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Cities represent unique spaces for climate mitigation where wide-ranging action to reduce emissions meets ambition and collaboration. This research work distils climate neutrality narratives for 362 cities that expressed interest in the European Mission on 100 Climate-Neutral and Smart Cities and focuses on the 112 cities selected to spearhead the process of reaching climate neutrality by 2030 (representing a mitigation potential of 318.3 megatonnes of carbon dioxide equivalent emissions). The method involves steps that profile the characteristics of these cities, enunciate cross-cutting patterns in cities' visions by thematic groupings, and compare 14 contextual factors with 77 possible main barriers. There are both similarities and differences among the results as a basis for learning together and certain barriers can be relatively more dominant in some thematic groupings, such as fragmentation of responsibilities. As a synthesis of the main findings, the original analyses are used to derive and prioritise nine high-level recommendations based on the cities' visions, contextual factors, and expected main barriers. Opportunities for mobilising transformative change relate to transforming siloed into integrated approaches, inclusive climate governance and collaborations, innovative financing, welfare and just transition as well as planning, implementation, and policy coherence. The advances provide pioneering steps for stimulating co-learning processes among Mission Cities and beyond to support the transition to climate neutrality and open up opportunities to progress together in climate action while producing impact with global reach. [Display omitted] • Visions and narratives for achieving climate neutrality by 2030 are enunciated across cities. • The 112 Mission Cities represent an emissions reduction potential of 318.3 MtCO 2 eq. • Thematic groupings are formed by cross-comparing degree of ambition and collaboration. • Recommendations are prioritised based on enablers and barriers in the thematic groupings. • Cross-cutting patterns in cities' visions provide opportunities to stimulate co-learning. [ABSTRACT FROM AUTHOR]

There is a lack of empirical analysis of macro-level energy policy through a gender lens, and there exists a research gap in tools for such analysis. This paper proposes a novel empirical approach to explore the gender dimension of the language used in energy policy documents such as the National Energy and Climate Action Plans (NECPs) of European Union (EU) member states. We first review the literature to identify existing approaches that analyse the energy/gender nexus. We then describe how we adapt Natural Language Processing (NLP) techniques to quantify the degree to which the language used in the NECPs is male or female associated. Our work shows the gap in suitable tools. We demonstrate using NLP that all EU NECPs tend to use more male associated language than female. In a ranking of EU member states, the Portuguese NECP demonstrated the most bias, while the Slovenian demonstrated the least. Our work provides novel insights using NLP to understand the genderised use of language, and contributes a methodology to conduct empirical analysis of energy policy documents. [Display omitted] • Review of methods used in energy/gender nexus analysis. • Empirical approach to analyse energy/gender concepts in the Global North. • Measurement of a gender dimension (bias) of the language used in European Union National Energy and Climate Plans. • Identification of Energy Domain NLP training corpora and vocabulary. [ABSTRACT FROM AUTHOR]

Ethylene is one of the most important products in the emissions-intensive petrochemical industry. Decarbonizing the ethylene industry is thus important for achieving global carbon neutrality. This study is the first to explore future long-term zero-emissions production pathways for the ethylene industry in China, the world's biggest ethylene producer. An optimization model was built in the context of China's carbon neutrality target of 2060. Four scenarios were developed where the policy ambitions for climate mitigation and for plastic management including waste were varied. Based on this, authors assessed the cumulative total emissions, technology options, future geographical location of ethylene production, and policy challenges associated with each scenario. This is also the first time that scope 3 emissions from waste incineration are included, motivated by the short lifetime of most ethylene products. Results show the cumulative CO 2 emissions for the scenarios differ considerably, ranging from 4.3 to 7.8 Gt, even if carbon neutrality by 2060 is achieved in all scenarios. The results suggest that ambitious plastic focused policies can result in lower costs and less cumulative emissions compared to ambitious climate focused policies. The results demonstrate the importance of adopting CCS for waste incineration. This reduces cumulative CO 2 emissions by up to 2 Gt. However, reduced overall demand and increased recycling rates should be priority options due to CCS challenges. Results suggest Chinese ethylene industry should adopt a mixed portfolio of production technologies, where the share of emission-intensive coal-based methanol-to-olefins is limited. These findings on decarbonization pathways can contribute to achieving the Paris agreement. [Display omitted] • Ambitious plastic policies lead to 1.3 Gt less cumulative CO 2 than climate policies. • Cumulative CO 2 until 2060 can be reduced by 3.5 Gt compared to reference scenario. • Adopting CCS in incineration can reduce cumulative CO 2 emissions by 2 Gt. • Ethylene industry should adopt a mixed production portfolio due to uncertainties. • Coal-based MTO with CCS does not appear to be a cost-competitive option. [ABSTRACT FROM AUTHOR]

This study investigates the potential of utilizing carbon credits to finance innovative local energy communities in Europe, addressing a significant gap in academic literature. Despite the growing interest in voluntary carbon credits as a mechanism for offsetting carbon emissions, there is limited evidence connecting local energy systems to voluntary carbon markets. The study explores whether carbon credits could serve as a practical tool for funding the development of energy communities, contributing to sustainable energy transitions and climate mitigation strategies. The research employs a comprehensive methodology to assess the quality of carbon credit projects and examines ten innovative energy community projects in Europe. Key findings reveal there is potential for using carbon credits to finance energy community initiatives. However, challenges persist, particularly regarding financing barriers and the volatile nature of carbon markets. The study underscores the importance of policy support in establishing clear standards for voluntary markets and promoting the accessibility of carbon offsets. Furthermore, it suggests potential solutions such as pre-financing agreements and the utilization of carbon market derivatives to enhance project viability. Overall, the study offers insights into the intersection between voluntary carbon markets and local energy initiatives, providing a foundation for further research and policy development in the field of local sustainable development and climate change mitigation. [Display omitted] • Innovative local energy communities in Europe have significant carbon emissions reduction potential. • Carbon credit issuance could financially support the development of local energy initiatives. • Challenges persist in accessing financing and navigating volatile carbon markets. • Policy support is crucial in establishing clear standards for voluntary carbon markets. [ABSTRACT FROM AUTHOR]

CO 2 concentration in the atmosphere has crossed an unprecedented level of 420 ppm, causing catastrophic events like climate change. Climate change mitigation via carbon capture is crucial for reducing CO 2 emissions. Among various CO 2 capture technologies, adsorption is considered one of the most efficient and promising techniques. In recent times, substantial research has been conducted on producing cost-effective and efficient adsorbents for CO 2 capture via the thermal and chemical treatments of biomass. In this review, we discuss key scientific results to give broad insight into the recent progress in biomass conversion to activated porous carbon (APC). The effects of various chemical and thermal treatments on the textural properties and CO 2 adsorption capacity of APC are comprehensively discussed. CO 2 adsorption mechanism based on interaction with the surface functionality is thoroughly explained. The economic aspects of APC synthesis and post-combustion CO 2 capture using APC are systematically reviewed. [Display omitted] • Use of biomass based activate porous carbon (APC) for CO 2 capture is reviewed. • CO 2 adsorption mechanism on APC surface is thoroughly explained. • APC surface functionalization via metal doping and heteroatom doping is discussed. • Economics of APC synthesis & large-scale CO 2 capture on APC is critically reviewed. [ABSTRACT FROM AUTHOR]

