NMVOC Emissions Research Articles

Satellite‐Based Identification of Large Anthropogenic NMVOC Emission Sources

AbstractNonmethane volatile organic compounds (NMVOCs) emitted in excess from anthropogenic sources significantly contribute to the formation of harmful pollutants, thereby degrading air quality. While satellite measurements have become valuable tools for tracking anthropogenic emitters, they have primarily targeted inorganic species and methane (). This study demonstrates the potential of infrared atmospheric sounding interferometers (IASI) to detect anthropogenic NMVOC point sources on a global scale. Using an advanced oversampling technique, we enhance the spatial resolution of IASI measurements to identify emitters of three major NMVOCs: methanol (OH), acetylene (), and propylene (). These point sources are primarily associated with chemical and petrochemical facilities, coal‐burning activities, metallurgy, pharmaceutical manufacturing sites, and megacities. We also highlight the value of combining IASI measurements of NMVOCs with those of the inorganic species, such as sulfur dioxide () and ammonia (), to aid in the identification of anthropogenic point sources.

Sensitivities of ozone to its precursors during heavy ozone pollution events in the Yangtze River Delta using the adjoint method

Although the concentrations of five basic ambient air pollutants in the Yangtze River Delta (YRD) have been reduced since the implementation of the “Air Pollution Prevention and Control Action Plan” in 2013, the ozone concentrations still increase. In order to explore the causes of ozone pollution in YRD, we use the GEOS–Chem and its adjoint model to study the sensitivities of ozone to its precursor emissions from different source regions and emission sectors during heavy ozone pollution events under typical circulation patterns. The Multi-resolution Emission Inventory for China (MEIC) of Tsinghua University and 0.25° × 0.3125° nested grids are adopted in the model. By using the T–mode principal component analysis (T–PCA), the circulation patterns of heavy ozone pollution days (observed MDA8 O3 concentrations ≥160 μg m−3) in Nanjing located in the center area of YRD from 2013 to 2019 are divided into four types, with the main features of Siberian Low, Lake Balkhash High, Northeast China Low, Yellow Sea High, and southeast wind at the surface. The adjoint results show that the contributions of emissions emitted from Jiangsu and Zhejiang are the largest to heavy ozone pollution in Nanjing. The 10 % reduction of anthropogenic NOx and NMVOCs emissions in Jiangsu, Zhejiang and Shanghai could reduce the ozone concentrations in Nanjing by up to 3.40 μg m−3 and 0.96 μg m−3, respectively. However, the reduction of local NMVOCs emissions has little effect on ozone concentrations in Nanjing, and the reduction of local NOx emissions would even increase ozone pollution. For different emissions sectors, industry emissions account for 31 %–74 % of ozone pollution in Nanjing, followed by transportation emissions (18 %–49 %). This study could provide the scientific basis for forecasting ozone pollution events and formulating accurate strategies of emission reduction.

Air pollutant emissions caused by receiving international industrial transfer in Southeast Asian developing countries from 1990 to 2018

Receiving international industrial transfer (mainly foreign direct investment, FDI) is extremely important for economic development but also brings negative environmental impacts for Southeast Asian developing countries (SEADCs). Due to relatively low labor costs and large market potential, SEADCs have become an attractive destination for industrial transfer after China, while studies were far from sufficient on the associated air pollutant emissions that would worsen air quality and threaten human health. We develop an exploratory framework to estimate the long-term trends of relevant air pollutant emissions in eight major SEADCs, including Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Thailand, and Vietnam. During 1990–2018, the emissions generally show a fluctuating upward trend and increased significantly in Cambodia, Laos, Philippines, and Vietnam. The total emissions of CO, NMVOC, SO2, NOX, PM2.5, and NH3 from the eight SEADCs increased from 19.0, 4.3, 3.6, 1.5, 0.5, and 0.4 kilotons (kt) to 391.6, 260.9, 271.1, 182.4, 48.4, and 12.2 kt, respectively. The emission growth in almost all SEADCs accelerated after 2008 and faster than FDI growth. The disparities in emissions among SEADCs basically grew first and then declined to a level lower than that of 1990, but generally exceeded the disparities in FDI. Productivity gain and emission intensity decrease primarily caused the emission growth and reduction, respectively. Relatively small reductions in emission intensity are found for NOX and SO2. In general, most SEADCs have utilized FDI for economic development without sufficient efforts on air pollutant emission controls. Our outcomes can inform the formulation and optimization of relevant policies reconciling economic development and air quality improvement in SEADCs.

