Reduction Of Greenhouse Gas Emissions Research Articles

Exploring the synergy of enhanced weathering and Bacillus subtilis: A promising strategy for sustainable agriculture.

Climate change is one of the most urgent environmental challenges that humanity faces. In addition to the reduction of greenhouse gas emissions, safe and robust carbon dioxide removal (CDR) technologies that capture atmospheric CO2 and ensure long-term sequestration are required. Among CDR technologies, enhanced silicate weathering (ESW) has been suggested as a promising option. While ESW has been demonstrated to depend strongly on pH, water, and temperature, recent studies suggest that biota may accelerate mineral weathering rates. Bacillus subtilis is a plant growth-promoting rhizobacterium that can facilitate weathering to obtain mineral nutrients. It is a promising agricultural biofertilizer, as it helps plants acquire nutrients and protects them from environmental stresses. Given that croplands are optimal implementation fields for ESW, any synergy between ESW and B. subtilis can hold great potential for further practice. B. subtilis was reported to enhance weathering under laboratory conditions, but there is a lack of data for soil applications. In a soil-mesocosm experiment, we examined the effect of B. subtilis on basalt weathering. B. subtilis-basalt interaction stimulated basalt weathering and increased soil extractable Fe. The combined application displayed higher CDR potential compared to basalt-only application (3.7 vs. 2.3 tons CO2 ha-1) taking solid and liquid cation pools into account. However, the cumulative CO2 efflux decreased by approximately 2 tons CO2 ha-1 with basalt-only treatment, while the combined application did not affect the CO2 efflux. We found limited mobilization of cations to the liquid phase as most were retained in the soil. Additionally, we found substantial mobilization of basalt-originated Mg, Fe, and Al to oxide- and organic-bound soil fractions. We, therefore, conclude that basalt addition showed relatively low inorganic CDR potential but a high capacity for SOM stabilization. The outcomes indicated the importance of weathering rate-GHG emission integration and the high potential of SOM stabilization in ESW studies.

The Current Development and Outlook of China Certified Emission Reduction Trading Scheme

China’s trading scheme for voluntary greenhouse gas (GHG) emission reductions, i.e. China Certified Emission Reduction (CCER), is an important policy tool to promote GHG emission reduction through market mechanisms and help achieve carbon peaking and carbon neutrality goals (the “dual carbon” goals). The CCER trading scheme was initiated in 2012, and after five years of practical exploration, it has provided an effective channel for the whole society to actively participate in carbon emission reductions. Since 2023, the relevant state departments have issued the Measures for the Administration of Voluntary Greenhouse Gas Emission Reduction Trading (Trial) and released the first batch of four project-specific methodologies and five verification institutions, marking the basic completion of the institutional framework of the CCER trading market. In January 2024, the CCER trading market was officially launched, and has been operated in a stable and orderly way, with its policy role of low-cost emission reduction through market mechanisms gradually coming into play. It should be also noted that, in the early stage of its start-up, the market still faces problems such as insufficient market supply, uncertain integration with international schemes, and relatively lagging behind in capacity building, which need to be gradually addressed in the development process. On that basis, this paper gives an outlook.

Crop Residue Biochar Rather Than Manure and Straw Return Provided Short Term Synergism Among Grain Production, Carbon Sequestration, and Greenhouse Gas Emission Reduction in a Paddy Under Rice‐Wheat Rotation

ABSTRACTReturn of crop residues directly as straw, animal manure, or biochar are recommended management options for biowaste recycling and soil organic carbon (SOC) maintenance in agriculture. However, to address the soil health challenges associated with soil degradation and climate change, it is critical to determine if or which of these different forms of crop residues could deliver a synergic improvement in SOC storage, emission reduction, and crop productivity following field application. In this study, maize straw in the form of air‐dried biomass (CS), manure via cattle digestion (CM), and biochar via pyrolysis (CB) was respectively amended once at a dose of 10 t C ha−1, in comparison to no maize straw addition (CK), in a paddy field under rice‐wheat rotation. Changes in soil properties, SOC storage, greenhouse gas (GHG) emissions, and rice/wheat yield were examined over two consecutive rice/wheat rotation cycles following soil amendment. The total rice grain yield considerably increased by 6% under CM and CB, while it reduced by 6% under CS compared to CK. Soil nutrient content persistently increased under CM and CB by 4.2% ~ 17% and 11% ~ 26% for total nitrogen, 26% ~ 61% and 20% ~ 53% for available P, and 2% ~ 82% and 30% ~ 115% for available K, respectively. Topsoil SOC storage increased considerably by 8% under CM and 20% under CB, while remained unchanged under CS, compared to CK. The total methane (CH4) and nitrous oxide (N2O) emissions were considerably increased by 7 folds and 15% under CS and 3.5 folds and 61% under CM, respectively, compared to CK. In contrast, these emissions considerably decreased under CB by 33% for CH4 and 29% for N2O. Consequently, the C emission efficiency considerably reduced under CS and CM but increased under CB over the two rotation cycles monitored. Moreover, the soil quality index (SQI) considerably improved under CM and CB but remained unchanged under CS compared to CK. Among the different forms of straw return, manure, and biochar, straw amendments differed considerably in their effects on C sequestration, GHG emissions, and crop productivity. Only biochar from crop residues synergistically improved these functions in the short‐term following application to paddy soil.

