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ABSTRACT While global greenhouse gas (GHG) emissions are still rising, a number of countries have emerged with a sustained record of emissions reductions. In this article, we identify these countries and examine their progress, ex...
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ABSTRACT While global greenhouse gas (GHG) emissions are still rising, a number of countries have emerged with a sustained record of emissions reductions. In this article, we identify these countries and examine their progress, exploring how fast, how deep, and in which sectors they have reduced emissions. We analyse changes in all major GHG emissions sources, with both production – and consumption-based accounting, but exclude very small countries with high volatility, along with land-use, land-use change and forestry CO2 emissions. We find that 24 countries have sustained reductions in annual CO2 and GHG emissions between 1970 and 2018, in total equalling 3.2 GtCO2eq since their respective emissions peaks. In all but three countries, overall GHG reductions are less than energy and industrial CO2 reductions alone. We group countries into three types of emissions pathway: six former Eastern Bloc countries, where emissions declined rapidly in the 1990s and have continued on a downward trajectory since; six Long-term decline countries, which have sustained reductions since the 1970s; and 12 Recent peak countries, whose emissions decline began in the 2000s. In all cases, emissions reductions were achieved primarily in the energy systems sector, specifically in electricity and heat generation, which still remains the largest source of emissions in most countries. By contrast, in the transport sector, emissions tend to be stable or increasing. Transport is the second largest source of current emissions in Recent peak and Long-term decline countries. While the total GHG reductions of these 24 countries are trivial compared to recent global emissions growth, some have achieved a decline of up to 50% in their annual emissions, showing what is possible even under very moderate climate action. Most countries achieved emissions reductions alongside sustained economic growth, and some approached the fast annual rates of change that will be needed across the world in the coming decades to limit warming to 2°C. This raises the hope that more substantive climate policy, as planned in a growing number of countries, may bring about deeper and more rapid emissions reductions than some may expect today. Key policy insights 24 countries have sustained CO2 and GHG emissions reductions between 1970 and 2018The annual emissions reductions of some countries are within the range of those needed to limit global warming to 2°C, but not consistently, nor across all underlying sectorsMost emissions reductions were achieved in the energy sector; transport emissions have remained stable or continue to grow
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Emissions of air pollutants in East Asia play an important role in the regional and global atmospheric environment. In this study we evaluated the recent emission trends of sulfur dioxide (SO_2), nitrogen oxides (NO_x), particulat...
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Emissions of air pollutants in East Asia play an important role in the regional and global atmospheric environment. In this study we evaluated the recent emission trends of sulfur dioxide (SO_2), nitrogen oxides (NO_x), particulate matter (PM), and non-methane volatile organic compounds (NMVOC) in East Asia, and projected their future emissions up until 2030 with six emission scenarios. The results will provide future emission projections for the modeling community of the model inter-comparison program for Asia (MICS-Asia). During 2005–2010, the emissions of SO_2 and PM_(2.5) in East Asia decreased by 15 and 12 %, respectively, mainly attributable to the large-scale deployment of flue gas desulfurization (FGD) at China's power plants, and the promotion of highly efficient PM removal technologies in China's power plants and cement industry. During this period, the emissions of NO_x and NMVOC increased by 25 and 15 %, driven by rapid increase in the emissions from China due to inadequate control strategies. In contrast, the NO_x and NMVOC emissions in East Asia except China decreased by 13–17 %, mainly due to the implementation of stringent vehicle emission standards in Japan and South Korea. Under current regulations and current levels of implementation, NO_x, SO_2, and NMVOC emissions in East Asia are projected to increase by about one-quarter over 2010 levels by 2030, while PM_(2.5) emissions are expected to decrease by 7 %. Assuming enforcement of new energy-saving policies, emissions of NOx, SO2, PM2.5 and NMVOC in East Asia are expected to decrease by 28, 36, 28, and 15 %, respectively, compared with the baseline case. The implementation of "progressive" end-of-pipe control measures would lead to another onethird reduction of the baseline emissions of NO_x, and about one-quarter reduction of SO_2, PM_(2.5), and NMVOC. Assuming the full application of technically feasible energy-saving policies and end-of-pipe control technologies, the emissions of NO_x, SO_2, and PM_(2.5) in East Asia would account for only about one-quarter, and NMVOC for one-third, of the levels of the baseline projection. Compared with previous projections, this study projects larger reductions in NO_x and SO_2 emissions by considering aggressive governmental plans and standards scheduled to be implemented in the next decade, and quantifies the significant effects of detailed progressive control measures on NMVOC emissions up until 2030.
