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As a substitute for methyl bromide (CH 3 Br), sulfuryl fluoride (SO 2 F 2) is widely used and shows an increasing trend in global atmospheric mixing ratio. Long-term measurements of SO 2 F 2 were conducted at 10 stations of the China Meteorological Administration. The SO 2 F 2 mixing ratios of background events at five observation sites with long sequences (9 or 10 years) showed a similar increasing trend, which was also similar to the measurements at Mace Head in Ireland, a global background station of the Advanced Global Atmospheric Gases Experiment (AGAGE) network. The background mixing ratios of SO 2 F 2 increased from 1.8 ppt in 2011 to 2.6 ppt in 2019. From 2010 to 2016, the enhanced mixing ratios above background of all the 10 stations exhibited an increasing trend before 2017, while there are no obvious trends from 2017 to 2019. The highest enhanced mixing ratios appeared at Lin'an (LAN) and Jiangjin (JGJ) in all years, mainly due to production and application of SO 2 F 2 in the Yangtze River Delta and the Sichuan Basin. Also, the two stations are closer to sources than other stations. The Concentration Weighted Trajectory (CWT) was applied to identify the possible source areas associated with SO 2 F 2 pollution events. The potential source areas identified at the 10 stations covered the main economic zones of China. Additionally, the total SO 2 F 2 emissions of China and key emission regions from 2011 to 2019 were estimated by a tracer-ratio method, using carbon monoxide (CO) as a reference tracer. The estimated total SO 2 F 2 emission of China was 0.49 ± 0.49 Gg yr−1 during 2011 to 2016 and 0.32 ± 0.32 Gg yr−1 during 2017 to 2019, and China's per capita SO 2 F 2 emissions were lower than global averages during 2011-2019. • The long-term atmospheric mixing ratios of sulfuryl fluoride in China were reported for the first time. • Sulfuryl fluoride emissions of key regions and Chinese totals were estimated by trace ratio method. • Both enhanced sulfuryl fluoride mixing ratios in Eastern China and the national emissions have declined in recent years. [ABSTRACT FROM AUTHOR]

Cities have multiple fugitive emission sources of methane (CH4) and policies adopted by China on replacing coal with natural gas in recent years can cause fine spatial heterogeneities at the range of kilometers within a city and also contribute to the CH4 inventory. In this study, a mobile observatory was used to monitor the real-time CH4 concentrations at fine spatial and temporal resolutions in Beijing, the most important pilot city of energy transition. Results showed that: several point sources, such as a liquefied natural gas (LNG) power plant which has not been included in the Chinese national greenhouse gas inventory yet, can be identified; the ratio "fingerprints" (CH4:CO2) for an LNG carrier, LNG filling station, and LNG power plant show a shape of "L"; for city observations, the distribution of CH4 concentration, in the range of 1940–2370 ppbv, had small variations while that in the rural area had a much higher concentration gradient; significant correlations between CO2 and CH4 concentrations were found in the rural area but in the urban area there were no such significant correlations; a shape of "L" of CH4:CO2 ratios is obtained in the urban area in wintertime and it is assigned to fugitive emissions from LNG sources. This mobile measurement methodology is capable of monitoring point and non-point CH4 sources in Beijing and the observation results could improve the CH4 inventory and inform relevant policy-making on emission reduction in China. [ABSTRACT FROM AUTHOR]

This study presents atmospheric N2O mole fractions measured from discrete air samples from 2001 to 2018 at Mt. Waliguan (WLG) station (36°17′N, 100°54′E, 3816 m asl) in China, which is a global background station of the World Meteorological Organization/Global Atmosphere Watch Programme (WMO/GAW) in central Eurasia. Observed N2O characteristics of annual means, interannual variability, and seasonal cycles were investigated. Our results show that N2O at WLG possess a distinct increasing trend and a statistically significant seasonal cycle, with an average growth rate of 0.9±0.01 ppb yr−1 (1σ)(1ppb=10−9), which is close to the global mean. The detrended seasonal cycle shows a trough of −0.25±0.04 (1σ) ppb in June and a peak of 0.13±0.07 (1σ) ppb in September, with an amplitude of 0.38 ppb. The pattern is due to combined effects of variation in surface sources, vertical convection within the boundary layer and stratosphere to troposphere transportation (STE). The interannual variability in growth rate was partly driven by quasi-biennial oscillation (QBO) of tropical zonal wind through stratospheric transport into the troposphere. According to a cluster analysis of back trajectories and the corresponding average N2O load, most air masses cover arid and semi-arid areas in inner Asia with low N2O emissions, indicating that the atmospheric N2O at the WLG represents the background N2O level in central Eurasia. [ABSTRACT FROM AUTHOR]

Abstract Domestic trade flourishes with economic development and the spatial separation of production and consumption. Therefore, the prosperity of trade is accompanied by the transfer of pollution from the demand side to the supply side, which could potentially worsen the environmental quality of the supply side. Despite a large number of studies on the pollution haven hypothesis in international trade, little attention has been paid to testing the hypothesis in domestic trade. Here, combining a multiregional input–output analysis and a gravity model of trade in China, we provide an empirical test to address this problem for the first time. We also assess the factors affecting the SO 2 emissions embodied in trade, including population, economic development, coal consumption, distance, and environmental regulations. We found that domestic trade contributed approximate one third of the total SO 2 emissions in China, and interprovincial transfers of SO 2 embodied in trade were significantly determined by the population, economic development, coal consumption of the trade pairs, as well as their distance. SO 2 emission mitigation policies, such as emission reduction target and sulfur dioxide control zone, has a more significant influence on the direct transfer of SO 2 emission via direct bilateral trade, while their effects were largely offset by indirect trade (through third–party transfers). Our results do not support the pollution haven hypothesis existed in domestic trade in China during 2007–2012. Our paper sets an example and provides a reference for the domestic pollution transfer problem from an econometric perspective. Further attempts on testing pollution haven hypothesis in consideration of various pollutants are still needed to arrive at a robust conclusion. Graphical abstract Unlabelled Image Highlights • MRIO model was combined with gravity model to study the domestic SO 2 flows. • SO 2 pollution haven effect of domestic trade in China was tested and not found. • Policy effects were weakened by indirect SO 2 transfer embodied in trade. [ABSTRACT FROM AUTHOR]