Raising the bar: What determines the ambition level of corporate climate targets?

Since the launch of the Science Based Targets initiative (SBTi), we have witnessed a steady increase in the number of companies committing to climate targets for large-scale reduction of greenhouse gas (GHG) emissions. While recent studies present various methodologies for establishing climate targets (e.g., sectoral decarbonization approach, near-term, long-term, net zero), we still don’t understand the explanatory factors determining the level of ambition companies demonstrate in target setting. In this paper, a two-stage qualitative study is conducted with a sample of 22 companies from five countries. First, these companies’ publicly disclosed climate targets are evaluated according to four target ambition criteria: target type, scope, timeframe, and temperature alignment. Secondly, multiple explanatory factors for target setting were identified during the content analysis of the interviews to see how present these factors appear in the ambition levels. Within companies with highly ambitious climate targets, the findings indicate that certain factors are highly present, including leadership engagement, continual management support, employee involvement, participation in climate initiatives, and stakeholder collaboration. Conversely, none of these key factors are highly present in companies with less ambitious climate targets. Rather, these companies strongly identify the initiating factors of market-related pressures and non-market stakeholder influence as being the driving forces behind their target setting. This paper contributes to the literature on corporate responses to climate change by expanding our understanding of explanatory factors for different corporate climate target ambition levels.

Enhanced nitrogen removal and greenhouse gas reduction via activated carbon coupled iron-based constructed wetlands

Constructed wetlands (CWs) have been widely used to remove nitrogen in the effluent from sewage plants. Still, the removal capacity of nitrate (NO3−-N) in CWs is unsatisfactory due to the insufficient electron donor. This study explored the role of activated carbon (AC) in nitrogen removal and greenhouse gas (GHG) emissions reduction in different iron-based CWs. Long-term experimental results showed that pyrite and sponge iron-based CWs had higher NO3−-N removal rates (98.18 % and 94.10 %). Compared with the control group, AC promoted their total nitrogen (TN) removal efficiency (78.87–87.59 %) and reduced GHG emissions (CO2: 3.79–4.11 %, N2O: 2.97–8.78 %, CH4: 9.93–10.73 %). Moreover, AC not only promoted the values of electron transfer system activity (ETSA), the activity of nitrate reductase and nitrite reductase, but also significantly increased the microbial diversity and abundance of the substrate layer in pyrite/SI- based CWs. The relative abundance of the dominant bacteria in CWs with pyrite coupling with AC (PC-CW) was the highest (nirS: 77.60 %, nosZ: 88.98 %) compared with the other CWs. The higher relative abundance of Dechloromonas and Thiobacillus in PC-CW indicated that the composite substrates of pyrite and AC promoted the extracellular electron transfer of denitrifying microorganisms. This study provides new insights into optimizing inorganic electron donors to improve the removal of NO3−-N and the reduce of GHG emissions in CWs for low C/N wastewater treatment.

