Reduction Of Greenhouse Gas Emissions Research Articles

Environmental stewardship in the oil and gas sector: Current practices and future directions

This paper provides an overview of the current practices and future directions in environmental stewardship within the oil and gas industry, focusing on key areas of concern and strategies for improvement. The oil and gas industry has made significant strides in environmental stewardship in recent years, driven by a combination of regulatory requirements, corporate initiatives, and stakeholder pressure. One of the primary areas of focus has been the reduction of greenhouse gas emissions associated with extraction, refining, and transportation processes. Companies have implemented technologies such as carbon capture and storage to minimize their carbon footprint, alongside investments in renewable energy sources and energy efficiency measures to transition towards cleaner energy alternatives. Furthermore, the industry has placed increasing emphasis on the responsible management of water resources, recognizing the potential environmental impacts of water extraction and usage in oil and gas operations. Strategies for water recycling, reuse, and wastewater treatment have been adopted to mitigate pollution and minimize strain on local ecosystems. Biodiversity conservation has also emerged as a critical aspect of environmental stewardship in the oil and gas sector, with companies undertaking environmental impact assessments and collaborating with conservation organizations to minimize habitat disruption and restore ecosystems affected by their operations. Community engagement and social responsibility are integral components of environmental stewardship, with companies seeking to address the social impacts of their operations through employment opportunities, infrastructure development, and social programs benefiting local communities. However, the industry continues to face challenges and limitations in its efforts to minimize environmental impact. Accidental spills, leaks, and other incidents pose significant ecological risks, highlighting the importance of stringent safety regulations and emergency response protocols. Moreover, the transition to renewable energy presents challenges for traditional oil and gas companies, requiring substantial capital investment and strategic planning. To address these challenges and advance environmental stewardship, several future directions are proposed. These include accelerating the transition to renewable energy, enhancing transparency and accountability in reporting environmental performance, strengthening environmental regulations and enforcement, investing in research and development of innovative technologies, and fostering collaboration among industry stakeholders, governments, NGOs, and local communities. Keywords: Stewardship, Oil, Gas, Sustainability, Climate, Mitigation

Effect of ammonia energy ratio and diesel pilot-injection strategy on the performance of ammonia-diesel dual fuel engine

ABSTRACT The combustion strategy under a higher ammonia energy ratio (AER) is expected to improve the combustion performance of ammonia-diesel dual-fuel (ADDF) engines, leading to additional reductions in greenhouse gas (GHG) emissions. In order to meet the engine’s performance requirements while achieving the low carbon emissions, this study utilized CFD numerical simulations to analyze the combustion and emission characteristics for an ADDF engine at AER levels from 0% to 90%. It focused primarily on evaluating the effectiveness of diesel pilot-injection strategy in reducing GHG emissions at AER50%. The obtained results showed that the unburned NH3 and N2O emissions exhibited an upward trend with the increment of AER, leading to a degradation in the indicated thermal efficiency (ITE), while GHG emissions were more significant than in the original diesel-only combustion mode. Based on AER50%, the ITE exhibited a trend of initially rising and then falling with the increment of diesel pilot-injection ratio (DPR) from 0% to 60%, reaching a maximum value of 47.1% at DPR 40%. At this point, the unburned NH3 emission decreased by 42.4% compared to the DPR0%, and no longer declined after the DPR exceeded 40%. Based on AER 50% and DPR 40%, ITE peaked at 48.1% with the optimal timing for diesel pilot-injection, which represented a 1.6% rise in ITE relative to the original diesel-only combustion mode, while GHG emissions decreased by 35%, and NO emissions increased by 25%.

Cost-effective reductions in greenhouse gas emissions: Reducing fuel consumption or replacing fossil fuels with biofuels

Greenhouse gas emissions from the transport sector can be reduced by decreasing fuel use by different means, and by blending biofuels into fossil fuels. A cost-effective combination of these measures is determined by spatially specific characteristics such as fuel demand, feedstock production costs, and greenhouse gas emissions from the feedstock production. We developed a spatially explicit model to explore the role of reduced transport fuel use and increased use of domestically produced biofuel, respectively, in a cost-effective policy for greenhouse gas abatement. The model is applied to domestic lignocellulosic biofuel from agricultural land, gasoline, and diesel for road transport in Sweden. The results show that the use of biofuel is particularly cost-effective under low and modestly stringent abatement targets. For more stringent targets, decreased fuel end use dominates the abatement portfolio. Replacing the emissions target by a biofuel production target increases the marginal cost of reducing emissions by up to 250%. With the current vehicle fleet, technical constraints on blend-in possibilities limit the role of biofuels at higher target levels.

