Global Environmental Issues Research Articles

Does rural energy poverty alleviation really reduce agricultural carbon emissions? The case of China

Energy poverty has led to far-reaching global environmental issues as it can exacerbate carbon emissions, particularly in the rural areas. Alleviating rural energy poverty might be a potentially effective way to mitigate this problem. Accordingly, this paper proposes a novel and comprehensive measurement of Rural Energy Poverty Alleviation (REPA) of 30 provinces in China from 2000 to 2017. The overall REPA index has increased from 2000 to 2017, despite of obvious regional differences. We empirically verify the Environmental Kuznets Curve (EKC) between REPA and agricultural carbon emissions (ACE) through fixed effects model. The results show that REPA exerts an inverted U-shaped effect on ACE, which means that REPA will reduce ACE after a threshold. Notably, the sub-indicators of REPA, Rural Energy Service Availability (RESA) and Rural Energy Consumption Cleanliness (RECC), can jointly affect ACE through the incremental effect and the reduction effect. Moreover, through the panel threshold model, it can be found that REPA may play a greater role in increasing ACE in provinces with abundant agricultural endowments. Finally, several policy implications are highlighted for policymakers to better achieve the dual goals of alleviating rural energy poverty and reducing agricultural carbon emissions. This study may provide a better understanding of the nexus between REPA and ACE for the low-carbon agriculture development.

Simulating polyethylene pyrolysis from a generalized molecular-level kinetic model

Waste plastics have emerged as a global environmental issue. Polyethylene, accounting for about 25% of global plastic production, has been acknowledged as the major cause of “white pollution”. In this paper, a generalized molecular-level kinetic model was proposed to understand the pyrolysis of polyethylene applying structure-oriented lumping, Poisson distribution, and genetic algorithm. The number of ordinary differential equations derived from the reaction kinetics were dramatically reduced by this simplified network with 14-rule design. The generalizability was confirmed by case studies without any change in the rule design. Under most conditions, the mean relative error between experimental and model data could be controlled within 5%, while abnormal deviations indicate the obstacle of heat transfer. The simulation curve could provide guidance for the experiments by locating the peak value of products. From 400–470 °C in Case 2, the increase in the reaction proportion of producing light oil explains the experimental results from the perspective of molecular-level reaction network. The comparison between PE and PS pyrolysis elaborates different pyrolysis mechanisms based on the different molecular structures.

An Analysis of Circular Economy Literature at the Macro Level, with a Particular Focus on Energy Markets

Sustainability is a strategic approach to develop a more sustainable economy to support the environment and socio-economic development. Literature on sustainability has been concerned mainly with global warming and environmental degradation issues, whereas the Circular Economy (CE) concept has recently been suggested as an alternative solution to support market sustainability and deal with both environmental and socio-economic challenges. In order to tackle these challenges, countries must switch from linear economies that follow the “take-make-dispose” principle to circular and sustainable economies. This study applies a structural and conceptual literature review to elucidate the most decisive determinants in the formation of circular strategies, particularly in the context of the energy sector. This study examines obstacles that hinder CE adoption and formulates drivers and measures to overcome them. The strategic literature review shows that the circular approach is critical in achieving sustainable development. Circularity can be considered a novel and innovative approach to alleviating the contradiction between rapid economic growth and energy and raw materials shortages. The CE structure must be considered as a sustainable foundation to enhance economic growth by avoiding waste, preserving natural capital, managing resource scarcity, recycling materials, maximizing energy efficiency, and recirculating them into the economy. Analysis reveals that the circular system is a key pillar of sustainability, security, and efficiency in the energy sector. The sustainable energy transition requires incorporating the CE principles in the design process. It also revealed that both public and private sectors must move away from the linear paradigm towards circularity to achieve CE implementation.

