scholarly journals Current and future levels of mercury atmospheric pollution on global scale

2016 ◽  
Author(s):  
Jozef M. Pacyna ◽  
Oleg Travnikov ◽  
Francesco De Simone ◽  
Ian M. Hedgecock ◽  
Kyrre Sundseth ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Global Scale ◽  
Anthropogenic Sources ◽  
Anthropogenic Emissions ◽  
Emission Scenarios ◽  
Case Scenario ◽  
Mercury Emissions ◽  
Future Emission ◽  
The Eu ◽  
Air Concentrations

Abstract. An assessment of current and future emissions, air concentrations and atmospheric deposition of mercury world-wide are presented on the basis of results obtained during the performance of the EU GMOS (Global Mercury Observation System) project. Emission estimates for mercury were prepared with the main goal of applying them in models to assess current (2013) and future (2035) air concentrations and atmospheric deposition of this contaminant. The artisanal and small- scale gold mining, as well as combustion of fossil fuels (mainly coal) for energy and heat production in power plants and in industrial and residential boilers are the major anthropogenic sources of Hg emissions to the atmosphere at present. These sources account for about 37 % and 25 % of the total anthropogenic Hg emissions globally, estimated to be about 2000 tonnes. The emissions in Asian countries, particularly in China and India dominate the total emissions of Hg. The current estimate of mercury emissions from natural processes (primary mercury emissions and re-emissions), including mercury depletion events, were estimated to be 5207 tonnes per year which represent nearly 70 % of the global mercury emission budget. Oceans are the most important sources (36 %) followed by biomass burning (9 %). A comparison of the 2035 anthropogenic emissions estimated for 3 different scenarios with current anthriopogenic emissions indicates a reduction of these emissions in 2035 up to 85 % for the best case scenario. Two global chemical transport models (GLEMOS and ECHMERIT) have been used for the evaluation of future Hg pollution levels considering future emission scenarios. Projections of future changes in Hg deposition on a global scale simulated by these models for three anthropogenic emissions scenarios of 2035 indicate a decrease of up to 50 % deposition in the Northern Hemisphere and up to 35 % in Southern Hemisphere for the best case scenario. The EU GMOS project has proved to be a very important research instrument for supporting, first the scientific justification for the Minamata Convention, and then monitoring of the implementation of targets of this Convention, as well as, the EU Mercury Strategy. This project provided the state-of-the art with regard to the development of the latest emission inventories for mercury, future emission scenarios, dispersion modelling of atmospheric Hg on global and regional scale, and source – receptor techniques for Hg emission apportionment on a global scale.

scholarly journals Current and future levels of mercury atmospheric pollution on a global scale

2016 ◽  
Vol 16 (19) ◽  
pp. 12495-12511 ◽  
Author(s):  
Jozef M. Pacyna ◽  
Oleg Travnikov ◽  
Francesco De Simone ◽  
Ian M. Hedgecock ◽  
Kyrre Sundseth ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Global Scale ◽  
Anthropogenic Emissions ◽  
Emission Scenarios ◽  
Case Scenario ◽  
Mercury Emission ◽  
Mercury Emissions ◽  
Future Emission ◽  
The Eu ◽  
Air Concentrations

Abstract. An assessment of current and future emissions, air concentrations, and atmospheric deposition of mercury worldwide is presented on the basis of results obtained during the performance of the EU GMOS (Global Mercury Observation System) project. Emission estimates for mercury were prepared with the main goal of applying them in models to assess current (2013) and future (2035) air concentrations and atmospheric deposition of this contaminant. The combustion of fossil fuels (mainly coal) for energy and heat production in power plants and in industrial and residential boilers, as well as artisanal and small-scale gold mining, is one of the major anthropogenic sources of Hg emissions to the atmosphere at present. These sources account for about 37 and 25 % of the total anthropogenic Hg emissions globally, estimated to be about 2000 t. Emissions in Asian countries, particularly in China and India, dominate the total emissions of Hg. The current estimates of mercury emissions from natural processes (primary mercury emissions and re-emissions), including mercury depletion events, were estimated to be 5207 t year−1, which represents nearly 70 % of the global mercury emission budget. Oceans are the most important sources (36 %), followed by biomass burning (9 %). A comparison of the 2035 anthropogenic emissions estimated for three different scenarios with current anthropogenic emissions indicates a reduction of these emissions in 2035 up to 85 % for the best-case scenario. Two global chemical transport models (GLEMOS and ECHMERIT) have been used for the evaluation of future mercury pollution levels considering future emission scenarios. Projections of future changes in mercury deposition on a global scale simulated by these models for three anthropogenic emissions scenarios of 2035 indicate a decrease in up to 50 % deposition in the Northern Hemisphere and up to 35 % in Southern Hemisphere for the best-case scenario. The EU GMOS project has proved to be a very important research instrument for supporting the scientific justification for the Minamata Convention and monitoring of the implementation of targets of this convention, as well as the EU Mercury Strategy. This project provided the state of the art with regard to the development of the latest emission inventories for mercury, future emission scenarios, dispersion modelling of atmospheric mercury on a global and regional scale, and source–receptor techniques for mercury emission apportionment on a global scale.

