Driving co-abatement of Greenhouse Gas (GHGs) and Air Pollutants (APs) in the city level is crucial for fostering societal green and low-carbon transitions, yet comprehensive and refined researches at this level remain limited. To facilitate urban fine management of GHGs control and APs reduction, this study targeted nine categories of anthropogenic emission sources in Shanghai, a typical megacity of China, analyzing the co-benefits of three types of GHGs (CO2, CH4, N2O) and seven types of APs (SO2, NOx, CO, VOCs, NH3, PM2.5, PM10) via emissions flow, spatial distribution, hotspot regions identification, and scenario prediction. Results highlighted the source heterogeneity of different types and significant contributions of energy consumption. CO2 emissions showed a strong spatial correlation with SO2, NOx, and CO, followed by VOCs and PM. Hotspot regions for CO2-VOCs, CO2-NOx and CO2-SO2 co-abatement included power plants, petrochemical enterprises and chemical industrial parks in the southern coastal areas, iron and steel enterprises and power plants in the northern coastal areas, and airport areas in the central and eastern coastal areas, presenting great potential maximum reduction benefits. Achieving positive co-benefits in industrial sector would depend on the steady decline of CO2 emissions in power generation and steel industries. Introducing carbon capture devices and improving energy efficiency would be more beneficial to CO2 emission reduction, while increasing the share of clean energy and phasing out outdated vehicles, machinery, or production capacities are more effective in reducing APs. These mitigation measures could achieve 68.8 % and 47.6 % reduction for CO2 and APs by 2050, respectively, and the co-effect of CO2 and APs emission reduction would gradually increase with the continuous implementation of these measures.

BACKGROUND: The Greenhouse gas Observations of Biospheric and Local Emissions from the Upper sky (GOBLEU) is a new joint project by Japan Aerospace Exploration Agency (JAXA) and ANA HOLDING INC. (ANAHD), which operates ANA flights. GOBLEU aims to visualizes our climate mitigation effort progress in support of subnational climate mitigation by collecting greenhouse gas (GHG) data as well as relevant data for emissions (nitrous dioxide, NO2) and removals (Solar-Induced Fluorescence, SIF) from regular passenger flights. We developed a luggage-sized instrument based on the space remote-sensing techniques that JAXA has developed for Japan\'s Greenhouse gas Observing SATellite (GOSAT). The instrument can be conveniently installed on a coach-class passenger seat without modifying the seat or the aircraft.
RESULTS: The first GOBLEU observation was made on the flight from the Tokyo Haneda Airport to the Fukuoka Airport, with only the NO2 module activated. The collected high-spatial-resolution NO2 data were compared to that from the TROPOspheric Monitoring Instrument (TROPOMI) satellite and surface NO2 data from ground-based air quality monitoring stations. While GOBLEU and TROPOMI data shared the major concentration patterns largely driven by cities and large point sources, regardless of different observation times, we found fine-scale concentration pattern differences, which might be an indication of potential room for GOBLEU to bring in new emission information and thus is worth further examination. We also characterized the levels of NO2 spatial correlation that change over time. The quickly degrading correlation level of GOBLEU and TROPOMI suggests a potentially significant impact of the time difference between CO2 and NO2 as an emission marker and, thus, the significance of co-located observations planned by future space missions.
CONCLUSIONS: GOBLEU proposes aircraft-based, cost-effective, frequent monitoring of greenhouse emissions by GOBLEU instruments carried on regular passenger aircraft. Theoretically, the GOBLEU instrument can be installed and operated in most commercially used passenger aircraft without modifications. JAXA and ANAHD wish to promote the observation technique by expanding the observation coverage and partnership to other countries by enhancing international cooperation under the Paris Agreement.

OBJECTIVE: Research has demonstrated negative environmental impacts from in-person conferences. Nonetheless, there are benefits to in-person meetings. The 2023 American Pediatric Surgical Association (APSA) meeting was mostly attended in-person. To understand the environmental impact, this study quantifies the travel emissions generated from that meeting.
METHODS: The 2023 APSA meeting was held in Orlando, FL. Using a de-identified list of attendees, the distance between the attendee\'s home city and Orlando was determined. If ≤ 200 miles, it was assumed the attendee drove. If > 200 miles, the distance between the closest airport and Orlando International Airport was determined. Travel emissions factors represent emissions per person-mile traveled. The Environmental Protection Agency (EPA) Greenhouse Gas Inventory emissions factors for carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were multiplied by travel distances to determine the emissions generated from each attendee. These were aggregated to determine the total meeting travel emissions. The EPA Greenhouse Gas Equivalencies Calculator was used to convert the emissions to a relatable outcome.
RESULTS: There were 757 in-person and 135 virtual attendees. Fifty attendees drove and 707 attendees flew. This generated 267,279 kg CO2, 1222 gm CH4, and 8486 gm N2O; equivalent to the emissions generated from the average annual use of 60 gasoline-powered passenger vehicles in the United States.
CONCLUSIONS: Based on attendance to the 2023 APSA meeting, there is a preference for meeting in-person, though the associated environmental cost should be recognized. Based on these results, APSA should consider strategies to mitigate the environmental impact of its annual meeting.
METHODS: N/A.

