Search

The given text provides a comprehensive list of ongoing consultations, legal cases, and reports related to various environmental issues in the UK. The consultations cover topics such as air and water quality, renewable energy, waste management, and fisheries management. The legal cases involve disputes over issues such as pollution, energy assessments, and bin-related offenses. The reports highlight concerns and recommendations on topics such as nuclear energy, decarbonization, and environmental regulations. [Extracted from the article]

This article examines the complexities between air quality and climate change, highlighting the interconnected nature of these two critical environmental issues. Drawing from the latest scientific findings by the Intergovernmental Panel on Climate Change (IPCC), it elucidates the dual impact of emissions on local air quality and global climate systems. The discussion pivots on the roles of greenhouse gases (GHGs) and short-lived climate forcers (SLCFs), emphasising the need for integrated mitigation strategies that address both air quality and climate change. The article explores how some mitigation efforts can yield synergistic benefits for both domains, while others may present trade-offs. It also delves into the challenges of current GHG reporting protocols that focus predominantly on well-mixed GHGs, arguing for a more inclusive approach that accounts for the diverse effects of SLCFs. Ultimately, the article highlights the need for holistic environmental policies that balance the objectives of improving air quality and managing climate change. [ABSTRACT FROM AUTHOR]

The urgent and global concern of environmental problems transcends local and regional boundaries, posing significant challenges for policymakers in developing countries. Amid conflicting economic and environmental goals, evaluating the efficacy of regulatory policies becomes increasingly critical. This study investigates the effectiveness of public policy in incentivizing developing nations to prioritize environmental regulation, with a specific focus on China's most recent environmental policy, the Ecological Environmental Protection Plan. Using multilevel modeling and difference-indifferences estimation with data from six of China's most populous cities between 2014 and 2019, we see evidence of air quality improvements following the implementation of the policy. Furthermore, we observe greater enhancements in air quality in the cities most affected by the institutional details of the policy. This shows that well-crafted public policy can improve air quality, providing crucial insights for policymakers and scholars alike. [ABSTRACT FROM AUTHOR]

In 2023, Brazil achieved positive environmental strides in the Amazon, with a 22% reduction in deforestation rates and a 16% decline in total fire counts compared with 2022, attributed to renewed environmental policy implementation. However, despite progress, deforestation remains above the target, and forest wildfires in old‐growth Amazonian forests surged by 152% in 2023 versus 2022, threatening biodiversity and carbon stocks. The rise in fires poses challenges for traditional farmers, impacts urban areas' air quality, and necessitates urgent measures like enhanced firefighting capabilities and long‐term strategies for fire‐free production chains to protect the Amazonian standing forests—a global socio‐environmental asset. [ABSTRACT FROM AUTHOR]

The need to generate objective evidence and reliable information for decision makers to improve environmental policies for a better air quality, led us to evaluate the atmospheric aerosol components in the urban area of Carabayllo, by monitoring PM2.5 and PM10 to determine mass concentration and analyzing PM10 using k0-INAA and ICP–MS for metals quantification, ion chromatography for anions and the NIOSH method to determine organic and elemental carbon. The results obtained from mass concentration of PM2.5 and PM10 exceeded the permissible breathing annual average of WHO guidelines of 15 µgm−3 and 45 µgm−3, respectively, which evidence an unhealthy air quality. Likewise, using the model Positive Matrix Factorization five sources of pollutants were defined: metallurgical industry, sea salt, industrial activity, dust and non-exhaust emissions and vehicle emissions. [ABSTRACT FROM AUTHOR]

The European Union is increasingly resorting to a decentralised enforcement strategy in which it relies less on the Commission-initiated infringement procedure, and more on domestic litigation by particularly NGOs. In order to better understand whether this is a suitable strategy to tackle the compliance deficit, we need more insight into NGOs as decentralised enforcers of EU law. What do NGOs do to stimulate domestic compliance, and is this a potentially effective alternative to the centralised enforcement strategies? Analysing the actions by the German NGO Deutsche Umwelthilfe in relation to the Ambient Air Quality Directive, reveals high potential for the role to be played by NGOs. This exploratory case illustrates that particularly the strategy of flooding the country with a wave of legal proceedings was effective in increasing the salience of the topic, thereby indirectly releasing those capacities that the authorities had still lacked to comply. [ABSTRACT FROM AUTHOR]

There is extensive evidence linking air pollution exposure to physical health. Less is known about the mental health impacts of poor air quality, especially in developing countries. We use data from India and estimate the causal impact of air pollution exposure on feeling sad, experiencing cognitive difficulties, and feeling unable to control and cope with important things in life. We instrument for air pollution exposure using the annual number of nighttime thermal inversions and show that air pollution exposure in the previous calendar year significantly worsens mental health in the current year. We examine potential mechanisms and find that air pollution exposure negatively impacts self-reported physical health, worsens respiratory conditions, and increases the likelihood of experiencing sleeping difficulties. Accounting for mental health impacts of pollution exposure is critical to accurately estimating the true health costs of air pollution and designing optimal environmental policy. [ABSTRACT FROM AUTHOR]

The establishment of pilot zones for green finance reform and innovation (PZGFRI) is one of the important green finance policies in China and also an important means to achieve the goals of reaching peak carbon emissions and carbon neutrality. To further study the improvement effects of the PZGFRI on air quality, this study selected near-ground ozone concentration as the research object and empirically analyzed the impact of the PZGFRI on urban near-ground ozone pollution using the panel data of 215 cities in China from 2014 to 2019 by using the differential method and the synthetic control method. It further explored the moderating effect of foreign direct investment and financial development level and carried out robustness test by using event study, the placebo test, substitution of explained variables, control of other environmental policies, and quarterly data. The conclusions were as follows: ① During the sample period, the PZGFRI significantly reduced near-ground ozone pollution. There was heterogeneity in the impact of the PZGFRI in different geographical regions on near-ground ozone pollution. ② In the samples from the national level and the eastern region, foreign direct investment itself did not directly cause a significant‘ Pollution Heaven’ effect, but the increase of foreign direct investment was not conducive to the control of ozone pollution in the PZGFRI and indirectly caused the‘ Pollution Heaven’ effect. However, in the central and western regions, the increase of foreign direct investment was conducive to promoting the control of ozone pollution in the PZGFRI, which indirectly brought about the‘ Pollution Halo’ effect. ③ In the samples from the national level and the eastern region, the financial development level had no significant impact on ozone pollution itself, but the PZGFRI had a better effect on controlling ozone pollution in cities with a higher financial development level, i.e., the improvement of financial development level had strengthened the control effect of the PZGFRI on ozone pollution. However, in the central and western regions, the improvement in the financial development level did not significantly enhance the ozone pollution control effect of the PZGFRI. [ABSTRACT FROM AUTHOR]