This research aims to explore the current evidence on the sustainability of Bioenergy with Carbon Capture and Storage under a life cycle approach and to understand how research on this topic has evolved in the last decade. A systematic literature review was performed, and the main focus was identifying methodological shortcomings and analysing Global Warming Potential results. Forty-seven studies were selected for in-depth revision. Results show that the number of Life Cycle Assessment (LCA) studies on BECCS has increased in the last couple of years and that most of these studies report near-carbon neutral or carbon-negative results for electricity, biofuel energy, and other products. However, in many cases, some aspects have been omitted from the discussion, such as proper accounting of land use impacts, impact allocation procedure, accounting of leakage from storage sites, and impacts related to carbon utilisation. Despite this methodological variability, Global Warming Potential results are mostly carbon-negative and carbon-neutral for both power BECCS and industrial BECCS systems. Consequently, current scientific evidence suggests climate change mitigation benefits from BECCS despite methodological variability. However, it is still insufficient to reach a consensus on the sustainability of this technology as a solution for a global energy transition. It is recommended that further LCA research deals carefully with methodological and product systems variability, which may affect environmental impact results. Moreover, carbon capture approaches with high potential benefits should be further analysed, and the most optimal BECCS typologies should be identified. Finally, additional life cycle impact categories should be reported, along with the assessment of the economic and social dimensions of BECCS. [Display omitted] • Life Cycle Assessment (LCA) of Bioenergy with Carbon Capture and Storage (BECCS) was reviewed. • LCA methodology choices were discussed. • Global Warming Potential ranges between −3.873 and 0.366 kg CO 2 eq per MJ. • Current evidence is insufficient to confirm that BECCS is a sustainable solution for climate change mitigation. [ABSTRACT FROM AUTHOR]

A low-carbon future based on renewable energy systems is required to limit global warming to 1.5 °C above pre-industrial levels by the end of this century. However, economy-wide decarbonisation is projected to be highly material and energy intensive. Understanding the material-energy nexus through existing research would offer valuable insights for comprehensive resource management to achieve sustainable climate mitigation. This study provides the first systematic review of material-energy nexus literature published between 2002 and 2022, emphasising the interconnections and feedback loops between material and energy systems. The global knowledge-stock is comprehensively assessed regarding research focus, sustainability challenges, and corresponding circular economy strategies. Additionally, significant gaps in the research agenda and key policy implications for both material consuming-developed countries and producing-developing countries are proposed. Findings of this study underscore the vital role of international cooperation in managing primary and secondary material supply chains, grounded in the "common but differentiated responsibilities" principle under the Paris Agreement. Consuming-developed countries should support producing-developing countries in building renewable energy capacity, optimising energy saving technologies and measures, and adhering to high environmental standards for resources extraction and production. Meanwhile, both consuming-developed countries and producing-developing countries should take domestic mitigation measures. The former should focus on changing consumption behaviour, and the latter on increasing resource efficiency. [Display omitted] • M -E Nexus material focus moving from bulk materials to minor metals. • Demand-side energy efficiency equally important to renewable supply. • Metals co-production induce oversupply and undersupply of associated metals. • Reuse, repair, refurbish, remanufacture and repurpose are underrepresented. • Circular economy requires behavioural transition and economic incentives. [ABSTRACT FROM AUTHOR]

Integrated energy systems for multi-purpose applications are garnering increased interest in the international nuclear energy community, energy system designers and planners and decision makers in the context of deep decarbonization and net zero targets. They are expected to reduce costs and increase flexibility in operation of nuclear reactors when coupled with intermittent renewable energy sources, while also producing various commodities such as hydrogen or potable water. Adaptive solutions must be considered for each geographical area and based on the involved components of the energy system, available infrastructure, and policy in place. This paper provides an in-depth look at the strengths, weaknesses, opportunities, and threats of such systems, while addressing different aspects related to the creation of the business case for such systems including decentralization and digitalization of future energy systems. The regulatory aspects are the ones that impose challenges on the emerging hybrid energy systems and this paper highlights some of the considerations that are needed for the couplings involved, in terms of licensing procedures and safety analysis. The potential contribution of such integrated energy systems towards achieving the United Nations Sustainable Development Goals (UN SDGs) are also discussed. Concerning the stakeholders, special attention should be paid to building social acceptance and trust as this lays the foundation for successful implementation of such projects. By focusing on areas such as research and development, integration of technologies, policy support, market development, grid integration, energy storage, efficiency improvement, system modelling and simulations, significant advances in integrated/hybrid energy systems deployment can be achieved. • Role of integrated energy systems in deep decarbonization for climate change mitigation. • Strengths, weaknesses, opportunities, and threats of multigeneration energy systems. • Decarbonization, decentralization and digitalization based business models. • Integrated systems can help achieving sustainable development goals (SDG7,11,13). • Hybrid energy systems can address the challenges of intermittency and grid stability. [ABSTRACT FROM AUTHOR]

Promoting the adoption and maintenance of low-carbon consumption behaviors (LCBs) is a global climate action. Most prior studies have considered only the adoption of LCBs and not explored how behavioral characteristics and emotions influence individual behaviors. To address these limitations, this study builds a dual-level integrated model to detect the maintenance rate of various LCBs and identify what factors affect behavioral maintenance. Using data collected from 2052 residents in China, generalized linear mixed models are employed to examine the effects of behavioral and individual-level factors and of social interaction on the maintenance of LCBs. Robustness is checked using the instrumental variable method, least-squares dummy variable method, and Probit approach. The estimated maintenance rate for different LCBs ranges between 29.02 % and 83.49 %, while the estimated cessation rate ranges between 2.31 % and 6.58 %. Maintenance of LCBs is positively affected by context stability but negatively influenced by effort expectancy. Anticipated guilt is identified as the strongest driver (positive) of maintenance of LCBs for all tested variables, followed by symbol expectancy. However, neither behavior routinization nor anticipated pride is found to be significantly associated with behavioral maintenance. The effects of anticipated guilt, effort expectancy, and symbol expectancy on behavioral maintenance are moderated by social interaction. Regarding demographics, family size is positively associated with behavioral maintenance, while females are more likely than males to maintain LCBs. These findings address the under-studied effects of behavioral characteristics and emotions on behavioral maintenance, and provide new insights for redefining target interventions to engage the public in maintaining LCBs. [Display omitted] • Maintenance of low-carbon consumption behaviors (LCBs) is studied. • A dual-level integrated model incorporating social interaction is built. • Maintenance rate of LCBs is estimated between 29.02 % and 83.49 %. • Anticipated guilt is the strongest driver (positive) of maintenance of LCBs. • Symbol expectancy and context stability contribute to maintaining of LCBs. [ABSTRACT FROM AUTHOR]

Animal production faces challenges related to thermal comfort, air quality, and carbon dioxide (CO 2) emissions, thereby the need for more efficient and sustainable systems due to climate change. This study examines green roofs and their potential to absorb atmospheric CO 2 and reduce heat load through photosynthesis and evapotranspiration, resulting in decreased energy consumption and increased CO 2 emissions. The maximum CO 2 concentration limit in animal production facilities is 3000 ppm. Depending on the ventilation system used in broiler production facilities, the CO 2 concentration can exceed 2000 ppm. Dark House poultry facilities tend to have higher concentrations reaching up to 777 ppm. In pig farming, the nursery sector has higher concentrations of CO 2 , exceeding 1200 ppm. In dairy farming, the number of milkings, the type of ventilation system and local climatic conditions can affect the CO 2 concentration, reaching values of up to 1401 ppm. C3 plants have a CO 2 saturation point at 800 ppm and C4 plants at 200 ppm. The CO 2 balance in animal production facilities that use a green roof can be done considering the CO 2 produced and the CO 2 absorbed. Green roofs are therefore considered a sustainable solution for animal production. Its implementation enhances air quality in the facilities, supporting the reduction of environmental impacts and mitigation of climate change effects caused by the agroindustry. This investigation underscores the significance of green roofs, emphasizing their environmental, social, and economic benefits, as well as their applicability in animal production. • It is possible to estimate the CO 2 balance in animal production facilities with a green roof. • Green roof can improve air quality in animal production. • Green roof can reduce the thermal stress of the animals in the premises. • Green roof can contribute to the sustainability of animal production. [ABSTRACT FROM AUTHOR]

