Quantification and scenario analysis of CO2 emissions from the central heating supply system in China from 2006 to 2025

Policies associated with the central heating supply system affect the livelihoods of people in China. With the extensive consumption of energy for central heating, large quantities of CO2 emissions are produced each year. Coal-fired heating boiler plants are the primary source of emissions; however, thermal power plants are becoming much more prevalent, and gas-fired heating boiler plants remain uncommon. This study quantified the amount of CO2 emitted from the central heating supply system in China using a mass balance method with updated emission factors from the IPCC. Emissions increased from 189.04 Tg to 319.39 Tg between 2006 and 2015. From a spatial perspective, regions with larger central heating areas, durations and coverages produced more CO2 emissions. The central heating method depends on the level of electric power consumption, policies and regulations, and resource reserves at the local scale. Compared with the use of only coal-fired heating boiler plants to provide central heating, using thermal power plants and gas-fired heating boiler plants reduced CO2 emissions by 98.19 Tg in 2015 in China. A comparison of the CO2 emissions under various central heating scenarios showed that emissions will be 520.97 Tg, 308.79 Tg and 191.86 Tg for business as usual, positive and optimal scenarios through 2025, respectively. China has acknowledged the considerable potential for reducing central heating and will make efforts to pursue improved heating strategies in the future

Contrasting suitability and ambition in regional carbon mitigation

Substantially enhancing carbon mitigation ambition is a crucial step towards achieving the Paris climate goal. Yet this attempt is hampered by poor knowledge on the potential cost and benefit of emission mitigation for each emitter. Here we use a global economic model to assess the mitigation costs for 27 major emitting countries and regions, and further contrast the costs against the potential benefits of mitigation valued as avoided social cost of carbon and the mitigation ambition of each region. We find a strong negative spatial correlation between cost and benefit of mitigating each ton of carbon dioxide. Meanwhile, the relative suitability of carbon mitigation, defined as the ratio of normalized benefit to normalized cost, also shows a considerable geographical mismatch with the mitigation ambition of emitters indicated in their first submitted nationally determined contributions. Our work provides important information to improve concerted climate action and formulate more efficient carbon mitigation strategies

City-level livestock methane emissions in China from 2010 to 2020

Abstract Livestock constitute the world’s largest anthropogenic source of methane (CH4), providing high-protein food to humans but also causing notable climate risks. With rapid urbanization and increasing income levels in China, the livestock sector will face even higher emission pressures, which could jeopardize China’s carbon neutrality target. To formulate targeted methane reduction measures, it is crucial to estimate historical and current emissions on fine geographical scales, considering the high spatial heterogeneity and temporal variability of livestock emissions. However, there is currently a lack of time-series data on city-level livestock methane emissions in China, despite the flourishing livestock industry and large amount of meat consumed. In this study, we constructed a city-level livestock methane emission inventory with dynamic spatial-temporal emission factors considering biological, management, and environmental factors from 2010 to 2020 in China. This inventory could serve as a basic database for related research and future methane mitigation policy formulation, given the population boom and dietary changes

A Dual-Polarized Printed Antenna Based on a Tapered Slot SICL Balun for Airborne Radar Application

The substrate-integrated coaxial line (SICL) is a potential transmission line due to its good characteristics of high efficiency, nondispersive, and single operational mode. A tapered slot SICL balun is proposed, which can realize the impedance transformation from the microstrip line to the coplanar strip line (CPS). At the same time, the proposed balun can transform the quasi-TEM mode of the microstrip line to the TEM mode of CPS. A printed dipole radiator is designed and is fed by the proposed SICL balun to achieve the impedance matching. The dual-polarized radiation mode is realized by employing two orthogonal printed dipoles. For each polarization radiator, the CPS is bended to avoided the occlusion of two polarization ports and realize the direct assembling of two orthogonal printed circuits. What is more, the assembling method is advantageous to improve the port isolation degree and decrease the cross polarization level. To improve the ratio of front to back (F/B) of the radiation pattern, a cylindrical metal cavity is adopted. According to the results of simulation and experiments, the VSWR of each port is lower than 2, the isolation degree between two polarization ports is higher than 20 dB, and the cross polarization level at the boresight is lower than −20 dB at the operational frequency. The patterns of two ports are almost symmetric, and high radiation efficiency is obtained. The experimental results of the principle prototype verify the design schemes of the balun and the dual-polarized antenna. The proposed dual-polarized antenna fed by the tapered slot SICL balun is suitable for the airborne radar application

