation of Two Species of Macroalgae from Azores Sea as Potential Reducers of Ruminal Methane Production: In Vitro Ruminal Assay.

The utilisation of seaweeds as feed supplements has been investigated for their potential to mitigate enteric methane emissions from ruminants. Enteric methane emissions are the primary source of direct greenhouse gas emissions in livestock and significantly contribute to anthropogenic methane emissions worldwide. The aim of the present study is to evaluate the nutritional role and the in vitro effect on cumulative gas and methane production of Asparagopsis taxiformis (native species) and Asparagopsis armata (invasive species), two species of red algae from the Azorean Sea, as well as the ability to reduce biogas production when incubated with single pasture (Lolium perenne and Trifollium repens) as substrate. Four levels of concentrations marine algae were used (1.25%, 2.25%, 5%, and 10% DM) and added to the substrate to evaluate ruminal fermentation using the in vitro gas production technique. The total amount of gas and methane produced by the treatment incubation was recorded during 72 h of incubation. The results indicate that both algae species under investigation contain relatively high levels of protein (22.69% and 24.23%, respectively, for Asparagopsis taxiformis and Asparagopsis armata) and significant amounts of minerals, namely magnesium (1.15% DM), sodium (8.6% DM), and iron (2851 ppm). Concerning in vitro ruminal fermentation, it was observed that A. taxiformis can reduce enteric methane production by approximately 86%, during the first 24 h when 5% is added. In the same period and at the same concentration, A. armata reduced methane production by 34%. Thus, it can be concluded that Asparagopsis species from the Azorean Sea have high potential as a protein and mineral supplement, in addition to enabling a reduction in methane production from rumen fermentation.

Citizens' willingness to support farmers’ adoption of low crude protein diet in pig production

Livestock farming has a detrimental effect on the environment since it generates a lot of gas emissions. In pig farming, the use of feed is among the substantial sources of animal farm emissions among the European Union. Nevertheless, the use of Low Dietary Crude Protein (LCP) may reduce the environmental impacts of pig farming and provide diverse ecosystem services (ESs). Concurrently, these pig diets alternatives may result more expensive than the conventional ones, which may negatively affect farmers' intention to adopt these alternatives. Citizens’ payment for ESs may be a viable strategy to motivate farmers to implement more sustainable pig diets. The primary objective of this study is to assess the extent to which citizens of Catalonia (Spain) are willing to pay for the ESs generated by the implementation of a LCP diet in pig production. In pursuit of this goal, we conducted an online survey among 501 citizens, including a Discrete Choice Experiment. Participants evaluated three feed scenarios, and their choices were scrutinized using conditional logit model. Results revealed that citizens prefer the new pig diets, including both LCP and Very LCP (VLCP) diets, over the conventional pig diet. However, there is a clear preference toward the VLCP diet justified by their willingness to pay (WTP) of €67/year/adult.

Industrial fluoride emissions and their spatial characteristics in the Nansi Lake Basin, Eastern China.

Excessive fluoride emissions threaten ecological stability and human health. Previous studies have noted that industrial sources could be significant. However, quantifying industrial fluoride emissions has not been yet reported. In this study, both bottom-up and top-down approaches were used to estimate the fluoride emissions in the Nansi Lake Basin. Global and local spatial autocorrelation were adopted to reveal the spatial agglomeration effects. The fluoride emissions calculated by the bottom-up approach were larger than those calculated by the top-down method. The highest fluoride input mainly occurred in Zoucheng and Mudan. The highest fluoride emissions mainly occurred in Zoucheng and Rencheng using the bottom-up approach. The highest fluoride emissions mainly occurred in Zoucheng and Yanzhou using the top-down approach. Mining and washing of bituminous coal and anthracite (BAW) was the most significant source of fluoride input and emissions. A significant spatial agglomeration effect of fluoride emissions was found. These findings could provide a method for accurate industrial fluoride emission estimation, complement the critical data on the fluoride emissions of main industrial sectors, and provide a scientific basis for tracing fluoride sources.

FORMATION AND EMISSION OF DIOXINS IN THE ENERGY SECTOR OF UKRAINE

The development of national plans to reduce the emissions of Persistent Organic Pollutants (POPs) is one of the key requirements of the Stockholm Convention on POPs. Preliminary expert assessments show that the energy sector of Ukraine is the second largest producer of POPs after metallurgy. The largest sources of POPs emissions with relatively small volumes of combustion are plants that burn municipal solid waste and biomass. Optimizing the composition of the input fuel/raw material should provide a significant potential for reducing POPs emissions in such installations. Extraction of components that can become precursors or catalysts for the synthesis of dioxins during municipal solid waste incineration can be carried out through large-scale application of separate collection and preliminary mechanical and biological processing of waste. For biomass with high chlorine content and ash content (straw), it is advisable to use combined combustion with fossil fuels or waste containing dioxin synthesis inhibitors. When using biomass as an auxiliary fuel in industrial boilers and furnaces, it is advisable to equip gas cleaning systems with devices for sorption and catalytic removal of dioxins. Bibl. 28, Tab. 3.