The study aimed to investigate the effect of supplementing polyclonal antibodies (PAP) of avian origin against the ruminal methanogens Methanobrevibacter gottschalkii Ho (PAP-Ho) and M. ruminantium M1 (PAP-M1) on ruminal fermentation profile and methane production in Angus crossbred cattle (13 steers and 1 heifer). The experiment was conducted using a randomized block design with a 3 × 2 + 1 factorial arrangement, replicated in three periods. The factors included proportions of PAP against Ho and M1 in the mixture (100:0, 50:50, and 0:100 Ho:M1) and level of each mixture (3- or 6-mL per d). Cattle in control treatment did not receive PAP supplementation. Ruminal fluid was collected from the animals on d 0, 14 and 21 of treatment to determine of ruminal fermentation profile and ex vivo methane production. There was no effect of level of inclusion on ex vivo methane production. Supplementation with PAP-M1, either alone or in combination with PAP-Ho, decreased ex vivo methane output compared to the control group. Furthermore, in vivo molar proportion of propionate tended to be greater with PAP-M1, alone or combined with PAP-Ho, when compared with the control group. The study concluded that polyclonal antibodies against ruminal methanogens have the potential to decrease enteric methane emissions in cattle. The research provided important insights into the potential use of PAP as a strategy for reducing greenhouse gas emissions from cattle. Further research is needed to confirm these findings and to determine the practicality and feasibility of using PAP.

UNASSIGNED: Climate change and environmental pollution have known health effects. The recently introduced inflation reduction act (IRA) by the United States government includes funding initiatives to curb climate change, and reduce environmental pollution, in line with the nationally determined contribution (NDC) plan (40-50 % reduction in greenhouse gas [GHG] emissions by 2030, as compared with 2005). The projected cardiovascular health benefits of the IRA driven climate actions to achieve the NDC goals are not known.
UNASSIGNED: We used the Energy Policy Simulator (EPS), a simulation algorithm based on systems dynamics modelling estimating the impact of various energy policies, to model the impact of achieving NDC targets in the United States on health outcomes by 2050. We further investigated race-specific impact on mortality (absolute and relative) by 2050.We estimated the projected reduction in six adverse health outcomes between 2022 and 2050: asthma attacks, non-fatal heart attacks, hospital admissions, respiratory symptoms and bronchitis, lost workdays, and deaths.
UNASSIGNED: Achievement of NDC targets by 2050 will result in 987,415 avoided asthma attacks, 41,565 avoided nonfatal heart attacks, 18,993 avoided hospital admissions, 1,493,010 avoided respiratory symptoms and bronchitis, 3,317,250 avoided lost workdays, and 32,659 avoided deaths (22,839 among white individuals, 4993 among Black individuals, 2801 among Asian individuals, and 2026 among other/multirace individuals). By 2050, minority racial groups had higher relative change in avoided deaths (white -0.74 %, Black -1.01 %, Asian -1.24 %, and other/multirace -1.75 %). Similarly, Hispanics/latinos higher relative reductions in deaths (-1.4 %) compared with non-Hispanic/Latinos (-0.7 %) by 2050.
UNASSIGNED: The IRA facilitated achievement of NDC GHG reduction goals by 2050 would result in substantial number of avoided adverse health outcomes and death. Racial and ethnic minorities are expected to have the largest relative reductions in deaths by 2050. The current report underscores the importance of continued climate action investment irrespective of political differences. The appreciation of this aspect of the IRA may be more important to overall preservation of health, beyond the reduction in medication costs.

Saltmarshes along the Chinese coast are threatened by the invasion of Spartina alterniflora (S. alterniflora). This study was carried out in the Andong Shoal, Hangzhou Bay, China, with the aim of comprehending the intricate impacts of S. alterniflora invasion on greenhouse gases (GHG) production and emissions. To address this issue, we thoroughly examined the chemistry of dissolved organic matter (DOM) and the rate of surface water-porewater interaction. Porewater and surface water samples were collected from farm land, S. alterniflora invaded areas, and Scirpus mariqueter (S. mariqueter) dominated areas. The findings indicated that the invasion of S. alterniflora impeded the interaction between surface water and porewater, resulting in reduced porewater exchange rates within its affected region (0.015-0.440 cm d-1), in contrast to areas dominated by S. mariqueter (9.635-18.232 cm d-1). The invasion also increased dissolved organic carbon concentration in porewater and created a stable and closed soil environment that resulted in DOM with smaller molecule sizes and higher humification levels. The presence of high tryptophan-like fluorescent DOM caused an increase in the production of methane and carbon dioxide in S. alterniflora invaded area. However, both limited surface-porewater exchange and significant differences in GHG concentrations between porewater and surface water suggested that the aerenchyma tissues of S. alterniflora may play an important role in transporting GHG from soil to the atmosphere.

