Changes In Emissions Research Articles

A Community Seismic Network for the Early Detection of Seismic Activity Close to Active Volcanoes in Western El Salvador

Abstract Seismic monitoring can provide key constraints on volcanic processes, magma migration, and preparatory processes before volcanic eruptions. Nevertheless, the high cost of broadband networks limits the number of volcanoes that are actively monitored. Here, we test the capability of a network of raspberry shake (RS) seismographs to monitor volcanoes in El Salvador and characterize associated seismicity sequences in real time. We deployed seven three-component, short-period RS velocity seismometers around Santa Ana volcano, which has a long history of phreatomagmatic eruptions as recently as 2007. The new network primarily supports training, research, and outreach activities but also has the potential to provide early alerts before volcanic unrest. The seismometers were installed at schools, a university campus, and hotels within 20 km of Santa Ana volcano. We recorded an accelerating seismicity sequence within ∼15 km distance from the volcano between 28 December 2023 and 1 February 2024. Both magnitudes and seismicity rates increased systematically, culminating in two events above ML 4 on 28 January 2024 without causing detectable changes in temperature or gas emissions at the summit of Santa Ana. Detailed space–time clustering analyses reveal dominant mainshock–aftershock triggering at local to regional distances, similar to tectonic earthquake sequences. The new RS network around Santa Ana volcano demonstrates the ability of low-cost seismometers to improve seismic event detection, location, and classification. The observations suggest that dense volcano monitoring networks facilitate an early detection of unfolding seismicity sequences and improve tectonic versus volcanic event classifications—a key component of reliable eruption alerts.

Spatial–Temporal and Decoupling Effect of Agricultural Carbon Pollution Synergy in Ecologically Fragile Areas

As an important industry in ecologically fragile areas, the synergy of agricultural pollution control and carbon reduction is vital for the balanced development of industries and regional synergy. This paper aims to explore the synergistic result of agricultural pollution control and carbon reduction in ecologically fragile areas so as to clarify the weak links and solve carbon pollution in ecologically fragile areas. Leveraging the 2006–2021 municipal data of ecologically fragile areas, this paper calculates the coupling coordination degree (CCD) of agricultural non-point source pollution and agricultural carbon emission in ecologically fragile areas; calculates the decoupling relationship between agricultural carbon emissions, pollutants, and gross agricultural output based on the Tapio decoupling index; and quantitatively depicts the synergy of agricultural pollution control and carbon reduction in ecologically fragile areas. From 2006 to 2021, agricultural carbon emissions in ecologically fragile areas depicted a fluctuating and increasing trend. Agricultural non-point source pollution depicted an “inverted U-shaped” growth trend. The emission trends of agricultural carbon emissions and agricultural pollutants depict that although agricultural pollutants and carbon emissions are homologous, there is heterogeneity in the trend and change in emissions. The synergistic results of agricultural pollution control and carbon reduction show a fluctuating upward trend in ecologically fragile areas, and the coordination degree of ecologically fragile areas increased from 0.32 to 0.89, indicating that the level of coordinated development between agricultural pollution control and carbon reduction increased significantly. Taking into account the decoupling effect, the decoupling state of agricultural carbon pollution synergistic economic growth in ecologically fragile areas has changed from negative decoupling to strong decoupling to weak decoupling, mainly in the state of strong decoupling, negative decoupling of expansion, and weak decoupling; in addition, the synergistic capacity of agricultural pollution control and carbon reduction needs to be further optimized. Based on the research results, there is some room for improvement in agricultural carbon pollution synergy in ecologically fragile areas, and regions should strengthen regional cooperation.

Mesoscale modelling and three-dimensional experimental validation of heat transfer in shallow beds of polyamide powders for laser powder bed fusion