Federal regulations in the United States of America concerning the environment are currently in the process of being re-implemented and redeveloped after years of roll-back under the Trump Administration. This opinion recommends three steps that individual states could take to support stronger environmental policies, which are rooted in 'environmental justice' in relation to issuing emission permits, so as to mitigate the impact of industry upon overburdened communities, and in doing so improve air quality, whilst the federal government reworks its own standards. Given the current political situation, which is heavily contested, and the complicated legal structure of the USA the opinion concludes, that in the context of issuing permits, and having considered a range of environmental law issues at each level of the United States government, that states have a vital role to play in mitigating the 'environmental impact' of pollution on underserved communities, and in tackling other environmental problems. [ABSTRACT FROM AUTHOR]

While political environmentalism played an important role in social mobilization against communist regimes in Central and Eastern Europe before 1989, throughout the 1990s and early 2000s conservationism appeared to be in decline across the region, and external pressure from European institutions and Western donors influenced environmental policy. What explains the effectiveness of protest since the environmental movement emerged in the 1980s? We trace the emergence and evolution of Polish political environmentalism, looking at three levels of the environmental movement's legitimacy: the level of practices, societal support, and discourse. Each phase identified between 1980s and 2017 saw shifts on different levels of legitimacy, and each ended with a spectacular environmental protest or a decision, bearing implications for the following phase. Since 2010, we see a deep polarization of Polish politics, limiting the effectiveness of environmental protest despite the movement's regained triple legitimacy in large parts of the society. [ABSTRACT FROM AUTHOR]

The inspection/maintenance programmes exist in most countries, aiming at vehicular emission reduction through exhaust emission monitoring and compliance policy to the extant norms. However, considering the absence of an intra-vehicle approach, the higher success rate of vehicles towards compliance policy remains a grey area. The paper attempts to examine this issue through the application of an exhaust emission index (EEI) for petrol-driven cars. The study observed two different scales finding that the Bharat Stage emission norm scale method reports lower ranges of EEI compared with the linear scale (LS) method (EEImin-BSNS = 1.12 and EEImin-LS = 1.25; EEImax-BSNS = 20.70 and EEImax-LS = 29.54). The LS method and the maximum operator form of aggregation are recommended as these can find the highest number of non-compliant cars (21.81% and 12.03% of the 'poor' class, respectively) in the whole fleet tested. The EEI gives a more scientific approach to vehicular emission evaluation, like what the air quality index does in the case of the ambient air quality. It helps vehicle owners know their car's emission status as a quick reference index (EEI). The accurate status of such emission further helps the policymakers affect the better phasing-out norms. [ABSTRACT FROM AUTHOR]

Poor air quality in large cities such as Bogotá, due to fixed and mobile emission sources of particulate matter, negatively affects the social, economic and ecological systems of the city. Population growth is one of the main causes that influence air pollution. Therefore, it is considered necessary to analyze the cause-effect relationships of pollution, its sources and the effects on the population. For this reason, developing a model using computer tools such as system dynamics, which can evaluate different environmental policy scenarios, will help to reduce pollution levels and improve the life quality of the population. The methodology used was quasi-experimental with a quantitative approach, divided into four stages, gathering information, proposing the causal diagram, developing the simulation model and evaluating scenarios. Vensim® was the software used as the simulation tool. As a result, it was found that highly polluting stationary and mobile sources cause an uncontrolled increase in PM10. It was also found that annual conversion rates to clean technologies must be 10% per year or higher to achieve a 50% reduction in PM10 levels, in the medium and long term. The main conclusions were to determine that the use of simulation technologies such as system dynamics are very useful to formulate more effective environmental policies. The simulation presented the need for environmental policies to be long-term structural policies that do not vary depending on the change of government. [ABSTRACT FROM AUTHOR]

Fine particulate matter (PM) release is regulated by environmental policies in most countries. This study investigated long–term trends in the mass extinction efficiency (Qe) of aerosols in Northeast Asia. For this purpose, the Qe was calculated using visibility, PM2.5 recorded between 2015 and 2020, and PM10 recorded between 2001 and 2020 at eight Korean sites. The Qe of PM10 (Qe,10) showed an increasing trend with 0.06~0.22 (m2/g)/yr in seven cities except for Jeju. The Qe of PM2.5 (Qe,2.5) also showed an increasing trend with 0.28–2.47 (m2/g)/yr in all cities. In this study, PM10 and PM2.5, were divided into low, moderate, and high concentrations, and the Qe value change by year was examined. Qe,10 showed a tendency to decrease at low concentrations (19–21 μg/m3). However, at moderate (69–71 μg/m3) and high concentrations (139–141 μg/m3), Qe,10 increased in most regions. Qe,2.5 showed an increasing trend at low concentration (9–11 μg/m3), moderate concentration (29–31 μg/m3), and high concentration (69–71 μg/m3), except for Suwon and Pohang, where data were insufficient for analysis. Both Qe,10 and Qe,2.5 showed an increasing trend. The increase in Qe indicated that the visibility-impairing effect of PM can increase even if the same concentration of PM is present. The visibility-impairing effects of PM vary based on the composition, size and other characteristics of the particles in the atmosphere at a given point in time and not simply the quantity of particles. This means that reducing the quantity of particles does not reliably produce a proportionate improvement in visibility. Air quality policies must take the variable nature of PM particles and their effect on visibility into account so that more consistent improvements in air quality can be achieved. [ABSTRACT FROM AUTHOR]

Air pollutant concentrations forecasting is essential for detrimental public exposure prevention, air quality enhancement, and effective environmental policy shaping. Recently, air pollutant concentrations forecasting based on machine learning has been considerably advanced with the development of data-driven approaches. However, multi-source data constraints and architectural complexity in machine learning approaches limit the use of machine learning in actual scenarios. Herein we present a window-based multi-output gradient boosting regression tree (WM-GBRT) approach to predict air pollutant concentrations for the next 48 h at each monitoring station, considering air pollutant monitoring data, meteorological monitoring data, NECP-GFS data, and GEOS-CF data. The key innovation of our approach lies in the flexible input window configuration and the implementation of an multi-step independent strategy. The experiments were conducted in China and compared to existing data-driven baselines, we show that our approach achieved the superior performance in forecasting concentrations of six air pollutants, with a considerable improvement of 6.94 % (PM 2.5), 12.3 % (PM 10), 3.84 % (O 3), 30.6 % (SO 2), 9.84 % (NO 2), and 93.9 % (CO) when compared to the second-best baselines. This simple yet efficient approach can be easily applied, providing a reliable technical method for predicting air pollutant concentrations. [Display omitted] • Propose a WM-GBRT approach for predicting air pollutant concentrations. • The WM-GBRT delivers hourly updates on air pollutant concentrations for the next 48 h. • The key innovation of WM-GBRT is its flexible input window configuration and multi-step independent strategy. • Outperforming existing data-driven baselines, WM-GBRT demonstrates superior accuracy and stability. • The WM-GBRT offers a reliable and cost-effective approach for air pollutant concentrations forecasting. [ABSTRACT FROM AUTHOR]