Cost effective media optimization for PHB production by Bacillus badius MTCC 13004 using the statistical approach

Polyhydroxybutyrate (PHB) has significant potential for replacing non-biodegradable traditional plastic, which is responsible for several global environmental issues. The main problem with switching to bio-based alternatives for petrochemical plastics is the large price gap on the market. To overcome this problem, the present research was focused on the utilization of inexpensive substrates i.e. agricultural residues for cost-effective PHB production by endospore-forming bacteria Bacillus badius MTCC 13004. For efficient PHB production, Box-Behnken Design (BBD) was selected for media optimization and to observe the interactive effects of four variables i.e. pH, Na acetate, Banana peel, and mustard cake. PHB yield of 2.11 g/L was attained under optimized conditions compared to non-optimized conditions (0.72 g/L). FTIR spectra analysis of PHB extracted from Bacillus badius was found to be similar to commercial PHB. NMR data was also matched with the chemical shift signals CH, CH2, and CH3 of PHB. The melting temperature (Tm) and glass transition temperature (Tg) of PHB from Bacillus badius was found to be 165.14 and 2.68 °C, respectively. Further, PCR protocol was also designed to amplify key enzymes of the PHB synthesis pathway i.e. PHB synthase (phb C gene).

Metal-Organic Frameworks for Photocatalytic Water Splitting and CO2 Reduction.

Photocatalytic water splitting and carbon dioxide (CO2 ) reduction provide promising solutions to global energy and environmental issues. In recent years, metal-organic frameworks (MOFs), a class of crystalline porous solids featuring well-defined and tailorable structures as well as high surface areas, have captured great interest toward photocatalytic water splitting and CO2 reduction. In this review, the semiconductor-like behavior of MOFs is first discussed. We then summarize the recent advances in photocatalytic water splitting and CO2 reduction over MOF-based materials and focus on the unique advantage of MOFs for clarifying the structure-property relationship in photocatalysis. In addition, some representative characterization techniques have been presented to unveil the photocatalytic kinetics and reaction intermediates in MOF-based systems. Finally, the challenges, and perspectives for future directions are proposed.

Metal‐Organic Frameworks for Photocatalytic Water Splitting and CO2Reduction

AbstractPhotocatalytic water splitting and carbon dioxide (CO2) reduction provide promising solutions to global energy and environmental issues. In recent years, metal‐organic frameworks (MOFs), a class of crystalline porous solids featuring well‐defined and tailorable structures as well as high surface areas, have captured great interest toward photocatalytic water splitting and CO2reduction. In this review, the semiconductor‐like behavior of MOFs is first discussed. We then summarize the recent advances in photocatalytic water splitting and CO2reduction over MOF‐based materials and focus on the unique advantage of MOFs for clarifying the structure‐property relationship in photocatalysis. In addition, some representative characterization techniques have been presented to unveil the photocatalytic kinetics and reaction intermediates in MOF‐based systems. Finally, the challenges, and perspectives for future directions are proposed.

Factors and thresholds determining sediment delivery pathways between forest road and stream in mountainous watershed

Road erosion is a global environmental issue. The transport of eroded sediment from road to stream can devastatingly impact water quality. Research efforts to combat this issue have prioritized maintaining roads and preventing erosion. Little research has explored the fate of eroded road materials in their transport from road to stream. Therefore, taking the Xiangchagou watershed in the Dabie Mountains of China as a case, this study investigated how local geography determines the formation and thresholds of different delivery pathways (gullied, partially gullied, and diffuse pathways) for road-eroded sediment through runoff, based on the binary logistic regression analysis, random forest model, and the lowest point data fitting methods. It explored how these different pathways have variable impacts on local plant and soil communities. Our results showed that soil D50, bulk density, shrub-grass coverage, and local plant diversity varied significantly (p < 0.05) between different delivery pathways. In particular, soil bulk density and local plant diversity varied significantly (p < 0.05) among different position of these delivery pathways. Specifically, the diffuse pathways are characterized by lower soil bulk density, looser soil structure, and higher species diversity, likely explained by the deposition of sediment-loaded runoff. Gullied pathways, conversely, had significantly more compacted surface soil and lower local plant diversity, likely as a result of scouring by sediment-loaded runoff. Slope gradient of upslope catchment (Us), road segment (Rs), and lower hillslope (Ds) and effective contributing area (Eca), which determine the intensity and kinetic energy of sediment-loaded runoff, are the main external drivers that determine the occurrence of gullied pathways. By contrast, the soil median particle size, surface roughness, and shrub-grass cover of lower hillslope, which contribute to erosion resistance of hillslope, are the primary intrinsic drivers promoting development of pathways from partial to full gully. Furthermore, we found that the critical topographic thresholds for the initiation of the gully pathways and the continued development of gully from partial to complete gully pathways could be expressed as Ds = 0.35Eca−0.13 and Ds = 0.41Eca−0.17, respectively. These results are expected to provide basis for understanding the formation and development mechanism of sediment delivery pathways from road to stream.

