Conditional effect of governance quality on the finance-environment nexus in a multivariate EKC framework: evidence from the method of moments-quantile regression with fixed-effects models

This paper investigates the mitigating effect of governance quality on the finance-environment nexus in a multivariate EKC framework in 123 selected countries during the 1990–2017 period. We mainly employ the method of moments-quantile regression (MM-QR) with the fixed-effects model, among others. First, the MM-QR estimator reveals that financial development reduces environmental quality more significantly in countries with initially higher levels (the 75^th and 90^th quantiles) of CO₂ emissions than in other countries (the 25^th and 10^th quantiles). Second, the attenuating effect of governance quality on the finance-environment nexus is more remarkable in nations with low initial levels (the 25^th and 10^th quantiles) of CO₂ emissions. Third, we find that the marginal positive effect of financial development on CO₂ emissions is smaller under a good regulatory framework than under corruption control and the rule of law, especially in the top emitters (the 75^th and 90^th quantiles). Fourth, unlike oil, which has a considerable negative impact on the environmental quality of the major emitters, renewable energy usage reduces CO₂ emissions in countries in all quantiles, primarily in the lowest quantiles. Fifth, the findings also show that urbanization dramatically worsens environmental quality in all economies, particularly those in the lowest quantiles. Finally, we confirm that the EKC hypothesis holds in all countries across different quantiles. The study’s final section discusses policy implications for sustainable development in all countries.

     

Indirect effect of nutrient accumulation intensified toxicity risk of metals in sediments from urban river network

The levels of metals in sediments of urban river ecosystems are crucial for aquatic environmental health and pollution assessment. Yet little is known about the interaction of nutrients with metals for environmental risks under contamination accumulation. Here, we combined hierarchical cluster, correlation, and principal component analysis with structural equation model (SEM) to investigate the pollution level, source, toxicity risk, and interaction associated with metals and nutrients in the sediments of a river network in a city area of East China. The results showed that the pollution associated with metals in sediments was rated as moderate degree of contamination load and medium-high toxicity risk in the middle and downstream of urban rivers based on contamination factor, pollution load index, and environmental toxicity quotient. The concentration of mercury (Hg) and zinc (Zn) showed a significant correlation with toxic risks, which had more contribution to toxicity than other metals in the study area. Organic nitrogen and organic pollution index showed heavily polluted sediments in south of the study area. Though correlation analysis indicated that nutrients and metals had different input zones from anthropogenic sources in the urban river network, SEM suggested that nutrient accumulation indirectly intensified toxicity risk of metals by 13.6% in sediments. Therefore, we suggested the combined consideration of metal toxicity risk with nutrient accumulation, which may provide a comprehensive understanding to identify sediment pollution.

Toxicity rate of metals in sediments from urban river network indirectly intensified by nutrients accumulation

     

Biofuel consumption,biodiversity, and the environmental Kuznets curve: trivariate analysis in a panel of biofuel consuming countries

This study examined the relationship between biofuel consumption, forest biodiversity, and a set of national scale indicators of per capita income, foreign direct investment (FDI) inflows, trade openness, and population density with a panel data of 12 biofuels consuming countries for a period of 2000 to 2013. The study used Global Environmental Facility (GEF) biodiversity benefits index and forest biodiversity index in an environmental Kuznets curve (EKC) framework. The results confirmed an inverted U-shaped relationship between GEF biodiversity index and per capita income, while there is flat/no relationship between carbon emissions and economic growth, and between forest biodiversity and economic growth models. FDI inflows and trade openness both reduce carbon emissions while population density and biofuel consumption increase carbon emissions and decrease GEF biodiversity index. Trade openness supports to increases GEF biodiversity index while it decreases forest biodiversity index and biofuel consumption in a region.

     

Does tradeoff between financial and social indicators matters in environmental consideration: evidence from G7 region

The study tries to discover the impact of financial and social indicators’ growth towards environmental considerations to understand the drivers of economic growth and carbon dioxide emissions change in G7 countries. The DEA-like composite index has been used to examine the tradeoff between financial and social indicator matters in environmental consideration by using a multi-objective goal programming approach. The data from 2008 to 2018 is collected from G-7 countries. The results from the DEA-like composite index reveals that there is a mixed condition of environmental sustainability in G-7 countries where the USA is performing better and Japan is performing worse among the set of other countries. The further result shows that the energy and fiscal indicators help to decrease the dangerous gas emissions. Divergent to that, the human and financial index positively contributes to greenhouse gas emissions. Fostering sustainable development is essential to successfully reduce emissions, meet established objectives, and ensure steady development. The study provides valuable information for policymakers.