Abstract A good understanding of temperature-dependent material properties and the associated process parameters is required to successfully model the heat transfer in laser powder bed fusion (LPBF). To quantify the temperature distribution along the depth and top surface, a stationary laser sintering experimental set-up equipped with two infrared cameras is constructed in this study. A shallow bed of polymeric powder is spread on infrared-transparent Zinc Selenide (ZnSe) glass, so that one of the thermal cameras can see the heat transfer along the depth from the bottom. Two carbon black powders of treated polyamide (PA12 CB of 60 μm and PA6 CB of 80 μm) are used. A 3D finite-element heat transfer model is developed considering conductive, convective, radiative heat transfer, and phase change. Temperature-dependent material properties, such as thermal conductivity, density, specific heat, and emissivity, are estimated and considered. The model's accuracy is validated by comparing the temperature data along XYZ directions with the experimental values. The PA6 CB powder exhibits higher laser absorption and thermal conductivity than PA12 CB. This finding is evident from the rapid heating of PA6 CB due to higher laser absorption and faster cooling rate due to higher thermal conductivity. The emissivity of the powder bed is nearly uniform with the temperature for both powders and drastically increases at the melt pool. This change in emissivity is captured in the model.

Historical Drivers and Reduction Paths of CO2 Emissions in Jiangsu’s Cement Industry

With global climate challenges intensifying, the cement industry, as a major CO2 emitter, has attracted significant attention regarding its emission reduction potential and strategies. Advanced economies like the European Union use carbon pricing to spur innovation, while emerging countries focus on incremental solutions, such as fuel substitution. Combining LMDI decomposition and the LEAP model, this study examines Jiangsu Province as a test bed for China’s decarbonization strategy, a highly efficient region with carbon intensity 8% lower than the national average. Historical analysis identifies carbon intensity, energy mix, energy intensity, output scale, and economic effects as key drivers of emission changes. Specifically, the reduction in cement production, real estate contraction, lower housing construction, and reduced production capacity are the main factors curbing emissions. Under an integrated technology strategy—including energy efficiency, fuel and clinker substitution, and CCS—CO2 emissions from Jiangsu’s cement sector are projected to decrease to 17.28 million tons and 10.9 million tons by 2060 under high- and low-demand scenarios, respectively. Clinker substitution is the most significant CO2 reduction technology, contributing about 60%, while energy efficiency gains contribute only 3.4%. Despite the full deployment of existing reduction methods, Jiangsu’s cement industry is expected to face an emissions gap of approximately 10 million tons to achieve carbon neutrality by 2060, highlighting the need for innovative emission reduction technologies or carbon trading to meet carbon neutrality goals.

Comparison of High-Resolution Gridded Emission Maps of Anthropogenic Carbon Dioxide in Europe: GRACED & CAMS-REG.

Gridded maps of CO2 emissions are increasingly being applied in emission change analyses and atmospheric studies. In this study, we compared two high-resolution gridded estimates of anthropogenic CO2 emissions in Europe for 2019-2021: the near-real-time Global gridded daily CO2 emission data set (GRACED, latest updated version May 2024) and the Copernicus Atmosphere Monitoring Service regional inventory (CAMS-REG, v6 for 2019-2020, and v7 for 2021). Total CO2 emissions of the two data sets are comparable, with a 2.4% emission difference, and the total emissions' spatial determination coefficient (R) at 0.1° is 0.66 in 2021. However, the sectoral emissions and spatial patterns show significant differences. At the grid level, the absolute value of the median of relative percent difference (RPD) of power, ground transportation, and shipping across the domain all reach 200%. CAMS-REG is recommended for fine-scale historical emission analysis in Europe due to its higher spatial resolution and the use of localized data sets. GRACED, with a maximum latency of 3 months, is more appropriate for applications requiring near-real-time data. This work characterizing the difference between two state-of-the-art emission maps is also valuable for atmospheric modelers who need to account for the uncertainty of a priori fossil fuel emissions when performing inverse calculations of land and ocean CO2 sinks.

A study on the forecast of fine dust emissions in the future according to the introduction of eco-friendly ships.

A study on the forecast of fine dust emissions in the future according to the introduction of eco-friendly ships.

Integrating the updated HONO formation mechanism to better understand urban O3 formation chemistry.

Integrating the updated HONO formation mechanism to better understand urban O3 formation chemistry.

Influence of top-down adjusted upwind emissions on PM2.5 concentrations: The case of long-range transport in South Korea.

Influence of top-down adjusted upwind emissions on PM2.5 concentrations: The case of long-range transport in South Korea.

Impacts of meteorology and precursor emission change on PM2.5 and O3 and identification of synergistic emission reduction pathway: A case of combined pollution event in Beijing, China.