The sixth Coupled Model Intercomparison Project (CMIP6) scenarios provide opportunities to explore global climate and pollution mitigation pathways with socioeconomic features, but they might be limited on regional-scale projections due to inadequate consideration of local policies. Here, we simulated China's PM2.5 air quality with local policy-based scenarios (Dynamic Projection for Emissions in China (DPEC)) and the CMIP6 scenarios. We found both emission inventories can reproduce China's base-year PM2.5 and chemical aerosols while using DPEC emissions could better match in-situ observations. In addition, DPEC mitigation scenarios can better capture China's PM2.5 decline during 2015-2019 (22% under SSP2-45-policy and 30% under SSP1-26-best) with observations (~28%) than CMIP6 emissions. With the effects of current-year bias and inadequate considerations of pollution control policies, PM2.5 projections in 2030 and 2050 with CMIP6 mitigation scenarios are 42%-48% (9-13 µg/m3) and 59%-73% (8-12 µg/m3) higher than projections with DEPC. Our study suggests the community should incorporate more region-specific environmental policy in future scenario designs. Plain Language Summary Global emission scenarios might be limited on regional-scale air quality projections because of inadequate consideration of local environmental policy. Here, we simulated China's air quality variations through 2050 with global emission data sets and local policy-based emission scenarios. Both global and local emissions can reasonably estimate China's air quality; however, estimations with local emission scenarios are more correlated with surface observations and can better capture China's rapid air quality improvement during 2015-2019. Local policy deficiencies and current year bias further make future air quality projections driven by global emission scenarios 42%-73% higher than driven by local policy-based scenarios. Our findings could offer insights for the research community to incorporate more detailed regional information in future global scenario designs, which might help to better investigate the climate change impacts and improve global scenario applicability to regional scales. [ABSTRACT FROM AUTHOR]

Visualizing tools are now capable of synthesizing satellite imagery with Computational Fluid Dynamics (CFD) results. The new method is applied in Augsburg, Germany, and consists of two main phases: pre-processing and post-processing. The pre-processing phase involves creating geometry, mesh, and extracting results from simulations of traffic pollutant dispersion. In the post-processing phase, the results are combined with satellite images to produce visually optimized results. The demonstration of road traffic air pollution is based on real data from local air quality measurements and specific scenarios. The results indicate that using these visualization tools produce understandable and impressive images and videos. This enhances the public's comprehension of scientific results and raises awareness of environmental issues. An increased understanding of scientific results can reinforce the implementation of environmental policies by pressuring responsible authorities to take action. This paper provides a valuable tool for visualizing air pollution and facilitating public engagement with environmental issues. • A new visualization tool capable of combining earth-observation images with CFD results which represent air-pollution dispersion. • Numerical simulation of air pollution fed to scientific visualization with 3D computer graphics to create photo-realistic images. • Photo-realistic results can guide environmental policies down to local level. • Easily comprehensible results make the general audience understand environmental conditions and enhance action. [ABSTRACT FROM AUTHOR]

Air quality in Kazakhstan cities has been poorly investigated despite their deteriorating situations. This study evaluates the national air pollution monitoring network data (PM10, NO2, SO2, and O3) in Kazakhstan cities, and provides the estimates of excess mortality rates associated with PM2.5 exposure using the Global Exposure Mortality Model (GEMM) concentration-response function. Morbidity rates associated with PM10 exposure were also estimated. Firstly, an air quality-based priority ranking of the cities was suggested based on the annual concentrations of the pollutants during the period of 3 years between 2015 and 2017. Nur-Sultan, Almaty, Ust-Kamenogorsk, and Aktobe were identified as the most polluted cities by PM10, NO2, SO2, and O3 respectively. Then, the exposure-response assessment was conducted for 21 cities. In major cities of Kazakhstan attributable to ambient air pollution per capita, mortality rate is 1 193 per 100 000 population per year, which is 8.97 times higher than in Europe. It is estimated that fine particulate matter exposure in the major cities of Kazakhstan causes 101 139 premature deaths annually. This study provides quantitative information on potential public health risks and impacts of air pollution, which is valuable for decision-makers to justify national environmental policies. Implications: Quantitative information on health impacts from air pollution can be useful for decision makers in Kazakhstan to justify environmental policies and identify policy and funding priorities for tackling air pollution issues. It can be also useful for policy makers in improving the quality of government funded environmental reports and strategic documents as they have many shortcomings in terms of selection of air quality indicators, identification of priority pollutants, identification of sources of pollution. This study has high significance due to the lack of data and knowledge in the region of Central Asia, in particular, of Kazakhstan. [ABSTRACT FROM AUTHOR]

Air pollution causes severe environmental problems and has become a major health risk for livelihood in Delhi. With increase in population, there is an increase in emissions from various utilities as well. The main source of air pollution is crop residue burning followed by vehicular and industrial emission. Crop residue burning during winter produces a thick cloud of smoke and causes major threats to human health by deterioration in air quality. This crucial matter was also discussed in the Indian parliament. The National Green Tribunal and various Courts of India have directed to the Delhi government and various concerned agencies to resolve the air pollution problem. The present study discusses human health safety caused by air pollution, analysis and mitigation of air pollution using suitable environmental policies and application of biomass energy. [ABSTRACT FROM AUTHOR]

Central transfer payment for the key ecosystem zones has become the most funded payments for ecosystem services program in China. The ecological fiscal transfer (EFT) aims to improve the eco-environmental quality of the targeted counties by providing supplementary fiscal funds, though not strictly specifying the usage. This study employs a time-varying difference-in-difference strategy to investigate the impact of EFT on environmental outcome by using a comprehensive county-level dataset covering 1949 counties from 2004 to 2015. Estimates show that the policy had a positive impact on local air quality, whereas the dynamic effect is diminishing. The policy effect is achieved through more stringent environmental regulation and stricter industrial access. Reduction of industrial dust emission is more noticeable than that of sulfur dioxide. There is an economic scale effect that the scale of a county can increase effectiveness of EFT on air quality improvement, whereas an opposite development stage effect will undermine its effectiveness. Heterogeneities were detected concerning transfer intensity, intervention period, geographical region, and ecosystem type. These findings facilitate a deep understanding how EFT could play a significant role in protecting local environment in large developing countries. Several policy implications are drawn to enhance the effectiveness of the largest EFT program. • Ecological fiscal transfer is an emerging instrument in combating eco-environmental degradation. • China's ecological fiscal transfer (EFT) is taken as a quasi-experiment to evaluate its effectiveness. • A time-varying DID technique is employed by using unique county-level datasets. • China's EFT is effective in improving local air quality with a diminishing dynamic effect. • Various heterogeneities of effect were detected and impact mechanisms were identified. [ABSTRACT FROM AUTHOR]