Observing Downwind Structures of Urban HCHO Plumes From Space: Implications to Non‐Methane Volatile Organic Compound Emissions

AbstractNon‐methane volatile organic compounds (NMVOCs) have a significant impact on air quality in urban areas. Detecting NMVOCs emission with its proxy HCHO on urban scales from space, however, has been limited by the lack of discernible enhancement. Here we show clear urban HCHO plumes from 16 cities over the globe by rotating TROPOspheric Monitoring Instrument HCHO pixels according to wind directions. We fit the downwind structure of the plumes with the exponentially modified Gaussian approach to quantify urban HCHO effective production rates between 7.0 and 88.5 mol s−1. Our results are in line with total NMVOC emissions from the EDGAR inventory (r = 0.76). Our work offers a new measure of total NMVOC emissions from urban areas and highlights the potential of satellite HCHO data to provide new information for monitoring urban air quality.

Assessing the impacts and feasibility of emissions reduction scenarios in the Po Valley

This study is focused on a pivotal objective: enhancing air quality and attaining pollutant concentrations in accordance with WHO guidelines. The study extensively evaluates the feasibility of reducing emissions, specifically targeting an 80% decrease in SOX, NOX, PM, NH3, and NMVOC emissions within a limited timeframe. Despite notable emission curtailments of 50% and 80%, the research reveals that recommended pollutant levels are unlikely to be met across most areas of the Po Valley region. Even when implementing the finest available technologies across various sectors, particularly within the Lombardia region, this goal remains unattainable without simultaneous reductions in activity levels. This involves diminishing factors like vehicle miles traveled, energy consumption for heating, and industrial, agricultural, and livestock production. Overall, achieving improved conforming to the new AQG limits is a multifaceted endeavor involving numerous stakeholders and diverse strategies. Successful adherence to Air Quality limits mandates the implementation of Source-Specific emissions standards at the EU level, alignment of the National Emission Reduction Directive with limits specified in the Air Quality Directive, and the formulation of comprehensive Air Quality Plans at national, regional, and local tiers.

Dynamic quantification of on-road emissions in Hong Kong: Impact from traffic congestion and fleet composition variation

Policymakers need a good understanding of on-road air pollutant emission patterns to manage air quality effectively, but it can be challenging to dynamically capture emission patterns with high spatial and temporal resolutions in cities. In this study, we used traffic congestion index extracted from Google Map, traffic density model and local emission factors to develop a dynamic on-road emission inventory for Hong Kong. The pollutants include NOx, CO, NMVOC, CO2, PM2.5, PM10, and CH4. On weekdays, exhaust emissions increased by up to 50.0% compared with those on Sunday due to higher traffic congestion index. High emission rates were observed on highways during weekday evening peak hours and shifted to regional centers on Sunday evenings. Public light buses, goods vehicles, and taxis were the most significant contributors of NMVOC, NOx, and CO emissions, respectively. Control policy testing showed that replacing diesel-fueled buses with electric buses could significantly reduce NOx and PM exhaust emissions, whereas replacing liquefied petroleum gas fueled public light buses with electric buses could efficiently control NMVOC emissions. Eliminating private cars older than 15 years could effectively reduce CO emissions. This study provides a dynamic on-road emission inventory for Hong Kong with high temporal and spatial resolutions. The results can be extended to real-time air quality simulations and human exposure research in the future.