Impacts of meteorology and precursor emission change on PM2.5 and O3 and identification of synergistic emission reduction pathway: A case of combined pollution event in Beijing, China.

Investigating the response of China's surface ozone concentration to the future changes of multiple factors

Abstract. Climate change and associated human response are supposed to greatly alter surface ozone (O3), an air pollutant generated through photochemical reactions involving both anthropogenic and biogenic precursors. However, a comprehensive evaluation of China's O3 response to these multiple changes has been lacking. We present a modeling framework under Shared Socioeconomic Pathways (SSP2-4.5), incorporating future changes in local and foreign anthropogenic emissions, meteorological conditions, and biogenic volatile organic compound (BVOC) emissions. From the 2020s to 2060s, daily maximum 8 h average (MDA8) O3 concentration is simulated to decline by 7.7 ppb in the warm season (April–September) and 1.1 ppb in the non-warm season (October–March) over the country, with a substantial reduction in exceedances of national O3 standards. Notably, O3 decreases are more pronounced in developed regions such as Beijing–Tianjin–Hebei (BTH), the Yangtze River Delta (YRD), and the Pearl River Delta (PRD) during the warm season, with reductions of 9.7, 14.8, and 12.5 ppb, respectively. Conversely, in the non-warm season, the MDA8 O3 in BTH and YRD will increase by 5.5 and 3.3 ppb, partly attributed to reduced NOx emissions and thereby a weakened titration effect. O3 pollution will thus expand into the non-warm season in the future. Sensitivity analyses reveal that local emission change will predominantly influence future O3 distribution and magnitude, with contributions from other factors within ±25 %. Furthermore, the joint impact of multiple factors on O3 reduction will be larger than the sum of individual factors, due to changes in the O3 formation regime. This study highlights the necessity of region-specific emission control strategies to mitigate potential O3 increases during the non-warm season and under the climate penalty.

Integrated Multispectral Modulator with Efficient Radiative Cooling for Innovative Thermal Camouflage

AbstractThermal camouflage technology offers critical countermeasures against infrared detection, yet persistent challenges remain in environmental adaptability, multispectral compatibility, and concurrent thermal management. To address these limitations, a spectrally selective modulator is pioneered that synergistically integrates radiative cooling with electrochromic tunability. The proposed modulator achieves spectrally selective emissivity modulation, demonstrating a remarkable emissivity change (Δɛmax = 0.76) within infrared detection bands (3–5 µm and 8–14 µm) while preserving high emissivity (ɛmax = 0.79) in non‐detection bands for passive heat dissipation. Multispectral operability is further evidenced by dynamic diffuse reflectivity control (Rlowest = 0.07/0.05 across visible and near‐infrared band) and terahertz absorptivity modulation (ΔAmax = 0.66), enabling full‐spectrum adaptive concealment. The device achieves ≈10 °C apparent temperature modulation without external heating, effectively disguising a 70 °C target as 40 °C. Radiative cooling efficacy is validated through theoretical modeling (peak cooling power: 367 W m−2) and experimental verification (≈6 °C reduction vs conventional wide‐spectrum stealth surfaces at 60 °C). With rapid switching (<6 s), exceptional cyclability (>103 cycles), and programmable information encryption capabilities. This work resolves the long‐standing trade‐off between adaptive camouflage and thermal regulation through wavelength‐selective emissivity engineering, establishing a versatile foundation for next‐generation intelligent camouflage systems across defense, aerospace, and energy‐efficient thermal regulation applications.

Modeling Long-Term Dynamics of Biogenic Volatile Organic Compounds (BVOCs) in Germany Based on Major Precursors.

Biogenic Volatile Organic Compounds (BVOCs) are organic chemicals emitted primarily by flora. They impact climate and human health, and their presence is influenced by environmental conditions. Despite the intense effects of climate change, there is lack of information about the spatiotemporal variations in BVOC emissions and underlying driving factors. This study aims to quantify the variation of BVOCs in Germany and attribute it to deriving factors. We first conducted a detailed study covering the period from 1979 to 2024, during which satellite observations were first became available. Then, using historical records and projected future climate-change scenarios, we simulated the dynamics of BVOCs over an extended timeframe (1790-2065). To track changes in BVOCs emissions, we accounted for constant emission factors and used remotely sensed proxies, summarized into five main factors: biomass, temperature, carbon dioxide, soil moisture, and wildfire. Our results show that the trend of BVOCs emissions declining reversed in 1978 ± 1, with increases now being observed. Since this year, the average BVOCs emissions in Germany increased by ∼54%. Spatially, eastern-central Germany and urban areas exhibit the highest increase. Future projections indicate a continued increase in emissions over the coming decades. Our results were validated by analyzing the Total Column Ozone and Formaldehyde.