Highlights • The impact of the ETS on social equity is assessed. • A dynamic CGE model with disaggregated labor and household sectors is developed. • Employment in China's coal industry will decline by 75% in 2030 in the ETS scenario. • ETS revenue will peak at 2278 billion yuan in 2042 in our scenario. • ETS revenue redistribution can reduce the Gini coefficient by 10% compared to BAU. Abstract Carbon dioxide emissions trading systems (ETS) are an important market-based mitigation strategy and have been applied in many regions. This study evaluates the potential for a national ETS in China. Using a dynamic computable general equilibrium (CGE) model with detailed representations of economic activity, emissions, and income distribution, we examine alternative mitigation policies from now until 2050. Based on statistical and survey data, we disaggregate the labor and household sectors and simulate the impacts of ETS policies on the incomes of different household groups. We find that ETS has the potential to reconcile China's goals for sustained, inclusive, and low-carbon economic growth. Results show some key findings. First, the number of unemployed people in energy-intensive industries such as coal and construction will continue to increase; by 2050, employment in the coal industry will decline by 75%. Second, if the scope of the carbon market extends to all industries in China, carbon market revenues will continue to increase, reaching a maximum of 2278 billion yuan ($336 billion) in 2042 to become the world's largest carbon market. Third, the distribution of benefits from the national ETS can help achieve greater social equity. By comparing different distribution policies, we find that the combination of targeted subsidies for unemployed coal workers and direct household subsidies based on proportional per capita will reduce the social income gap to the greatest extent compared with other scenarios. By 2050, this distribution policy will reduce the Gini coefficient in China by 10% compared to the Business as Usual (BAU) scenario. [ABSTRACT FROM AUTHOR]

In January 2012, Beijing began releasing air quality report of PM 2.5. The move has been credited as a major breakthrough in China’s environmental governance as it is argued that online environmental activists in China were the major driving force behind it. Since then, the issue of air pollution has reemerged as one of the hottest issues and a series of new policies addressing air pollution have been adopted. Facing a relatively new phenomenon (wumai) and heightened public concerns, to what extent is the state still capable of guiding the pubic perception and opinions about the issue? By analyzing the discourse of air pollution in People’s Daily and comparing it with public opinion survey data, the paper finds that the state’s ability to guide public opinion is rather limited, indicating that opportunities do exist for civil society to play a bigger role in China’s environmental governance. [ABSTRACT FROM AUTHOR]

There are open debates on whether the amount of emission reduction could fulfil the anthropogenic PM 2.5 (particulate matter smaller than 2.5 μm) mitigation in China. This study evaluated the long-term historical aerosol simulations for 1970–2010 in eastern China from three models (CACTUS, WRF-CMAQ, and GISS-E2-R). We introduced 95% Confidence Interval of n -year Moving Difference ( n -year CIMD, n  = 1…10) in the long-term simulated PM 2.5 concentrations to determine how long PM 2.5 change in history is significant and how many increases in historical emissions raised the amount of PM 2.5 that we want to reduce today. The results show that the annual trends for the simulated PM 2. 5 ranged from 0.42 to 0.72 μg m −3  year −1 lying within the 95% confidence intervals for the trend in the satellite-derived PM 2.5 . There was a reasonable change in PM 2.5 chemical compositions with increasing nitrate and declining OA mass fractions from 1970 to 2010. Particulates were more neutralized as the quick increases in ammonia and the control on SO 2 emissions. The significant analysis of changes indicates that at least a 5-year CIMD for PM 2.5 could be distinguished from the PM 2.5 fluctuations due to emission uncertainties and meteorological interannual variations. At least a 10-year CIMD for PM 2.5 could be distinguished from the multi-model uncertainties. The historical relationship between PM 2.5 and emissions suggests that the minimum PM 2.5 reduction targeted in the China's 12th Five-Year Plan (FYP; 2011–2015) would require the emission changes compared with 2010 in SO 2 , NOx, and NH 3 by 41%, 29%, and 42%, respectively. The amounts were larger than the emission reduction planned for the 12th FYP. This suggests that the past emission policies and PM 2.5 control pledges were incompatible and a stricter emission reduction is needed to attain the 13th FYP (2016–2020). [ABSTRACT FROM AUTHOR]

Normally, the temperature decreases with altitude, allowing air pollutants to rise and disperse. During inversion episodes, warmer air at higher altitude traps air pollutants at the ground. By merging vertical temperature profile data from NASA with pollution monitors and health care records, we show that inversions increase the PM10 levels by 25% and children's respiratory health problems by 5.5%. Low-income children are particularly affected, and differences in baseline health seem to be a key mediating factor behind the effect of pollution on the SES health gap. Policies that improve dissemination of information on inversion status may hence improve child health, either through private action or via policies that curb emissions during inversion episodes. [ABSTRACT FROM AUTHOR]

Highlights • Real-world emission parameters for estimating MSW open burning. • A country specific and global EFs for estimating GHGs and other harmful pollutants. • MSW open burning practices more prevalent in sub-urban area than municipality core. • Lower waste collection efficiency reveals higher fraction of population burning MSW. Abstract Open burning of municipal solid waste (MSW) is a poorly-characterized and frequently-underestimated source of air pollution in developing countries. This paper estimates the quantity of MSW that was burned in five erstwhile municipalities of the Kathmandu valley, Nepal. A household survey, a transect walk survey, an experiment to measure the fraction of waste that is combustible, a survey on fraction of population burning waste outside their houses, and a survey of the fraction of MSW burned at dump sites were performed in this study, whereas burning/oxidation efficiency, municipal populations, MSW generation rates, and emission factors were derived from the literature. The total mass of MSW burned during 2016 is estimated to be 7400 tons (i.e., 20 tons/day), which was of 3% of the total MSW generated in the valley municipalities that year. This exceeds Government estimates by a factor of three. Multiplying the burned MSW mass by emission factors, the air pollutant emissions are estimated as PM 2.5 55 tons (OC 42 tons and EC 1.4 tons), PM 10 60 tons, BC 25 tons, CO 2 11,900 tons, CH 4 30 tons, SO 2 5.0 tons, NO x 19.2 tons, CO 630 tons, NMVOC 112 tons, and NH 3 5.7 tons per year. Open burning of MSW can trigger health impacts such as acute and chronic respiratory disease, heart diseases, and allergic hypersensitivity, in addition to impacts on local climate. Improved waste-segregation practices at the source and waste-collection systems throughout the valley are needed to mitigate this pollution source and its effects. [ABSTRACT FROM AUTHOR]