Towards near-real-time air pollutant and greenhouse gas emissions: lessons learned from multiple estimates during the COVID-19 pandemic

Abstract. The 2020 COVID-19 crisis caused an unprecedented drop in anthropogenic emissions of air pollutants and greenhouse gases. Given that emissions estimates from official national inventories for the year 2020 were not reported until 2 years later, new and non-traditional datasets to estimate near-real-time emissions became particularly relevant and widely used in international monitoring and modelling activities during the pandemic. This study investigates the impact of the COVID-19 pandemic on 2020 European (the 27 EU member states and the UK) emissions by comparing a selection of such near-real-time emission estimates, with the official inventories that were subsequently reported in 2022 under the Convention on Long-Range Transboundary Air Pollution (CLRTAP) and the United Nations Framework Convention on Climate Change (UNFCCC). Results indicate that annual changes in total 2020 emissions reported by official and near-real-time estimates are fairly in line for most of the chemical species, with NOx and fossil fuel CO2 being reported as the ones that experienced the largest reduction in Europe in all cases. However, large discrepancies arise between the official and non-official datasets when comparing annual results at the sector and country level, indicating that caution should be exercised when estimating changes in emissions using specific near-real-time activity datasets, such as time mobility data derived from smartphones. The main examples of these differences are observed for the manufacturing industry NOx (relative changes ranging between −21.4 % and −5.4 %) and road transport CO2 (relative changes ranging between −29.3 % and −5.6 %) total European emissions. Additionally, significant discrepancies are observed between the quarterly and monthly distribution of emissions drops reported by the various near-real-time inventories, with differences of up to a factor of 1.5 for total NOx during April 2020, when restrictions were at their maximum. For residential combustion, shipping and the public energy industry, results indicate that changes in emissions that occurred between 2019 and 2020 were mainly dominated by non-COVID-19 factors, including meteorology, the implementation of the Global Sulphur Cap and the shutdown of coal-fired power plants as part of national decarbonization efforts, respectively. The potential increase in NMVOC emissions from the intensive use of personal protective equipment such as hand sanitizer gels is considered in a heterogeneous way across countries in officially reported inventories, indicating the need for some countries to base their calculations on more advanced methods. The findings of this study can be used to better understand the uncertainties in near-real-time emissions and how such emissions could be used in the future to provide timely updates to emission datasets that are critical for modelling and monitoring applications.

Investigating exhaust gas emissions of yachts: Example of Turgutreis D‐Marin

AbstractYachts emit harmful gases to human health and the environment into the atmosphere and marinas and surrounding vicinity are the most affected regions by these pollutants. This study applied a bottom‐up approach involving emission factors to make an anthropogenic emissions inventory of yachts and to offer solutions for reducing emissions by investigating the NMVOC, NOx, NH3, CO, and PM emissions from 2002 yacht movements between June 1 and August 31, 2019 at Turgutreis D‐Marin in Bodrum Turkey. These emissions are categorized based on yacht operation modes and types. Quarterly yachting emissions are estimated as 3099 tons for NMVOC, 0.003 tons for NH3, 14,526 tons for NOx, 1896 tons for PM, and 15,576 tons for CO.

An integrated view of correlated emissions of greenhouse gases and air pollutants in China