Malaysia is actively addressing environmental responsibilities by pledging a 45 % reduction in greenhouse gas emissions by 2030, aided by a large-scale solar photovoltaic initiative. Nonetheless, the unprecedented meteorological events due to climate change such as extreme temperatures and precipitation may reduce the large-scale solar performance and lead to infrastructure damage. The primary objective of this study is to conduct a screening-level analysis from both technical and economic perspectives, in order to assess the effects of extreme temperature and precipitation on large scale solar in Malaysia. This study hypothesized that extreme temperature and precipitation reduce large scale solar performance and increase infrastructure damage. The results demonstrate that both extreme temperature and precipitation increase the power and efficiency loss over time. In general, infrastructure damages caused by extreme temperature and precipitation can result in degradation, a shortened lifespan, and ultimately a collapse. In this study, the costs of physical damage were estimated using the modified levelized cost of energy, and it was found that the cost of physical damage in extreme temperature conditions was approximately 30 % greater than the cost in extreme precipitation conditions, which was nine times greater than in normal condition. Compared to a no-adaptation scenario, it is possible to reduce the additional costs due to extreme temperature and precipitation by up to 53 % and 49 %, respectively. Enhancements, additional analysis, and validation of these findings could aid in the readiness for climate change mitigation efforts, not only for solar power systems but also for other types of energy systems. [Display omitted] • Generic screening-level analysis for assessing techno-economic impact of solar. • Extreme temperature and precipitation reduce solar performance and increase damage. • Study employs modified levelized cost of energy to estimate physical damage costs. • A proactive adaptation strategy reduced the additional cost for both scenarios. [ABSTRACT FROM AUTHOR]

Local governments are expected now more than ever to lead climate action planning as climate change intensifies and urbanization increases rapidly. However, studies indicate limitations in the comprehensiveness and level of integration of adaptation and mitigation in existing climate action plans. To develop suitable climate action plans that are comprehensive and consistent with globally accepted standards and benchmarks, this study proposed an Urban Climate Action Planning framework and pilot-tested it with 257 urban climate action plans. Overall, 43 criteria are included in the framework across three stages of climate planning. The pilot test revealed that more than half of the sampled plans have a medium level of suitability, with 39% having a weak level of suitability. About 51% of plans from Europe have a weak level of suitability. Surprisingly, none of the plans sampled from Africa and Latin America achieved a weak level of suitability despite lacking a significant share of global climate research and development funding. A Kruskal-Wallis test shows a statistically significant association between stages of climate planning and (a) city types (p-value of 0.004326) and (b) year of adoption or publication of climate plans and suitability scores (p-value of 0.0001027). Urban climate action plans adopted or published more recently (2018–2022) are likely more suitable than those adopted or published earlier. The sampled urban climate action plans from the Global South had higher average suitability scores than those from the Global North. The study presents key findings and considerations for urban climate action planning and future research. [Display omitted] • A framework for assessing the suitability of Climate Action Plans (CAPs) is proposed. • The framework is used to pilot-test the suitability of 257 urban CAPs. • Suitability analysis is done across city types, regions, and the global divide. • Most sampled plans achieved a medium level of suitability. • The CAPs lack criteria related to implementation and monitoring. [ABSTRACT FROM AUTHOR]

Decarbonisation strategies for eight German manufacturing companies of different industries (electrical, chemical, beverage, mechanical engineering, automotive, polymer processing) are developed and analysed. The abatement potential and economic feasibility of strategies depend to a large extent on individual preconditions e.g., the area available for renewable energy systems, and dynamic effects, for example the changing emission intensity of local electricity generation. The strategies lead to a reduction of between 41 % and 88 % for seven of the eight companies. The in-depth case studies show that energy efficiency measures and expanding the company's own renewable energy plants, except for solar heat, are particularly cost-effective, while shutting-down existing combined heat and power plants has the highest abatement costs between 169 and 1686 EUR/tCO 2 e. Decarbonising electricity procurement and switching from natural gas to biomethane have the highest greenhouse gas abatement potential in Scope 1 and 2. The novelty of this work is the linking of economic and ecological considerations of measures in the context of company-specific decarbonisation strategies. Using marginal abatement cost curves, different options for emission reductions are discussed and general conclusions for the development of decarbonisation strategies in the manufacturing sector are drawn. [Display omitted] • In-depth decarbonisation strategies are developed for eight manufacturing companies. • Abatement potential and economic feasibility depend largely on dynamic effects. • Energy efficiency and own renewable generation capacity are most cost-effective. • Marginal abatement cost curves link economic and ecological potential. • Greenhouse gas abatement costs are quantified for different industries. [ABSTRACT FROM AUTHOR]

The sustainability paradigm has gained global attention, and the same has been expected from the economies having increasing levels of environmental footprints over the past couple of decades. This research aims to investigate the nexus between clean energy technologies and climate change mitigation among the top ecologically pollutant (TEP) economies during 1996–2020. The research incorporated other drivers of climate change, including energy efficiency, industrialization, and sustainable policies through environmental regulations. The methodological context covers the necessary preliminary tests and the Method of Moment Quantile Regression (MMQR). The preliminary results indicate that TEP economies are interdependent with the heterogenous slope coefficients, stationarity data trends, and cointegrated relationships. The findings from the MMQR unveiled that clean energy technologies tend to mitigate climate change from 0.10th to 0.70th quantiles. Relatedly, energy efficiency reduces the environmental burden across all the quantiles except for the 0.10th one. Conversely, industrialization and economic growth cause an upward shift in climate change among TEP economies across all the quantiles, suggesting a need to shift production-based economies to more service-intensive ones. However, the study found no significant evidence for the nexus between sustainable environmental policies and climate change. The robustness checks also validate the MMQR estimations; however, their parameters' magnitude substantially varied. These outcomes encourage policymakers to implement holistic strategies supporting energy innovation, technologies, and efficiency improvements while controlling the adverse effects of industrialization and traditional growth models. [Display omitted] • Mitigating climate change needs a universal call. • A novel approach, MMQR, has been applied. • Both clean energy technologies and energy efficiency reduce ecological footprints. • Industrialization and economic growth disturb the sustainability paradigm. [ABSTRACT FROM AUTHOR]

Recently, electric fuels (E-fuel), which are the chemicals produced from the conversion of renewable-based hydrogen (H 2), are actively being developed as a sustainable energy carrier. Renewable methane is particularly a promising alternative to fossil-based natural gas, which can be produced from CO 2 or syngas methanation. In this work, techno-economic assessment (TEA) and life-cycle assessment (LCA) for renewable methane production are performed through syngas methanation, where CO 2 is collected using direct air capture (DAC) and syngas is produced by solid oxide electrolysis (SOE) with renewable-based electricity. This research considers the different technical, economic, and environmental performances of the systems for renewable methane production. A favorable reduction in a maximum of 23.3% of CH 4 production cost is observed by the scale-up effects of SOE system from 1 MW to 10 MW. TEA draws the conclusion that economic infeasibility is proved at the current level, but additional research and improvement of SOE system and a plunge in renewable electricity prices can lead to the economic equivalent of conventional natural gas. Furthermore, given that certain energy resources with low energy intensity (0.0394 kg CO 2 -eq MJ−1) are integrated with SOE system for methane production, the LCA results that renewable methane production at a large scale has a potential to access negative CO 2 emissions and accelerate climate change mitigation. Consequently, it is concluded that syngas methanation with renewable-based energy systems and DAC can make a considerable opportunity for climate change mitigation under the assumption that SOE system and renewable energy are significantly improved. [Display omitted] • Feasibility of renewable methane production from syngas methanation is investigated • Solid oxide electrolysis for syngas production with renewable energy is covered • Direct air capture as CO 2 capture technology is considered for renewable methane • Possibility of negative CO 2 emission is confirmed by utilizing direct air capture • Mitigating climate change is proved by renewable methane with direct air capture [ABSTRACT FROM AUTHOR]