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Nitrogen oxides (NOx) are key pollutants for the improvement of ambient air quality. Within this study we estimated the historical NOx emissions in China for the period 1995-2010, and calculated future NOx emissions every five yea...
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Nitrogen oxides (NOx) are key pollutants for the improvement of ambient air quality. Within this study we estimated the historical NOx emissions in China for the period 1995-2010, and calculated future NOx emissions every five years until 2030 under six emission scenarios. Driven by the fast growth of energy consumption, we estimate the NOx emissions in China increased rapidly from 11.0 Mt in 1995 to 26.1 Mt in 2010. Power plants, industry and transportation were major sources of NOx emissions, accounting for 28.4%, 34.0%, and 25.4% of the total NOx emissions in 2010, respectively. Two energy scenarios, a business as usual scenario (BAU) and an alternative policy scenario (PC), were developed to project future energy consumption. In 2030, total energy consumption is projected to increase by 64% and 27% from 2010 level respectively. Three sets of end-of-pipe pollution control measures, including baseline, progressive, and stringent control case, were developed for each energy scenario, thereby constituting six emission scenarios. By 2030, the total NOx emissions are projected to increase (compared to 2010) by 36% in the baseline while policy cases result in reduction up to 61% in the most ambitious case with stringent control measures. More than a third of the reduction achieved by 2030 between least and most ambitious scenario comes from power sector, and more than half is distributed equally between industry and transportation sectors. Selective catalytic reduction dominates the NOx emission reductions in power plants, while life style changes, control measures for industrial boilers and cement production are major contributors to reductions in industry. Timely enforcement of legislation on heavy-duty vehicles would contribute significantly to NOx emission reductions. About 30% of the NOx emission reduction in 2020 and 40% of the NOx emission reduction in 2030 could be treated as the ancillary benefit of energy conservation. Sensitivity analysis was conducted to explore the impact of key factors on future emissions.
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Multiple soil CO_2efflux surveys have been undertaken at the summit cone of Teide volcano, Tenerife, from 1997 to 2011, to determine the total CO_2 emissions from the summit cone and to evaluate the temporal variations of CO_2 eff...
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Multiple soil CO_2efflux surveys have been undertaken at the summit cone of Teide volcano, Tenerife, from 1997 to 2011, to determine the total CO_2 emissions from the summit cone and to evaluate the temporal variations of CO_2 efflux and their relationships with seismic-volcanic activity. Our results reveal significant fluctuations in degassing rate, which do not seem to be masked by atmospheric variations. These geochemical observations provide evidence for the unrest of the volcanic system, as has been suggested previously by anomalous seismic activity recorded in Tenerife during 22-29 April 2004. A new trend of increasing CO_2 efflux and CO_2/CH_4 ratio in fumarolic gas discharges was observed from 2006 to 2009, suggesting that subsurface magma movement is the cause for the observed changes in the total output of diffuse CO_2 emission at the summit cone of Teide.
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Reducing greenhouse gas (GHG) emissions is a global concern after Paris Agreement (PA). Identification of GHG emission sources and accurate and precise estimation of the corresponding emissions is the first step to meet reduction ...
