Local governments in Europe play a crucial role in achieving climate neutrality Alina Safronova at the Institute of Energy Systems and Environment, Riga Technical University, examines how local governments in Europe are one of the most important driving forces on the path to climate neutrality. Local governments in Europe are one of the most important driving forces on the path to climate neutrality. They set strategic directions for improving energy efficiency, developing renewable energy, and reducing local greenhouse gas (GHG) emissions. Local governments also play a crucial role in engaging the public and local stakeholders – without changing their citizens’ habits and behaviour, sustainable change is impossible. However, in practice, the potential of local governments often remains untapped. It is limited by a lack of skills, insufficient tools, and difficulties in calculating emissions and developing future scenarios.

Polymer electrolyte membrane (PEM) water electrolyzers are promising solutions for producing clean hydrogen owing to high energy-conversion efficiencies, low-operating temperatures, and zero local greenhouse gas emissions.1 While compression is required to prevent leakage and crossover, the impact of compression on the long-term durability is not fully understood.2,3 To resolve the compression-induced degradation mechanisms within a PEM water electrolyzer, we apply a multi-physics model that couples solid mechanics with electrochemical reactions and multiphase transport processes. Through this work, we found that the catalyst layer and membrane exhibited significantly more deformation compared to the porous transport layer. Moreover, the membrane experienced thinning, especially under the flow field lands, making the membrane land regions particularly susceptible to mechanical degradation. Although compression resulted in improved cell performance via the reduction of ohmic resistances, compression also led to higher mass transport resistances and local water starvation at the catalyst layer. This work illustrates the potential to optimize mechanical properties and compression ratios to reduce catalyst and membrane degradation for next generation electrolyzer design and performance. References X. Z. Yuan et al., Sustain. Energy Fuels, 6, 1824–1853 (2022).A. Martin et al., J. Electrochem. Soc., 169, 014502 (2022).C. Arthurs and A. Kusoglu, J. Electrochem. Soc., 171, 094510 (2024).

The reduction of greenhouse gas emissions is a central motivation for electrification of road traffic. Although electric vehicles (EVs) do not produce local greenhouse gas emissions during operation, their production and the generation of electrical energy required for operation might still result in a relevant carbon footprint. Accordingly, it is important to incorporate considerations regarding greenhouse gas emissions in the design process of new EVs and that way aim to minimize their carbon footprint. In the present work, this is achieved by consideration of both production emissions and in-use emissions in a design optimization method for electric axle drives (e-drives). Accordingly, the carbon footprint of an e‑drive can be directly minimized alongside the optimization of other design objectives, e.g., production cost, energy efficiency and package integration. The optimization result is represented as Pareto front of various optimal design solutions for specified e‑drive requirements. The proposed method is applied to a case study, which involves the optimization of an e‑drive for a passenger vehicle. The obtained Pareto front and found trade-offs between carbon footprint, cost and energy efficiency are discussed. Furthermore, a promising design solution from the Pareto front is selected to guide subsequent development phases.

Implicit in cities' decisions to engage in climate actions is the expectation that these efforts will result in significant greenhouse gas emissions reductions. Little research, however, has investigated this presumed cause-and-effect relationship in a manner that is both empirical and generalizable. This, in turn, challenges the design of evidence-based policy recommendations. We apply a difference-in-differences (DiD) approach to examine the impact that two frequently recommended capacity-building interventions—completing a greenhouse gas emissions (GHG) inventory and employing dedicated sustainability staff—have on the fossil fuel carbon dioxide (FFCO 2 ) emissions of the cities that have undertaken them. This is enabled by the construction of a unique dataset that combines city-level FFCO 2 emission estimates in 2010 and 2015 with multi-year survey-based data indicating the adoption of relevant local policy actions. Findings offer evidence that the completion of a community-wide emissions inventory facilitates local action that, even in a relatively short timeframe, significantly reduces emissions from onsite residential sources. • Linking municipal commitments, plans, and actions to changes in local outcomes is challenging. • A GHG inventory and dedicated staff are frequent recommendations for climate-active cities. • DiD estimates their impact on changes in US cities' emissions over 5 years. • Emissions inventory facilitates local action that reduces emissions from onsite residential sources.