A Continuous Plug-Flow Anaerobic-Multistage Anoxic/Aerobic Process Treating Low-C/N Domestic Sewage: Nutrient Removal, Greenhouse Gas Emissions, and Microbial Community Analysis

The anaerobic-multistage anoxic/aerobic (A-MAO) process has shown good potential for advanced nitrogen removal in recent years, but its greenhouse gas emissions still need to be fully explored. The effects of the influent distribution and external carbon source sodium acetate on nutrient removal, greenhouse gas emissions, and the microbial community structure in a continuous plug-flow A-MAO reactor fed with real low C/N ratio domestic sewage were investigated. The results showed that altering the allocation of carbon source resulted in average chemical oxygen demand (COD) and total nitrogen (TN) concentration in effluent reduced to 26.10 ± 4.86 and 6.65 ± 1.73 mg/L, respectively. Both operations reduced the emission rate of greenhouse gas. While the addition of external car-bon sources leaded to lower N2O emission rates and higher CO2 and CH4 emission rates. The addition of sodium acetate facilitated nitrification and denitrification processes, thereby leading to a reduction in N2O production. Meanwhile, it spurred the growth of methanogenic bacteria and heterotrophic microorganisms, thus boosting the production of CO2 and CH4. Influent distribution promoted the increase of Bacteroidota, Chloroflexi and Acidobacteriota of the reactor. The enrichment of typical hydrolytic bacteria and glycogen accumulating organisms (GAOs) increased the utilization efficiency of carbon sources in the system after the addition of sodium acetate. The significant increase of typical denitrifying bacteria (DNBs) Azospira reduced the N2O emission during heterotrophic denitrification process, which was considered to be an important functional genus for increasing nitrogen loss in this system. The rational utilization of carbon source makes the difference in metabolism function. The study provides a valuable strategy for comprehensively evaluating the pollutant removal and greenhouse gas emission reduction from the A-MAO process.

Decomposition of China’s Carbon Emissions Responsibility from the Perspective of Technological Heterogeneity

A global agreement has been reached on the reduction in greenhouse gas emissions. Worldwide, countries have implemented measures to tackle carbon emission issues by establishing aggregate targets and decomposing responsibilities. This study aims to decompose carbon emissions by creating an input–output model that incorporates multivariate factors like energy consumption and water consumption, together with a ZSG-DEA (zero-sum data envelopment analysis) model considering technological heterogeneity (Tech-ZSG-DEA). Based on the total carbon emission data predicted using the STIRPAT (Stochastic Impacts by Regression on Population, Affluence, and Technology) model, the carbon emission efficiency of 30 provinces in China is evaluated according to multiple principles. This is achieved by considering variations in population, economy, energy consumption, and water consumption across different locations. The efficiency findings indicate a discrepancy between the initial allocation and the highest efficiency value of 1. The traditional ZSG-DEA model overlooks regional disparities and may worsen carbon emission pressures in less developed areas. In contrast, the Tech-ZSG-DEA model, which considers regional technological diversity, allows more efficient regions to help alleviate some of the carbon emission burden and considers economic and social benefits. There is a large difference in the emission responsibility of the provinces based on the different decomposition principles. Finally, relevant policy recommendations are provided, such as the formulation of differentiated and inclusively coordinated emission plans. In addition, there are also mechanisms for coordinating interests and joint prevention among different regions.