Rapidly increasing catastrophic environmental incidents and changes in global climate have compelled researchers to take proactive measures for climate change mitigation. Consequently, reducing greenhouse gas emissions has become one of the most significant global targets. The transportation sector has a massive carbon footprint accounting for 22% of the total carbon dioxide emissions. In this regard, road transport contributes the largest fraction of the total emissions within the transportation sector. Conversely, the railway which is the cleanest form of transportation contributes slightly more than 1% of the total emissions. Moreover, since most of the rail systems are operated by government or private companies, it is relatively convenient to implement policies and replace conventional technology with environmentally friendly ones. This could be achieved by taking certain measures from technical and operational viewpoints for conserving energy to lower the carbon intensity of all transport modalities. Hence, this review paper focuses on investigating the railway sector to encourage a modal shift to the least carbon-intensive option. This study provides a critical review of the past and present rail technologies in terms of the environmental, economic, social, and technical perspectives. Moreover, a comparative assessment of the various locomotive types has been performed. The results reveal that battery-hydrogen hybrid locomotives are the best choice to be considered as a future locomotive technology. Hydrogen locomotives have the potential to be a promising alternative to diesel railway locomotives. However, certain technical barriers need to be overcome to enhance the overall system's performance and reliability to further improve the viability of its deployment in the railway sector. [Display omitted] • A critical review of the various rail technologies is provided through different viewpoints. • The assessment constitutes environmental, economic, social, and technical perspectives. • A decision-support tool for comparison of four rail technologies is also developed. • Battery-hydrogen hybrid locomotive results in the highest score of 1.47. • Standalone hydrogen locomotive results in the second highest score of 1.38. [ABSTRACT FROM AUTHOR]

Many ports and terminals endeavor to enhance energy efficiency as energy prices have increased through years and climate change mitigation is a key target for the port industry. Stricter environmental regulations are adopted by authorities to limit pollutants and GHG emissions arising from energy consumption. Increasingly, port operational strategies and energy usage patterns are under scrutiny. To ingrain sustainability and environmental protection of ports, the use of innovative technology appears as a critical conduit in achieving a transition from a carbon-intensive port industry (dependent on fossil fuels) to a low-carbon port model by harnessing renewable energy, alternative fuels (e.g. LNG, hydrogen, biofuel), smarter power distribution systems, energy consumption measurement systems. In this context, this paper conducts a systematic literature review to analyze operational strategies (e.g. peak shaving, operations optimization), technology usage (e.g. electrification of equipment, cold-ironing, energy storage systems), renewable energy, alternative fuels and energy management systems (e.g. smart grid with renewable energy) for improving the energy efficiency and environmental performance of ports and terminals. Research gaps and future research directions are identified. Analysis shows that there is a great potential for ports to achieve further energy efficiency and researchers have many impactful research opportunities. • A detailed literature review on energy efficiency in ports and container terminals is conducted. • Operational strategies such as optimization of port operations and peak shaving methods are presented. • Technologies such as electrification of equipment, cold-ironing, energy storage systems, smart grid, microgrid are reviewed. • Renewable energy and clean fuel use in ports are presented. • Methods regarding energy consumption and emission measuring/assessment are detailed for ports. [ABSTRACT FROM AUTHOR]

Although short-rotation coppice (SRC) is a sustainable cultivation technique, biodiversity issues keep policy makers from encouraging farmers to establish SRC. From the 47 reviewed publications of this review 91% reported on poplar or willow SRC, and 63% focused on animal diversity. The α- and β-diversity were most often studied by quantifying species richness and abundance. SRC had a positive effect on fungal diversity, which was negatively correlated to coppice rotation length, due to a higher nutrient demand after coppicing. In comparison with agricultural monocultures SRC provides a higher biodiversity, but it remains lower than that of mixed deciduous forests. Besides the planted genera and species, an understorey of generalist species similar to the previous land use develops and evolves to a forest-like understorey. At every coppice rotation the light availability changes and the planted area evolves from a bare field to a shrub-like vegetation, which later approaches a forest with a closed canopy. These changes in the plant community influence animal diversity. Bird populations similarly evolve from open-space to forest communities, continuously co-existing in shifting ratios. Arthropods and small mammals use the SRC to fulfil all of their habitat needs, while birds and large mammals only use the SRC for a limited number of resources. Recommendations for policy makers and SRC growers are provided, and areas for future research have been identified. It is concluded that introducing well-managed SRCs can enrich biodiversity in an agriculture-dominated landscape, but that SRCs most probably have a negative effect on biodiversity when introduced into a highly forested landscape. Image 1 • Short-rotation coppice provides a spatio-temporally dynamic habitat. • Biodiversity in short-rotation coppice is mainly influenced by coppice rotation length. • Size and shape determine short-rotation coppice's integration into the landscape. • SRC enhances biodiversity in otherwise homogeneous landscapes dominated by cropland. • Generalist plant and animal species are most common in short-rotation coppice. [ABSTRACT FROM AUTHOR]

The present study provides firstly a comprehensive review of studies on measuring the impacts of different biodiesel blends on exhaust emissions characteristics of urban busses under real-world operating conditions. Secondly, this paper discusses the errors that can be made in conducting case studies. Thirdly and finally, it shows lessons learned and provides guidelines to setup case studies, conduct the measurements, perform the statistical analysis and report the results to policy makers and the wider audience. To achieve climate change mitigation targets, using alternative fuels, e.g., biodiesel, hydrogen or electricty (EVs) for the urban fleets requires an in-depth analysis of the impacts under real-world operating conditions. Such experiments are generally very complex as numerous factors could directly or indirectly interfere with the results produced and potentially jeopardize the integrity of the research and the conclusions drawn. Results of the present research show that some vital parameters were ignored by many of the studies performed including the statistical uncertainties, driving cycle uncertainties and fuel uncertainties. Lack of appropriate experimental designs or clear assertions about the level of significance for differences in emissions/fuel consumption between alternative fuels (i.e. biodiesel) and the reference fuel used (i.e., diesel) could be regarded as the main weaknesses. Moreover, many other overarching and very influential factors (e.g., covariates/confounders) can interfere with the research outcomes as these were mostly overlooked by the reviewed studies. A careful and complete experimental design for assessments of alternative fueled vehicles (are critical when conducting real-world operating condition tests. The study findings help to formulate the guidelines for assessing real-world operating condition experiments to achieve the most feasibly and meaningful research outcomes that will have significant implication for local and global policy makers. The guidelines are of use for all types of research studies that want to evaluate the effects of alternative fuels for any transportation fleet. Image 1 • Real-world driving tests on urban buses were examined and discussed. • Key issues were uncertainties related to statistical design, driving cycle, and fuel. • Lack of appropriate experimental design was the main weakness in most studies. • Covariate/confounder factors were mostly overlooked. • Guidelines to perform more complete real-world diving test studies were presented. [ABSTRACT FROM AUTHOR]

A bottom-up approach that takes into account solar energy availability and land resource constraints is used to assess the technical potential for concentrating solar power (CSP) in Botswana. The CSP potential is estimated using a detailed geographical information system (GIS) based land exclusion criteria and land use data to determine land suitability in the ten districts of the country. On the basis of the national solar map of satellite-derived direct normal irradiance (DNI) information and observed DNI data combined with biogeophysical and human-induced land use constraints, it is shown that Botswana has approximately 220,016 km2 of available land to support CSP plants. Assuming that dry-cooled parabolic trough collector (PTC)-type CSP plants are deployed, an estimated nominal capacity of 3189.54 TWhy−1 or 363.86 GW could be accommodated by the available land area. The highest CSP potentials by district are found to be in the Central and Kgalagadi which have more than 90 GW each, collectively representing nearly half of the national potential. The largest proportion of available land relative to the district size was found to be the Southern District where more than two-thirds of the surface area was considered suitable for CSP. Based on the findings of the study, Botswana has a relatively huge CSP potential capable of exceeding the current peak energy demand by an order of a magnitude, subject to a policy framework that supports future investment in solar thermal power for a renewable energy mix as part of a climate change mitigation strategy. • Botswana has more than 1800 kWhy−1 of direct normal irradiance (DNI) which exceeds the threshold for economic viability of concentrating solar power (CSP) technology. • Botswana has approximately 220,016 km2 of available land to support CSP plants, which represents approximately 38% of the total land area. • The largest proportion of available land relative to the district size is the Southern District where two-third of land is available for CSP. • Dry-cooled parabolic trough collector-type CSP plants are recommended forr Botswana owing to its arid to semi-arid climate and inadequate lack of water resources for cooling in most districts.. • Botswana has a relatively huge CSP potential capable of exceeding the current peak energy demand by an order of a magnitude. [ABSTRACT FROM AUTHOR]