Battery electric vehicles (BEVs) are one promising approach to mitigating local greenhouse gas emissions. However, they still lag behind conventional vehicles in terms of maximum driving range. Using the heating, ventilation, and air-conditioning (HVAC) system reduces the maximum driving range of the vehicle even further since the energy for the HVAC system must come from the battery. This work investigates the impact of (1) an air–air heat exchanger and (2) an improved thermal insulation of a truck cabin on the heating performance of the HVAC system. Additionally, the required fresh-air volume flow rate to keep the CO2 level within the truck cabin below the critical value of 1000 ppm is factored in. The results show that the two simple measures proposed could increase the energy efficiency of the truck’s HVAC system by 22%. When two persons are present in the truck cabin, a fresh-air volume flow of around 100 m3/h is required to keep the CO2 concentration around 1000 ppm. These results prove that, even with simple measures, the energy efficiency of vehicles’ subsystems can be increased. In the future, more research will be necessary to further improve the energy efficiency of other vehicular subsystems.

The rapid evolution of Li-ion battery technologies and manufacturing processes demands a continual update of environmental impact data. The general objective of this paper is to publish up-to-date primary data on battery manufacturing, which is of great importance to the scientific community and decision-makers. The environmental impacts have been calculated and estimated based on publicly available data disclosed under Hungarian government regulations and official decrees. The gate-to-gate energy use, greenhouse gas (GHG) emissions, water consumption, and N-methyl-2-pyrrolidone (NMP) consumption are estimated for three battery factories in Hungary, with a total annual capacity of approximately 100 GWh. The factories use around 30–35 kWh energy per kWh of battery capacity and the associated GHG emissions are around 10 kgCO2eq per kWh of cell production. The water consumption varies considerably among factories, with one plant using 28 L per kWh and the other two using 56 and 67 L per kWh. The specific consumption of NMP was calculated for two factories, resulting in close values of 0.51–0.56 kg per kWh of cell production. As a new approach, we distinguish between global and local GHG emissions related to battery production. The main component of the latter is carbon dioxide from the combustion of natural gas, but the local transport related to the battery factories is also a source of emissions. Our estimations include not only the consumptions required directly for the manufacturing technology, but also those for social purposes (e.g., heating offices), giving a more complete picture of the factory’s environmental impact. We believe that up-to-date primary data are crucial for ensuring transparency and holds significant value for both the scientific community and decision-makers.

Often considered the most pristine natural areas, mountains are the third most important tourist destination in the world after coasts and islands, contributing significantly to the tourism sector (15–20%). Tourism is economically important for many mountain communities and is among the key drivers of economic growth in mountain regions worldwide. However, these high-altitude places are under increasing pressure from activities such as expeditions and trekking, which can contribute to the degradation of mountain ecosystems. In this study, we focused on the Italian expedition to K2 in July 2024, which celebrated the 70th anniversary of the first ascent in 1954. In particular, we assessed its environmental impact by estimating the expedition’s carbon footprint. We also discussed the different impact compared to the previous Italian expeditions. Overall, the 2024 Italian expedition to K2 had a carbon footprint of 27,654 kg CO2-eq, or 1383 kg CO2-eq per team member that flew from Italy. Air transport (i.e., the flight from Italy to Pakistan via Islamabad) was the largest source of emissions (91.7%, divided into 66.4% for passengers and 25.4% for cargo). Waste incineration was the smallest contributor (1.1%). Instead of using traditional diesel generators, the 2024 expedition used photovoltaic panels to generate electricity, eliminating further local greenhouse gas emissions. At the carbon credit price of 61.30 USD/ton of CO2 or 57.02 EUR/ton of CO2, offsetting the expedition’s emissions would cost 1695 USD or EUR 1577. This approach seems feasible and effective for mitigating the environmental impact of expeditions such as the one performed in 2024 by Italians.