Predicting Liquid Natural Gas Consumption via the Multilayer Perceptron Algorithm Using Bayesian Hyperparameter Autotuning

Reductions in energy consumption and greenhouse gas emissions are required globally. Under this background, the Multilayer Perceptron machine-learning algorithm was used to predict liquid natural gas consumption to improve energy consumption efficiency. Setting hyperparameters remains challenging in machine-learning-based prediction. Here, to improve prediction efficiency, hyperparameter autotuning via Bayesian optimization was used to identify the optimal combination of the eight key hyperparameters. The autotuned model was validated by comparing its predictive performance with that of a base model (with all hyperparameters set to the default values) using the coefficient of variation of root-mean-square error (CvRMSE) and coefficient of determination (R2) based on the Measurement and Verification Guideline evaluation metrics. To confirm the model’s industrial applicability, its predictions were compared with values measured at a small-to-medium-sized food factory. The optimized model performed better than the base model, achieving a CvRMSE of 12.30% and an R2 of 0.94, and achieving a predictive accuracy of 91.49%. By predicting energy consumption, these findings are expected to promote the efficient operation and management of energy in the food industry.

Assessing the Impact of Renewable Energy in Mitigating Climate Change: A Comprehensive Study on Effectiveness and Adaptation Support

The objective of this study is to evaluate the effectiveness of renewable energy in combating climate change and supporting adaptation efforts. By applying the ARDL model to data from 58 countries spanning the period from 1990 to 2022, this study sheds light on the opportunities and challenges associated with this involved relationship. The results indicate that renewable energy plays a significant role in reducing greenhouse gas emissions and mitigating temperature anomalies. Specifically, wind energy, biomass, geothermal energy, solar energy, and waste utilization demonstrate a positive correlation with greenhouse gas emission reduction. Moreover, wind energy, solar energy, waste utilization, and the proportion of renewable energy in primary energy consumption are also linked to a decrease in temperature anomalies. These findings emphasize the importance of implementing concrete measures such as promoting sustainable transportation, ensuring sustainable management of natural resources, raising awareness and enhancing education, increasing subsidies and incentives for renewable energy and strengthening regulations on greenhouse gas emissions.

Household-scale digesters in Rwanda: Performance analysis and net-greenhouse gas effect

In view of climate change mitigation, the production of biogas through anaerobic digestion has emerged as a prominent renewable fuel source, also in developing countries. The implementation of household-scale digesters in these regions is instrumental in achieving the Sustainable Development Goal 7 of ensuring clean and affordable energy. However, a rigorous quantification of the biogas production and net-greenhouse gas effect of these household digesters, taking into account fuel use, biogas leakage and fertiliser types, is lacking. This study quantified both biogas production and net-greenhouse gas emissions, utilizing Rwanda as a reference region. Through a field survey, biogas measurements, and model simulations, the study revealed that a reference case featuring a fixed dome digester of 4 m3, fed with manure of on average 2 cows produces 0.38 m3 biogas.d−1 which meets 65% of the cooking need of an average family of 4 adults and 2 children. The addition of a toilet to the household-scale digester increased the daily biogas production by 16%. Conversely, the use of a bare soil floor in the cow shed results in a 28% reduction in biogas production, emphasizing the recommendation for a concrete floor. Net-greenhouse gas emissions from a household-scale digester, including an estimated 9% leak percentage, result in a reduction of 2.4 tCO2,eq.year−1 per household compared to wood-only cooking. Besides, using the digestate as a fertiliser further enhances the reduction to a total of 2.5 tCO2,eq.year−1. The main opportunities for minimizing emissions include optimizing temperature, manure flow and reducing leakages, which needs to be considered during design, operation, and policy formulation. In summary, household-scale digesters provide sustainable waste management, renewable energy, and significant greenhouse gas emission reduction, making them a promising technology for decentralized energy solutions in developing regions.

Solar -Powered Lawn Care: Revolutionizing Yard Maintenance with Automated Grass Cutting

The introduction of paper adeptly articulates the significance of solar energy as a clean, abundant, and renewable resource. The emphasis on its non-polluting nature distinguishes it as a pivotal player in addressing environmental concerns, particularly the reduction of greenhouse gas emissions. By drawing attention to the environmental impact of traditional grass cutters reliant on fuel, it highlights a critical issue – their contribution to both the greenhouse effect and air pollution. Additionally, The acknowledgment of the manual labor involved in operating electric-powered grass cutters underscores the multifaceted challenges associated with conventional methods. This succinctly sets the stage for a solution-oriented exploration, suggesting that an automatic grass cutter powered by renewable energy could provide a promising resolution. The subsequent transition in your discourse towards the central theme of the paper - technological progress in automatic solar grass cutters - adds depth and specificity to the argument. This direction allows for a comprehensive examination of how advancements in technology can directly address the identified problems. The mention of keywords such as"Fully Automated Grass Cutter," "Solar Panel," "Internet of Things," and "Fire Detection Mechanism in Grass Cutter" hints at a investigation into cutting edge development