We develop a novel hypothesis around the impact of a related technology on the development of an experience curve. We explore the implications of this hypothesis in the case of wind energy, which has been historically developed onshore and is currently experiencing rapid growth in deployment offshore. We look at the impact of modelling offshore wind energy as (1) a fully new technology, (2) a direct offshoot of onshore wind, and (3) a hybrid. Focusing on the levelized cost of electricity of offshore wind, we find that assumptions about its relatedness to onshore wind are equally important as assumptions about future growth scenarios. This research highlights a previously neglected factor in experience curve analysis, which may be especially important for technologies, such as offshore wind energy, that are expected to contribute significantly to climate change mitigation. [ABSTRACT FROM AUTHOR]

Extensive scientific literature exists on the risks associated with climate change in cities. Contrarily, the analysis on the risks local governments face in moving towards zero emissions targets is sparse, topical, and local. In this study, we provide a first-of-its-kind synoptic risk analysis directly based on cities' experiences, inputs, and prospects for the future, collated through the questionnaire to express interest in the European Mission for 100 Climate-Neutral and Smart Cities by 2030. This novel dataset contains a variety of information 362 cities provided in relation to all critical (technological and non-technological) elements that contribute to climate mitigation, while enucleating the risks that may arise along the way. The analysis focuses on nine risk domains (including political, financial, regulatory, operational, organisational, collaborative, social, environmental, and safety/security risks) and delves into possible solutions. These insights will be extremely useful and timely to i) design precautions and safeguards, ii) motivate new policies and instruments, iii) inform assistance services and forms of support, and iv) inspire other cities in the creation of an enabling and inclusive environment for zero-emission futures. Furthermore, the analysis reveals a substantial lack of supportive scientific literature when it comes to non-technological aspects of the transition to climate neutrality. [Display omitted] • A broad analysis of risks cities face in pursuing climate neutrality is performed. • The analysis builds on a unique survey of climate-ambitious cities. • Nine risk categories are identified and analysed. • Solutions and recommendations to design safeguards and precautions are extracted. [ABSTRACT FROM AUTHOR]

The Intergovernmental panel on climate change raised awareness on the urgent need for action to limit climate change. Answers include bioenergy with carbon capture and storage (BECCS), which could theoretically generate negative emissions. The life cycle assessment (LCA) method needs to be applied to BECCS systems to assess their negative emission potential and prevent transfers from one environmental impact category to another. To allow for informed decision-making, the quality of LCA results should be evaluated. The quality of results is related to the quality of the data used. The purpose of this article is thus to review the life cycle inventory data that are used for BECCS LCA. To this end, 35 recent BECCS LCA were selected and the inventory data they used was collected. Synthesis inventory tables were then compiled, including the observed range of variability for each data item. These tables cover biomass harvesting, pre-treatment, combustion, gasification, and carbon dioxide capture with a monoethanolamine (MEA) based solvent. Data quality is also reviewed, through the representativeness, reproducibility and completeness of the life cycle inventories highlighted in the selected articles. Only a third of the articles (13/35) provide life cycle inventory tables. Only half of the articles assess the impact on climate change leading to inventory cut-offs. BECCS systems including combustion followed by MEA-based capture have been most referenced (12/35 articles). More transparency on data quality is recommended. Certain promising BECCS systems should also be further studied. This applies, for instance, to BECCS systems that involve second-generation solvents. • A review of the data quality used in life cycle assessment (LCA) of BECCS is assessed. • Only a third of the studied articles provide their life cycle inventory tables. • Inventory data currently used in LCA of BECCS is compiled into synthesis tables. • BECCS systems including MEA-based capture are most frequently referenced. • BECCS systems that should be further assessed with LCA are identified. [ABSTRACT FROM AUTHOR]

Green roofs can mitigate climate change through various mechanisms, including carbon sequestration, thermal process regulation, and building energy savings. While those mechanisms have been well studied, it remains unclear how to quantify carbon dioxide reduction and design green roofs properly for optimal performance. This review summarizes the processes, factors, and quantitative methods for carbon dioxide reduction from peer-reviewed literature. Firstly, the processes that account for how green roofs reduce carbon dioxide directly (by absorbing ambient CO 2 and storing it in biomass and substrate) and indirectly (thermal process regulation reduces energy consumption) are focused. The factors affecting CO 2 reduction (i.e., vegetation, substrate, building environment, and maintenance) are then discussed to investigate how these factors impact the performance of green roofs. Lastly, quantitative methods, including field experiments and simulation models to evaluate direct and indirect CO 2 reductions from green roofs, are discussed considering different spatial scales. The review found that a better understanding of green roofs' carbon reduction mechanisms is needed. Recommendations also should be developed on customized green roof system designs for various climate conditions. Lastly, there is a lack of green roof decarbonization evaluation at multiple spatial and temporal scales to effectively implement green roofs in urban areas. Overall, this comprehensive review facilitates an understanding of how green roofs reduce CO 2 , the driving factors, and quantitative methods, which will advance research on designing and building green roofs as effective climate mitigation solutions in urban areas. • Analysis of the carbon sequestration and energy savings processes of green roofs. • Evaluation of factors affecting carbon sequestration and thermal performance. • Summarizing methods to quantify the carbon dioxide reduction services of green roofs. [ABSTRACT FROM AUTHOR]

Among the sufficiency, efficiency, and renewable frameworks for reducing energy use and energy-related carbon emissions, Building Energy Sufficiency (BES) is gaining attention from policy makers and engineers. Despite the significant role of the building sector in the success of national energy and climate plans, there is a lack of research on the drivers, technologies, and effective policy instruments required to achieve BES in the building operational phase. To fill this gap, this study presents a systematic review of the definition and paradigm of BES and concludes that BES should address both occupant demand and energy or emissions requirements simultaneously. The characteristics of occupant demand in building services are divided into four dimensions: time and space, quality and quantity, control and adjustment, and flexibility. Technical options regarding the building architecture, the envelope system, and the building energy system are reviewed. Finally, policy implications and recommendations are discussed. The multiple benefits and multidisciplinary nature of BES justify further research and accelerated policy implementation in developed and developing countries. [Display omitted] • Building Energy Sufficiency(BES) are important to address building energy and climate issues, but research is lacking. • Building occupant demand is partial in time and space, diversified and heterogeneous in quality and quantity, and requires adjustment. • Passive and flexible architecture, and building integrated photovoltaics are effective in reducing building demand at the building level. • Decentralized design and operation, and flexible terminals are sufficient measures from building energy systems perspective. • Different policy pathways are recommended for different regions according to their own status. [ABSTRACT FROM AUTHOR]