The primary drivers of private-sphere pro-environmental behaviour in five European countries during the Covid-19 pandemic

Nowadays, when fighting climate change and other global environmental issues is of utmost urgency, the understanding of what drives pro-environmental behaviour has become a hot topic in both academic and practical circles. Some earlier studies unravelled the complexity of the underlying factors of pro-environmental conduct, yet more studies are needed to understand the socio-cultural premises of such behaviour in different countries. The main aim of this paper is to offer a comprehensive analysis of the importance of pro-environmental behaviour drivers across five countries in Europe, namely Greece, Poland, Portugal, Sweden, and the United Kingdom. The survey using computer-assisted web interviews (N = 2502) was implemented in July 2020, the first summer of the Covid-19 pandemic. Hierarchical linear models were employed to analyse individuals’ behaviour, defined as self-perceived declaration of the willingness to contribute to environmental conservation. The results showed that attitudinal and value-related factors are more significant than demographics. Biospheric values and relationship to nature generally affect pro-environmental behaviour positively. Similarly, the experience of Covid-19 exerted a positive influence. In terms of country-level predictors, greenhouse gas emissions were found to have affected pro-environmental behaviour negatively, while the share of renewable energy sources influenced it positively. The cumulative country Covid-19-related mortality at the time of investigation did not have discernible impact. Based on the results it is suggested that, in order to foster PEB, a stronger emphasis on environmental education and attitudes towards nature should be employed.

Integrated assessments of land degradation on the Qinghai-Tibet plateau

Land degradation has become a catastrophic global environmental issue. The current status of land degradation and changing trends of land remain unclear on the Qinghai-Tibet Plateau (QTP). This study integrated an Optimal Land Degradation Index (OLDI) and spatial footprints of three land degradation pathways (i.e., salinization, desertification and soil erosion) to investigate changing trends and degradation risks from 2001 to 2021 on the QTP. The results showed that land improvements were the dominant changing trends on the QTP compared to land degradation, accounting for 18.83% of the whole plateau. The regions with land improvements were mainly distributed in the northeastern QTP. High-risk degraded land covered an area of 0.55 million km2, and low-risk degraded land covered 0.78 million km2. The spatial distribution of high-risk degraded land varied gradually from scattered small areas to increasingly frequent connected patches from southeast to northwest. Potential driving factor analysis illustrated that land degradation resulted from multidimensional driving forcings, including topography, climatic factors, and human activities. The findings in this study can provide great insight for alpine ecosystem development and make adaption to achieve carbon neutrality with global warming.

The neonicotinoid insecticide imidacloprid has unexpected effects on the growth and development of soil amoebae