BackgroundAir pollution in China has raised great concerns due to its adverse effects on air quality, human health, and climate. Emissions of air pollutants (APs) are inherently linked with CO2 emissions through fossil-energy consumption. Knowledge of the characteristics of APs and CO2 emissions and their relationships is fundamentally important in the pursuit of co-benefits in addressing air quality and climate issues in China. However, the linkages and interactions between APs and CO2 in China are not well understood.ResultsHere, we conducted an ensemble study of six bottom-up inventories to identify the underlying drivers of APs and CO2 emissions growth and to explore their linkages in China. The results showed that, during 1980–2015, the power and industry sectors contributed 61–79% to China’s overall emissions of CO2, NOx, and SO2. In addition, the residential and industrial sectors were large emitters (77–85%) of PM10, PM2.5, CO, BC, and OC. The emissions of CH4, N2O and NH3 were dominated by the agriculture sector (46–82%) during 1980–2015, while the share of CH4 emissions in the energy sector increased since 2010. During 1980–2015, APs and greenhouse gases (GHGs) emissions from residential sources generally decreased over time, while the transportation sector increased its impact on recent emissions, particularly for NOx and NMVOC. Since implementation of stringent pollution control measures and accompanying technological improvements in 2013, China has effectively limited pollution emissions (e.g., growth rates of –10% per year for PM and –20% for SO2) and slowed down the increasing trend of carbon emissions from the power and industrial sectors. We also found that areas with high emissions of CO, NOx, NMVOC, and SO2 also emitted large amounts of CO2, which demonstrates the possible common sources of APs and GHGs. Moreover, we found significant correlations between CO2 and APs (e.g., NOx, CO, SO2, and PM) emissions in the top 5% high-emitting grid cells, with more than 60% common grid cells during 2010–2015.ConclusionsWe found significant correlation in spatial and temporal aspects for CO2, and NOx, CO, SO2, and PM emissions in China. We targeted sectorial and spatial APs and GHGs emission hot-spots, which help for management and policy-making of collaborative reductions of them. This comprehensive analysis over 6 datasets improves our understanding of APs and GHGs emissions in China during the period of rapid industrialization from 1980 to 2015. This study helps elucidate the linkages between APs and CO2 from an integrated perspective, and provides insights for future synergistic emissions reduction.

Impacts of travel bans and travel intention changes on aviation emissions due to Covid-19 pandemic.

The online version contains supplementary material available at 10.1007/s10668-023-02916-8.

Calculation of emissions into the air of non-road mobile machinery from the landfill

Waste disposal is just one of the segments in solid municipal waste management system. During the entire life cycle of waste, starting from waste generation, through storage, collection, transport, recycling, treatment and disposal, several different pollutants are emitted. By disposing solid waste, non-road mobile machinery (NRMM) emits various pollutants into the air such as CO2, CO, NMVOC, PM, PAHs, heavy metals, etc. These substances can pose certain problems for human health and the environment. The subject of this study is the calculation of air emissions of CO2, CH4, N2O, NMVOC, PM10, CO, Cd, Cr and PAHs (chrysene and benz[a]anthracene) from NRMM which are included in the activities of receiving and disposing of waste at the Banja Luka landfill. The study evaluates the emission of pollutants using the EEA guidelines for the assessment of the emission of pollutants into the air, based on the consumption of diesel fuel during the year. This study, which is based on the calculation of NRMM emissions at the Banja Luka landfill, should serve as an example not only to other landfills but also to sectors that use NRMM on the importance of keeping track of pollutant emissions. The goal is to look at these emissions and introduce changes and improvements in this sector by replacing old NRMMs with new ones, optimizing operation, using diesel of satisfactory quality, etc.

Development of current and future high-resolution gridded emission inventory of anthropogenic air pollutants for urban air quality studies in Hanoi, Vietnam

A high-resolution (1 km × 1 km) emission inventory was developed for Hanoi for 2017 and 2018. The total annual emissions of PM2.5, BC, OC, NOx, SO2, NMVOC, NH3, CH4, and CO were 14.9, 1.6, 2.9, 56.7, 19.1, 109.2, 23.0, 37.9, and 472.7 Gg, respectively. Transportation, industry, and agriculture contributed 89.1%, 92.2%, and 81.3% to the total emissions of PM2.5, BC, and OC, respectively. Transportation contributed 72.4%, 52.1%, and 72.5% to the emissions of NOx, NMVOC, and CO, respectively. Industry contributed 64.9% to the emissions of SO2. Agriculture was a major source of NH3 and CH4, contributing 84.2% and 76.6%, respectively. Future emissions of select sectors were estimated for 2030. The emissions from transportation can increase in the range of 26.9% (CH4) to 245.8% (NH3), despite the consideration of the EURO 5 standard. For domestic cooking, transitioning from coal to liquefied petroleum gas can help reduce the emissions of most pollutants in the range of 10.4% (NH3) to 52.6% (OC), except NOx and NMVOC. The crop residue burning (CRB) ban could reduce emissions in the range of 0.27 Gg (SO2) to 138.4 Gg (CO) in 2030, respectively. The study can help policy-makers to develop strategies for air pollution mitigation in developing economies such as Hanoi.