Greenhouse gas emissions of shipping with onboard carbon capture under the FuelEU Maritime regulation: A well-to-wake evaluation of different propulsion scenarios

International shipping has extended its decarbonization strategy to reduce greenhouse gas emissions beyond onboard CO2 emissions. Onboard carbon capture and storage systems are being investigated as a potential solution for fossil-fueled ships, however there is a lack of knowledge on the reduction of well-to-wake greenhouse gas emissions that could be enabled. Considering the ambitious emission reduction targets, this may lead to inaccurate estimations of the future fuel mix in the maritime sector and the market share of marine engines. This study defines nine ship propulsion scenarios based on combinations of fossil fuels and marine engines. To better understand the greenhouse gas emission reduction of onboard carbon capture, this study calculates the well-to-wake greenhouse gas intensity of each scenario with and without onboard carbon capture and storage from the ship’s main engine(s). Deploying onboard carbon capture and storage systems notably reduces the tank-to-wake greenhouse gas intensity (54–68 % depending on the scenario). Contrary to onboard emissions, oil-fueled ships with onboard carbon capture and storage are found to be less greenhouse gas intensive and more cost-effective than LNG-fueled ships. The four-stroke oil-fueled engine achieves the lowest well-to-wake greenhouse gas intensity of 38.31 gCO2eq/MJ, while the four-stroke LNG-fueled engine has the highest intensity of 50.34 gCO2eq/MJ. The greenhouse gas emission levels enabled by onboard carbon capture from the main engine would allow fossil-fueled ships to comply with the FuelEU Maritime greenhouse gas intensity requirement until 2044. To be compliant in subsequent periods, onboard carbon capture and storage systems will need to consider carbon capture from the auxiliary boiler and generator and higher capture rate, as well as measures to reduce upstream emissions from fossil fuel production and transport.

GHG emission quantification and reduction pathway of subway shield tunnel engineering: a case study on Guangzhou Metro, China.

The shield method is a commonly used construction technique in subway tunnel engineering. However, studies on greenhouse gas (GHG) emissions specifically in subway shield tunnel engineering are lacking. This study aims to investigate the GHG emission characteristics and GHG reduction pathways during the construction period of subway shield tunnels. Firstly, based on the life cycle assessment (LCA) method, a greenhouse gas (GHG) emission quantification model for the shield tunnel construction period was developed using a multi-level decomposition of construction. Then, the GHG emission level and intensity during the construction period of a case project are quantified, and its emission characteristics and GHG reduction potential points are assessed. Finally, a comprehensive path for GHG reduction in subway shield tunnel engineering is proposed. The research results indicate that constructing 1 km of subway shield tunnel can generate 19,294.28 t CO2eq. Among these, material production element dominates the emissions with a percentage of 89.05%, while transportation and mechanical construction elements contribute 1.81% and 9.14%, respectively. From the structure perspective, the main structure contributes 88.73% of total emissions, while the ancillary structure contributes 11.27%. Among them, the working shaft and tunnel segments are the main sources of emissions for the main structure, accounting for 23.65% and 65.08%, respectively. Connecting channel and end reinforcement are the main emission sources of the ancillary structures, accounting for 43.63% and 31.30%, respectively. These findings provide a scientific foundation for the environmentally friendly transformation of urban railway development regarding pursuing "carbon peaking and carbon neutrality" strategic goals.

Optimal resource reallocation can achieve water conservation, emissions reduction, and improve irrigated agricultural systems

CONTEXTCrop production consumes large volumes of fresh water and is a key contributor to anthropogenic greenhouse gas (GHG) emissions. Increasing crop output to ensure adequate food supplies under water and land scarcity relies excessively on intensive agricultural inputs (e.g., fertilizers, pesticides, and agricultural films), leading to irreparable environmental consequences (water scarcity and degradation and GHG emissions). Therefore, research on a nexus approach and resource optimization model were carried out. OBJECTIVETo fill the gap of objectives priority and optimal allocation of water resources at irrigation area scale, this study constructed a model to achieve optimal water conservation, GHG emissions reduction, and economic benefit improvement, covering the cumulative environmental burden of agricultural inputs, production processes, trade and consumption related to agricultural activities. METHODSBased on a resource-environmental-economic framework, we took the blue water footprint (WFblue) as a decision variable and developed an integrated water resource optimization model, which was solved by the non-dominated Sorting Genetic Algorithm-II in Matlab. Minimizing crop water footprint (WFcrop), minimizing crop carbon emissions (CEcrop) and maximizing crop economic benefits (EBcrop) were the objectives of the model, and blue water resource, food security, electric energy consumption and land security were the constraint conditions. In addition, three scenarios were tested based on the priority of the objective functions. RESULTS AND CONCLUSIONSAnnually, WFcrop was 1234.29 × 106 m3 and CEcrop was 522.45 Gg CO2 eq for food production in Lianshui Irrigation District from 2005 to 2019. Grain crops exhibited a greater WFcrop and contributed significantly more to CEcrop than oilseed crops. Virtual water and carbon flows increased with food transfer. By adjusting the WFblue of crops compared to the baseline scenario (BS), the average WFcrop decreased by 10.0 %, CEcrop decreased by 4.0 %, and EBcrop increased by 6.4 % under Scenario 2 (minimizing WFcrop and maximizing EBcrop), respectively. Similarly, there were average reductions of 9.2 % in WFcrop, 6.2 % in CEcrop, and EBcrop increased by 5.6 % under Scenario 3 (minimizing CEcrop and maximizing EBcrop) compared to the BS. Therefore, the integrated model achieved the optimization objectives. SIGNIFICANCEThis research not only broadens the scope of traditional environmental impact assessments in agricultural production, but also underscores the positive impact of scientifically and rationally redistributing resources for water conservation, GHG emissions reduction, and economic benefit improvement.