Neonicotinoid pesticides are the most widely used insecticides worldwide and have become a global environmental issue. Previous studies have shown that imidacloprid, the most used neonicotinoid, can negatively affect a wide range of organisms, including non-target insects, fish, invertebrates, and mammals. Imidacloprid can also accumulate and persist in soils, posing threats to the terrestrial ecosystem. However, we know little about one ecologically important group of organisms, the single-celled soil protists. In this study, we used a soil amoeba, Dictyostelium discoideum, to test whether and how imidacloprid affects the growth and development of soil amoebae. We provide the first empirical evidence that environmental concentrations of imidacloprid negatively impact the fitness and development of soil amoebae. In addition, the adverse effects did not show a dose-response relationship with increased imidacloprid concentrations, where no significant difference was observed among the treatment groups. Further transcriptome analyses showed that imidacloprid affected amoeba's key DEGs related to phagocytosis, cell division, morphogenesis, and cytochrome P450. Moreover, soil amoebae show both conserved and novel transcriptional responses to imidacloprid. In conclusion, this study has expanded the non-target list of imidacloprid from animals and plants to single-celled protists, and we believe the impact of neonicotinoid pesticides on the microbiome is significantly underestimated and deserves more studies.

A guided-liquid-based hybrid triboelectric nanogenerator for omnidirectional and high-performance ocean wave energy harvesting

Ocean wave energy is a promising clean and renewable energy source to mitigate the global energy crisis and environmental issues. Here, a guided-liquid-based isotropic triboelectric–electromagnetic-hybrid nanogenerator (iTEHG) is developed for efficient and sustainable harvesting of omnidirectional ocean wave energy. The fully-enclosed iTEHG is based on a triboelectric nanogenerator (TENG) and electromagnetic generator (EMG), with the structure design of a unique concentric circular electrode pair built on a tilted satellite-dish-inspired plate for gravity-guided motion of the liquid. The newly-designed ocean wave harvester solves the wear and insufficient contact problems of mainstream solid–solid-interfaced TENGs, prolonging the device lifetime, and improves controllability of liquid compared with other solid–liquid-interfaced TENGs. This produces immediate power and current densities of 7.25 µW·cm–3 and 4.85 µA·cm–3 with undifferentiated 360° coverage. The iTEHG can charge a 0.1 F supercapacitor to 3.1 V and continuously drive a wireless thermometer for over 26 min. It exhibits superior performance for practical applications in real ocean environments, proven by continuously driving 320 high luminosity LEDs in Sanya Bay, China, even during quiet periods of ocean activity. The proposed design is expected to have a broad prospect for future blue energy harvesting and inspire development of self-sufficient ocean sensors.

Robust multi-objective optimization for the Iranian electricity market considering green hydrogen and analyzing the performance of different demand response programs

Using renewable energy sources (RES) and green hydrogen has increased dramatically as one of the best solutions to global environmental issues. Applying demand response programs (DRPs) in this context could enhance the system’s efficiency. Evaluating different DRPs’ performances and assessing economic impacts on different parts of the electricity market is essential. The inherent uncertainty of RES and prices is inevitable in electricity markets. As a result of the lack of information, it is crucial to mitigate the risks as much as possible, such as risks related to changes in demand, unit outages, or other traders’ bid strategies. This research introduces a robust multi-objective optimization method to reach the most confident plan for the retailer based on uncertainty in RES and price. The integration of different DRPs is assessed according to the cost to retailers and benefits for consumers using a multi-objective model to survey the impacts of different parts’ decisions on each other. The trade-off among DRPs is considered in this model, and they are traded using a new model to illustrate the daily effect of these programs in monthly operations. This paper uses hydrogen storage (HS) integrated with PV as a distributed energy resource. As the Iranian electricity market has just been established, this research proposes a framework for decision-making in new electricity markets to join future smart energy systems. The mid-term pricing evaluates the system’s performance for more accurate monthly results. Also, the operation cost of the hydrogen storage is modeled to assess its performance in non-robust and robust scheduling. Mixed-integer linear programming (MILP) has been used to model this problem in GAMS. A developed linearizing method is considered with a controllable amount of errors to reduce the volume and time of the computation. Finally, the cost of consumers in non-robust and robust market planning in the presence of DRPs is reduced by 8.77 % and 9.66 %, respectively, and HS has a compelling performance in peak-shaving and load-shifting.