Emissions and spatial distribution of air pollutants from anthropogenic sources in Jakarta

This study aims to develop emission inventory and emission spatial distribution of NOX, CO, PM2.5, PM10, NMVOC, BC, and SO2 from anthropogenic sources in Jakarta from 2015 to 2030, using 2015 as a baseline year. The results from this study can be very important to improve the emission data for Jakarta and contribute to the global emission model. Emissions of these pollutants were calculated using GAINS (Greenhouse gas Air pollution INteractions and Synergies) model, considering implementation of emission standards for transport and stationary combustion sources as well as policies stimulating accelerated electrification of vehicle fleets and vehicle scrapping programs. The impact of current policies to emission reduction was also evaluated in this study. The total 2015 emissions of NOX, CO, PM2.5, PM10, NMVOC, BC and SO2 were estimated at around 53 Gg, 144 Gg, 4.6 Gg, 6 Gg, 48.6 Gg, 1.2 Gg, and 20 Gg, respectively. The biggest contribution for NOx, CO, BC and NMVOC emissions originated from road transportation sector which contributed about 57%, 93% and 75%, 96% respectively, while for SO2, industrial combustion contributed about 67%. Heavy duty vehicles contribute the most NOx and BC emissions in the transport sector, while motorcycles emit the most CO. PM2.5 and PM10 in Jakarta are mostly emitted from road transportation and industrial combustion sectors, which contributed around 43%–46% for each sector. Heavy duty vehicles were still the highest contributor of PM2.5 emission in the transport sector. Based on emission spatial distribution and the AERMOD dispersion model, the highest concentration of all pollutants was found in the central of Jakarta, where traffic activities are very busy. Policy implementation could effectively reduce pollution levels in Jakarta. The accelerated implementation of electric vehicles, stringent emission standards, and transport management measures like electronic road pricing could significantly contribute to the reduction of PM2.5, PM10 as well as BC.

Emission profiles of volatile organic compounds from various geological maturity coal and its clean coal briquetting in China

Coal is a dominant energy source used in household cooking and warming in rural China. Its combustions generate a large quantity of gaseous and particulate phase's pollutants. In between, the volatile organic compounds (VOCs) is a critical class of chemical that shows strong environmental and health impacts. In this study, the VOC emission characteristics, influencing factors and briquette technology that affected the combustions of different maturity coals were investigated. Emission factors (EFs) of targeted non-methane VOCs (EFNMVOCs) for different coal samples ranged from 233 ± 89.8 to 1690 ± 722 mg/kg. The EFNMVOCs decreased with volatile content (VC). Besides, EFNMVOCs for the briquette coals showed 5.31–51.5% lower than that of the raw coals except the anthracite. Alkanes and alkenes are the two most dominated chemical groups, accounting for >50% of the total NMVOCs emissions. Coefficient of divergence (CD) values showed that a significant difference (>0.6) between the emissions of high-volatile and low-volatile raw coals, representing that the coal content should be sub-classified for either source apportionment or emission profile database development. Correlation analysis reported that VC is the most significant factor that correlated with EFNMVOCs (R = 0.78), while modified combustion efficiency (MCE) negatively correlated (R = −0.78). The calculations of ozone formation potentials (OFP) and secondary organic aerosol potentials (SOAP) deducted that alkenes and aromatics are the top two contributors to the formations of these secondary pollutants. In addition, the briquette technology has been proved to reduce both OFP and SOAP from coal combustions. Our results perceptibly support that the use of low VC coals could efficiently reduce the emissions of VOC and the formations of more environmental and health harm substances, and the application of briquetting technology also has a certain effect especially in bituminous coals. The key findings provide feasible solutions to improve regional air quality regarding residential coal combustion in northwest China.