Exploring the dynamics of urban energy efficiency in China: A double machine learning analysis of green finance influence

Analysing the impact of green finance policies on urban energy efficiency contributes to finding solutions to promote the development of China's low-carbon energy system and the global reduction of greenhouse gas emissions. Utilizing Chinese urban data from 2006 to 2021, the study employs an enhanced non-radial distance function (NDDF) model to evaluate the energy efficiency of 282 prefecture-level cities. It examines the 'Green Finance Reform and Innovation Pilot Zone' policy as a quasi-natural experiment. It uses a double machine learning model to analyze its effect on urban energy efficiency and its mechanisms. The research demonstrates that green finance policies significantly improve energy efficiency, mainly through strengthening environmental regulation, fostering green technology innovation, and optimizing industrial structure. Additionally, an in-depth analysis of regional heterogeneity reveals variations in the policy's effectiveness across eastern, central, and western regions and between resource-rich and resource-poor cities. The findings suggest that the efficacy of green finance policies, while generally positive, is influenced by regional economic development and resource endowment differences. The study suggests targeted strategies to improve the green finance system, customize policies according to regional specifics, incentivize corporate green innovation, and foster cross-sectoral collaboration. By offering novel insights into sustainable development and providing actionable policy recommendations, this research contributes to advancing Chinese urban centres' economic and environmental sustainability through the strategic application of green finance.

Comprehensive Review on Technical Developments of Methanol-Fuel-Based Spark Ignition Engines to Improve the Performance, Combustion, and Emissions

Abstract Methanol (CH3OH) is emerging as a viable alternative to fossil-based fuels, addressing the increasing global energy demand while promoting sustainability. The spark ignition (SI) engines are widely used to run the automobile sector. Methanol as a widely available and cheap source of energy can be strongly replaced with expensive and limited fossil-based fuels to power the SI engines. The prime objective of this study is to evaluate the advancements made in improving the fuel blends, performance, combustion, and emission characteristics of methanol-fueled SI engines. The investigation commences by examining the various technical improvements implemented in methanol-fueled SI engines to optimize their overall performance. These developments include advancements in fuel blends, engine design, combustion strategies, fuel injection systems, ignition systems, engine load, etc. The impacts of these developments on the performance parameters including brake thermal efficiency, power output, torque, fuel efficiency, thermal efficiency, etc., combustion parameters including ignition delay, combustion duration, heat release rate, in-cylinder pressure and temperature, etc., emission parameters including hydrocarbon, carbon monoxide, nitrogen oxide, formaldehyde, unburned methanol, etc., is reviewed comprehensively. The effectiveness of emission control techniques and the potential for meeting stringent environmental regulations are explored. The review paper then considers the wider implications of methanol-fueled SI engines by examining their technical, environmental, economic, and renewable applications. The technical aspects cover the compatibility of methanol-fueled SI engines with existing infrastructure and the associated challenges and opportunities. The environmental considerations delve into the potential reduction of greenhouse gas emissions and the overall sustainability of methanol as a renewable fuel. Finally, the research direction of methanol SI engines is discussed, highlighting the emerging trends and prospects in this field. The review paper concludes with recommendations for further research and development, addressing the key areas that require attention to unlock the full potential of methanol as an efficient and sustainable fuel for SI engines.

Examining elevation and thermoregulatory trait differences of endemic tropical swallowtail butterflies to assess their vulnerability to climate change