     

Continuous integration in urban social-ecological systems science needs to allow for spacing co-existence: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Urbanization

Urbanization brings benefits and burdens to both humans and nature. Cities are key systems for integrated social-ecological research and the interdisciplinary journal of Ambio has published ground-breaking contributions in this field. This reflection piece identifies and discusses integration of the human and natural spheres in urban social-ecological research using the following foundational papers as important milestones: Folke et al. (1997), Ernstson et al. (2010) and Andersson et al. (2014). These papers each take unique approaches that aim to uncover core properties—processes, structures, and actors—of urban systems and set them into mutual relationship. This piece will end with a forward-looking vision for the coming 50 years of urban sustainability and resilience study in Ambio.     

Gasoline prices and economic policy uncertainty: what causes what,and why does it matter? Evidence from 18 selected countries

In this paper, we examine asymmetric causal relationships between gasoline prices and economic policy uncertainty in a panel of 18 countries over the period 1998–2017, using the recently introduced panel causality approach of Hatemi et al (Appl Econ, 48:2301–2308, 2016) that accounts for asymmetric dynamics and is robust to both cross-sectional dependence and slope heterogeneity. Empirical findings reveal asymmetric causal relationships between gasoline prices and economic policy uncertainty in the sampled countries. Specifically, results show that economic policy uncertainty and gasoline prices have positive and negative asymmetric bidirectional causal relations in 13 countries. No feedback causality was detected between gasoline prices and economic policy uncertainty in 5 countries. Based on the results, we infer that positive and negative asymmetric causal relations exist between economic policy uncertainty and gasoline price, with attendant policy implications in sampled regions.

     

Temporal variations of surface water quality in urban, suburban and rural areas during rapid urbanization in Shanghai, China

As the economic and financial center of China, Shanghai has experienced an extensive urban expansion since the early 1980s, with an attendant cost in environmental degradation. We use an integrated pollution index to study the temporal variations of surface water quality in urban, suburban and rural areas between 1982 and 2005. Data on monitored cross-sections were collected from the Shanghai Environmental Monitoring Center. The results indicated that the spatial pattern of surface water quality was determined by the level of urbanization. Surface water qualities in urban and suburban areas were improved by strengthening the environmental policies and management, but were worsening in rural areas. The relationship between economic growth and surface water quality in Shanghai showed an inversed-U-shaped curve, which reflected a similar pattern in most developed countries. This research suggests that decision makers and city officials should be more aware of the recent pollution increases in Shanghai.     

Occurrence and risk assessment of currently used organophosphate pesticides in overlying water and surface sediments in Guangzhou urban waterways,China

Organophosphate pesticides (OPPs) are one type of the most massively used pesticides and ubiquitously detected in aquatic environments, which may pose potential risks to the aquatic organisms and human health. In the present study, the spatiotemporal distribution and potential risks of OPPs were investigated in overlying water and surficial sediments from urban waterways of Guangzhou. For all studied sites, in general, four target OPPs (i.e., malathion, chlorpyrifos, terbufos, and diazinon) were present in the overlying water, with malathion and chlorpyrifos as major components. Higher concentrations of the four OPPs were found for the water and sediments collected in the dry season compared to the wet season, possibly because of the dilution effect of heavy rains. The results of Pearson’s analyses and principal coordinate analyses (PCoA) suggested similar sources for target OPPs in the water and sediments across the Guangzhou urban waterways. Potential ecological risks of the OPPs to three representative taxons (algae, aquatic invertebrates, and fish) were evaluated via toxic units (TUs) and risk quotients (RQs), while risk assessment on human health was performed using hazard index (HI). Although TU results showed no acute risks to the aquatic organisms in the overlying water and surface sediments, RQ results of the mixture showed high risks to the aquatic invertebrate and fish in all water samples. Individual HI values and cumulative HI values were on the order of 10^?6–10^?3 for children and adults, suggesting no potential risks to either children or adults through drinking and bathing.