Impacts of O2:CH4 ratios and CH4 concentrations on the denitrification and CH4 oxidations of a novel AME-AD system

Aerobic methane (CH4) oxidation coupled to denitrification (AME-D) is a promising process for the denitrification of low C/N wastewater. Compared with anaerobic denitrifying bacteria, aerobic denitrifying bacteria may enable AME-D have high denitrification ability under aerobic conditions. This study constructed a novel aerobic methane oxidation coupled to aerobic denitrification (AME-AD) system using the typical aerobic denitrifying bacteria Paracoccus pantotrophus ATCC35512 and the typical aerobic methane oxidizing bacteria Methylosinus trichosporium OB3b. The denitrification and CH4 oxidations of AME-AD with different O2:CH4 ratios (0:1, 0.25:1, 0.5:1, 0.75:1, 1:1 and 1.25:1) and CH4 concentrations (0, 14000, 28000, 42000, 56000 and 70000 mg m−3) were investigated in batch experiments. Higher O2:CH4 ratios can significantly improve the denitrification and CH4 oxidations of the AME-AD (P < 0.05). The treatment with an O2:CH4 ratio of 1.25:1 had the highest denitrification rate (0.036 mg h−1) and highest CH4 oxidation rate (0.20 mg h−1). The CH4 concentration in the headspace was positively correlated with the AME-AD denitrification rate. The calculated CH4/NO3−(mol/mol) in most treatments ranged from 5.76 to 6.84. In addition, excessively high O2 and CH4 concentrations can lead to increased nitrous oxide (N2O) production in AME-AD. The N2O production rate was up to 1.00 μg h−1 when the O2:CH4 was 1.25:1. These results can provide data support for the application of AME-AD for low-C/N wastewater treatment and greenhouse gas emission reduction.

Biodiesel from Crude Palm Oil: A Sustainable Development Strategy for Energy Security

The study investigates the synthesis process, catalyst preparation, and implications of CPO biodiesel production, focusing on energy security, environmental sustainability, and greenhouse gas emissions reduction. The study uses eggshell-derived calcium oxide (CaO) catalysts for catalyst preparation, demonstrating a novel approach to catalyst synthesis. Results show consistent biodiesel yields of 78.6%, demonstrating the efficiency of the synthesis process. The study also highlights the environmental benefits of CPO biodiesel production, including reduced carbon emissions and sustainable cultivation practices. The study emphasizes the potential of CPO biodiesel as a sustainable energy solution, paving the way for a cleaner, more resilient future.

Strategies to enhance energy sustainability in line with Sustainable Development Goal (SDG) 7 (affordable and clean energy): case of Ghana