scholarly journals Determining the Role of Acidity, Fate and Formation of IEPOX-Derived SOA in CMAQ

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 707
Author(s):  
Petros Vasilakos ◽  
Yongtao Hu ◽  
Armistead Russell ◽  
Athanasios Nenes
Keyword(s):  
Significant Influence ◽  
Organic Aerosol ◽  
Liquid Water Content ◽  
Anthropogenic Emissions ◽  
So2 Emissions ◽  
Aerosol Acidity ◽  
A Value ◽  
Future Emission ◽  
The Impact

Formation of aerosol from biogenic hydrocarbons relies heavily on anthropogenic emissions since they control the availability of species such as sulfate and nitrate, and through them, aerosol acidity (pH). To elucidate the role that acidity and emissions play in regulating Secondary Organic Aerosol (SOA), we utilize the 2013 Southern Oxidant and Aerosol Study (SOAS) dataset to enhance the extensive mechanism of isoprene epoxydiol (IEPOX)-mediated SOA formation implemented in the Community Multiscale Air Quality (CMAQ) model (Pye et al., 2013), which was then used to investigate the impact of potential future emission controls on IEPOX OA. We found that the Henry’s law coefficient for IEPOX was the most impactful parameter that controls aqueous isoprene OA products, and a value of 1.9 × 107 M atm−1 provides the best agreement with measurements. Non-volatile cations (NVCs) were found in higher-than-expected quantities in CMAQ and exerted a significant influence on IEPOX OA by reducing its production by as much as 30% when present. Consistent with previous literature, a strong correlation of isoprene OA with sulfate, and little correlation with acidity or liquid water content, was found. Future reductions in SO2 emissions are found to not affect this correlation and generally act to increase the sensitivity of IEPOX OA to sulfate, even in extreme cases.

scholarly journals Upper limits on the extent of seafloor anoxia during the PETM from uranium isotopes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Matthew O. Clarkson ◽  
Timothy M. Lenton ◽  
Morten B. Andersen ◽  
Marie-Laure Bagard ◽  
Alexander J. Dickson ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Global Scale ◽  
Uranium Isotopes ◽  
Biogeochemical Model ◽  
Emission Scenarios ◽  
Isotope Data ◽  
Upper Limit ◽  
Thermal Maximum ◽  
Upper Limits ◽  
Anoxic Events

AbstractThe Paleocene Eocene Thermal Maximum (PETM) represents a major carbon cycle and climate perturbation that was associated with ocean de-oxygenation, in a qualitatively similar manner to the more extensive Mesozoic Oceanic Anoxic Events. Although indicators of ocean de-oxygenation are common for the PETM, and linked to biotic turnover, the global extent and temporal progression of de-oxygenation is poorly constrained. Here we present carbonate associated uranium isotope data for the PETM. A lack of resolvable perturbation to the U-cycle during the event suggests a limited expansion of seafloor anoxia on a global scale. We use this result, in conjunction with a biogeochemical model, to set an upper limit on the extent of global seafloor de-oxygenation. The model suggests that the new U isotope data, whilst also being consistent with plausible carbon emission scenarios and observations of carbon cycle recovery, permit a maximum ~10-fold expansion of anoxia, covering <2% of seafloor area.

scholarly journals Sources of black carbon aerosols in South Asia and surrounding regions during the Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)

2015 ◽  
Vol 15 (10) ◽  
pp. 5415-5428 ◽  
Author(s):  
R. Kumar ◽  
M. C. Barth ◽  
V. S. Nair ◽  
G. G. Pfister ◽  
S. Suresh Babu ◽  
...  
Keyword(s):  
Spatial Variability ◽  
South Asia ◽  
Black Carbon ◽  
Biomass Burning ◽  
Regional Scale ◽  
Anthropogenic Sources ◽  
Radiation Budget ◽  
Anthropogenic Emissions ◽  
Spatial And Temporal Variability ◽  
Mass Concentrations