Air pollution scenario analyses of fleet replacement strategies to accomplish reductions in criteria air pollutants and 74 VOCs over India

Traffic emissions are a major source of air pollution and associated damage to human health in India. Many of the Indian metro cities urgently require cleaner transportation technologies to ensure cleaner air. Here, using newly compiled spatially disaggregated, gridded, high-resolution (0.1° × 0.1°) road transport emission inventory for India for 2030 (RTEII) of 74 speciated VOCs, CO, SO 2 , NOx, NH 3 , CH 4 , CO 2, BC, OC and PM 2.5 from varied fuels and vehicle technologies that are currently in use in India, we investigated changes in emission in response to substitution of the existing vehicular fleet by cleaner alternatives. Three “what-if” intervention scenarios were considered to assess the extent in improvement of air quality due to the reduction in the primary emission of air pollutants. The results show that significant reductions in direct emission of pollutants (Non-Methane VOCs, −91%; CO, −80%; PM 2.5 , 44%) including toxic VOCs (e.g., isocyanic acid, −76%; BTEX, −93%; as well as individual VOC classes (e.g., sum of OVOCs, −61% and sum of alkenes, −80%) can likely be achieved in 2030 by shifting from highly polluting Internal Combustion Engine (ICE) based 2 and 3-wheeled vehicles to Electric Vehicles (EVs) under scenario 1. The amount of secondary pollutants such as SOA and O 3 that can potentially be formed from traffic also showed significant reduction of 94% and 84%, respectively, under scenario 1. Conversion of diesel fuelled vehicles to CNG under scenario 2 can lead to a larger reduction in black carbon emissions (−50%). Scenario 3, in which the benefits of scenarios 1 and 2 are combined, represents the best long-term strategy moving forward, which can result in massive emission reductions of pollutants through existing technologies of greener transport fleets over India. Large scale conversion of the vehicle fleets as explored here can lead to a substantial reduction of air pollution and fewer lives lost. • Study examines 2030 road-transport emission reductions for India. • Three “what-if” intervention scenarios with electric vehicles and greener fuels. • 2&3-wheeler vehicles replacement by EVs reduced NMVOC emissions by 91%. • Conversion of diesel fuelled vehicles to CNG reduced primary BC by 50%. • Combining EVs and diesel to CNG for HDVs can improve air quality over India greatly.

GIS-based determination of Turkish domestic flights emissions

Aviation emissions directly affect the troposphere and stratosphere layers of the atmosphere. Growing vehicle fleets, an increase in the number of flights, and growing airports have negative effects on ambient air quality. This study aims to determine the air pollution caused by emissions arising from domestic flights of Turkey and to express them via the Geographic Information Systems (GIS). Within the scope of this study, the aviation emissions of SO2, CO2, CO, NOx, NMVOC, CH4, N2O, and PM2.5 are determined. Emission factors, published by the EMEP/EEA emission inventory guidebook, are utilized in the study. Activity statistics are obtained from non-scheduled flight statistics published by the General Directorate of State Airports Authority and from several websites. The flight routes and spatial positions of the airports are transferred to the GIS environment. In the compilation of the inventory, both airport activities (landing, takeoff, and taxi), and cruise emissions are considered separately. Tier 3A methodology is applied in inventory calculations for the first time for Turkish domestic flights. With the aid of spatial analysis, aviation emissions are distributed over Turkish cities. According to the results, the total emissions were calculated as 1.67 million tons CO2, 6472.23 tons NOx, 2839.03 tons CO, and 80.52 tons PM2.5. Cruise emissions contributed to 43.8%, 37.1%, 16.5%, and 57.9% of total CO2, NOx, CO, and PM2.5 emissions, respectively. Besides, thematic maps of total emissions reveal the impacts of aviation emissions on the cities. Some cities without airports have been affected by cruise emissions.