High-solid anaerobic digestion (HSAD) is an attractive organic waste disposal method for bioenergy recovery and climate change mitigation. The development of HSAD is facing several challenges such as low biogas and methane yields, low reaction rates, and ease of process inhibition due to low mass diffusion and mixing limitations of the process. Therefore, the recent progress in HSAD is critically reviewed with a focus on transport phenomena and process modelling. Specifically, the work discusses hydrodynamic phenomena, biokinetic mechanisms, HSAD-specific reactor simulations, state-of-the-art multi-stage reactor designs, industrial ramifications, and key parameters that enable sustained operation of HSAD processes. Further research on novel materials such as bio-additives, adsorbents, and surfactants can augment HSAD process efficiency, while ensuring the stability. Additionally, a generic simulation tool is of urgent need to enable a better coupling between biokinetic phenomena, hydrodynamics, and heat and mass transfer that would warrant HSAD process scale-up. • HSAD suffers from limited heat and mass transfer due to moisture deficit. • Reactor designs and operational strategies can mitigate potential challenges. • HSAD reactor control algorithm must be informed with feedstock properties. • Integrating biokinetic models, CFD and ML will improve process simulation. • Novel engineered-materials can improve transport characteristics of HSAD process. [ABSTRACT FROM AUTHOR]

Abstract Fourth generation biofuel (FGB) uses genetically modified (GM) algae to enhance biofuel production. Although GM algae biofuel is a well-known alternative to fossil fuels, the potential environmental and health-related risks are still of great concern. An evaluation of these concerns and accordingly devising appropriate mitigation strategies to deal with them are important to a successful commercialized production of FGB. While extensive research has been carried out on genetic modification and other technologies that aim to increase the productivity of algae strains, only a handful of them deal with the legislative limitations imposed on exploiting and processing GM algae. This paper examines this legislation and the mitigation strategies to meet potential risks associated with the exploitation and processing of FGB. Open-pond system is an economic solution for large-scale cultivation of microalgae; however, the concern regarding the health and environmental risk of cultivating GM algae and the associated stringent regulations is considered as the main barrier of FGB production. Disposal of the residue is another important issue that should be considered in FGB production. The byproducts obtained from energy extraction step and residual water from the harvesting process may contain plasmid or chromosomal DNA that may cause the risk of lateral gene transfer. Hence an appropriate mitigation practices should be used for replacement of the hazardous water residue and by-products with more environmentally friendly alternatives. The results obtained from several field testing projects for open-environment exploitation of GM algae show that under the various conditions used, there was no apparent proof to support possible horizontal gene transfer in release of GM algae. Graphical abstract fx1 Highlights • Focuses on the risks involved in production of fourth generation biofuel. • Focuses on strategies to deal with risks in the exploitation and processing stages. • Discusses the water footprint in FGB production. • Discusses the mitigation strategies for health and environmental risk of FGB. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study is to evaluate and quantify the impacts of different biogas and related policies on the agricultural sector as well as their performance in terms of climate change mitigation and associated costs. To do so we coupled the partial equilibrium approach simulating the market clearing process with the perspective of Life Cycle Assessment of GHG applying it to the well-documented Lombardy case. Results show that the recent Italian biogas policy – prompting manure utilization and reducing the average subsidy per kWh – effectively increased the environmental sustainability of the system, which only now seems able to counteract global warming. Synergies are observed when the recent Common Agricultural Policy greening reform is simultaneously considered by the model. Highlights • Detail the impacts of different biogas and related policies on the agricultural sector as well as their environmental performance in terms of climate change mitigation and associated costs. • Development of partial equilibrium approach simulating the market clearing process in the biogas sector. • Consider agents decisions feedback to the Life Cycle Assessment for consequential analysis. • The latest Italian biogas policy – prompting manure utilization and reducing the average subsidy per kWh – effectively increased the environmental sustainability of the system, regarding global warming. • Synergies are observed when the recent Common Agricultural Policy greening reform is simultaneously considered by the model. [ABSTRACT FROM AUTHOR]

Abstract Biochar-based carbon management networks (CMNs) offer a means of achieving negative net greenhouse gas (GHG) emissions. Such systems rely on relatively mature technologies for biochar production, distribution and application by tillage; thus, the prospects for near-term scale-up, especially in developing countries with agriculture-intensive economies, are promising. The main technological gap lies in the capability to predict, optimize and monitor the actual climate change mitigation benefits. Computer-aided planning of biochar-based CMNs will be needed to maximize GHG reductions while minimizing any potential adverse environmental impacts. Such models can help decision-makers to understand and optimize the cost/benefit aspects of such systems to accelerate their commercial deployment. This paper gives a brief review of the available scientific literature, and discusses prospective areas for further research to facilitate the large-scale use of biochar as a negative emissions technology (NET). Highlights • Biochar application to soil is a potentially scalable negative emissions technology. • Biochar-based carbon management networks can be operated based on this concept. • Computer-aided planning, optimization and monitoring are required. • An integrated modelling framework should be developed for effective decision support. [ABSTRACT FROM AUTHOR]

Abstract This study reviews conservative political party policy positions in six European countries with high greenhouse-gas emissions (France, Germany, the Netherlands, Poland, Spain, and the U.K.). Using party platform statements from recent election campaigns, the positions of moderate conservative parties are compared with those of far-right political parties to investigate similarities and differences on energy-transition policy. Three areas of policy are considered: climate-change mitigation, fossil-fuel development or sunsetting, and renewable energy and energy efficiency development. In the countries examined, moderate conservative parties generally remain committed to climate-mitigation policy and renewable energy and energy efficiency policy, but there are some roll-backs of support, and there is variation in their support for fossil-fuel development. Far-right parties tend to show evidence of rejection of climate science, opposition to decarbonization in general, support for natural gas hydraulic fracturing technologies, support for continued use of coal, and opposition to some types of policy favorable to renewable energy and energy efficiency. However, some far-right parties, notably in France and Spain, share several important positions with the center-right parties. The study cautions against assuming an automatic linkage between far-right parties and opposition to energy-transition policies and against assuming that far-right parties will oppose all types of energy-transition policies. Highlights • Skepticism and rejection of climate science appears in some of the platforms of far-right Euroskeptic parties. • The far-right parties of Germany, the Netherlands, and the U.K. are strongly opposed to a range of energy-transition policies. • The far-right parties of France and Spain have more moderate positions that are close to center-right parties. • Far-right parties tend to be opposed to wind power but less so to energy efficiency and distributed solar. [ABSTRACT FROM AUTHOR]

Abstract Global advocacy to mitigate climate change impacts on pristine environments, wildlife, ecology, and health has led scientists to design technologies that harness solar energy with remotely sensed, freely available data. This paper presents a study that designed a regionally adaptable and predictively efficient extreme learning machine (ELM) model to forecast long-term incident solar radiation (ISR) over Australia. The relevant satellite-based input data extracted from the Moderate Resolution Imaging Spectroradiometer (i.e., normalized vegetation index, land-surface temperature, cloud top pressure, cloud top temperature, cloud effective emissivity, cloud height, ozone and near infrared-clear water vapour), enriched by geo-temporal input variables (i.e., periodicity, latitude, longitude and elevation) are applied for a total of 41 study sites distributed approximately uniformly and paired with ground-based ISR (target). Of the 41 sites, 26 are incorporated in an ELM algorithm for the design of a universal model, and the remainder are used for model cross-validation. A universally-trained ELM (with training data as a global input matrix) is constructed, and the spatially-deployable model is applied at 15 test sites. The optimal ELM model is attained by trial and error to optimize the hidden layer activation functions for feature extraction and is benchmarked with competitive artificial intelligence algorithms: random forest (RF), M5 Tree, and multivariate adaptive regression spline (MARS). Statistical metrics show that the universally-trained ELM model has very good accuracy and outperforms RF, M5 Tree, and MARS models. With a distinct geographic signature, the ELM model registers a Legates & McCabe's Index of 0.555–0.896 vs. 0.411–0.858 (RF), 0.434–0.811 (M5 Tree), and 0.113–0.868 (MARS). The relative root-mean-square (RMS) error of ELM is low, ranging from approximately 3.715–7.191% vs. 4.907–10.784% (RF), 7.111–11.169% (M5 Tree) and 4.591–18.344% (MARS). Taylor diagrams that illustrate model preciseness in terms of RMS centred difference, error analysis, and boxplots of forecasted vs. observed ISR also confirmed the versatility of the ELM in generating forecasts over heterogeneous, remote spatial sites. This study ascertains that the proposed methodology has practical implications for regional energy modelling, particularly at national scales by utilizing remotely-sensed satellite data, and thus, may be useful for energy feasibility studies at future solar-powered sites. The approach is also important for renewable energy exploration in data-sparse or remote regions with no established measurement infrastructure but with a rich and viable satellite footprint. Highlights • Solar energy from Australia's 41 metro, remote, & regional sites modelled with ELM. • ELM enriched with geo-temporal input (periodicity, latitude, longitude, elevation). • ELM (Random Forest, M5 Tree, & MARS) accuracies follow distinct geographic signatures. • ELM can predict solar energy in data-sparse regions with viable satellite footprints. • ELM can greatly benefit sites with unestablished measurement infrastructure. [ABSTRACT FROM AUTHOR]