Graphical abstract

     

Characteristics of single atmospheric particles in a heavily polluted urban area of China: size distributions and mixing states

To investigate the chemical composition, size distribution, and mixing state of aerosol particles on heavy pollution days, single-particle aerosol mass spectrometry was conducted during 9–26 October 2015 in Xi’an, China. The measured particles were classified into six major categories: biomass burning (BB) particles, K-secondary particles, elemental carbon (EC)–related particles, metal-containing particles, dust, and organic carbon (OC) particles. BB and EC-related particles were the dominant types during the study period and mainly originated from biomass burning, vehicle emissions, and coal combustion. According to the ambient air quality index, two typical episodes were defined: clean days (CDs) and polluted days (PDs). Accumulation of BB particles and EC-related particles was the main reason for the pollution in Xi’an. Most types of particle size were larger on PDs than CDs. Each particle type was mixed with secondary species to different degrees on CDs and PDs, indicating that atmospheric aging occurred. The mixing state results demonstrated that the primary tracers were oxidized or vanished and that the amount of secondary species was increased on PDs. This study provides valuable information and a dataset to help control air pollution in the urban areas of Xi’an.

Graphical abstract

     

SARS-CoV-2 phase I transmission and mutability linked to the interplay of climatic variables: a global observation on the pandemic spread

The study aims to determine the impact of global meteorological parameters on SARS-COV-2, including population density and initiation of lockdown in twelve different countries. The daily trend of these parameters and COVID-19 variables from February 15th to April 25th, 2020, were considered. Asian countries show an increasing trend between infection rate and population density. A direct relationship between the time-lapse of the first infected case and the period of suspension of movement controls the transmissivity of COVID-19 in Asian countries. The increase in temperature has led to an increase in COVID-19 spread, while the decrease in humidity is consistent with the trend in daily deaths during the peak of the pandemic in European countries. Countries with 65°F temperature and 5 mm rainfall have a negative impact on COVID-19 spread. Lower oxygen availability in the atmosphere, fine droplets of submicron size together with infectious aerosols, and low wind speed have contributed to the increase in total cases and mortality in Germany and France. The onset of the D614G mutation and subsequent changes to D614 before March, later G614 in mid-March, and S943P, A831V, D839/Y/N/E in April were observed in Asian and European countries. The results of the correlation and factor analysis show that the COVID-19 cases and the climatic factors are significantly correlated with each other. The optimum meteorological conditions for the prevalence of G614 were identified. It was observed that the complex interaction of global meteorological factors and changes in the mutational form of CoV-2 phase I influenced the daily mortality rate along with other comorbid factors. The results of this study could help the public and policymakers to create awareness of the COVID-19 pandemic.

     

Economic complexity,ICT, biomass energy consumption,and environmental degradation: evidence from Iran

Economic complexity, biomass energy consumption, and information communication technology (ICT) have diverse impacts on energy consumption and carbon dioxide (CO₂) emissions. Nevertheless, analysis of these variable effects is not addressed in the previous literature; the antiqueness of this article is stuffing this gap. This study assessed the relationship between gross domestic product (GDP) per capita, biomass consumption, economic complexity index (ECI), ICT, and CO₂ emissions in Iran in 1994–2018. The autoregressive distributed lag (ARDL) model and the quantile regression (QR) econometric technique were used to investigate the factors affecting CO₂ emissions in the tails of the conditional distribution. The share of each influential factor was predicted through the variance decomposition analysis (VD) for the next 10 years. The empirical results showed a long-run relationship between the variables. So, the variables of biomass consumption, ECI, and ICT improve the quality of the environment in Iran by reducing CO₂ emissions, and the per capita GDP variable increases CO₂ emissions. Results suggest no evidence indicating the presence of environmental Kuznets curve (EKC); however, QR demonstrated the existence of EKCs in the lower quantiles of the conditional distribution. The ECI will have the most share to change the CO₂ emissions in the future. The income threshold should be determined at the turning point of the EKC to increase economic development. Moreover, investing in increasing biomass consumption is vital. Policymakers also need to consider strict added value for the export of products.

     

Assessing the impact of converting roundabouts to traffic signals on vehicle emissions along an urban arterial corridor in Qatar

The type of control at intersections has a major effect on the operation of any urban corridor. Different predefined procedures are available to calculate some of the main operational characteristics, such as capacity, delay, and level of service, in order to select the best type of control. However, there are other important factors that affect major arterials operational characteristics, factors that are not fully addressed, such as the impact of emissions. In this study, a microscopic simulation approach using VISSIM and MOVES was developed to assess the environmental effect of converting four three-lane roundabouts to signalized intersections along a heavily congested urban corridor in Qatar. A decision was made to switch all roundabouts to traffic signals for better operations. Preliminary results indicated that the signal control outperformed the roundabout in the range of 37% to 43% reduction in emissions. A more detailed analysis revealed that roundabout corridor operations’ effects on emission rates are divergent from those of signalized corridors, particularly upstream and downstream of the intersections. Immediate roundabout upstream approaches are driver behavior dependent, characterized by substantial coasting at lower speeds and subsequent re-accelerating with less idling, described as acceleration events, which resulted in high emission rates, while signalized corridors are signal timing dependent, characterized by ample idling with less coasting and re-acceleration, resulting in reduced emission rates. The results also revealed that there was no significant difference between emission rates in the vicinity of the two types of control. Both recorded nearly the same emission rate.