Abstract Tropical montane insects are vulnerable to climate change if up‐hill range retractions reduce range sizes and increase extinction risk. Endemic species will be particularly at risk if they disproportionately occur at higher elevations, although threats may be ameliorated if they have morphological traits associated with improved thermoregulatory ability. We examine the vulnerability of endemic swallowtail butterflies on Sulawesi (Indonesia) to climate change by quantifying inter‐specific variation in traits associated with thermoregulation (body size and melanism) and whether species' traits are associated with the elevation of species' ranges. We collected data on size, melanism and elevation of 29 swallowtail butterfly species (Lepidoptera: Papilionidae) from 754 specimens at the Natural History Museum (United Kingdom) and the Zoologische Staatssammlung München (Germany). Endemic butterflies were less melanised (16 endemic species, mean = 83% melanised; 13 non‐endemic species = 89% melanised) but similar to non‐endemics in size (endemic, mean = 56 mm; non‐endemic = 53 mm) and elevation (endemic, mean = 345 m.a.s.l.; non‐endemic: 291 m). There was no evidence that species size or melanism patterns were related to elevation in either group. Few differences in elevation of endemic and non‐endemic species imply that endemic swallowtail butterflies are not disproportionately more threatened by climate‐driven mountaintop extirpation than non‐endemic species. Further work is needed to examine whether paler wings alter the ability of endemic species to thermoregulate and adapt to changing climates. In the absence of reductions in anthropogenic global greenhouse gas emissions, on‐going climate warming will continue to threaten tropical montane species.

Greenhouse gas reduction in a medium-duty compression ignition engine with optimization for B20

Soy-based biodiesel can reduce well-to-wheels greenhouse gas (GHG) emissions per unit energy (i.e., gCO2e/MJ) by 66%–72% as compared to the petroleum-based diesel fuel with currently adopted agricultural and industrial practices. Biodiesel can reduce particulate matter and carbon monoxide emissions with a manageable degree of increase in NOx emissions. From the perspective of GHG emissions reduction per unit travelling distance (i.e., gCO2e/mile), the application of B20 in compression ignition engines without the adjustment in engine control unit (ECU) settings will not extract the best carbon emissions reduction that B20 could achieve. Optimizing the engine control settings permits re-calibration to achieve the maximum brake fuel conversion efficiency (BFE) based on comprehensive understanding on the impact of both “fuel” and “ECU calibration” on BFE and other criteria pollutant emissions. The maximum GHG emissions reduction with B20 application is experimentally measured with the optimized ECU calibration, thus providing the understanding of the combined impact of biodiesel fuel and calibrations on engine performance and emissions. Six steady operating modes were considered, that can be combined to estimate the US federal test procedure BFE and emissions over the Federal Test Protocol (FTP) 75 cycle. Combined with the weight factors to simulate the EPA FTP 75 cycle from these 6 “mini-map” test points, 0.53% improvement in the energy requirement per unit traveling distance (i.e., MJ/mile) is achieved for B20 with the final ECU calibration, in addition to the degree of GHG emissions reduction on a “gCO2e/MJ” basis from the use of B20 blend of soy biodiesel of ∼12.5% reduction in gCO2e/MJ, for a total GHG emissions reduction of 13%.

Economic and environmental benefits of natural treatment systems for sewage treatment: A life cycle perspective

Sewage treatment involves a trade-off of land vs. energy and the location of installing Sewage Treatment Plants (STPs) strongly impacts the decisions regarding treatment technologies. In the wake of rapid urbanization, deteriorating freshwater quality and water scarcity, it is crucial to plan adequate and low-cost sewerage infrastructure that can improve the quality of life in rural and urban areas. The present work involves a novel life cycle analysis through six scenarios generated from a holistic perspective that can aid urban planners and urban local bodies in planning the sewage treatment facilities in their cities, towns or villages. Instead of planning sewerage infrastructure for a long-term period of thirty years, it is suggested to create and operate the STPs only for the upcoming decade. Further, owing to the drawbacks of mechanized and natural treatment systems, adopting a mix of these treatment approaches in planning infrastructure is suggested and the benefits of implementing the same are quantified and discussed. Implementing these strategies results in almost 30 % cost savings and 40 % reduction in greenhouse gas emissions, hence, investing in land for natural treatment systems is suggested instead of incurring heavy electricity bills for mechanized treatment systems. The land cost significantly affects the decision-making regarding treatment technology selection; hence, the variation in the life cycle cost of different sewage treatment approaches is assessed for varying land rates in India.

Developing an Environmental Assessment Framework for an Insect Farm Operating in Circular Economy: The Case Study of a Montréal (Canada) Mealworm Farm.