Ingestion of rubber tips of artificial turf fields by goldfish

Marine microplastics are one of the global environmental issues. The present study examined whether rubber tips of artificial sports fields could be marine microplastics. We observed the migration of rubber tips from the artificial turf field to the surrounding ditch connected to sewer pipes and then examined the ingestion of rubber tips using the goldfish Carassius auratus. The rubber tips found in sediments in the ditch suggest that the rubber tips could be sent to the river and released into the ocean. The goldfish ingested rubber tips with or without fish feed, and rubber tips were found in the intestine. However, the fish discharged the rubber tips within 48 h after ingestion. These results indicate that ingestion of the rubber tips was not accidental but an active behavior. Therefore, artificial turf sports fields could be a source of marine microplastics and may cause hazardous effects on wild fishes through ingestion.

Impact of Investments and R&amp;D Costs in Renewable Energy Technologies on Companies’ Profitability Indicators: Assessment and Forecast

Renewable energy technologies play a crucial role in solving global energy and environmental issues, and the pace of the energy transition directly depends on improving their efficiency. Presently, the development and implementation of renewable energy systems are ensured mainly through state funding, the possibilities of which are limited. The potential of attracting private investments depends directly on their impact on companies’ profitability indicators, and the uncertainty regarding the return on investments is one of the main barriers affecting investors’ decision-making. Based on a vector autoregressive model for analysing the stationary time series, the paper explores the impact of long-term investments and research and development costs in renewable energy technologies on the financial performance of ten of the largest companies operating in this field. The study’s results showed that investments and spending on research and development positively affect such companies’ profitability indicators as earnings before interest, taxes, depreciation and amortisation, earnings before interest and tax, net income, and return on investment. The obtained results can be used to substantiate the economic effectiveness of investments in developing and improving renewable energy technologies when forming the companies’ financial policies to support them.

Effects of temperature on incidence of bacillary dysentery in a temperate continental arid climate city in northwest China.

The effect of ambient temperature on health continues to draw more and more attention with the global warming. Bacillary dysentery (BD) is a major global environmental health issue and affected by temperature and other environmental variables. In the current study, we evaluated the effect of temperature on the incidence of BD from January 1st, 2008 to December 31st, 2011 in Jiayuguan, a temperate continental arid climate city in the Hexi Corridor of northwest China. A distributed lag non-linear model (DLNM) was performed to evaluate the lag effect of temperature on BD up to 30 days. Results showed the risk of BD increased with temperature significantly, especially after 8°C. The maximum risk of BD was observed at extreme high temperature (29°C). The effect of temperature on BD risk was significantly divided into short-term effect at lag 5 days and long-term effect at lag 30 days. Age ≤ 15 years were most affected by high temperature. The maximum cumulative risk for lag 30 days (25.8, 95% CIs: 11.8-50.1) was observed at 29°C. Age ≤ 15 years and females showed short-term effect at lag 5 days and long-term effect at lag 30 days, while age > 15 years and males showed acute short-term effect at lag 0 and light long-term effect at lag 16 days.

Soil Erosion Characteristics and Scenario Analysis in the Yellow River Basin Based on PLUS and RUSLE Models.

Soil erosion is an important global environmental issue that severely affects regional ecological environment and socio-economic development. The Yellow River (YR) is China's second largest river and the fifth largest one worldwide. Its watershed is key to China's economic growth and environmental security. In this study, six impact factors, including rainfall erosivity (R), soil erosivity (K), slope length (L), slope steepness (S), cover management (C), and protective measures (P), were used. Based on the revised universal soil loss equation (RUSLE) model, and combined with a geographic information system (GIS), the temporal and spatial distribution of soil erosion (SE) in the YR from 2000 to 2020 was estimated. The patch-generating land use simulation (PLUS) model was used to simulate the land-use and land-cover change (LUCC) under two scenarios (natural development and ecological protection) in 2040; the RUSLE factor P was found to be associated with LUCC in 2040, and soil erosion in the Yellow River Basin (YRB) in 2040 under the two scenarios were predicted and evaluated. This method has great advantages in land-use simulation, but soil erosion is greatly affected by rainfall and slope, and it only focuses on the link between land-usage alteration and SE. Therefore, this method has certain limitations in assessing soil erosion by simulating and predicting land-use change. We found that there is generally slight soil erosivity in the YRB, with the most serious soil erosion occurring in 2000. Areas with serious SE are predominantly situated in the upper reaches (URs), followed by the middle reaches (MRs), and soil erosion is less severe in the lower reaches. Soil erosion in the YRB decreased 11.92% from 2000 to 2020; thus, soil erosion has gradually reduced in this area over time. Based on the GIS statistics, land-use change strongly influences SE, while an increase in woodland area has an important positive effect in reducing soil erosion. By predicting land-use changes in 2040, compared to the natural development scenario, woodland and grassland under the ecological protection scenario can be increased by 1978 km2 and 2407 km2, respectively. Soil erosion can be decreased by 6.24%, indicating the implementation of woodland and grassland protection will help reduce soil erosion. Policies such as forest protection and grassland restoration should be further developed and implemented on the MRs and URs of the YR. Our research results possess important trend-setting significance for soil erosion control protocols and ecological environmental protection in other large river basins worldwide.