The inefficient nitrogen removal in constructed wetlands (CWs) can be attributed to insufficient carbon sources for low carbon-to-nitrogen (C/N) ratio wastewater. In this study, sugarcane bagasse fermentation liquid (SBFL) was used as a supplemental carbon source in intermittently aerated CWs to enhance nitrogen removal. The impact of different regulated influent C/N ratios on nitrogen removal and greenhouse gas (GHG) emissions was investigated. Results demonstrated that SBFL addition significantly enhanced the denitrification capacity, resulting in faster NO3--N removal compared to sucrose. Moreover, intermittently aerated CWs significantly improved NH4+-N removal efficiency compared to non-aerated CWs. The highest total nitrogen removal efficiency (98.3 %) was achieved at an influent C/N ratio of 5 in intermittently aerated CWs with SBFL addition. The addition of SBFL resulted in a reduction of N2O emissions by 17.8 %-43.7 % compared to sucrose. All CWs exhibited low CH4 emissions, with SBFL addition (0.035-0.066 mg·m-2h-1) resulting in lower emissions compared to sucrose. Additionally, higher abundance of denitrification (nirK, nirS and nosZ) genes as well as more abundant denitrifying bacteria were shown in CWs of SBFL inputs. The results of this study provide a feasible strategy for applying SBFL as a carbon source to improve nitrogen removal efficiency and mitigate GHG emissions in CWs.

Due to the heterogeneity of recycled paper materials and the production conditions, pollutants in papermaking wastewater fluctuate sharply over time. Quality control of the papermaking wastewater treatment process (PWTP) is challenging and costly. As regulations are also growing about the environmental effects of the PWTP on greenhouse gas (GHG) emission, energy consumption, etc., the PWTP formulates a complex multiobjective optimization problem. This research established a multiagent deep reinforcement learning framework to simultaneously optimize process cost, energy consumption, and GHG emission in the PWTP, subjected to the effluent quality, to realize economic, energy, and environmental (3E) goals. The biological treatment process of wastewater in paper mills was simulated using benchmark simulation model no. 1 (BSM1). The data generated based on the BSM manual was utilized for model training, and real data acquired from a local papermaking factory was used to estimate the model performance. The results show that the proposed method outperforms conventional techniques in identifying the best control strategies for multiple targets.

Ethane, the second most abundant gaseous hydrocarbon in vast anoxic environments, is an overlooked greenhouse gas. Microbial anaerobic oxidation of ethane can be driven by available electron acceptors such as sulfate and nitrate. However, despite nitrite being a more thermodynamically feasible electron acceptor than sulfate or nitrate, little is known about nitrite-driven anaerobic ethane oxidation. In this study, a microbial culture capable of nitrite-driven anaerobic ethane oxidation was enriched through the long-term operation of a nitrite-and-ethane-fed bioreactor. During continuous operation, the nitrite removal rate and the theoretical ethane oxidation rate remained stable at approximately 25.0 mg NO2 -N L-1 d-1 and 11.48 mg C2H6 L-1 d-1, respectively. Batch tests demonstrated that ethane is essential for nitrite removal in this microbial culture. Metabolic function analysis revealed that a species affiliated with a novel genus within the family Rhodocyclaceae, designated as \'Candidatus Alkanivoras nitrosoreducens\', may perform the nitrite-driven anaerobic ethane oxidation. In the proposed metabolic model, despite the absence of known genes for ethane conversion to ethyl-succinate and succinate-CoA ligase, \'Ca. A. nitrosoreducens\' encodes a prospective fumarate addition pathway for anaerobic ethane oxidation and a complete denitrification pathway for nitrite reduction to nitrogen. These findings advance our understanding of nitrite-driven anaerobic ethane oxidation, highlighting the previously overlooked impact of anaerobic ethane oxidation in natural ecosystems.

Reservoirs in arid regions often provide critical water storage but little is known about their greenhouse gas (GHG) footprint. While there is growing appreciation of the role reservoirs play as GHG sources, there is a lack of understanding of GHG emission dynamics from reservoirs in arid regions and implications for environmental policy. Here we present initial GHG emission measurements from Lake Powell, a large water storage reservoir in the desert southwest United States. We report CO2-eq emissions from the shallow (< 15 m) littoral regions of the reservoir that are higher than the global average areal emissions from reservoirs (9.4 vs. 5.8 g CO2-eq m-2 d-1) whereas fluxes from the main reservoir were two orders of magnitude lower (0.09 g CO2-eq m-2 d-1). We then compared our measurements to modeled CO2 + CH4 emissions from the reservoir using four global scale models. Factoring these emissions into hydropower production at Lake Powell yielded low GHG emissions per MWh-1 as compared to fossil-fuel based energy sources. With the exception of one model, the estimated hydropower emissions for Lake Powell ranged from 10-32 kg CO2-eq MWh-1, compared to ∼400-1000 kg CO2-eq MWh-1 for natural gas, oil, and coal. We also estimate that reduced littoral habitat under low water levels leads to ∼50% reduction in the CO2 equivalent emissions per MWh. The sensitivity of GHG emissions to reservoir water levels suggests that the interaction will be an important policy consideration in the design and operation of arid region systems.