The concept of a circular food economy, particularly through insect farming using food waste, has gained increasing attention in recent years. This approach holds the potential to reduce the environmental impacts of food production by repurposing food waste as insect feed, while simultaneously offering an alternative source of protein. Although the environmental advantages of insect farming are well established, limited research exists on insect farming in colder regions with cleaner grid electricity, such as Quebec, Canada. In this paper, a framework is developed to evaluate the greenhouse gas emissions of a mealworm farm within a circular economy context. The benefits of circular economy practices are assessed through multiple different feed acquisition scenarios (virgin feed and feed diverted from composting, anaerobic digestion, and landfilling). Furthermore, the benefits of mealworm farming are assessed through a comparative analysis with other sources of protein. The framework consists of five stages: feed acquisition, transformation, heating, transportation, and fertilizer production. The results show that farming mealworms using virgin feed emits +14.94 Kg CO2eq/Kg protein. However, using diverted food waste as feed eliminates the need for conventional waste management and leads to a reduction of greenhouse gas emissions of –1.54, –2.48, and –16.39 Kg CO2eq/Kg protein for food waste diverted from composting, anaerobic digestion, and landfilling, respectively. This study highlights that mealworm farming with virgin feed generates lower greenhouse gas emissions compared to beef and pork and is on par with chicken production. Overall, this study demonstrates the environmental superiority of mealworm farming, whether or not food waste is utilized, in a Canadian context.

A proposal to recognize investment in breastfeeding as a carbon offset.

Policy-makers need to rethink the connections between the economy and health. The World Health Organization Council on the Economics of Health for All has called for human and planetary health and well-being to be moved to the core of decision-making to build economies for health. Doing so involves valuing and measuring what matters, more and better health financing, innovation for the common good and rebuilding public sector capacity. We build on this thinking to argue that breastfeeding should be recognized in food and well-being statistics, while investments in breastfeeding should be considered a carbon offset in global financing arrangements for sustainable food, health and economic systems. Breastfeeding women nourish half the world's infants and young children with immense quantities of a highly valuable milk. This care work is not counted in gross domestic product or national food balance sheets, and yet ever-increasing commercial milk formula sales are counted. Achieving global nutrition targets for breastfeeding would realize far greater reductions in greenhouse gas emissions than decarbonizing commercial milk formula manufacturing. New metrics and financing mechanisms are needed to achieve the health, sustainability and equity gains from more optimal infant and young child feeding. Properly valuing crucial care and environmental resources in global and national measurement systems would redirect international financial resources away from expanding carbon-emitting activities, and towards what really matters, that is, health for all. Doing so should start with considering breastfeeding as the highest quality, local, sustainable first-food system for generations to come.

The integration of solar-hydrogen hybrid renewable energy systems in oil and gas industries for energy efficiency: Optimal sizing using Fick's Law optimisation Algorithm

The global demand for sustainable energy solutions in the oil and gas industry has stimulated interest in the integration of renewable energy sources. This paper investigates the techno-economic and environmental aspects of incorporating a solar-hydrogen-based hybrid renewable energy system (SHRES) into oil and gas processing facilities.The proposed SHRES, comprising Solar PV modules, hydrogen production and storage systems, and a gas turbine generator (PV-FC-EL-Tank-GT), aims to enhance energy efficiency and reduce the carbon footprint of energy-intensive operations. The study utilises a multidisciplinary approach, encompassing engineering, economics, and environmental analysis. The techno-economic evaluation employs detailed modelling and optimisation using Fick's Law Algorithm, ensuring efficient energy production and cost-effectiveness. Ecological assessments quantify potential reductions in greenhouse gas emissions and other environmental impacts.The technical and economic evaluation identifies the electrolyser system as the most significant cost contributor (57%). The optimised system balances energy sources with 45% from PV modules, 35% from fuel cells, and 20% from gas turbines, showcasing substantial reliance on renewable energy while maintaining required power generation.Addressing the urgent need for sustainable energy solutions in the oil and gas industry, the study highlights the potential of SHRES integration. By employing Fick's Law Algorithm, alongside with 80 % of renewable energy integration, the research optimises system components to optimise the annualised cost to be $57,539.85, decrease to zero the Loss of Power Supply Probability (LPSP), and mitigate CO2 emissions to a lowest value of 0.147 gCO2eq/kWh (by 80 %). The electrolyser system's pivotal role and the distribution of power generation sources are emphasised.This study presents a novel approach to integrating solar-hydrogen systems into oil and gas processing facilities, aiming for sustainability. The findings underscore the significance of the electrolyser system and the distribution of power generation sources in optimising the SHRES. Recommendations for renewable energy integration and potential reductions in CO2 emissions and costs are discussed, providing valuable insights for future energy policies.