Purpose Human activities in recent years with the excessive emission of greenhouse gases have had a negative impact on increasing global temperatures. In this regard, one of the best ways to control it is to move toward sustainability with more use of renewable energy. Therefore, this study aims to assess the indicators of sustainable energy, explore benefits of sustainable energy and evaluate strategies to enhance energy sustainability in line with Sustainable Development Goal (SDG) 7. Design/methodology/approach Quantitative research strategy was adopted. Questionnaires were developed and administered through convenience and snowball sampling techniques to professionals in the energy sector. Data collected was validated by using Cronbach’s alpha coefficient and discriminant validity, whereas objectives were analyzed by using the relative importance index, mean score ranking and Kruskal–Wallis test. Findings From the findings, the significant indicators of sustainable energy were as follows: reduction in greenhouse gas emissions from energy production, use of renewable energies and policies on proper utilization of energy resources. Furthermore, a reduction in greenhouse gas emissions, less harm caused to the environment and an increase in the economic and social development process were the major benefits of sustainable energy. Finally, the findings of the study revealed that a strong and accounted policy program, adopting sustainable energy indicators and strategic communication are the significant strategies needed to be put in place to enhance energy sustainability. Practical implications The study serves as a reminder to policymakers of the crucial role they have to play in enhancing energy sustainability by putting in place suitable policy programs and methods. Originality/value The originality of this study is that it is arguably a pioneering study in Ghana and contributes to the body of knowledge on energy sustainability.

Decarbonizing the US Energy System

Recent rapid and unexpected cost reductions in decarbonization technologies have accelerated the cost-effective decarbonization of the US economy, with greenhouse gas (GHG) emissions falling by 20% from 2005 to 2020. The literature on US economy-wide decarbonization focuses on maximizing long-term GHG emissions reduction strategies that rely mostly on renewable energy expansion, electrification, and efficiency improvements to achieve net-zero GHG emissions by 2050. While these studies provide a valuable foundation, further research is needed to properly support decarbonization policy development and implementation. In this review, we identify key decarbonization analysis gaps and opportunities, including issues related to cross-sectoral linkages, spatial and temporal granularity, consumer behavior, emerging technologies, equity and environmental justice, and political economy. We conclude by discussing the implications of these analysis gaps for US decarbonization pathways and how they relate to challenges facing major global emitters.

Potential of e-bikes to replace passenger car trips and reduce greenhouse gas emissions

In Sweden, the transport sector accounts for 32% of greenhouse gas emissions, with passenger cars contributing to 62% of these. In this context, electric bikes, commonly known as e-bikes, have emerged as a promising solution for reducing carbon emissions in the transport sector. This paper explores the potential of e-bikes in substituting passenger car trips and reducing transportation-related emissions. To achieve this objective, we use a synthetic population in the Västra Götaland (VG) region, Sweden, with daily activity schedules and simulate an average weekday of travelling with e-bikes instead of their private cars. For assessing the potential for e-bike substitution, the current literature often relies on trip-level analysis, which does not adequately consider people’s daily travel-activity plans, resulting in an unrealistic estimation of replaceable trips and their carbon emissions reduction. Combining an e-bike speed model by agents’ characteristics and an open-source routing engine, our simulation identifies potential car trips that can be replaced with e-bikes, considering all activities and the travel between them for an average weekday. The simulation results suggest that e-bikes could replace 57.6% of car trips. Building on this, we explore the potential reduction in greenhouse gas emissions from car trips taken by residents in the study area. If the top 70% of feasible car users, ranked by shortest to longest daily travel distances, switch to e-bikes, emissions could be reduced by 10.1% compared to 2018 levels. If all feasible car users adopt e-bikes, a reduction of up to 22.8% in emissions could be achieved, representing the upper limit presented by our study. The findings also reveal that males under 40 years old provide the highest e-bike substitution rates in their daily activity schedules, and in areas with a high population density, replaceable car trips are more common than in rural areas. This research provides valuable insights into e-bike substitution and its impact on emission reduction. It contributes to the existing literature through its modelling approach that realistically considers individuals’ socio-demographic characteristics and daily activity schedules when assessing the substitution potential.

Mechanism underlying revetment effects on the spatial distribution of nitrogen removal and N2O emissions in riparian zones at summer