“Supply-side structural reform” (SSSR) has been the most important ongoing economic reform in China since 2015, but its important environmental health effects have not been properly assessed. The present study addresses that gap by focusing on reduction of overcapacity in the coal, steel, and iron sectors, combined with reduction of emissions of sulfur dioxide (SO 2 ), nitrogen oxide (NO x ), and fine particulate matter (PM 2.5 ), and projecting resultant effects on air quality and public health across cities and regions in China. Modeling results indicate that effects on air quality and public health are visible and distributed unevenly across the country. This assessment provides quantitative evidence supporting projections of the transregional distribution of such effects. Such uneven transregional distribution complicates management of air quality and health risks in China. The results challenge approaches that rely solely on cities to improve air quality. The article concludes with suggestions on how to integrate SSSR measures with cities' air quality improvement attainment planning and management performance evaluation. [ABSTRACT FROM AUTHOR]

For many national parks and wilderness areas with special air quality protections (Class I areas) in the western United States (U.S.), wildfire smoke and dust events can have a large impact on visibility. The U.S. Environmental Protection Agency’s (EPA) 1999 Regional Haze Rule used the 20% haziest days to track visibility changes over time even if they are dominated by smoke or dust. Visibility on the 20% haziest days has remained constant or degraded over the last 16 yr at some Class I areas despite widespread emission reductions from anthropogenic sources. To better track visibility changes specifically associated with anthropogenic pollution sources rather than natural sources, the EPA has revised the Regional Haze Rule to track visibility on the 20% most anthropogenically impaired (hereafter, most impaired) days rather than the haziest days. To support the implementation of this revised requirement, the EPA has proposed (but not finalized) a recommended metric for characterizing the anthropogenic and natural portions of the daily extinction budget at each site. This metric selects the 20% most impaired days based on these portions using a “delta deciview” approach to quantify the deciview scale impact of anthropogenic light extinction. Using this metric, sulfate and nitrate make up the majority of the anthropogenic extinction in 2015 on these days, with natural extinction largely made up of organic carbon mass in the eastern U.S. and a combination of organic carbon mass, dust components, and sea salt in the western U.S. For sites in the western U.S., the seasonality of days selected as the 20% most impaired is different than the seasonality of the 20% haziest days, with many more winter and spring days selected. Applying this new metric to the 2000-2015 period across sites representing Class I areas results in substantial changes in the calculated visibility trend for the northern Rockies and southwest U.S., but little change for the eastern U.S. Implications: Changing the approach for tracking visibility in the Regional Haze Rule allows the EPA, states, and the public to track visibility on days when reductions in anthropogenic emissions have the greatest potential to improve the view. The calculations involved with the recommended metric can be incorporated into the routine IMPROVE (Interagency Monitoring of Protected Visual Environments) data processing, enabling rapid analysis of current and future visibility trends. Natural visibility conditions are important in the calculations for the recommended metric, necessitating the need for additional analysis and potential refinement of their values. [ABSTRACT FROM AUTHOR]

Transboundary air pollution is a global environmental and public health problem including in the U.S., where pollution emissions from China, the largest emitter of anthropogenic air pollution in the world, can travel across the Pacific Ocean and reach places like California and Oregon. We examine the effects of transboundary air pollution following major events in China, specifically sandstorms, a natural-occurring source of air pollution, and Chinese New Year, a major 7-day holiday, on background air quality in the U.S. We focus on high elevation sites on the west coast between 2000 and 2013. We use regression analysis and a natural experiment to exploit the variation in the timing of these events in China, which are plausibly uncorrelated to other factors that affect air quality in China and the U.S. We find that sandstorms are associated with statistically significant increases in background coarse and fine particulate matter (PM) in the U.S., representing between 16 and 39% of average weekly PM levels. We also find Chinese New Year is associated with modest reductions in background air quality in the U.S., representing between 0.4 and 2.5% of PM levels. Findings are robust to different models and falsification tests. These results suggest that regression analysis could be a powerful tool to complement other, more widely used techniques in the environmental sciences that study this problem. This also has important implications for policymakers, who could track major sandstorms in China and prepare for possible increased foreign pollution emissions in the U.S. [ABSTRACT FROM AUTHOR]

This article surveys the use of process tracing as a method in research on global and comparative environmental politics. It reveals that scholars have been reluctant to explicitly embrace the method, even though a great deal of environmental politics research relies on process tracing and studies causal mechanisms. I argue that the growing number of critiques that the subfield is overly descriptive and insufficiently focused on explanation is one consequence of the reluctance to explicitly embrace process tracing. Drawing on recent debates on causal mechanisms within the philosophy of social science and a growing literature on how to trace processes, this article outlines best practices in the application of the method in the study of environmental politics. I consider some ways in which the use of process tracing in the study of environmental politics may be different from its use in other areas of comparative politics and international relations. [ABSTRACT FROM AUTHOR]

Eurpean Union (EU) environmental policy has increasingly advanced multi-level governance (MLG) to improve policy implementation. MLG approaches mandate (sub-) national planning and introduce functional governance layers to match the biophysical scale of environmental problems. Whereas the literature on policy implementation has focused on thechallengesposed by multi-level systems, the described EU approach relies on MLG as astrategy to better policy implementation. This contribution studies the implementation of EU air quality directives, drawing on all 137 German air quality and action plans, to explore how requirements of multi-level implementation are delivered on the ground. Overall, we find the model of implementing air quality policy through MLG of limited success. In particular, sub-national policy-makers use their new planning competencies but struggle to implement functional governance layers. Mirroring experiences from neighbouring EU policy fields, our findings raise the broader issue of ‘failed’ implementation versus a still untapped potential for adaptation and governance learning. [ABSTRACT FROM AUTHOR]