Influence of the Supply Voltage Variation on the Conducted Emission in the Frequency Range up to 150 kHz Injected into the Power Grid by CFL and LED Lamps—Case Study

In normal operating conditions, the mains voltage level provided by low-voltage distribution networks follows time-varying patterns within permissible limits. The statistical characterisation of disturbances inserted into the power grid by nonlinear electrical devices is useful since operators are able to establish power quality limits and assess the residual capacity of networks for new smart installations, which may include a multitude of power electronic devices. Existing standards related to emission tests recommend using a power supply source in the measurement circuit with a nominal voltage parameter. However, the range of permissible variations of relevant supply voltage parameters may have an impact on conducted emissions. It can also be considered that the symptoms of supply voltage variations may manifest themselves differently depending on the equipment’s architecture and also the range of frequency observation with reference to harmonics and supraharmonics. The purpose of this study is to measure and analyze non-intentional conducted emissions injected into the power grid by lighting devices, methodically, by numbers of studies under different supply voltage conditions within two frequency bands. The emission is evaluated separately in two ranges: up to 2 kHz and 9-150 kHz. Obtained results show that the level of conducted emission introduced into the low voltage network by modern lighting sources like fluorescent and LED lamps varies with the supply voltage level compared to the emission generated in the nominal voltage level condition. Additionally, in the case of a spectrum of higher frequencies, some trends of shifting of the characteristic frequency bands are recorded. The potential of the obtained results is to complement the knowledge of the emission of modern lighting sources, which can be further used for digital models of these devices and to estimate the impact on the grid under real working conditions.

Characteristics and Formation Mechanism of Ozone Pollution in Demonstration Zone of the Yangtze River Delta, China

Emerging research indicates that ground-level ozone (O3) has become a leading contributor to air quality concerns in many Chinese cities, with the Yangtze River Delta (YRD) region facing particular challenges. This study investigated the characterization of air pollutants in Wujiang, which is located within the YRD demonstration zone, during the warm season (April–September) of 2022. The contributions of emission and meteorology to O3 were identified, the O3-NOX-VOC sensitivities were discussed, and the VOC sources and their contributions to O3 formation were analyzed. A random forest model revealed that the high O3 concentration was mainly caused by a combination of increased emission intensity due to the resumption of work and production after the COVID-19 pandemic, along with adverse meteorological conditions. The results revealed more than 92% of the pollution days were related to O3 during the warm season, and the impact of O3 precursor emissions was slightly greater than that of the meteorological conditions. O3 formation was in the VOC-limited regime, and emission reduction strategies targeting VOCs, particularly aromatics such as toluene and xylene, have been identified as the most effective approach for mitigating O3 pollution. Changes in O3-NOX-VOC sensitivity were also observed from the VOC-limited regime to the transitional regime, which was primarily driven by variations in the NOX concentrations. The VOC source analysis results showed that the contributions of gasoline vehicle exhaust and diesel engine exhaust (mobile source emissions) were significantly greater than those of the other sources, accounting for 20.8% and 16.5% of the total VOC emissions, respectively. This study highlights the crucial role of mobile source emission control in mitigating O3 pollution. Furthermore, prioritizing the control of VOC emission sources with minimal NOX contributions is highly recommended within the VOC-limited regime.

Detection, localization, and quantification of single-source methane emissions on oil and gas production sites using point-in-space continuous monitoring systems

We propose a modular framework for methane emission detection, localization, and quantification on oil and gas production sites that uses concentration and wind data from point-in-space continuous monitoring systems. The framework leverages a gradient-based spike detection algorithm to estimate emission start and end times (event detection) and pattern matches simulated and observed concentrations to estimate emission source location (localization) and rate (quantification). The framework was evaluated on a month of non-blinded, single-source controlled releases ranging from 0.50 to 8.25 h in duration and 0.18 to 6.39 kg/h in size. All controlled releases are detected and 82% are localized correctly; 5.5% of estimated events are false positives. For emissions ≤1 kg/h, the framework underestimates the emission rate by −3.9% on average, with 90% of rate estimates falling within a percent difference of [−74.9%, 195.2%] from the true rate. For emissions &amp;gt;1 kg/h, the framework overestimates the emission rate by 4.3% on average, with 90% of rate estimates falling within a percent difference of [−49.3%, 78.8%] from the true rate. Potential uses for the proposed framework include near real time alerting for rapid emission mitigation and emission quantification for use in measurement-informed inventories on production sites.