Implications: A microscopic simulation approach using VISSIM and MOVES was developed to assess the environmental effect of converting four three-lane roundabouts to signalized intersections along a heavily congested urban corridor in Doha, Qatar. Intersection geometries along with the control type have significant impact on emission rates and play a major role in assessing environmental impacts. US EPA MOVES was calibrated to Qatar conditions which can be used to estimate emission factors and quantify vehicular emissions along other corridors in the country. The results can also be beneficial for other countries within the region.     

Opportunities and Challenges to Capturing the Multiple Potential Benefits of REDD+ in a Traditional Transnational Savanna-Woodland Region in West Africa

The REDD+ scheme of the United Nations intends to offer developing countries financial incentives to reduce the rates of deforestation and forest degradation for reducing global CO₂ emissions. This is combined with building carbon stocks in existing wooded ecosystems and fostering other soil, biodiversity and water conservation objectives. Successful application of REDD+ to the Xylophone Triangle of West Africa faces substantial challenges and risks to both meeting REDD+ objectives and to the local people’s rights and livelihoods. The transnationality of the culturally coherent area requires collaboration of three national governments. The opportunities, however, are great to capitalize on the region’s biodiversity, the well-developed traditional ecological knowledge and the use of local medicinal plants as an integral part of the agro-ecosystem. Possibilities open to, not only sequester carbon, but also to increase the resilience of the ecosystem and of independent rural livelihoods in the face of climate change and globalization.     

Vermicompost addition influences symbiotic fungi communities associated with leek cultivated in metal-rich soils

In the context of urban agriculture, where soils are frequently contaminated with metal(loid)s (TM), we studied the influence of vermicompost amendments on symbiotic fungal communities associated with plants grown in two metal-rich soils. Leek (Allium porrum L.) plants were grown with or without vermicompost in two metal-rich soils characterized by either geogenic or anthropogenic TM sources, to assess the influence of pollutant origin on soil-plant transfer. Fungal communities associated with the leek roots were identified by high throughput Illumina MiSeq and TM contents were measured using mass spectrometry. Vermicompost addition led to a dramatic change in the fungal community with a loss of diversity in the two tested soils. This effect could partially explain the changes in metal transfer at the soil-AMF-plant interface. Our results suggest being careful while using composts when growing edibles in contaminated soils. More generally, this study highlights the need for further research in the field of fungal communities to refine practical recommendations to gardeners.

Graphical abstract

     

Quantifying nitrate sources in a large reservoir for drinking water by using stable isotopes and a Bayesian isotope mixing model

Drinking water reservoirs are threatened globally by anthropogenic nitrogen pollution. Hydrochemistry and isotopes were analyzed to identify spatial and temporal varieties of main nitrate sources in a large drinking water reservoir in East China. The results showed that NO₃^? was the main nitrogen form in both the dry and wet seasons, but dissolved organic nitrogen (DON) was increased in the wet season. The δ¹⁵N-NO₃^? values (+?1.3‰ to +?11.8‰) and δ¹⁸O-NO₃^? values (+?2.5‰ to +?13.5‰), combined with principal component analysis (PCA), indicated that chemical fertilizer was the main nitrate source during the dry season, while chemical fertilizer, soil N, and sewage/manure were the main nitrate sources during the wet season in the Qiandao Lake area. And, the nitrate isotopes showed the significant nitrification and assimilation in the Qiandao Lake area. A Bayesian isotopic mixing model (Stable Isotope Analysis in R) was applied to the spatial and seasonal trends in the proportional contribution of four NO₃^? sources (chemical fertilizer (CF), soil nitrogen (SN), sewage and manure (SM), and atmospheric deposition (AD)) in the Qiandao Lake area. It was revealed that CF was the most important nitrate source in the dry season, accounting for 53.4% with 19.2% of SM and 18.9% of SN, while the contribution of SN increased in the wet season, accounting for 31.6%, followed by CF (30.8%) and then SM (24.2%). The main nitrate sources in the urban area, rural area, and central lake area were CF and SN, accounting for 66.1% in the urban area, 71.7% in the rural area, and 68.2% in the central lake area. Measures should be made to improve chemical fertilizer use efficiency and to reduce nitrogen loss in the Qiandao Lake area.