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Reducing greenhouse gas (GHG) emissions is a global concern after Paris Agreement (PA). Identification of GHG emission sources and accurate and precise estimation of the corresponding emissions is the first step to meet reduction targets under PA. Increasing share of agricultural emissions in the global concentration has raised concerns on this sector. Now, reducing agricultural emissions without compromising food security is a real challenge. The present study was aimed to provide the current emission profile of Pakistan's agriculture, historical emission trends and future projections under agricultural growth scenarios according to prescribed guidelines of Intergovernmental Panel on Climate Change (IPCC) for national GHGs inventory development. In this study, GHG emissions were estimated using United Nations Framework Convention on Climate Change (UNFCCC) Non-Annex-I Inventory Software (NAIIS), version 1.3.2 as per prescribed Revised 1996 IPCC Guidelines. In these emission estimations, tier-1 approach (which employs default emission factors) was used in accordance with national circumstances and data availability in the country. The emissions baseline was projected for 2030 under business as usual (BAU), food security (FS) and enhanced consumption pattern (ECP) scenarios. Agriculture sector emitted 174.6 million tons (Mt) of carbon dioxide equivalent (CO2-equivalent) emissions, of which 89.8 Mt is methane (CH4) and 83.7 Mt is nitrous oxide (N2O). Carbon monoxide (CO) emissions were found to be 1.07 Mt of CO2-equivalent. Emission from agricultural soils constituted 45.5% of the total agricultural emissions followed by 45.1% from enteric fermentation and 6.5% from livestock manure management. The rest of 1.7% of the emissions were from rice cultivation followed by 1.1% from burning of crop residue. Historical emission trends showed that the agricultural emissions grew from 71.6 to 174.6 Mt of CO2-equivalent from 1994 to 2015, a 143.8% increase over the period of 21 years. Emissions baseline projections were found to be 271.9, 314.3 and 362.9 Mt tons of CO2-equivalent under BAU, FS and ECP scenarios, respectively.
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We present fleet average VOC emission rate trends for the longest running in-use light-duty gasoline Vehicle Surveillance Program (VSP) in Southern California. Tailpipe emissions data from a limited number of vehicles tested as pa...
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We present fleet average VOC emission rate trends for the longest running in-use light-duty gasoline Vehicle Surveillance Program (VSP) in Southern California. Tailpipe emissions data from a limited number of vehicles tested as part of the VSP show that the 2003 fleet average emissions decreased by about 80% for most VOCs relative to the 1995 fleet. Vehicle evaporative emission rates decreased more than 90% for most compounds from the 1999 to the 2003 fleet. Tailpipe benzene-normalized emission rate ratios for most compounds were relatively stable. Evaporative emission rate ratios and weight percentages have changed significantly from the 1999 fleet to the 2003 fleet indicating a significant change in the evaporative emission species patterns. The tailpipe NMHC (Non-Methane Hydrocarbon) emission reductions observed between the 1995 fleet and the 2003 fleet likely resulted from the retirement of non-catalyst vehicles in the fleets (49%) and the combined effect of the turn-over of catalyst-equipped vehicles and switch to Phase III gasoline (27%). Our results are consistent with those observed in the Swiss tunnel study. Benzene-normalized emission rate ratios for C2 compounds, aldehydes, and 1,3 butadiene are much higher in tailpipe exhaust than those in evaporative emissions. C4-C5 hydrocarbon ratios in evaporative emissions are much higher than those in exhaust. C8 aromatic compound ratios are comparable for tailpipe and evaporative emissions (hot-soak). Such ratio differences can be used to estimate the relative contributions of vehicle exhaust and evaporative emission to ambient VOCs. The contribution of emissions from malfunctioning vehicles to total fleet emissions increased from 16% to 32% for the 1995 fleet to the 2003 fleet even though the percentage of malfunctioning vehicles in the fleet decreased from 10% to 5%. Most malfunctioning vehicles are vehicles that are at least 10 years old and generally have higher acetylene emission rate ratios. The effective identification and control of these malfunctioning vehicles will become increasingly important for improving mobile source emission estimates as well as reducing future tailpipe emissions.
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This paper considers the spatial and temporal variability in concentrations of the potentially acidifying ions in precipitation in Lithuania during the 1981-2004 period. Chemical analysis of precipitation included measurements of ...