The article discusses methods for the artificial production of gas hydrates for the utilization of greenhouse gases. Experimental and theoretical works on the formation of hydrates are analyzed. The conditions for the formation of methane and carbon dioxide hydrates are presented, and the possibility of storing greenhouse gases in the form of hydrates in comparison with the compressed state is shown. Methods for producing hydrates by bubbling gases through water, intense mixing and exposure to pressure waves are considered. Methods for recycling greenhouse gases by injecting them into permafrost, underground formations and snow masses are described. Attention is paid to the duration of the hydrate formation process and methods of its intensification. The conditions for the effective production of hydrates for the utilization of greenhouse gases are considered. Technological schemes for the production of hydrates for their industrial use in order to reduce local greenhouse gas emissions are presented.

Due to the contribution of cities to fight climate change, approaches and methodologies for GHG emissions inventories have multiplied; research is growing and numerous initiatives support local authorities in developing their local emissions inventories. The complexity of cities and the lack of data make necessary simplifications and assumptions in inventorying GHG emissions. Despite significant progresses in the compilation of inventories, there are still limitations and uncertainties on aggregation approaches. Therefore, it becomes crucial disclosing the methodologies underlying any emissions accounting frameworks, together with any simplifications and assumptions, with the aim to produce reliable support on local measures and data- driven decision-making in the form of a trustworthy emissions inventory. This study aims at identifying divergences and potential gaps in two approaches for GHG emission inventories at local level complementing the results of previous studies. It is intended as exemplificative of potential issues and limitations occurring in emissions accounting and aggregation. The two approaches are EDGAR (Emissions Database for Global Atmospheric Research), in place for the GHSL (Global Human Settlement Layer Urban Centre Database) (GHS-UCDB R2019A) and the BEI (Baseline Emission Inventory) approach developed within the Covenant of Mayors initiative. The main limitations uncovered here feature disagreements on spatial and time coverage, on the emissions sources and allocation and the types of emissions considered. Results show that despite the diverse approaches, data is comparable. Therefore, to identify and correct inconsistencies and to ensure the quality of emission inventories available to decision makers, analysis and consistent comparisons between results originating from different and independent methodologies are essential.

Research has shown that the healthcare sector is among the least green sectors and constitutes one of the largest contributors to greenhouse gas (GHG) emissions, posing risks to human health. This review discusses the development of a knowledge translation tool that aims to compare a range of interventions that can be applied in hospital settings to reduce the local GHG emissions and associated financial costs. It discusses several interventions that potentially have the most impact on GHG reduction and compares these to interventions that are commonly used in different hospital departments. The authors propose opportunities to advance the implementation of these interventions within hospital operations across many other geographic locations.

This paper proposes the use of decomposition analysis to assess the effect of local energy-related actions towards climate change mitigation, and thus improve policy evaluation and planning at the local level. The assessment of the impact of local actions has been a challenge, even from a strictly technical perspective. This happens because the total change observed is the result of multiple factors influencing local energy-related greenhouse gas (GHG) emissions, many of them not even influenced by local authorities. A methodology was developed, based on a recently developed decomposition model, that disaggregates the total observed changes in the local energy system into multiple causes/effects (including local socio-economic evolution, technology evolution, higher-level governance frame and local actions). The proposed methodology, including the quantification of the specific effect associated with local actions, is demonstrated with the case study of the municipality of Malmö (Sweden) in the timeframe between 1990 and 2015.

The demanding energy storage requirements of many commercial vehicle applications are extremely difficult to meet for pure battery electric vehicles (BEVs) due to the limited energy density of batteries. Fuel cells appear to be the only viable propulsion technology that is able to meet commercial vehicle powertrain requirements with zero local greenhouse gas emissions. Since almost all fuel cell vehicles (FCVs) contain a high voltage battery, some additional complexity is introduced since the hybrid energy storage system must be sized and controlled appropriately. An understanding of the strengths and weaknesses of each system is therefore essential in FCV design. The aim of this technology review is to provide an overview of fuel cell technologies in commercial vehicle applications including assessments of alternative powertrain and fuel cell types, advantages and disadvantages of fuel cell and battery systems and the implications of these on the powertrain sizing as well as control considerations of FCVs.