Study Region, Shanghai, China, Study FocusUrban riparian zones can mitigate or even control nitrogen pollution in rivers through nitrification and denitrification processes. However, these processes also produce N2O, a potent greenhouse gas. During urbanization, various types of revetments have been constructed in riparian zones. These revetments alter the exchange of materials and energy between the riparian zone and the river, which in turn affects the nitrification and denitrification processes in the riparian zone. However, the mechanisms by which revetments impact nitrogen removal and N2O emissions in riparian zones are not yet clear, and the ways in which revetments balance nitrogen removal and N2O emissions remain unknown. Therefore, in a single river section, natural (NR), permeable (PR), and impervious revetment (IR) types were replicated. Measurements are taken of nitrogen removal, N2O emissions, and related environmental indicators in both the river-riparian interface (RRI) and the riparian zone area outside the RRI (RZ). The study analyzes the differences in environmental factors, nitrification and denitrification potentials, and N2O emission rates among the different revetments to identify the main factors affecting nitrogen removal and N2O emissions in the riparian zone. It also explores the potential mechanisms by which revetments influence the spatial distribution of nitrogen removal and N2O emissions in the summer riparian zone.New Hydrological Insights for the Region: PR exhibit greater denitrification potential and lower N2O emission rates. The denitrification potential is higher in the RRI compared to RZ, while the N2O emission rate is lower than in RZ. nirK is the primary factor influencing denitrification potential, whereas nosZII predominantly affects N2O emissions. The lower soil carbon-to-nitrogen ratio in PR increases the abundance of nirK, thereby enhancing the riparian zone's denitrification potential. Moreover, greater aboveground vegetation biomass increases the abundance of nosZII, reducing the N2O emission rate. The study results could provide guidance for urban ecological restoration and greenhouse gas emission reduction.

Supplying the ethanol demand for 2030 in Brazil as a land-based climate change mitigation alternative: Implications on greenhouse gases emissions

Transitioning from a fossil-based to a bio-based economy is crucial to climate action and achieving neutrality in greenhouse gas (GHG) emissions. Biofuel production is an essential land-based GHG mitigation alternative. However, it raises concerns about biodiversity conservation, competition with food production, and net GHG emissions associated with direct land-use change (dLUC). This study aims to assess how the location and conversion routes influence GHG emissions for sugarcane expansion in Brazil to supply ethanol demand projections for 2030. A consistent and significant reduction in GHG emissions is achievable by implementing a strategy that prioritizes the spatial distribution for ethanol biorefinery expansions based on georeferenced life cycle emissions, including dLUC emissions associated with sugarcane production. Because of conservative zoning for sugarcane expansion, dLUC emissions are not an overriding factor, representing less than 9.1 % of the total GHG mitigation potential. Despite that, accounting for georeferenced dLUC emissions when prioritizing expansion facilities leads to spatial differences. Regarding conversion routes and land requirements, using cellulosic biorefineries could meet future projected demand based on sugarcane production from 3.1 million hectares, mostly in currently degraded pastureland. Conventional refineries would require 5.5 million hectares to meet the same demand of 71 billion liters. Despite the 77 % higher land demand to produce the same volume of ethanol, conventional refineries with straw recovery could be considered if electricity generation is a priority. This study illustrates how Brazil can achieve GHG mitigation targets while attending to future energy demand and protecting areas with high biodiversity.

Enhancing environmental and economic benefits of constructed wetlands through plant recovery: A life cycle perspective

Plant recovery plays a vital role in reclaiming bioresources from constructed wetland wastewater treatment systems. A comprehensive understanding of the environmental impacts and economic benefits associated with various wetland plant resourcing methods is critical for advancing both plant resource recovery and the application of wetlands in wastewater treatment. In this study, life cycle assessment was employed to evaluate the environmental impacts and costs of seven wetland plant recovery methods. In addition, the potential benefits of extending plant resource recovery within system boundaries were explored to enhance the overall advantages of constructed wetlands for wastewater treatment. The use of wetland plants for biofertilizer production had the lowest environmental impact (−8.52E-03), whereas the use of wetland plants for biochar production was the most cost-effective approach (−0.80€/kg). The introduction of a plant resource recovery component could significantly reduce the environmental impacts of constructed wetland wastewater treatment systems. The environmental impacts and costs of constructed wetland wastewater treatment systems that incorporate plant resource recovery into the system boundary are better than activated sludge methods and highly efficient algal ponds, except for the global warming potential (GWP). The use of plants for biofertilizer production could cut the environmental impacts of constructed wetland wastewater treatment systems by up to 85 % and the costs by 65 %, making it the most suitable method of plant use. Additionally, prioritizing the reduction of greenhouse gas emissions from constructed wetlands should be a primary optimization goal. The findings of this study provide valuable support for the implementation of wetland plant resourcing in constructed wetland wastewater treatment systems.