Future CH4 as modelled by a fully coupled Earth system model: prescribed GHG concentrations vs. interactive CH4 sources and sinks

Abstract We have used the NASA Goddard Institute for Space Studies (GISS) Earth system model GISS-E2.1 to study the future budgets and trends of global and regional CH4 under different emission scenarios, using both the prescribed GHG concentrations as well as the interactive CH4 sources and sinks setup of the model, to quantify the model performance and its sensitivity to CH4 sources and sinks. We have used the Current Legislation (CLE) and the maximum feasible reduction (MFR) emission scenarios from the ECLIPSE V6b emission database to simulate the future evolution of CH4 sources, sinks, and levels from 2015 to 2050. Results show that the prescribed GHG version underestimates the observed surface CH4 concentrations during the period between 1995 and 2023 by 1%, with the largest underestimations over the continental emission regions, while the interactive simulation underestimates the observations by 2%, with the biases largest over oceans and smaller over the continents. For the future, the MFR scenario simulates lower global surface CH4 concentrations and burdens compared to the CLE scenario, however in both cases, global surface CH4 and burden continue to increase through 2050 compared to present day. In addition, the interactive simulation calculates slightly larger O3 and OH mixing ratios, in particular over the northern hemisphere, leading to slightly decreased CH4 lifetime in the present day. The CH4 forcing is projected to increase in both scenarios, in particular in the CLE scenario, from 0.53 W m−2 in the present day to 0.73 W m−2 in 2050. In addition, the interactive simulations estimate slightly higher tropospheric O3 forcing compared to prescribed simulations, due to slightly higher O3 mixing ratios simulated by the interactive models. While in the CLE, tropospheric O3 forcing continues to increase, the MFR scenario leads to a decrease in tropospheric O3 forcing, leading to a climate benefit. Our results highlight that in the interactive models, the response of concentrations are not necessarily linear with the changes in emissions as the chemistry is non-linear, and dependent on the oxidative capacity of the atmosphere. Therefore, it is important to have the CH4 sources and chemical sinks to be represented comprehensively in climate models.

Isoprene Emissions, Oxidation Chemistry and Environmental Impacts

Isoprene emissions can affect the oxidizing capacity of the atmosphere and are likely to increase with an increase in the world’s biomass. The emission of isoprene is strongest in tropical forested regions, suggesting a major portion of tropospheric chemistry occurs in the tropics. As well as deforestation and reforestation having a direct impact on the world’s climate through land cover, there is also an indirect environmental impact (e.g., global warming, air pollution) through the resulting change in isoprene emissions. Previously, incomplete understanding of isoprene oxidation chemistry caused a model-measurement breakdown for concentrations of HOx radicals observed over certain low-NOx regions, such as the pristine Amazon rainforest. Over the last decade, however, understanding of isoprene oxidation chemistry has been vastly improved. Numerous research studies have provided evidence for the involvement of 1,6-H and 1,5-H shift reactions in the isoprene oxidation mechanism, which increases the level of HOx recycling that occurs. As well as helping to reduce the model-measurement breakdown observed, the updated isoprene oxidation mechanism affects the tropospheric burdens of other species, including carbon monoxide (CO), methane (CH4), ozone (O3), organic peroxides (ROOH), secondary organic aerosol (SOA), and organic nitrates (RONO2). There are still gaps in the understanding of the impacts and oxidation chemistry of isoprene emissions, which this literature review identifies and discusses. In the future, there is still much scope for further research, including modeling future reforestation scenarios with isoprene emissions and their impacts on both global and regional scales.