Under rapid industrialization and urbanization, the conservation and management of agricultural heritage systems is facing many threats and challenges, such as the massive outflow of working labor, land abandonment, and the difficulty in maintaining traditional knowledge systems. Promoting land transfer and carrying out moderate-scale management play an active role in the conservation of agricultural heritage systems. While land transfer brings economic benefits to heritage sites, its environmental impacts to heritage sites are worthy of attention. However, empirical studies are scarce. This study took Qingtian rice-fish culture system in Zhejiang Province as an example, which was designated as Globally Important Agricultural Heritage Systems (GIAHS) in 2005. Small farmer management model and land scale management model were distinguished, while the life cycle method was used to calculate the carbon footprints of two models. The results showed that the carbon footprints of small farmer management model and land scale management model were 6510.80 and 5917.00 kg CO2-eq·hm-2, respectively, while the carbon footprints per unit output were 0.13 and 0.10 kg CO2-eq·yuan-1, respectively. Compared with small farmer management model, land scale management model had lower greenhouse gas emission and lower environmental impact of per unit output. As farmers expanded the scale of land management, local greenhouse gas emissions had been reduced by 4097.20 kg CO2-eq. Furthermore, the accumulation of CH4 in agricultural production accounted for the largest proportion of carbon footprint. The input of compound fertilizer among agricultural production materials was next to CH4 accumulation, becoming the second largest source of greenhouse gas emission. Corn and wheat being used as fish feed also had a significant impact on greenhouse gas emission in small farmer management model. Therefore, the promotion of moderate scale land management is conducive to the win-win of economic and environmental benefits of traditional agricultural systems and plays an important role in the conservation of agricultural heritage systems.

PurposeThe purpose of this study is to examine the effects of three strategic environmental options on reducing greenhouse gas (GHG) emissions. Namely, we examine the effects of pollution prevention and waste management (PPWM) practices, green supply chain (GSC) practices, and outsourcing on reducing local and supply chain GHG emissions.Design/methodology/approachUsing ASSET4 and deploying first-differencing fixed-effects panel data models, the study conducts a large-scale empirical examination on the effects of these focal strategic environmental options on GHG emissions.FindingsThis study finds that PPWM practices reduce local GHG emissions and that GSC practices reduce supply chain GHG emissions. The results also show that outsourcing does not reduce local GHG emissions and has an adverse effect on supply chain GHG emissions.Practical implicationsThe study findings indicate that environmental practices are effective in reducing GHG emissions. However, they are effective only in their corresponding domain. Further, outsourcing is not a viable strategic option, and managers should be mindful of its undesired environmental consequences.Originality/valueFirms undertake strategic environmental options, such as implementing environmental practices and reallocating production activities, to improve their environmental performance. Nevertheless, the effectiveness of these options on reducing GHG emissions has not been thoroughly examined.

Efforts to reduce greenhouse gas emissions are ongoing in many East Asian countries; however, their influences on future drought remain unknown. We analyzed future changes in drought intensity over East Asia using the Representative Concentration Pathway (RCP) 8.5 and the new two limiting local greenhouse gas emission scenarios in East Asia: National Institute of Environmental Research (NIER)-H scenario for high emission and NIER-L scenario for low emission. The two scenarios were made by a fully coupled global climate model with prescribed gas boundaries of high and low greenhouse gas emissions from an atmospheric chemistry model reflecting the up-to-date environmental policies of South Korea, China, and Japan. The application of a clustering analysis to the calculated drought index time series identified four zonally distributed drought regions in the present-day period (1951 -2016). Among these regions, higher latitude regions showed a more rapidly increasing trend in drought intensity than other regions for the present-day period. All future scenarios projected the continuation of this meridional intensification trend of drought until 2100; however, the intensification rates in the NIER-L were much smaller than those in the RCP8.5 and NIER-H scenarios. Our results suggest that reducing greenhouse gas emissions is critical for East Asian countries to alleviate the potential damages of future droughts.