Designing additional CO2 in-situ surface observation networks over South Korea using bayesian inversion coupled with Lagrangian modelling

Efforts to enhance greenhouse gas (GHG) emission reduction in East Asia play a pivotal role on both global and regional scales in advancing climate mitigation strategies. This study aimed to better constrain anthropogenic CO2 emission estimates by expanding the network of near-surface in-situ stations for CO2 observations across South Korea. To achieve an optimal CO2 network design, we conducted an Observing System Simulation Experiment (OSSE) coupled with the Stochastic Lagrangian Transport model (STILT), utilizing meteorological data from the Korean Integrated Model (KIM). Our inversion setup incorporated two CO2 emission datasets with a 0.1o resolution: EDGAR v6 for prior emissions and GRACED for truth emissions. A uniform model-mismatch error of 3 ppm was introduced across sites. The effectiveness of the existing five in-situ stations, termed the base network, in South Korea was evaluated to gauge their ability to constrain CO2 surface flux estimates. However, the findings revealed a reduction in flux uncertainty of only 29.2%, which fell short of the desired uncertainty reduction goal. In this base network, the Lotte World Tower (LWT: 37.5126°E, 127.1025°E) in Seoul and the Anmyeondo (AMY: 36.538576° N, 126.330071° E) site in Taean county stood as major contributors, with estimated reductions of 17.48% and 6.35%, respectively. Consequently, we proposed and developed an extended network, identifying seven candidate sites based on consideration of logistical factors, existing infrastructures, and proximity to the emission source regions. An incremental optimization scheme ranked their contributions, resulting in an additional 25% reduction, bringing the total to 54.13%. However, it is noteworthy that diminishing returns (ranging from 13% to less than 0.1%) were observed with an increase in station count mainly due to the possibility that adding a station earlier in the sequence might render subsequent stations redundant. Despite this, the proposed CO2 network successfully reduced uncertainty in emissions, narrowing the gap with the objectives of the Global Greenhouse Gas Watch (G3W).

Evolution and determinants of precipitation chemistry in a plateau city, China: Insight from the pollutants source identification and environmental effect

Rainfall-related chemical ions deposition processes have important environment effects on earth-surface, which is also a vital sink of urban air pollutants. Therefore, identifying the rainwater chemical evolution and determinants, and source is essential. The daily-based rainwater samples during 2022– 2023 and the historical rainwater data in a typical plateau city (Kunming) were investigated. The Ca2+ and NH4+, SO42− and NO3− dominated the rainwater cations and anions, with the cationic and anionic percentages of 78% and 10%, 50% and 33%. The historical variations in ions percentages revealed the achievement of environmental protection. The precipitation amount and the seasonal changes of source emission were critical determinants for the variations of rainwater chemistry. Using the stoichiometry and receptor model, the contributions of potential origins to rainwater chemicals were assessed. 86% of NO3− and 40% SO42− were from combustion-related anthropogenic source, volatilization-related source contributed 85% of NH4+ (e.g., agricultural/municipal wastes emissions), whereas marine input was the main contributor of Cl− (59%) and Na+ (52%). Mg2+ (58%) and Ca2+ (41%) were primary from terrestrial input source. The risk of wet deposition-caused acidification was limited due to the high rainwater neutralization level, whereas the impact of nitrogen-related deposition on gross primary productivity (GPP) was non-negligible and further attention was need. Overall, the present study clarified the rainfall chemical features of plateau city region and further provided decision support for more effective urban air environmental management programs.

Environmental and economic multi-objective real options analysis: Electrification choices for field development investment planning

Hydrocarbons combustion is one of the primary sources of greenhouse gas emissions, causing climate change. As large volumes of gas are burned to power the energy-consuming oil and gas production on offshore platforms, the Norwegian petroleum industry contributes significantly to the country’s emissions, making it a target for environmental regulations. Hence, Norwegian petroleum companies are facing the challenge of finding solutions to comply with increasing environmental requirements while being economically feasible. Offshore platforms electrification helps to reduce carbon emissions, but relevant investment decisions are complicated by uncertainty related to market fluctuations and regulations. In this study, we analyze how considering environmental and economic objectives simultaneously affects optimal investment strategies under uncertainty. We develop a novel methodology for determining the project value and the best investment policy for field development, considering several objectives and uncertain factors. By introducing multi-objective optimization into a real options investment valuation model, economic and environmental objectives are combined using the weighted sum method. The optimization model allows to determine trade-offs between the objectives of the project along with a flexible investment policy. Such optimal solutions result in a significant decrease in carbon emissions at only a marginal reduction in economic value.