Seawater intrusion alters nitrogen cycling patterns through hydrodynamic behavior and biochemical reactions: Based on Bayesian isotope mixing model and microbial functional network

Seawater intrusion is a global coastal environmental issue of great concern and significantly impacts the regional biogeochemical environment and material cycles, including nitrogen cycling. To reveal the mechanism of seawater intrusion altering nitrogen cycling patterns through hydrodynamic behavior and biochemical reactions, the Bayesian mixing model (δ15N-NO3– and δ18O-NO3–) and 16S rDNA gene amplicon sequencing are used to establish nitrogen cycling pathways and microbial functional network. The results show that the nitrate in the coastal groundwater is from manure and septic waste (M&S, over 44 %), soil organic nitrogen (SON, over 20 %), and nitrogen fertilizer (FN, over 16 %). The hydrological interaction has promoted the coupling between material cycling and microbial community in the coastal groundwater systems. Among them, precipitation infiltration has caused the gradual decrease of specific microbes along the flow direction, such as Lactobacillus, Acinetobacter, Bifidobacterium, etc. And seawater intrusion has caused the mutations of specific microbes (Planktomarina, Clade_Ia, Wenyingzhuangia, Glaciecola, etc.) and convergence of microbial community at the salt-freshwater interface in the aquifer. In the coastal intruded aquifer systems, the nitrogen cycling pattern can be divided into oxidation and reduction processes. The oxidation process involves the enhancement of nitrification while the weakening of denitrification and anammox with the increase of aquifer depth. The reduction process consists of the enhancement of denitrification and anammox while the erosion of nitrification and ammonification with increased seawater intrusion. In addition, seawater intrusion can mitigate nitrate contamination by promoting denitrification and anammox in coastal areas.

Investigation on physical properties of nanobubbled water using gas water circulation method: Environmental perspective

AbstractThe objective of this present study is to examine the effect of nanobubbles on the physical properties improvement in the chosen water sample. So far, the research outcomes stated that the physical properties could be enhanced by addition of nanoparticles, but very few studies were performed with nanobubbles. The unique properties of nanobubbles (70–120 nanometers) explain their use in a wide range of engineering fields. Simple method for producing nanobubbles in a variety of aqueous solutions along with examples of their use is outlined in this work. Global environmental issues, including the deterioration and depletion of water supply are driving today's need for water treatment technology. As a solution, the use of micro‐ and nano‐bubble (MNB) technologies in wastewater treatment has evolved. This page discuss the fundamentals of water treatment research, including their stability of bubbles, manufacturing processes, and chemical and physical features.

Energy and Climate Change Effects on Global Environmental Issues

Energy and Climate Change Effects on Global Environmental Issues

Metal–organic framework-derived single atom catalysts for electrocatalytic reduction of carbon dioxide to C1 products

Electrochemical carbon dioxide reduction reaction (eCO2RR) is an efficient strategy to relieve global environmental and energy issues by converting excess CO2from the atmosphere to value-added products.