Unlocking the potential of ponds and pondscapes as nature-based solutions for climate resilience and beyond: Hundred evidences

Unlocking the full potential of ponds (small water bodies) and pondscapes (network of ponds) as Nature-based Solutions (NbS) is critical pursuit for enhancing ecosystems and societal resilience to climate change and other societal challenges. Despite scattered initiatives for pond/pondscape creation, restoration and management—each considered here a distinct NbS—there is a significant knowledge gap in utilising ponds/pondscapes as effective NbS. We aimed to assess these NbS in terms of their objectives, outcomes, effectiveness, multifunctionality, delivery of potentially conflicting effects, and the implementation process while considering their Nature's Contributions to People (NCPs, i.e., benefits to society). We compiled data on 183 NbS actions implemented across 93 ponds/pondscapes from 24 countries, predominantly from Europe, via a questionnaire distributed to experienced stakeholders implementing NbS in ponds/pondscapes. One single pond/pondscape may imply more than one NbS action. Two-thirds were in rural areas, and one-third in urban settings. Our analysis revealed that Creation of habitat for biodiversity was a primary delivery objective (targeted NCP) in the implementation of most NbS in ponds/pondscapes, often also combined with other NCPs such as Learning and inspiration, Regulation of water quantity, and Physical and psychological experiences, showcasing their intended multifunctionality. Implemented NbS primarily focused on climate change adaptation (especially Regulation of hazards and extreme events, and water quantity) rather than mitigation, with less emphasis on measures like direct greenhouse gas emissions reduction or enhancing carbon sinks. The costs associated with pond's NbS varied significantly depending on factors such as project scope, objectives, location, socio-economic-cultural system, and specific implementation requirements. The creation of ponds/pondscapes often entailed the highest financial investment, much more than their restoration or their management. In conclusion, our study underscores the multifunctionality of ponds/pondscapes and provides insights about their significant potential as cost-effective NbS for enhancing ecosystem and societal resilience to climate change and biodiversity. It underscores the importance of further research to fully understand and measure the diverse range of NbS they offer, particularly in the context of climate change mitigation. Standardised measurements of the NCP provided by these NbS in ponds/pondscapes are essential for validating managers' claims and exploring their role in addressing climate change.

Renewable hydrogen production through electrolysis: An analysis of the cost gap for its economic competitiveness in Italy

With global policies targeting greenhouse gas emission reduction, renewable hydrogen produced by water electrolysis powered with renewable electricity appears a promising alternative to fossil fuels. However, still high capital costs, reliance on intermittent renewable electricity sources, and high electricity cost hinder the economic viability of electrolyzers. This work develops a comprehensive analysis for assessing the need of an incentive to make renewable hydrogen economically viable, identifying different archetypes of electrolysis plant representative of a wide range of applications. A techno-economic optimization model is set up that minimize the average hydrogen production cost and compute the cost gap that makes hydrogen economically competitive with the fossil alternative, defining the optimal size and operation of the plant components while satisfying the hydrogen demand. The model is applied to the Italian case study. Sensitivity analyses investigate the impact of economy of scales, renewable electricity availability and introduction of the emission trading system. Cost gaps ranging between 8.1 €/kg and 29.9 €/kg highlights the need of an incentive to allow the deployment of this technology, thus meeting the hydrogen penetration targets.

Accelerating the transition to zero-emissions ferries

This study investigates how the authorities in Norway have managed to reduce greenhouse gas (GHG) emissions from the ferry sector by implementing a strategic tendering process for domestic ferry services. The study was conducted using interviews and document analysis. The authorities used competitive dialogue to implement zero-emissions technology in the procurement process, rendering the tender process and contract period longer than traditional tenders. The authorities’ first competitive environmental bid process was announced in 2011, and all new ferry tenders are now based on hybrid or zero-emissions technology. The authorities employed push and pull strategies to advance a successful green transition in ferry operations. These measures have led to a significant reduction in GHG emissions from this transport sector but an increase in investment costs compared with traditional diesel ferries. How the authorities used the tender system to make ferry transport more environmentally friendly is useful knowledge for others with similar objectives.