ABSTRACTSparked by their emergence as innovative climate policy leaders, cities’ decisions to engage in greenhouse gas (GHG) mitigation planning have been the subject of extensive examination over the last decade. The impact that these planning and subsequent local policy actions have on addressing actual emissions, however, remains under-explored and even less is known about the conditions under which cities’ climate planning efforts result in meaningful mitigation. Data limitations, specifically the sporadic and unstandardized accounting of local GHG emissions, underlie the minimal empirical attention given to understanding cities’ climate policy outcomes. To circumvent these data challenges, we quantify the impact of local efforts through expert evaluation. We utilize nation-wide survey data collected from U.S. cities in 2010 and 2015 to empirically assess how community and city government characteristics influence the extent to which cities’ climate planning efforts serve as the basis for emissions reductions. The results suggest that the dynamics shaping cities’ decisions to complete an inventory are different from those that influence whether it is used as a basis for emissions reductions. Results also point to the positive effect of regular inventory updates and to the importance of stability in the administrative leadership of sustainability in a city’s government.

A hydronic pavement system (HPS) is an alternative method to clear snow and ice, which avoids the use of salt, sand, and fossil fuel in conventional snow clearance, and minimizes the risk of accidents. The aim is to analyze the performance of different control strategies for a 35,000 m2 HPS utilizing heat from a district heating and cooling (DHC) system. The key performance indicators are (1) energy performance of the HPS, and (2) primary energy use, (3) electricity production and (4) greenhouse gas (GHG) emissions from the DHC system. The methodology uses a simulation model of the HPS and an optimization model of the DHC system. Three operational strategies are analyzed: A reference scenario based on the current control strategy, and scenarios where the HPS is shut down at temperatures below −10 °C and −5 °C. The study shows that the DHC return temperature is suitable for use. By operational strategies, use during peak demand in the DHC system can be avoided, resulting in reduced use of fossil fuel. Moreover, the energy use of the HPS could be reduced by 10% and the local GHG emissions by 25%. The study emphasizes that the HPS may have positive effects on global GHG emissions, as it enables electricity production from renewable resources.

In order to ensure high-quality and on-time delivery in logistic distribution processes, it is necessary to efficiently manage the delivery fleet. Nowadays, due to the new policies and regulations related to greenhouse gas emission in the transport sector, logistic companies are paying higher penalties for each emission gram of CO2/km. With electric vehicle market penetration, many companies are evaluating the integration of electric vehicles in their fleet, as they do not have local greenhouse gas emissions, produce minimal noise, and are independent of the fluctuating oil price. The well-researched vehicle routing problem (VRP) is extended to the electric vehicle routing problem (E-VRP), which takes into account specific characteristics of electric vehicles. In this paper, a literature review on recent developments regarding the E-VRP is presented. The challenges that emerged with the integration of electric vehicles in the delivery processes are described, together with electric vehicle characteristics and recent energy consumption models. Several variants of the E-VRP and related problems are observed. To cope with the new routing challenges in E-VRP, efficient VRP heuristics and metaheuristics had to be adapted. An overview of the state-of-the-art procedures for solving the E-VRP and related problems is presented.

Terrain has been one of very significant impact factors of air pollution formation and distribution. The relationship between air-pollution and terrain has been studied for a long time. It is still a very hot topic, especially in the context of global environmental deterioration, being represented by severe haze, acid rain, local area air pollution and greenhouse gas emission as well. It is significant to obtain deeper insight into this relationship. This paper overviewed the mechanism of air-pollution terrain nexus, summarised some methods for modelling, monitoring and predicting the air pollutants distribution, flow and settling that influenced by terrain. The limitation and challenges of related studies were discussed. In conclusions, this paper aims at reviewing the nexus of terrain and air pollutions and the methods in this field, trying to highlight the current challenges.

Medium-to-long-term coupled strategies for energy efficiency and greenhouse gas emissions reduction in Beijing (China)