Impartial policymakers prefer to impose carbon pricing to capping, especially when combined with offsets

Sustainable socio-economic development requires a global reduction of greenhouse gas emissions. We utilize an incentivized experiment to map the preferences of ‘policymakers’ over climate actions of ‘decision-makers’. Our design guarantees that these preferences are unaffected by selfish motives such as a concern about being re-elected or an unwillingness to pay for the greater good. Few of our impartial policymakers choose interventions that leave the autonomy of decision-makers' completely untouched. The choice patterns of those who intervene suggest that policymakers care not only about minimizing emissions, but also about how emissions are reduced. Policymakers strongly prefer pricing policies over capping emissions, and among the pricing policies, they prefer those that include voluntary carbon offsets, even if this leaves considerable scope for decision-makers to selfishly emit CO2. The reason is that policymakers expect decision-makers to voluntarily offset some of their emissions at their own cost, and believe that this would eventually improve the outcome in terms of both emissions and the decision-makers' profit relative to a standard carbon pricing policy (without offsetting). Our decision-making data confirm this expectation.

Pricing electricity from blue hydrogen to mitigate the energy rebound effect: A case study in agriculture and livestock

As the world's second largest producer of natural gas, Iran relies heavily on natural gas for 70% of its energy needs. There are, however, challenges associated with energy supply in remote regions attached to the gas pipeline network, particularly during the cold season when fuel oil is required for heating and energy provisioning. To address this issue, this research proposes the use of alternative energy sources, such as hydrogen, for non-residential energy consumption, including agriculture and livestock. A key objective of this study is to develop an optimization model for the generation of electricity from hydrogen resources, as well as formulate a robust strategy to assist electricity producers in maximizing their profits. Using this model, producers are able to set prices in accordance with their risk tolerance and present them to the market, thus mitigating price fluctuations. In the targeted sectors, the results indicate that appropriate pricing models can prevent rebound effects. Specifically, the implementation of this model can reduce natural gas consumption by up to 20% and fuel oil usage by 15% during peak seasons. Additionally, the optimal pricing strategy can lead to a 10% reduction in greenhouse gas emissions. The results of this research provide stable and reliable solutions to the energy supply challenges in these regions, thus making the energy market more resilient and environmentally friendly.

Risks in the design of regional hydrogen hub systems: A review and commentary.

Early investments in regional hydrogen systems carry two distinct types of risk: (1) economic risk that projects will not be financially viable, resulting in stranded capital, and (2) environmental risk that projects will not deliver deep reductions in greenhouse gas emissions and through leaks, perhaps even contribute to climate change. This article systematically reviews the literature and performs analysis to describe both types of risk in the context of recent efforts in the United States and worldwide to support the development of "hydrogen hubs" or regional systems of hydrogen production and use. We review estimates of hydrogen production costs and projections of how future costs are likely to change over time for different production routes, environmental impacts related to hydrogen and methane leaks, and the availability and effectiveness of carbon capture and sequestration. Finally, we consider system-wide risks associated with evolving regional industrial structures, including job displacement and underinvestment in shared components, such as refueling. We conclude by suggesting a set of design principles that should be applied in developing early hydrogen hubs if they are to be a successful step toward creating a decarbonized energy system.

Towards more eco-friendly gaseous detectors

In the last years, the particle detector community faced a new challenge: how to convert existing and future gaseous detectors in more eco-friendly ones. Indeed, several detectors make use of greenhouse gases (GHGs) since they allow achieving excellent performance and long-term stability. With a growing concern on climate change and future restrictions, it is fundamental to look for solutions that can balance detector performance with an eco-friendly approach. CERN was a pioneer in developing strategies to reduce the use of GHGs in particle detection. Three different strategies have been implemented: the use of gas recirculation and recuperation systems for existing and future detector systems and the search of alternative eco-friendly gas mixtures. Thanks to the first two approaches, it is possible to recycle the gas mixture supplied to the detectors and to retrieve GHGs from the used gas mixtures, allowing a reduction of GHG emissions up to 95%–100% at the LHC experiments. By looking at the long-term operation and future particle detector applications, the search of alternative eco-friendly gas mixtures must be envisaged. A big effort is on-going for the C2H2F4 replacement for the Resistive Plate Chamber (RPC) detectors, which nowadays account for most of CERN particle detector emissions. Several eco-friendly gas mixtures have been identified and tested but finding a suitable replacement for the LHC experiments is particularly challenging. Alternatives to SF6, which is the most powerful GHG, are under studies for RPCs in term of detector performance and chemical characterisation. Last point is increasingly crucial since most of the so-called eco-friendly gases belong to the PFAS family which is very likely to be subject to new regulations soon.