The Environmental Emission and Climate Change Impact of Hydrogen Fuel Derived from Photocatalysis Water‐Splitting Reaction

Hydrogen fuel is widely received as the most promising clean fuel to substitute fossil fuel in power grid, home heating, and automotive industry to achieve net‐zero target. Photocatalysis hydrogen route, which fulfills the Gibbs free energy of water‐splitting reaction with solar energy, has been a promising approach to produce green hydrogen. However, there are limited study on the environmental performance of this hydrogen evolution process, particularly the potential emission of the photocatalyst synthesis process. In this work, the environmental emission of photocatalytic hydrogen evolution process is investigated through life cycle analysis (LCA) based on a pilot scale reaction system. The individual processing steps with its corresponding material flows that contributed significantly to environmental emission are identified from the LCA simulation. Excessive use of sacrificial reagent in the photocatalysis reaction has been identified as one of the main contributors to the environmental emission of this reaction system. The results observed can be feedback to the process design and improvisation of such photocatalysis reaction system to help improvise the existing technology for better environmental potential for upscale production to meet the ever‐rising demand on hydrogen fuel.

Evaluating public health co-benefits of New York state’s climate leadership and community protection act

ABSTRACT New York State enacted the Climate Leadership and Community Protection Act (Climate Act) in 2019, setting the state on a path toward greenhouse gas (GHG) neutrality by 2050. Achieving these GHG emission reduction targets would also result in a significant decrease in emissions of other air pollutants, such as fine particulate matter (PM2.5) and other precursor pollutants. This study analyzes potential air quality and associated public health benefits from Climate Act implementation scenarios. In this study, we estimate reductions in emissions associated with the reduction in fuel combustion necessary to meet the Climate Act targets, including primary PM2.5 and precursors to PM2.5 formation — nitrogen oxides, sulfur dioxide, ammonia, and volatile organic compounds. We estimated changes in emissions for both a policy scenario and a reference (business-as-usual) case for the following sectors: (1) electric-generating units; (2) on-road vehicles; (3) non-road engines; and (4) industrial, commercial, and residential buildings. We used the U.S. EPA’s CO-Benefits Risk Assessment Health Impacts Screening and Mapping Tool (COBRA) to model the effect of emissions reductions on PM2.5 concentrations and ensuing public health effects. We found notable reductions in annual PM2.5 emissions (55% by 2050) and NOx emissions (80% by 2050). The greatest projected contributors to health benefits are the commercial and residential buildings sector (60%) followed by on-road transportation (18%). Contributions from the electricity sector are relatively small, regardless of renewable electricity choices. Our findings indicate significant public health benefits, including more than 10,000 avoided premature deaths and thousands of avoided hospitalizations and emergency room visits. These benefits are valued at over $100 billion from 2020 to 2050, with urban areas experiencing greater benefits due to higher emissions reductions and larger populations.

Contrasting the roles of regional anthropogenic aerosols from the western and eastern hemispheres in driving the 1980–2020 Pacific multi-decadal variations

Abstract. The multi-decadal variations in the Pacific climate are extensively discussed as being influenced by external forcings such as greenhouse gases (GHGs) and anthropogenic aerosols (AAs). Unlike GHGs, the potential impacts of AAs could be more complex because of the heterogeneity of spatial distribution during the past few decades. Here we show, using regional aerosol forcing large-ensemble simulations with the Community Earth System Model 1 (CESM1), that the increasing fossil-fuel-related aerosol emissions over Asia (EastFF) and the reduction in aerosol emissions over North America and Europe (WestFF) have remarkably different impacts on driving the Pacific circulations and sea surface temperature (SST) changes since the 1980s. EastFF excites a typical El Niño-like SST pattern in the tropical Pacific and weakens the climatological Pacific Walker circulation. WestFF induces a central Pacific (CP)-type El Niño-like SST pattern with warming in the middle region of the equatorial Pacific, which is consistent with the second leading empirical orthogonal function (EOF) pattern of the observation. Over the North Pacific region, EastFF, located at low to middle latitudes, favors an Interdecadal Pacific Oscillation (IPO)-like SST pattern (horseshoe-like SST pattern in the North Pacific) through a teleconnection pathway between the tropical and extratropical Pacific but is overwhelmed by internal variability evolving from a positive phase to a negative IPO phase. In contrast, WestFF, located at middle to high latitudes, strongly affects the North Pacific via a west-to-east mid-latitude pathway and induces extensive warming. The competing effects of the heterogeneously distributed regional aerosol forcings are expected to exhibit different patterns in the near future, especially the redistribution of aerosol emissions within the domain of EastFF (i.e., from East Asia to South Asia) and changes in aerosol composition. The complex future changes in anthropogenic aerosol emissions are likely to introduce more profound impacts of aerosol forcing on the Pacific multi-decadal variations.