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Air pollution characteristics associated with mesoscale atmospheric patterns in northwest continental Europe

An impact related daily air quality index (DAQx), calculated for 15 air quality monitoring stations (traffic, background, and industry) in Belgium, France, Germany and Luxembourg, was compared to mesoscale atmospheric patterns between 2001 and 2007. Meteorological conditions were described by the Hess and Brezowsky synoptic weather classification system and gridded data of the EU FP6 ENSEMBLES project of total precipitation and mean surface temperature. DAQx values indicate sufficient to poor air quality in the urban area of Brussels and at urban traffic stations, as well as satisfactory air quality at the background stations. The air quality index refers to more than 90% to the presence of high PM₁₀, O₃ and NO₂ concentrations. SO₂ and CO play only a minor role. The investigation of weather regimes indicates that zonal and mixed cyclonic circulation regimes are associated with better air quality than meridional and anticyclonic weather regimes. In general, weather regimes with high daily precipitation lead to better air quality than dryer air masses because of lower contribution of PM₁₀ to the air quality index. A trend analysis of weather regimes from 1978 to 2007 shows significant (α = 0.05) positive trends for weather classes associated with lower PM₁₀ concentrations. The results of a case study at a German station examining the relationship between PM₁₀ concentrations and local meteorological quantities (wind speed and precipitation) confirm the results of the regional analysis.     

The role of green innovations,environmental policies and carbon taxes in achieving the sustainable development goals of carbon neutrality

The green innovations, environmental policies, and carbon taxes are the tools to achieve sustainable development goals (SDGs) in the mitigation process. This study is intended to examine the impact of innovation, carbon pricing (CTAX), environmental policies (EP), and energy consumption (ECON) on PM_2.5 and greenhouse gas (GHG) emission for Central-Eastern European countries. The panel effect during 2000–2018 is tested using a dynamic panel data model while the Granger causality approach obtains country-related outcomes. The outcomes reveal that eco-friendly innovations have a more profound effect on carbon mitigation. Environmental policies reduce emissions by 2.7% in the short run and 17.4% in the long run. Similarly, CTAX mitigates GHG emissions by 8.6% in the short-run and PM2.5 by 0.9% and 5.7% in the short and long run. However, urbanization, energy consumption and trade openness are the leading polluters in the region. The main findings remain dominant in the country-specific results and find unidirectional and bidirectional causality evidence among variables. The research concludes that green innovations and strict environmental policy can lead towards achieving sustainable development goals using carbon taxes as a tool on the way.

Graphical abstract

     

Which visibility indicators best represent a population’s preference for a level of visual air quality?

Several studies have been carried out over the past 20 or so years to assess the level of visual air quality that is judged to be acceptable in urban settings. Groups of individuals were shown slides or computer-projected scenes under a variety of haze conditions and asked to judge whether each image represented acceptable visual air quality. The goal was to assess the level of haziness found to be acceptable for purposes of setting an urban visibility regulatory standard. More recently, similar studies were carried out in Beijing, China, and the more pristine Grand Canyon National Park and Great Gulf Wilderness. The studies clearly showed that when preference ratings were compared to measures of atmospheric haze such as atmospheric extinction, visual range, or deciview (dv), there was not a single indicator that represented acceptable levels of visual air quality for the varied urban or more remote settings. For instance, using a Washington, D.C., setting, 50% of the observers rated the landscape feature as not having acceptable visual air quality at an extinction of 0.19 km^?1 (21 km visual range, 29 dv), while the 50% acceptability point for a Denver, Colorado, setting was 0.075 km^?1 (52 km visual range, 20 dv) and for the Grand Canyon it was 0.023 km^?1 (170 km visual range, 7 dv). Over the past three or four decades, many scene-specific visibility indices have been put forth as potential indicators of visibility levels as perceived by human observers. They include, but are not limited to, color and achromatic contrast of single landscape features, average and equivalent contrast of the entire image, edge detection algorithms such as the Sobel index, and just-noticeable difference or change indexes. This paper explores various scene-specific visual air quality indices and examines their applicability for use in quantifying visibility preference levels and judgments of visual air quality.

Implications: Visibility acceptability studies clearly show that visibility become more unacceptable as haze increases. However, there are large variations in the preference levels for different scenes when universal haze indicators, such as atmospheric extinction, are used. This variability is significantly reduced when the sky–landscape contrast of the more distant landscape features in the observed scene is used. Analysis suggest that about 50% of individuals would find the visibility unacceptable if at any time the more distant landscape features nearly disappear, that is, they are at the visual range. This common metric could form the basis for setting an urban visibility standard.