The world population is demonstrating an increasing awareness about the ecological impacts of air quality, including impacts on human health. The Veneto region and, more generally, the Po Valley (NE Italy), are characterised by frequent exceedance of limit values for air quality, in particular particulate matter (PM 10), which causes these areas to be listed as hotspots; thus, this region has some of the worst air pollution in Europe. The aim of the current research was to analyse a 10 year-long time series of air quality data (2011–2021) in the Veneto region to investigate the influence of selected factors on air quality, such as natural processes (meteorological conditions), environmental policies, and health emergency measures due to the COVID-19 pandemic. Generally, the considered pollutants, PM 10 , NO, and NO 2 , presented a decreasing trend during the last ten years. The reduction in nitrogen oxides was clearly improved after the implementation of a specific environmental protocol (the "New Agreement of Po Valley Basin"). Conversely, the PM 10 concentration seemed to be affected by other important emission sources, such as domestic heating systems, agricultural activities, and animal farms, which are not as strongly regulated as emission sources such as traffic. The 2020 lockdown mainly influenced nitrogen oxide concentrations. • Italy has infringed on the EU law regarding ambient air quality. • One of the more polluted Italian areas is the Po Valley, including the Veneto region. • A long time series of the air quality data region was statistically analysed. • Only nitrogen oxide concentrations were significantly reduced during the last ten years. • Environmental policies have mainly addressed traffic emissions. [ABSTRACT FROM AUTHOR]

Growing evidence indicated an association between PM 2.5 exposure and cognitive function, but the causal effect and the cognitive effect of prenatal PM 2.5 exposure remain elusive. We obtained 15,099 subjects from a nationally representative sample of China and measured their cognitive performance. We ascertained subjects' prenatal PM 2.5 exposure and chronic PM 2.5 exposure of the recent two years. Using this national sample, we found that PM 2.5 exposure during the mid- to late-pregnancy was significantly associated with declined cognition and income; chronic PM 2.5 exposure was also independently associated with cognition and income measured at adulthood with greater magnitude. Negative effect modification was observed between prenatal and chronic PM 2.5 exposure. Instrumental variable approach and difference-in-difference study verified causal effects: every 1 μg/m3 increase in prenatal and chronic PM 2.5 exposures were causally associated with −0.22% (−0.38%, −0.06%) and −0.17% (−0.31%, −0.03%) changes in cognitive function, respectively. People with low cognition and low income were more vulnerable to PM 2.5 exposure with greater cognitive and income decline. In the future, although China's improved air quality continues to benefit people and reduce cognitive decline induced by chronic PM 2.5 exposure, high prenatal PM 2.5 exposure will continue to hurt the overall cognition of Chinese population, since in total 360 million people were born during the 2000–2020 polluted era. Prenatal PM 2.5 -induced cognitive decline would remain largely unchanged before 2050 and gradually reduce after 2065, regardless of environmental policy scenarios. The long-lasting cognitive impact of PM 2.5 is worth considering while enacting environmental policies. • Prenatal PM 2.5 exposure adversely impacted adulthood cognition and income. • Chronic PM 2.5 exposure impacted adulthood cognition and income with greater magnitude. • People with low cognition and low income were more vulnerable to PM 2.5 exposure. • Prenatal PM 2.5 -induced cognitive decline would remain unchanged before 2050. • Prenatal PM 2.5 -induced cognitive decline would gradually reduce after 2065. [ABSTRACT FROM AUTHOR]

China’s tremendous economic growth in the past three decades has resulted in a number of environmental problems, including the deterioration of air quality. In particular, fine particulate matter (PM) has received increasing attention from scientists, governmental agencies, and the public due to its adverse impacts on human health. Monitoring the spatiotemporal patterns of air pollution is important for understanding its transport mechanisms and making effective environmental policies. The main goal of this study, therefore, was to quantify the spatial patterns and movement of air pollution in China at annual, daily, and hourly scales, so that the underlying drivers could be better understood. We used remote sensing data and landscape metrics together to capture spatiotemporal signatures of air pollution. Our results show that, at the annual scale, PM 2.5 concentrations in China increased gradually from 1999 to 2011, with the highest concentrations occurring in the North China Plain as well as the middle and lower reaches of the Yangtze River Basin. The total population affected by air pollution was about 975 million in 2010 (about 70% of China’s population). Our more detailed analysis on daily and hourly scale further revealed that a heavy air pollution event occurred, expanded, aggregated, and finally dissipated over Northern China during Oct. 6–12, 2014, suggesting that the Beijing-Tianjin-Hebei region a center of severe pollution. Crop stalks burning in agricultural areas in this region seemed to be one of the leading drivers, along with coal burning and transportation emissions. Our study demonstrates that spatial pattern analysis with landscape metrics is effective for analyzing source-sink dynamics of air pollution and its potential drivers. Our findings of major source areas and movement trajectories should be useful for making air pollution control policies to improve China’s air quality. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of low emission zones on air quality and birth outcomes in Germany. The staggered introduction of the policy measure creates a credible natural experiment and a natural control group for births and air pollution measurements in cities that enact low emission zones. I show that the introduction of the most restrictive type of low emission zone decreases average levels of fine particulate matter by about 4 percent and by up to 8 percent at a city's highest-polluting monitor. Low emission zones also reduce the number of days per year on which legal pollution limits are exceeded by three. However, these reductions are too small to translate into substantial improvements in infant health. My results are not driven by changes in maternal or city specific characteristics, and are robust to variations in specification and to the choice of control group. [ABSTRACT FROM AUTHOR]

Estimating the future state of air quality associated with transport policies and infrastructure investments is key to the development of meaningful transportation and planning decisions. This paper describes the design of an integrated transportation and air quality modelling framework capable of simulating traffic emissions and air pollution at a refined spatio-temporal scale. For this purpose, emissions of Nitrogen Oxides (NO x ) were estimated in the Greater Montreal Region at the level of individual trips and vehicles. In turn, hourly Nitrogen Dioxide (NO 2 ) concentrations were simulated across different seasons and validated against observations. Our validation results reveal a reasonable performance of the modelling chain. The modelling system was used to evaluate the impact of an extensive regional transit improvement strategy revealing reductions in NO 2 concentrations across the territory by about 3.6% compared to the base case in addition to a decrease in the frequency and severity of NO 2 hot spots. This is associated with a reduction in total NO x emissions of 1.9% compared to the base case; some roads experienced reductions by more than half. Finally, a methodology for assessing individuals’ daily exposure is developed (by tracking activity locations and trajectories) and we observed a reduction of 20.8% in daily exposures compared to the base case. The large difference between reductions in the mean NO 2 concentration across the study domain and the mean NO 2 exposure across the sample population results from the fact that NO 2 concentrations dropped largely in the areas which attract the most individuals. This exercise illustrates that evaluating the air quality impacts of transportation scenarios by solely quantifying reductions in air pollution concentrations across the study domain would lead to an underestimation of the potential health gains. [ABSTRACT FROM AUTHOR]