Global Impacts of a Bilateral Trade Policy on Ballast Water-Mediated Species Spread Risk: A Case Study of Sino-US Trade

A trade policy could generate both economic and environmental impacts. This work is focused on the impacts of a bilateral trade policy on ballast water-mediated nonindigenous species (NIS) spread risk. Taking the hypothetical Sino-US trade restriction as an example, we integrate a computable general equilibrium model and a higher-order NIS spread risk assessment model to examine the impacts of bilateral trade policy on both the economy and NIS spread risks. We have two important findings. First, the Sino-US trade restriction would cause decreases in NIS spread risks to China and the US, as well as to three quarters of worldwide countries/regions. However, the rest one fourth would experience increased NIS spread risks. Second, the relationship between changes in exports and changes in NIS spread risks might not be directly proportional. This is observed with 46% of countries and regions that would see their exports increase but their NIS spread risks drop, with positive impacts on both their economies and environment under the Sino-US trade restriction. These results reveal both broader global impacts as well as the decoupled economic and ecological impacts of a bilateral trade policy. These broader impacts demonstrate the necessity for national governments, which are parties to bilateral agreements to give due consideration to the economic and environmental impacts on countries and regions outside of the agreement

Quantification of methane emissions from municipal solid waste landfills in China during the past decade

Methane is responsible for 20% of the global warming resulting from greenhouse gas emissions. Municipal solid waste (MSW) landfills are the third largest anthropogenic source of methane and are thus important to estimating the global methane budget and evaluating its contribution to global greenhouse gas emissions. Based on the greenhouse gas inventory guidelines from the Intergovernmental Panel on Climate Change (IPCC) and the first-order decay method used to estimate emissions from MSW landfills - and in line with MSW management in various regions we calculated methane emissions from MSW landfills in various Chinese provinces from 2003 to 2013. During this period, methane emissions from MSW landfills increased from 1141.10 Gg to 1858.98 Gg, representing a mean annual increase of 71.79 Gg. MSW emissions tended to increase more in the northern and western provinces than in the southern and eastern provinces, as methane emissions strongly and positively correlated with population and socioeconomic demographics. MSW decontamination is growing rapidly in China, and landfills predominate in all MSW treatments; moreover, incineration has also dramatically increased in recent years

Global Impacts of a Bilateral Trade Policy on Ballast Water-Mediated Species Spread Risk: A Case Study of Sino-US Trade

A trade policy could generate both economic and environmental impacts. This work is focused on the impacts of a bilateral trade policy on ballast water-mediated nonindigenous species (NIS) spread risk. Taking the hypothetical Sino-US trade restriction as an example, we integrate a computable general equilibrium model and a higher-order NIS spread risk assessment model to examine the impacts of bilateral trade policy on both the economy and NIS spread risks. We have two important findings. First, the Sino-US trade restriction would cause decreases in NIS spread risks to China and the US, as well as to three quarters of worldwide countries/regions. However, the rest one fourth would experience increased NIS spread risks. Second, the relationship between changes in exports and changes in NIS spread risks might not be directly proportional. This is observed with 46% of countries and regions that would see their exports increase but their NIS spread risks drop, with positive impacts on both their economies and environment under the Sino-US trade restriction. These results reveal both broader global impacts as well as the decoupled economic and ecological impacts of a bilateral trade policy. These broader impacts demonstrate the necessity for national governments, which are parties to bilateral agreements to give due consideration to the economic and environmental impacts on countries and regions outside of the agreement

Design and Verification of Crab Steering System for High Clearance Self-Propelled Sprayer