Abstract The Canadian province of Quebec has set for 2030 a greenhouse gas (GHG) emission reduction target of 37.5% below 1990 levels. Meeting such a reduction target requires in particular a rapid transition to a low-carbon energy system. This paper proposes prospective energy scenarios for Quebec up to 2030, under different GHG emission reduction constraints (up to a 40% reduction). The main objective is to explore the role of bioenergy in achieving the reduction targets. Our analysis is based on the North American TIMES Energy Model (NATEM). It belongs to the MARKAL/TIMES family of models supported by the International Energy Agency, and includes a detailed bioenergy sector. Compared to the reference case (baseline), our results indicate a larger share of bioenergy in 2030 (up to a threefold increase in the most stringent GHG reduction scenario), with up to a fourfold increase in the total amount of feedstock used for bioenergy production. Our study envisions thus a much larger penetration of bioenergy than the one proposed by the government of Quebec in its 2030 Energy Policy. Highlights • Prospective energy scenarios for the Province of Quebec under GHG reduction targets. • Use of a TIMES optimization energy model to derive socially optimal solutions. • Explore the role of bioenergy in achieving the reduction targets. • Results indicate a larger penetration of bioenergy than the one proposed by the government of Quebec in its 2030 Energy Policy. [ABSTRACT FROM AUTHOR]

Abstract 1.1 billion of the world's population still does not have access to electricity in the 21st century. Most of that population resides in the rural communities in developing countries in South Asia, Latin America and Sub-Saharan Africa. Access to electricity can eliminate existing problems related to health, education, social life, economy and the environment, and can increase the income of underserved communities. Most of the yet to be energized regions are in remote, isolated areas, that cannot be serviced through the central grid. While decentralized diesel generators can potentially be installed in these areas, they have a poor effect on climate change mitigation. Clean renewable energy alternatives for off-grid systems are being deployed to reduce the non-electrification rate in the world, and The United Nation Foundation's 2030 Agenda has the objective of universal access to electricity by 2030. While there has been some progress towards that goal, the challenges are countless. If no changes in models, policies and practices are made, the universal access objective will not be achieved, especially in Sub-Saharan Africa that has a level of electrification projection of 30% by 2030. To determine the necessary changes, this paper reviews the rural electrification initiatives in eight developing countries, from Asia to Sub-Saharan Africa to Latin America, and aims to provide an assessment of their success and to discuss the lessons that can be learned and applied on future initiatives. Highlights • Different approaches to first-access systems have been studied. • The role of policy-making and its impact on project success is highlighted with real examples. • Experiences of different countries and different regions have been compared. • Lessons learned from these experiences are shared and keys parameters for more effective project development have been shared. • The research direction of this field and possible future work are documented. [ABSTRACT FROM AUTHOR]

Abstract Green gas is a promising renewable energy carrier compatible with existing gas networks, whose environmental impact and capacity to decarbonise the energy sector is evaluated by life cycle assessment (LCA). This articles reviews 42 LCAs applied to biomethane, produced by anaerobic digestion, and bio-SNG, produced by gasification and methanation, discussing the main methodological choices and their effects on the results, and highlighting the limits of the use of LCA as a stand-alone approach in real-case applications. While uncertainty analysis was performed in 34 of the reviewed studies, only 3 studies integrated the LCA with process modelling or geospatial modelling. The lack of data for pre-commercial or newly-commercialised technologies has necessitated to the introduction of thermodynamic models giving mass and energy flows, especially in the case of bio-SNG. Limits due to geospatial case-specific constraints have been overcome by two studies introducing geographical information systems (GIS) based models to evaluate the impact of green gas production system on a regional level. Facility siting and sizing has been also found to be fundamentally important in evaluating the trade-off between profitability and environmental impact. Finally, this work highlights the need for a hybrid LCA, in which LCA is integrated with thermodynamic models of the process, GIS-based infrastructure design, and uncertainty quantification, in order to inform stakeholders of the economic, environmental and energy potential of green gas production systems. Graphical abstract fx1 Highlights • 42 LCAs of bio-SNG and biomethane production have been reviewed. • Thermodynamic models overcome the lack of data for emerging technology. • GIS-based models are used to design the supply chain in a limited number of reviewed LCAs. • A hybrid-LCA has been proposed for the evaluation of sustainability of green gas production. [ABSTRACT FROM AUTHOR]

Political decision-makers need to consider the various challenges and opportunities that climate change can bring, and they must take decisions under high uncertainty to achieve resilient cities. Here, we synthesise the push and pull approaches reported in the literature and employed in practice to achieve sustainable and resilient cities. First, we present a literature review which identified the major research fields on transition theories, frameworks and methods that underpin this concept. We analyse the conditions for change, identify enablers or triggers for change at governance level for transitioning a city towards sustainability and resilience. We discuss the theories, frameworks and methods which can be used to address the urban climate change challenge at city level. Second, we present an empirical approach based on stakeholder participation that we conducted to detect the conditions for change. We report on the design and implementation of stakeholder exercises that helped us detecting the conditions for changes. Third, we combine the information obtained from these stakeholder exercises with that extracted from the literature in order to provide a fuller picture on how stimulate the transition and transformation to achieve sustainable and resilient cities. Based on our literature review and empirical approach, we formulate an integrated conceptual model for transition that enables the design of adaptation (and mitigation) strategies that consider the triggers of change. Uniquely we identified 8 triggers of change, including authority and political leadership, learning from disasters, co-responsibility, increased public-private interface, social participation and the living lab approach to innovation. The proposed model can be applied to the whole city or to a certain sector of the city (e.g. energy). We demonstrate that triggers of change help to overcome planning and implementation barriers and move the socio-ecological and socio-technical systems of any city towards those of a resilient city. [ABSTRACT FROM AUTHOR]

Global firms are increasingly adopting greenhouse gas mitigation targets in response to climate change. These targets serve as a spur for carbon mitigation initiatives, provide guidelines to select appropriate mitigation actions, and set the standards to measure the progress of the mitigation efforts. Despite their important functionalities, firm-level mitigation targets have rarely been studied. In this paper we aim to provide a comparative view on mitigation targets set by global firms across different countries and industrial sectors. The analysis focuses on four dimensions, i.e., adoption, metric, scope, and stringency. We find Japan far leads the other major countries in terms of target adoption, but the targets of Japanese firms are generally less stringent. Canadian firms are laggards in both target adoption and target stringency. The mitigation targets are also considerably uncommon among Australian firms. Firms in developing countries fall behind in target stringency and display a significantly greater divergence than developed countries in sectoral adoption rate. The European Union firms are most likely to cover the emissions in their supply chains in targets. Target stringency has substantially tightened from 2005 to 2012. For all the countries in this study, around 95% of the firm-level targets are more stringent than the Intended Nationally Determined Contributions submitted to the Paris Agreement. Setting mitigation target has a significant positive impact on both the likelihood of investing in renewable energy and the amount of investment in renewable energy. However, there is no evidence that more stringent targets lead to higher investment. These findings point to the most pressing issues with regard to corporate mitigation target-setting that policymakers and corporate management should address. [ABSTRACT FROM AUTHOR]