Urban air quality represents a major public health burden and is a long-standing concern to European citizens. Combustion processes and traffic-related emissions represent the main primary particulate matter (PM) sources in urban areas. Other sources can also affect air quality (e.g., secondary aerosol, industrial) depending on the characteristics of the study area. Thus, the identification and the apportionment of all sources is of crucial importance to make effective corrective decisions within environmental policies. The aim of this study is to evaluate the impacts of different emissions sources on PM 2.5 concentrations and compositions in a mid-size city in the Po Valley (Treviso, Italy). Data have been analyzed to highlight compositional differences (elements and major inorganic ions), to determine PM 2.5 sources and their contributions, and to evaluate the influence of air mass movements. Non-parametric tests, positive matrix factorization (PMF), conditional bivariate probability function (CBPF), and concentration weighted trajectory (CWT) have been used in a multi-chemometrics approach to understand the areal-scale (proximate, local, long-range) where different sources act on PM 2.5 levels and composition. Results identified three levels of scale from which the pollution arose: (i) a proximate local scale (close to the sampling site) for traffic non-exhaust and resuspended dust sources; (ii) a local urban scale (including both sampling site and areas close to them) for combustion and industrial; and (iii) a regional scale characterized by ammonium nitrate and ammonium sulfate. This approach and results can help to develop and adopt better air quality policy action. [ABSTRACT FROM AUTHOR]

The Department of Energy's Clean Cities program was created in 1993 to reduce petroleum usage in the transportation sector. The program promotes alternative fuels such as biofuels and fuel-saving strategies such as idle reduction and fleet management through coalitions of local government, non-profit, and private actors. Few studies have evaluated the impact of the program because of its complexity that include interrelated strategies of grants, education and training and diversity of participants. This paper uses a Difference-in-Differences (DiD) approach to evaluate the effectiveness of the program between 1990 and 2010. We quantify the effectiveness of the Clean Cities program by focusing on performance measures such as air quality, number of alternative fueling stations, private vehicle occupancy and transit ridership. We find that counties that participate in the program perform better on all these measures compared to counties that did not participate. Compared to the control group, counties in the Clean Cities program experienced a reduction in days with bad air quality (3.7%), a decrease in automobile commuters (2.9%), an overall increase in transit commuters (2.1%) and had greater numbers of new alternative fueling stations (12.9). The results suggest that the program is a qualified success. [ABSTRACT FROM AUTHOR]

The frequent occurrence of extreme haze episodes in China in recent years has triggered the Chinese government to take action to tackle the serious air quality problems. Fine particulate matter (PM 2.5 ) accounts for much of China's poor air quality; given the health risks associated with such pollution, the spatiotemporal characteristics of urban PM 2.5 concentrations constitute a matter of significant interest within the Chinese research and policy communities. Using the first long-term datasets available in relation to PM 2.5 levels, obtained from a year-long monitoring program of concentrations utilizing 945 monitoring stations in 190 cities in China in 2014, we found significant differences in PM 2.5 concentrations among cities, ranging between 18.7 and 131.4 μg/m 3 , with an average of at 61 ± 20 μg/m 3 ; only 18 (or 9.5%) of the 190 monitored cities could meet the National Ambient Air Quality Standards of China. PM 2.5 concentrations are generally highest in the cities east of the Hu Line and north of the Yangtze River due to high PM emissions from transport and coal combustion and unfavorable atmospheric conditions. We also observed marked seasonal variations in concentration levels, with the highest levels occurring during winter and the lowest in summer. By grouping Chinese cities according to their size, our econometric analysis shows a positive correlation between PM 2.5 concentrations and the size of the urban area, urban population, share of secondary industry and population density, and a first increasing and then decreasing relationship between GDP per capita and PM 2.5 concentration. Urban expansion and structural economic change has thus contributed to an increase in urban PM 2.5 emissions. Without careful planning, continuing urbanization will precipitate further severe air pollution causing significant health risks. [ABSTRACT FROM AUTHOR]

Driving restrictions are often introduced as an urban management method for reducing the air pollution and traffic congestion by prohibiting drivers from using their vehicles on given days, based on the last digits of vehicles’ license plates. A number of cities in developing countries have used driving restrictions. This paper proposes an empirical strategy to estimate the effects of driving restrictions on air quality. The strategy combines internet based semi-structured data source, big data processing procedure, and different estimation methods of regression discontinuity design to carry out the analysis. The results show that the driving restrictions are effective for short-run period, but are ineffective for long-run time period. Heterogeneity in short-run effect for different cut-points has also been observed. The results of the study are helpful in understanding the effectiveness of current driving restriction policies and to improve these further to achieve better results in future. [ABSTRACT FROM AUTHOR]

In their theory of social constructions of target populations, Schneider and Ingram argue that in degenerative policy systems policy designs and policy outcomes will disproportionately benefit those socially constructed as Advantaged and disproportionately harm those socially constructed as Deviants (1997). Though heretofore unexamined, an implication of Schneider and Ingram's model presented in Policy Design for Democracy (1997) is that the effects of policy with widespread outcomes should be rankable with respect to targets' social constructions, with Advantaged receiving less than Contenders who receive less than Dependents who receive less than Deviants of bad outcomes, and vice versa for good outcomes. Air pollution policies affect members of all four types of socially constructed groups, air pollution is well known to have social justice components, and air pollution is of particular interest because of its seeming universal application. So we performed an empirical, quantitative analysis of this rank-order hypothesis using data on air pollution in cities in California's Central Valley. The analysis finds evidence that social constructions of subpopulations in Central Valley cities help to explain the incidence of air pollution in the hypothesized rank-order way. The results provide new evidence of the value of the Schneider and Ingram (Policy design for democracy. University Press of Kansas, Lawrence, 1997) model in the area of outcomes, and new evidence regarding the social justice of seemingly universal policies. [ABSTRACT FROM AUTHOR]

In this paper, we present ten scenarios developed using the IMAGE2.4 framework (Integrated Model to Assess the Global Environment) to explore how different assumptions on future climate and air pollution policies influence emissions of greenhouse gases and air pollutants. These scenarios describe emission developments in 26 world regions for the 21st century, using a matrix of climate and air pollution policies. For climate policy, the study uses a baseline resulting in forcing levels slightly above RCP6.0 and an ambitious climate policy scenario similar to RCP2.6. For air pollution, the study explores increasingly tight emission standards, ranging from no improvement, current legislation and three variants assuming further improvements. For all pollutants, the results show that more stringent control policies are needed after 2030 to prevent a rise in emissions due to increased activities and further reduce emissions. The results also show that climate mitigation policies have the highest impact on SO 2 and NO X emissions, while their impact on BC and OC emissions is relatively low, determined by the overlap between greenhouse gas and air pollutant emission sources. Climate policy can have important co-benefits; a 10% decrease in global CO 2 emissions by 2100 leads to a decrease of SO 2 and NO X emissions by about 10% and 5%, respectively compared to 2005 levels. In most regions, low levels of air pollutant emissions can also be achieved by solely implementing stringent air pollution policies. The largest differences across the scenarios are found in Asia and other developing regions, where a combination of climate and air pollution policy is needed to bring air pollution levels below those of today. [ABSTRACT FROM AUTHOR]