Develop a clean air action plan based on scientific data: a case of Ho Chi Minh city

Ho Chi Minh City (HCMC) has quickly become a modernized and industrialized city undergoing a rapid population growth affecting on the local environment, especially the air quality and human health. It's urgent need to have a Clean Air Action Plan (CAP) for HCMC. The aim of this research is to develop a clean air plan for HCMC based on scientific basis by integrating results of emissions inventory, air emssion loading capacties and results of the impact of air pollution on people's health. This research applied the Clean Air For Smaller City in ASEAN Region project (CASC) method of Germany to develop the CAP. Emission inventory resulted from the integration of two approaches of bottom-up and top-down. The results of simulation of air pollution dispersion and air emission loading capacities were from the TAPM-CTM model system. Method of calculating the impact of air pollution on the health of people in Ho Chi Minh City was based on BENMAP model theory. The results showed that the source of traffic accounts for the largest emissions of all pollutants, contributed respectively, 99%, 97%, 93%, 78%, 23%, 64% and 45% of total CO, NMVOC emissions, NOx, SO2, TSP, CH4, and PM2:5 of the whole HCMC. For some central areas, the city was no longer able to receive more emissions of CO and NOx. Assessing the impact of air pollution on health showed that the great impact of PM2:5 on public health accounted for 81.45% of the total deaths caused by all three pollutants ( PM2:5, SO2, NO2). Finally, a CAP was suggested with 13 proposals and 1 recommendation for reducing air pollution in HCMC for the period of 2020–2025. This is the first comprehensive study on CAP in Vietnam. This result supports government authorities to promulgate plans and actions to reduce emissions protecting human health and the environment for a sustainable development.

Development of 2015 Vietnam emission inventory for power generation units

The 2010 and 2015 Emission Inventories (EIs) for Vietnam Thermal Power Plants (TPP) were concurrently developed using the bottom-up approach. Local activity data, emission factors, and pollution control efficiencies were applied to estimate the annual emissions of individual power plants. As the EIs consider all emission control activities with relevant unit upgrades, the estimated SO2, NOx and PM species were found to be lower than most of the reported EIs by 20–70%. An overestimation (i.e., 3.8 times) of SO2 has been observed in Emission Database for Global Atmospheric Research (EDGAR) EI, which can possibly be attributed to the assumption of no air pollution controls in their inventory. Overall, the newly developed EIs indicate that the annual emissions of coal-fired TPPs were highest among the various types of TPPs, and the largest uncertainty occurred in NOx with ranges between −23% and +31%. In terms of regional distribution, the most significant emission sources of CO2, N2O, SO2, NOx, PM10, PM2.5, BC, and OC were from the Red River Delta region resulted from coal-fired TPPs, while the Southeast region had the largest sources of CO, NMVOC, and CH4 caused by gas-fired TPPs. The study reveals that from 2010 to 2015, the growths of NOx, CO, NMVOC, PM10, PM2.5, BC, OC, CO2, CH4, and N2O emissions were 51%, 39%, 41%, 109%, 88%, 9%, 107%, 58%, 33%, and 119%, respectively, while ~19% reduction in SO2 was found resulted from the decommission of oil-fired TPPs.