A crab steering system aiming at improving the steering flexibility and operation efficiency of the high clearance sprayer was designed. First, a steering transmission mechanism of the high clearance sprayer was designed according to the operational and structural characteristics of the sprayer. Meanwhile, a crab steering hydraulic system based on load sensing was designed, and a mathematical model of the steering transmission mechanism and hydraulic system was established to describe the working characteristics of the crab steering system. On the basis of analyzing the operating environment of the sprayer and the operating characteristics of crab steering mode, a control strategy and algorithm of the crab steering system were proposed. The simulation model of the crab steering control system was built according to the established mathematical model, and the simulation analysis of the crab steering system was carried out. The simulation results showed that under the excitation of step signal, the average deviation of the two front wheels is 0.063°, and the absolute value of the maximum deviation is 2.75°, which is within the allowable range of deviation and meets the crab steering demand of the sprayer. Additionally, in order to verify the effectiveness of the designed system, an actual vehicle test platform of the crab steering system was built based on the 3WPG-3000 high clearance self-propelled sprayer independently developed by the research group, and the field test results revealed that the average deviation of the four wheels was 0.285°, the maximum absolute deviation was 2.587°, the rotation deviation was small, within the allowable and reasonable range. Altogether, the results of the simulation and field test verify the accuracy, stability and practicability of the crab steering system, which effectively improved the maneuverability of the sprayer

Clonal Dissemination of Multidrug-Resistant and Hypervirulent Klebsiella pneumoniae Clonal Complex in a Chinese Hospital

The emergence of high antimicrobial-resistant and hypervirulent Klebsiella pneumoniae (hvKp) clones in clinics has become a cause of concern in recent years. Despite the global spread of the clonal complex (CC) 258, hvKp of other non-CC258 subgroups also emerged. Here, by performing a retrospective study from July 2019 to August 2020 in a Chinese hospital, we obtained 25 K. pneumoniae isolates belonging to CC15. By antimicrobial susceptibility testing and whole genome sequencing and analysis, we obtained the resistant phenotypes and genotypes of these isolates. Twenty-one isolates (84%) were carbapenem-resistant, and eighteen were blaKPC-2 positive. In addition, ten isolates were identified as putative hvKp and seven were carbapenem-resistant hvKp. Nine isolates carried the pLVPK-like virulence plasmid, which contains the fragment including rmpA2, peg-589, iutA, and iucABCD. Another isolate carried iucA. Phylogenetic analysis revealed that the isolates belonged to four lineages, and the putative hvKp isolates were identified in three of these. Two independent sublineages of putative hvKp were caused by the acquisition of pLVPK-like virulence plasmid. Based on comparative genomic analysis, the number of pairwise single nucleotide polymorphisms amongst the four sublineages, Lineage 1a, 1b, 2a, and 2b, were 1–43, 2–13, 129–279, and 3–4, respectively, indicating clonal transmission of Lineage 1a, 1b, and 2b. These results indicate that multiple lineages of CC15 carbapenem-resistant hvKp have emerged in the hospital and caused nosocomial transmission, and that the spreading of virulence plasmids among classic K. pneumoniae subtypes might become more common and happen more easily. These findings highlight the importance of surveillance of local epidemics of non-CC258 subgroups in hospitals

Global Impacts of a Bilateral Trade Policy on Ballast Water-Mediated Species Spread Risk: A Case Study of Sino-US Trade

A trade policy could generate both economic and environmental impacts. This work is focused on the impacts of a bilateral trade policy on ballast water-mediated nonindigenous species (NIS) spread risk. Taking the hypothetical Sino-US trade restriction as an example, we integrate a computable general equilibrium model and a higher-order NIS spread risk assessment model to examine the impacts of bilateral trade policy on both the economy and NIS spread risks. We have two important findings. First, the Sino-US trade restriction would cause decreases in NIS spread risks to China and the US, as well as to three quarters of worldwide countries/regions. However, the rest one fourth would experience increased NIS spread risks. Second, the relationship between changes in exports and changes in NIS spread risks might not be directly proportional. This is observed with 46% of countries and regions that would see their exports increase but their NIS spread risks drop, with positive impacts on both their economies and environment under the Sino-US trade restriction. These results reveal both broader global impacts as well as the decoupled economic and ecological impacts of a bilateral trade policy. These broader impacts demonstrate the necessity for national governments, which are parties to bilateral agreements to give due consideration to the economic and environmental impacts on countries and regions outside of the agreement