Abstract Dirty industries tend to relocate to regions with looser environmental regulations, thus turning those regions into pollution havens. Numerous studies have tested the pollution haven effect of inter-country industrial relocation. However, little attention has been paid to the effect that is hidden in domestic industry relocation. Considering that domestic investment is about 10-fold that of foreign investment, it is vital to examine this issue to ensure the achievability of China's international pledge of mitigating carbon emissions. This research integrated multiregional input-output analysis and a center of gravity model to visualize the dislocation between carbon emissions, value added, and outputs at a sectoral level from 2007 to 2012 in China. Carbon emissions were also decomposed to three segments of final demand. We also investigated the movement of the center of gravity of these segments, and their dislocation with the outputs. Our analysis found that more carbon emissions had relocated from east to west with domestic industry relocation, yet the opposite was found for value added. Specifically, carbon intensive sectors showed clear tendencies of shifting west. Capital formation was the major cause of the pollution haven effects for the economy as a whole. Thus, our results suggest that pollution haven effects exist in the relocation processes of most sectors. In turn, our findings support the idea that mitigation policies should differ by region and by industry. Our recommendations include a negative list for regions in the west, a mitigation policy for industries with high pollution, and differentiated supply chain management for final demands. Graphical abstract Image Highlights • MRIO and center of gravity are used to visualize the pollution haven effect. • Center of gravity is decomposed by final demand categories. • Most industries moving to the north and the west have pollution haven effect. • Capital formation is the major cause of pollution haven effect. [ABSTRACT FROM AUTHOR]

Energy use is often accompanied with air emissions including SO x , NO x , CO 2 , etc. It is essential to consider both the energy and environmental performance of various sectors to ensure better policymaking. This study considered air pollution by calculating energy-environmental efficiency (EEE) at the sectoral level. A few studies have previously applied the slack-based measure (SBM) model to multi-sector EEE assessments. Despite the advantages of SBM model, potential improvements have rarely been proposed. Therefore, a super-efficiency SBM model with undesirable outputs (S-U-SBM) was used to evaluate the EEE of 31 sectors in China. The policy implications of improving EEE, in microcosmic (potential improvement) and macroscopic (influencing factors) terms, were considered. The results indicated that for all sectors there was an overall trend of increasing EEE from 1995 to 2009, except for Rent and Other Business Activities, and Health and Social Work. The average annual potential for energy-saving and emission-reducing measures in all sectors was 1.396 × 10 17 J and 7.0780 × 10 7 tons, respectively. Chemicals and Chemical Materials had the highest potential to save energy and reduce emissions. A panel regression indicated that the relationship between EEE and gross output was U-shaped for all industry, but had an inverted-U shape for heavy industry. Sectoral size, technology, and the proportion of energy demand satisfied by coal significantly influenced EEE. [ABSTRACT FROM AUTHOR]

This study developed a framework for combining multi-regional input-output analysis and network indicators to assess the interregional CO 2 flows in China. The interregional CO 2 flows of eight regions were calculated and visualized based on a multiregional input-output (MRIO) model for China. The focus of the research was intermediate use. The results of the network indicators showed that refined petroleum, coke, nuclear fuel and chemical products (07), and basic metals and fabricated metal sectors (09) played key roles in the complex networks. and these sectors in most regions controlled a large share of CO 2 transfer by functioning as key hubs and authorities. They along with commerce, transport, storage, and post (16) acted as agents that brokered the CO 2 flows within and between regions. The roles of some other industrial sectors were also identified, e.g., construction (15) functioned as the largest authority. The results demonstrated the importance and effectiveness of network indicators for identifying the characteristics of CO 2 emissions embedded in the domestic supply chain, and provided new information relevant to policy implementation. [ABSTRACT FROM AUTHOR]

The collapse of the plastic waste trade (PWT) amplifies the threats of mismanaged plastic waste to the ecological system and human health, posing a risk as well as an opportunity to the global circular economy. Although trade barriers in the PWT continue to impact waste management systems, there are few analyses that propose global mitigation strategies in response to trade fluctuations. Here, we show that most countries have been overloaded with plastic waste compared to their ordinary capacity since China's import ban in 2017. We apply a cascading failure model to quantify the collapse process worldwide and find that 183 countries become overloaded as this collapse cascades, with nearly 6% of countries experiencing over 1.5 times their ordinary load. However, this overload could be greatly alleviated if leading countries were to sharply increase their capacity to treat plastic waste based on scenario analysis. Although waste exporters should take more responsibility and scenario analysis results show that top exporters could effectively mitigate global plastic waste levels by increasing their treatment capacity, cooperation between key exporters, importers, and intermediators has the best mitigation effects. Our analysis suggests that key countries should as soon as possible take responsibility for and cooperate in mitigating potential plastic waste pollution related to trade fluctuations. • Many countries show plastic waste overloading due to China's import ban. • Structural change of plastic waste trade could lead cascading failure worldwide. • Overload situation will be greatly alleviated, if leading countries work for it. • The cooperation strategy has the best mitigation effect. [ABSTRACT FROM AUTHOR]