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This paper considers the spatial and temporal variability in concentrations of the potentially acidifying ions in precipitation in Lithuania during the 1981-2004 period. Chemical analysis of precipitation included measurements of pH, conductivity, sulfate (SO42-), nitrate (NO3-), chloride (Cl-), ammonium (NH4+), sodium (Na+), potassium (K+), and calcium (Ca2+). Temporal trends in the potentially acidifying ion concentrations in precipitation and wet deposition were evaluated using the non-parametric Mann-Kendall test and Sen's slope estimator. A statistically significant decline was observed in non-sea salt sulfate (nssSO(4)(2-)) and hydrogen (H+) ions concentrations (82% and 79%, respectively) and wet depositions (88% and 74%, respectively). Temporal trends both in concentration and wet deposition of nitrate and ammonium were not as pronounced as trends in sulfate concentration. Analysis of air mass backward trajectories was applied to reveal the influence of air mass originating in different regions on wet deposition of acidifying species in Lithuania. Sector analysis clearly showed that wet deposition of sulfur and nitrogen in Lithuania is to a large extent anthropogenic and the main source regions of acidifying species contributing to wet deposition in Lithuania are in South and Central Europe.
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We applied the global 3-D chemical transport model GEOS-Chem to examine the anthropogenic and meteorological contributions in driving summertime (JJA) surface ozone (O3) trend in China during the Clean Air Action period 2012-2017....
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We applied the global 3-D chemical transport model GEOS-Chem to examine the anthropogenic and meteorological contributions in driving summertime (JJA) surface ozone (O3) trend in China during the Clean Air Action period 2012-2017. The model captures the observed spatial distribution of summertime O_3 concentrations in China (R = 0.78) and reproduces the observed increasing trends in two most populated city clusters: North China Plain (NCP) and Yangtze River Delta (YRD). Trend of simulated maximum daily 8-h average (MDA8) O_3 concentration is 0.58 ppbv yr~(-1) in NCP and 1.74 ppbv yr~' in YRD in JJA 2012-2017. Sensitivity studies show that both changes in anthropogenic emissions and meteorology favored the MDA8 O_3 increases in these two regions with respective contributions of 39% and 49% in NCP, and 13% and 84% in YRD. In NCP, the 49% meteorology impact includes a considerable contribution from natural emissions (19%). Changes in biogenic VOCs, soil NO_x, and lightning NO_x emissions are estimated to enhance MDA8 O_3 in NCP with a rate of 0.14,0.10, and 0.14 ppbv yr~(-1), respectively. In YRD, natural emissions made small contributions to the MDA8 O_3 trend. Statistical analysis shows that higher temperatures and anomalous southerlies at 850 hPa in 2017 relative to 2012 are the two major meteorological drivers in NCP that favored the O_3 increases, while weaker wind speed and lower relative humidity are those for YRD. We further examined the trend of fourth highest daily maximum 8-h average (4MDA8) O_3 among a specific month that linked with extreme pollution episodes. Trends of simulated 4MDA8 O_3 in NCP and YRD are 34-46% higher than those of MDA8 O_3 and are found more meteorology-induced. Our results suggest an important role of meteorology in driving summertime O_3 increases in China in recent years.
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The use of energy is essential for socio economic development. Under current conditions, the extraction, transformation and use of energy carriers are associated with a range of environ- mental impacts. These vary according to fue...
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The use of energy is essential for socio economic development. Under current conditions, the extraction, transformation and use of energy carriers are associated with a range of environ- mental impacts. These vary according to fuel, sector and technologies employed. The effect of the environmental impact also varies in terms of dissatisfaction, appreciation, cost or ben- efit. This paper discusses various emissions indicators, relating emissions to energy and eco- nomic activities.
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Current atmospheric emissions of As, Cd, Cr, Ni, and Pb (reference year 2000) from major anthropogenic sources in Europe are presented in this paper. Combustion of fuels in stationary sources was the main emission source for As, C...
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Current atmospheric emissions of As, Cd, Cr, Ni, and Pb (reference year 2000) from major anthropogenic sources in Europe are presented in this paper. Combustion of fuels in stationary sources was the main emission source for As, Cd, Cr, and Ni (more than a half of the total anthropogenic emissions), while combustion of gasoline was the main source of for lead. There is a continuous reduction of heavy metal emissions in Europe during the last 40 years. Better knowledge of heavy metal sources, emissions, pathways, and fate in the environment, and progress in developing efficient emission control equipment has resulted in more efficient regulatory efforts to curb heavy metal emissions from anthropogenic sources very substantially. There is a potential for further reduction of these emissions until the year 2010 up to about 40% for As, Cd, Cr, and Ni and about 57% for Pb, as estimated within various emission scenarios presented in the paper.
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