Abstract. This study examines differences in the surface black carbon (BC) aerosol loading between the Bay of Bengal (BoB) and the Arabian Sea (AS) and identifies dominant sources of BC in South Asia and surrounding regions during March–May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget, ICARB) period. A total of 13 BC tracers are introduced in the Weather Research and Forecasting Model coupled with Chemistry to address these objectives. The model reproduced the temporal and spatial variability of BC distribution observed over the AS and the BoB during the ICARB ship cruise and captured spatial variability at the inland sites. In general, the model underestimates the observed BC mass concentrations. However, the model–observation discrepancy in this study is smaller compared to previous studies. Model results show that ICARB measurements were fairly well representative of the AS and the BoB during the pre-monsoon season. Elevated BC mass concentrations in the BoB are due to 5 times stronger influence of anthropogenic emissions on the BoB compared to the AS. Biomass burning in Burma also affects the BoB much more strongly than the AS. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 60 and 37% of the average ± standard deviation (representing spatial and temporal variability) BC mass concentration (1341 ± 2353 ng m−3) in South Asia. BC emissions from residential (61%) and industrial (23%) sectors are the major anthropogenic sources, except in the Himalayas where vehicular emissions dominate. We find that regional-scale transport of anthropogenic emissions contributes up to 25% of BC mass concentrations in western and eastern India, suggesting that surface BC mass concentrations cannot be linked directly to the local emissions in different regions of South Asia.

scholarly journals Regional climate change scenarios for Greece: future temperature and precipitation projections form ensembles of RCMs

2013 ◽  
Vol 14 (4) ◽  
pp. 407-421 ◽  
Keyword(s):  
Regional Climate ◽  
Regional Climate Change ◽  
Summer Temperature ◽  
Climate Change Scenarios ◽  
Emission Scenarios ◽  
Temperature And Precipitation ◽  
The Future ◽  
Future Emission ◽  
Spatial Grid ◽  
Of Greece

The potential regional future changes in seasonal (winter and summer) temperature and precipitation are assessed for the greater area of Greece over the 21st century, under A2, A1B and B2 future emission scenarios of IPCC. Totally twenty-two simulations from various regional climate models (RCMs) were assessed; fourteen of them with a spatial grid resolution of 50km for the period 2071-2100 under A2 (9 simulations) and B2 (5 simulations) scenarios and eight of them with an even finer resolution of 25km under A1B scenario for both 2021-2050 and 2071-2100 time periods. The future changes in temperature and precipitation were calculated with respect to the control period (1961-1990). All the models estimated warmer and dryer conditions over the study area. The warming is more intense during the summer months, with the changes being larger in the continental than in the marine area of Greece. In terms of precipitation, the simulations of the RCMs estimate a decrease up to -60% (A2 scenario). Finally it is shown that the changes in the atmospheric circulation over Europe play a key role in the changes of the future precipitation and temperature characteristics over the domain of study in a consistent way for the different emission scenarios.

scholarly journals Social Bots and Fake News as (not) seen from the Viewpoint of Digital Education Frameworks

2017 ◽  
Vol 2017 (Occasional Papers) ◽  
pp. 61-80 ◽  
Author(s):  
Dietmar Janetzko
Keyword(s):  
Digital Media ◽  
Digital Literacy ◽  
Global Scale ◽  
Academic Disciplines ◽  
Fake News ◽  
Digital Competence ◽  
Digital Education ◽  
Research Activities ◽  
Set Up ◽  
The Eu

Over recent years, international organisations like the EU and UNESCO have set up a number of proposals, models and frameworks that seek (i) to map and to conceptualize digital literacy and related concepts, e. g. information, digital or media literacy, digital competence, digital skills and (ii) to formulate policies and recommendations based on the conceptualizations developed. The resulting frameworks, such as Digital Competence (DigComp) developed by the EU, or Media and Information Literacy (MIL) developed by UNESCO, have a strong formative power on a global scale. Affected are policies, laws, regulations, research activities, and academic disciplines like media pedagogy and mindsets. Do these frameworks consider the effects of disruptive attempts by digital media to intervene in public debates e. g. social bots, fake news and other manifestations of biased or false information online? Do they offer avenues for reflection and action to address them? Guided by these questions, this paper studies the flagship frameworks on digital education of the EU and UNESCO, DigComp and MIL. It finds biases in both frameworks. To different degrees, both tend to overemphasize the practical and instrumental use of digital literacy.