Intercomparison of Magnitudes and Trends in Anthropogenic Surface Emissions From Bottom‐Up Inventories, Top‐Down Estimates, and Emission Scenarios

AbstractThis study compares recent CO, NOx, NMVOC, SO2, BC, and OC anthropogenic emissions from several state‐of‐the‐art top‐down estimates to global and regional bottom‐up inventories and projections from five Shared Socioeconomic Pathways (SSPs) in several regions. Results show that top‐down emissions derived in several recent studies exhibit similar uncertainty as bottom‐up inventories in some regions for certain species and even less in the case of Chinese CO emissions. In general, the largest discrepancies are found outside of regions such as the United States, Europe, and Japan where the most accurate and detailed information on emissions is available. In some regions such as China, which has recently undergone dynamical economic growth and changes in air quality regulations, the top‐down estimates better capture recent emission trends than global bottom‐up inventories. These results show the potential of top‐down estimates to complement bottom‐up inventories and to aide in the development of emission scenarios, particularly in regions where global inventories lack the necessary up‐to‐date and accurate information regarding regional activity data and emission factors such as Africa and India. Areas of future work aimed at quantifying and reducing uncertainty are also highlighted. A regional comparison of recent CO and NOx trends in the five SSPs indicate that SSP126, a strong pollution control scenario, best represents the trends from the top‐down and regional bottom‐up inventories in the United States, Europe, and China, while SSP460, a low‐pollution control scenario, lies closest to actual trends in West Africa. This analysis can be useful for air quality forecasting and near‐future pollution control/mitigation policy studies.

The moving of high emission for biomass burning in China: View from multi-year emission estimation and human-driven forces

Biomass burning (BB) has significant impacts on air quality, climate and human health. In China, the BB emission has changed substantially over the past decades while the multi-year variation held high uncertainty and the driving forces have addressed little attention. Here, this research aimed to conduct a comprehensive and systematic analysis of BB variation in China and provided precise and targeted BB emission reduction suggestions. The moving of high emission for BB from 2003 to 2014 was clearly identified, by the view of reliable emission estimation and anthropogenic impacts. Multiple satellite products, field survey, time varying biomass loading data and measured emission factors were adopted to better estimating BB emission and reducing the uncertainty. Social-economic analysis was added to assess the anthropogenic impacts on high emission variation quantitatively. Results showed that the cumulative BB emissions of OC, EC, CH4, NOX, NMVOC, SO2, NH3, CO, CO2, PM2.5 and PM10 during 2003-2014 were 1.6 × 104, 5.64 × 103, 3.57 × 104, 1.7 × 104, 5.44 × 104, 2.96 × 103, 6.77 × 103, 6.5 × 105, 1.15 × 107, 5.26 × 104 and 6.04 × 104 Gg, respectively. Crop straw burning (in-field and domestic) in northeast China plain (NEP), north China plain (NCP), northern arid and semiarid region and loess plateau were the key sources, averagely contributed 73% for all the pollutants emission. While domestic straw burning and firewood burning in Sichuan basin (SB), Yunnan-Guizhou plateau and southern China were main contributors, averagely accounting for 70% of all the pollutants emission. On regional level, high emissions were mainly found in SB, NCP and NEP. Temporally, high emissions were mainly found in crop sowing harvesting and heating seasons. From 2003 to 2014, the BB emission for different biomass species has changed significantly in different regions. High emission has gradually moved from SB to NCP and NEP. Firewood burning and domestic straw burning emission decreased by 47% and 14% in SB, respectively. In-field straw burning emission increased by 52% and 231% in NCP and NEP respectively and domestic straw burning emission increased by 62% in NEP. Emissions from heating season have decreased while emissions in corn harvest season were continuously increased. Analysis of Environmental kuznets curve, agricultural productivity level, human burning habits, rural energy structure and local control policies revealed the internal human driving strength of the variation for BB emission. The unbalanced development of social economy and the policy bias were primary drivers of limiting the BB management. BB emission will alleviate in NCP and aggravate in NEP. For the further emission reduction, effective measures for corn sources management, straw returning and rural energy utilization should be systematically considered. This research provides a clear evidence for the multi-year variation pattern of BB emissions, which is critical for pollution prediction, air quality modeling and targeted mitigation strategies for the key regions of China.