A lot of scholarly attention has focused on why groups choose to pursue their policy goals in one venue over another. This manuscript adds to the literature by testing a new theory of venue shopping, the Adaptive Venue Shopping Framework. This manuscript finds empirical support that groups choose venues by strategically assessing the institutional context which involves three primary elements: the group's mix of resources, their opponent's resource strengths, and the degree of venue accessibility, which is a combination of opponents' degree of control over a venue and a venue's image amiability or receptivity. In addition to confirming these findings, this case study links the literature on venue shopping with recent scholarship about 'vested interests' by demonstrating how a powerful agricultural group came to dominate in a legislative venue, how it protected its policy victories from reversal, and how it kept policy making from shifting into alternative venues, thus leading to long-term policy stability. Furthermore, it demonstrates how newly emerged groups can achieve policy success against stronger opponents by threatening to seek their policy goals in alternative institutions. [ABSTRACT FROM AUTHOR]

Critical operations of chemical process industry (CPI) plants such as ethylene plant shutdowns could emit a huge amount of VOCs and NOx, which may result in localized and transient ozone pollution events. In this paper, a general methodology for studying dynamic ozone impacts associated with flare emissions from ethylene plant shutdowns has been developed. This multi-scale simulation study integrates process knowledge of plant shutdown emissions in terms of flow rate and speciation together with regional air-quality modeling to quantitatively investigate the sensitivity of ground-level ozone change due to an ethylene plant shutdown. The study shows the maximum hourly ozone increments can vary significantly by different plant locations and temporal factors including background ozone data and solar radiation intensity. It helps provide a cost-effective air-quality control strategy for industries by choosing the optimal starting time of plant shutdown operations in terms of minimizing the induced ozone impact (reduced from 34.1 ppb to 1.2 ppb in the performed case studies). This study provides valuable technical supports for both CPI and environmental policy makers on cost-effective air-quality controls in the future. [ABSTRACT FROM AUTHOR]

To improve air quality, knowledge of the sources and locations of air pollutant emissions is critical. However, for many global cities, no previous estimates exist of how much exposure to fine particulate matter (PM 2.5), the largest environmental cause of mortality, is caused by emissions within the city vs. outside its boundaries. We use the Intervention Model for Air Pollution (InMAP) global-through-urban reduced complexity air quality model with a high-resolution, global inventory of pollutant emissions to quantify the contribution of emissions by source type and location for 96 global cities. Among these cities, we find that the fraction of PM 2.5 exposure caused by within-city emissions varies widely (μ = 37%; σ = 22%) and is not well-explained by surrounding population density. The list of most-important sources also varies by city. Compared to a more mechanistically detailed model, InMAP predicts urban measured concentrations with lower bias and error but also lower correlation. Predictive accuracy in urban areas is not particularly high with either model, suggesting an opportunity for improving global urban air emission inventories. We expect the results herein can be useful as a screening tool for policy options and, in the absence of available resources for further analysis, to inform policy action to improve public health. • The contributions of different air pollution sources vary widely among cities. • The contributions of within-city vs. external emission sources to a city's air pollution also varies widely among cities. • The contributions above cannot be accurately predicted without air quality modeling. • An opportunity exists to improve global emission inventories in urban areas. [ABSTRACT FROM AUTHOR]

An extremely severe and persistent haze event occurred over the middle and eastern China in January 2013, with the record-breaking high concentrations of fine particulate matter (PM 2.5 ). In this study, an online-coupled meteorology-air quality model, the Weather Research and Forecasting Model with Chemistry (WRF/Chem), is applied to simulate this pollution episode over East Asia and northern China at 36- and 12-km grid resolutions. A number of simulations are conducted to examine the sensitivities of the model predictions to various physical schemes. The results show that all simulations give similar predictions for temperature, wind speed, wind direction, and humidity, but large variations exist in the prediction for precipitation. The concentrations of PM 2.5 , particulate matter with aerodynamic diameter of 10 μm or less (PM 10 ), sulfur dioxide (SO 2 ), and nitrogen dioxide (NO 2 ) are overpredicted partially due to the lack of wet scavenging by the chemistry-aerosol option with the 1999 version of the Statewide Air Pollution Research Center (SAPRC-99) mechanism with the Model for Simulating Aerosol Interactions and Chemistry (MOSAIC) and the Volatility Basis Set (VBS) for secondary organic aerosol formation. The optimal set of configurations with the best performance is the simulation with the Gorddard shortwave and RRTM longwave radiation schemes, the Purdue Lin microphysics scheme, the Kain-Fritsch cumulus scheme, and a nudging coefficient of 1 × 10 −5 for water vapor mixing ratio. The emission sensitivity simulations show that the PM 2.5 concentrations are most sensitive to nitrogen oxide (NO x ) and SO 2 emissions in northern China, but to NO x and ammonia (NH 3 ) emissions in southern China. 30% NO x emission reductions may result in an increase in PM 2.5 concentrations in northern China because of the NH 3 -rich and volatile organic compound (VOC) limited conditions over this area. VOC emission reductions will lead to a decrease in PM 2.5 concentrations in eastern China. However, 30% reductions in the emissions of SO 2 , NO x , NH 3 , and VOC, individually or collectively, are insufficient to effectively mitigate the severe pollution over northern China. More aggressive emission controls, which needs to be identified in further studies, are needed in this area to reach the objective of 25% PM 2.5 concentration reduction in 2017 proposed in the Action Plan for Air Pollution Prevention and Control by the State Council in 2013. [ABSTRACT FROM AUTHOR]

Beijing has been publishing daily reports on its air quality since 2000, and while the air pollution index (API) shows that the air quality has improved greatly since 2000, this is not the perception of Beijing's residents. The new national ambient air quality standard (NAAQS-2012), which includes the monitoring of PM2.5, has posed stricter standards for evaluating air quality. With the new national standard, the air quality in Beijing is calculated using both NAAQS-2012 and the previous standard. The annual attainment rate has dropped from 75.5% to 50.7%. The spatial analysis of air quality shows that only a background station could attain the national standard, while urban and suburban stations exceed the national standard. Among the six pollutants included in the NAAQS-2012, PM2.5 is the major contributor to the air quality index (AQI) comparing with the five other pollutants. The results indicate that under previous NAAQS without PM2.5 monitoring, the air quality has improved greatly in the past decade. By considering PM2.5, the air quality attainment has dropped greatly. Furthermore, a great effort is needed for local government to bring down the PM2.5 concentration. [ABSTRACT FROM AUTHOR]