Groundwater phosphorus concentrations: global trends and links with agricultural and oil and gas activities

2021 ◽  
Author(s):  
Jessica Warrack ◽  
Mary Kang ◽  
Christian von Sperber
Keyword(s):  
Oil And Gas ◽  
Comprehensive Evaluation ◽  
Significant Risk ◽  
Surface Water Quality ◽  
The United States ◽  
Global Scale ◽  
Anthropogenic Sources ◽  
High Concentration ◽  
Oil And Gas Development ◽  
Global Trends

&lt;p&gt;Although observations show that anthropogenic phosphorus (P) can reach groundwater supplies, there has been no comprehensive evaluation of P in groundwater at the global scale. Additionally, there have been minimal studies on distributed sources, such as agriculture, and the effects of oil and gas activities on P contamination in groundwater are poorly understood. We compile and analyze 181,653 groundwater P concentrations from 13 government agencies and 8 individual research studies in 11 different countries in order to determine the extent of P pollution at the global scale. We find that every country with data has groundwater P concentrations that pose a significant risk of eutrophication to surface waters. In Canada and the United States, we study the relationship between land use, focusing on crop/pastureland, and increased P concentrations in groundwater. In Ontario and Alberta, two Canadian provinces with different histories of oil and gas development, we find areas with a high concentration of P groundwater pollution to coincide with regions of intense oil and gas activity. Understanding the effects of anthropogenic sources on phosphorus contamination of groundwater and identifying all possible pathways through which contamination can occur will assist regulators in planning and implementing effective strategies to manage groundwater and surface water quality and sustain ecosystem health.&lt;/p&gt;

Present and Future Land Suitability Analysis for Almond and Pistachio Crops in the Beira Baixa Region Using Spatial Multicriteria Decision Systems

2022 ◽  
pp. 249-265
Author(s):  
Luís Quinta-Nova ◽  
Dora Ferreira
Keyword(s):  
Decision Making ◽  
Pairwise Comparison ◽  
Fruit Tree ◽  
Emission Scenarios ◽  
Suitability Analysis ◽  
Almond Tree ◽  
Decision Systems ◽  
Hierarchical Levels ◽  
The Face ◽  
Future Emission

The objective of this study is to determine the suitability for the cultivation of emerging fruit crops in the Beira Baixa region. The suitability was examined for the present time and in the face of two future emission scenarios (RCP 4.5 and 8.5). For this purpose, the biophysical criteria determining the cultivation of pistachio tree and almond tree were processed using a G. The analysis was performed by the AHP. After dividing the problem into hierarchical levels of decision making, a pairwise comparison of criteria was performed to evaluate the weights of these criteria, based on a scale of importance. In the present conditions, about 16.4% of the study area is classified as highly suitable for almond tree and 15.9% to pistachio tree. For the future scenarios, the area with high suitability will increase both for almond tree and pistachio tree. The AHP was adequate in the evaluation of the emerging fruit tree species suitability, since it allowed the integration of the several criteria studied, being a useful tool, which allows the decision making and the resolution of problems.

scholarly journals The acidity of atmospheric particles and clouds

2020 ◽  
Vol 20 (8) ◽  
pp. 4809-4888 ◽  
Author(s):  
Havala O. T. Pye ◽  
Athanasios Nenes ◽  
Becky Alexander ◽  
Andrew P. Ault ◽  
Mary C. Barth ◽  
...  
Keyword(s):  
Fine Particles ◽  
Aerosol Particles ◽  
Reaction Rates ◽  
Global Scale ◽  
Anthropogenic Emissions ◽  
Central Component ◽  
Condensed Phases ◽  
Model Calculations ◽  
Phase Partitioning ◽  
Acids And Bases

Abstract. Acidity, defined as pH, is a central component of aqueous chemistry. In the atmosphere, the acidity of condensed phases (aerosol particles, cloud water, and fog droplets) governs the phase partitioning of semivolatile gases such as HNO3, NH3, HCl, and organic acids and bases as well as chemical reaction rates. It has implications for the atmospheric lifetime of pollutants, deposition, and human health. Despite its fundamental role in atmospheric processes, only recently has this field seen a growth in the number of studies on particle acidity. Even with this growth, many fine-particle pH estimates must be based on thermodynamic model calculations since no operational techniques exist for direct measurements. Current information indicates acidic fine particles are ubiquitous, but observationally constrained pH estimates are limited in spatial and temporal coverage. Clouds and fogs are also generally acidic, but to a lesser degree than particles, and have a range of pH that is quite sensitive to anthropogenic emissions of sulfur and nitrogen oxides, as well as ambient ammonia. Historical measurements indicate that cloud and fog droplet pH has changed in recent decades in response to controls on anthropogenic emissions, while the limited trend data for aerosol particles indicate acidity may be relatively constant due to the semivolatile nature of the key acids and bases and buffering in particles. This paper reviews and synthesizes the current state of knowledge on the acidity of atmospheric condensed phases, specifically particles and cloud droplets. It includes recommendations for estimating acidity and pH, standard nomenclature, a synthesis of current pH estimates based on observations, and new model calculations on the local and global scale.

Sign in / Sign up

Export Citation Format

Share Document