Analysis of the National Air Pollutant Emissions Inventory (2021) in the Republic of Korea

In the Republic of Korea, air pollutant emissions are annually estimated and published. These emissions are used to formulate and evaluate national air quality policies. In this study, the 2021 National Air Pollutant Emissions Inventory in the Republic of Korea was estimated. In addition, emission sources and primary causes affecting changes in emissions were analyzed. As a result, air pollutant emissions in the Republic of Korea were 57,317 tons of PM-2.5, 160,993 tons of SOx, 884,454 tons of NOx, 1,002,810 tons of VOCs, and 262,008 tons of NH3. PM-2.5, SOx, and NOx emissions in 2021 were lower than those in 2020 because of the reduction policy effects, such as the shutdown of old coal-fired power plants and stricter emission standards in workplaces. However, emissions of VOCs and NH3 in 2021 increased those in 2020 due to socioeconomic effects, particularly in everyday activity sector. Specifically, it was caused by increased use of paint for construction and shipbuilding to meet rising demands as well as a rise in cattle numbers due to increased meat consumption. Spatially, Gyeonggi-do had the highest emissions of PM-2.5, NOx, and VOCs due to its dense populations and heavy traffic, while Ulsan and Chungcheongnam-do had the highest emissions of SOx and NH3 from production process in their large national industrial complexes.

Competitive Phase Transition of NaYS2 in Non‐Vacuum Environment for Cutting‐Edge Anti‐Counterfeiting

AbstractRecently, chalcogenides with layered structures exhibit promising applications in the fields of information chaos processing and compilation remodeling, yet facile synthesis of their microcrystals with multi‐temporal and multi‐modal luminescence remains a major challenge. Herein, a competitive phase transition to generate orderly layered NaYS2 microcrystals is achieved by lattice reconstruction with introduction S2− occupying a unique anionic site in non‐vacuum sulfur‐rich environment, revealing crucial role of competitive phase transitions in regulating material structure and properties. Simultaneous photoinduced luminescent chromism and photo‐stimulated luminescence are attained by introducing Pr3+. Interestingly, broadband long‐wavelength visible afterglow emission in 4f15d1 cluster state is achieved and a reversible temporary change in upconversion emission from orange broadband to green narrowband occurs under continuous 980 nm excitation, which is attributed to ordered polarization of Pr3+ in YS6 layer and injection of defects. Furthermore, by integrating long‐lived down‐conversion emission and relatively short‐lived up‐conversion emission in Pr3+‐doped NaYS2, a multilevel dynamic optical anti‐counterfeiting platform is constructed based on transient and long afterglow luminescence. This work implements a competitive phase transition to generate NaYS2 with 2D structure, providing a new model of tunable space‐time resolved emission for spatiotemporal optoelectronic multiplexing, which are applicable to large‐capacity information encryption, optical data storage, and biosensing.

Impact of Vehicle Aging and Mileage on Air Pollution Emissions

The research described in this paper aimed to verify the impact of road vehicle aging on air pollutant emissions. The problem of vehicle aging and the resulting changing air pollutant emissions was identified with the operational mileage of passenger cars. The validity of such an approach to research on air pollutant emissions changing over time was confirmed by a preliminary review of publications in scientific databases such as Scopus and Web of Science. The research problem presented in this paper was to assess the impact of vehicle aging on essential air pollutant emissions (CO, CO2, NOX). The research method included measuring the actual RDE air pollutant emissions using research equipment, i.e., the SEMTECH DS gaseous exhaust gas component analyzer. This study was conducted on vehicles with diesel engines, different operating ages, different mileages, and engines with similar displacement, mostly 1.9–2.0 dm3, and equipped with manual transmissions. The tests were conducted in the Poznań agglomeration. The results of measured air pollutant emissions in the RDE mode allowed for mapping the changes in air pollutant emissions for diesel engine vehicles with similar displacement as a function of operating age (mileage) and also for collecting preliminary data for analyses in the field of modeling road air pollutant emissions within the vehicle aging phenomenon.