To meet the global climate change mitigation targets, more attention has to be paid to the decarbonization of the heating and cooling sector. Aquifer Thermal Energy Storage (ATES) is considered to bridge the gap between periods of highest energy demand and highest energy supply. The objective of this study therefore is to review the global application status of ATES underpinned by operational statistics from existing projects. ATES is particularly suited to provide heating and cooling for large-scale applications such as public and commercial buildings, district heating, or industrial purposes. Compared to conventional technologies, ATES systems achieve energy savings between 40% and 70% and CO 2 savings of up to several thousand tons per year. Capital costs decline with increasing installed capacity, averaging 0.2 Mio. € for small systems and 2 Mio. € for large applications. The typical payback time is 2–10 years. Worldwide, there are currently more than 2800 ATES systems in operation, abstracting more than 2.5 TWh of heating and cooling per year. 99% are low-temperature systems (LT-ATES) with storage temperatures of < 25 °C. 85% of all systems are located in the Netherlands, and a further 10% are found in Sweden, Denmark, and Belgium. However, there is an increasing interest in ATES technology in several countries such as Great Britain, Germany, Japan, Turkey, and China. The great discrepancy in global ATES development is attributed to several market barriers that impede market penetration. Such barriers are of socio-economic and legislative nature. [ABSTRACT FROM AUTHOR]

Renewable energy is an efficient tool to support China's endeavors to keep energy independence and mitigate climate change. This paper applies a Divisia index approach to investigate the factors governing renewable energy development in China, including the supply mix, energy security, carbon emission, and to forecast these requirements for the year 2020 and 2030. Grey relational model is employed to verify the relationships between renewable energy and its drivers. The results of the forecasts reveal the challenges of long-term deployment for renewable energy technologies. Other results show that during the research period, energy security makes a major contribution to renewable energy development. Energy security and substitution rate have relatively closer relationships with new and total renewable energy consumption respectively than that of other factors. Scenario analyses suggest that strong and continuing renewable energy policies will be helpful to achieve sustainable energy development in China and a strong synergy between renewable energy and energy security would emerge in the future. [ABSTRACT FROM AUTHOR]

Anthropogenic activities and advancements in industries boost global energy demand and increase fossil fuel consumption, causing several global environmental problems, such as climate change. As a climate change mitigation strategy, the use of renewable energy technologies has gained unprecedented interest. In particular, the thermochemical processing of lignocellulosic biomass integrated with other renewable energy technologies has emerged rapidly. It is critical to select appropriate integrated renewable energy system configurations for sustainable and feasible power generation towards higher environmental benefits. Understanding the possible configurations of thermochemical lignocellulosic biomass processing technologies (gasification, pyrolysis, hydrothermal gasification, or hydrothermal carbonization) integrated with renewable energy technologies (solar thermal, fuel cell, fusion power, or energy storage) is crucial for the further development and propagation of the integrated renewable energy system. Hence, we provide a systematic review of the thermochemical conversion of lignocellulosic biomass integrated with the other renewable energy technologies. Finally, the challenges associated with the implementation of these systems and suggestions for future research on the systems are discussed. • Renewable energy technology is integrated with thermochemical biomass conversion process. • The integrated bioenergy systems help overcome limitations of single-source energy systems. • Challenges and prospects for the integrated systems are highlighted. [ABSTRACT FROM AUTHOR]

This study investigates the climate emergency declaration (CED) movement in cities and its effects and synergies with local climate planning. Urban areas are experiencing a wide range of climate-induced extreme events, particularly those located in the Mediterranean hotspot. The focus is on Italian cities, which have only recently become key players in climate planning. The method is based on the collection, analysis, and comparison of data on CEDs and local climate plans (LCPs), integrated with information on city membership in climate networks, to extrapolate key performance indicators of the CED movement. The results show that the CED movement can motivate municipalities to become more ambitious in climate action. As of February 2021, the "climate emergency" movement was supported by 105 Italian cities geographically concentrated in the northern regions (66.7%). The motivation behind a CED is often attributable to local populations calling for concrete climate action (91.1% referred to the Fridays for Future movement) but also to a greater perception of the impacts of climate change (85.6% referred to the Special Report on Global Warming of 1.5 °C). Networking plays an important role (85 cities in the Covenant of Mayors). Interestingly, 36 cities (34.3%) were not engaged in local climate planning previously, but the CED shows now they see the urgency to act. 24.4% cities aim at carbon neutrality in their CEDs (most with local adaptation aspirations), with a much smaller fraction of cities doing so in LCPs and generally lower ambition in terms of greenhouse gas emission reduction targets. [Display omitted] • Case study: 105 IT cities that have declared climate emergency (66.7% in the north). • Motivation: 91.1% refer to the FFF movement, 85.6% to the 2018 IPCC Special Report. • Networking: 85 cities are members of CoM and 33 of the Italian Green City Network. • 34.3% of the CED cities had not previously a mitigation or adaptation plan. • 24.4% of CEDs aim at carbon neutrality, while LCPs have less ambitious GHG targets. [ABSTRACT FROM AUTHOR]

Providing children with a clear understanding of climate change drivers and their mitigation is crucial for their roles as future earth stewards. To achieve this, it will be necessary to reverse the declining interest in STEM (Science, Technology, Engineering and Mathematics) education in schools in the UK and other countries, as STEM skills will be critical when designing effective mitigation solutions for climate change. The 'Heat-Cool Initiative' was co-designed and successfully implemented in five primary/secondary UK schools, as a playful learning tool to unleash student interest in STEM subjects. 103 students from two cohorts (years 5–6 and 7–9) participated in five Heat-Cool activity sessions where they used infrared cameras to explore the issue of urban heat. Their learning was evaluated using a multi-functional quantitative assessment, including pre- and post-session quizzes. Climate change literacy increased by 9.4% in primary school children and by 4.5% in secondary school children. Analyses of >2000 infrared images taken by students, categorised into 13 common themes, revealed age-related differences in children's cognitive development. At primary school age, images of the 'self' dominated; secondary school children engaged more with their physical environment. This novel approach demonstrated the importance of developing tailored technology-enhanced STEM education programmes for different age cohorts, leading to a high capacity for improving learning outcomes regarding climate change. Such programmes, embedded in school curricula nationally and internationally, could become a much-needed positive contribution to reaching the United Nation's Sustainable Development Goals, especially Goals 4 (Quality Education) and 13 (Climate Action). [Display omitted] • Heat-Cool (how building heats and trees cool cities) was designed and implemented. • Awareness in ∼22% school children improved with ≥80% marks in post-sessions quiz. • 79% primary and 62% secondary school students' knowledge increased on climate change. • Positive motivation and engagement were observed in ≥89% of the student subgroups. • Students took 2195 images to indicate their excitement with the activity. [ABSTRACT FROM AUTHOR]

The decarbonization of industry and industrial systems is a pressing challenge given the relative lack of low-carbon options available for "hard to decarbonize" sectors such as steelmaking, cement manufacturing, and chemical production. Carbon capture utilization and storage (CCUS) represents a promising and crosscutting solution to this formidable problem. This review takes a systematic and sociotechnical perspective to examine how CCUS can support industrial decarbonization and relevant associated technical, economic, and social factors. This includes a focus on the energy and climate impacts of carbon emitting activities, the role, and options for CCUS in global responses to climate change, technical aspects of capture, transport, storage, and utilization, as well as policy implications and areas requiring further research. In doing so, the Review examines hundreds of published studies on the topic over the previous twenty years to offer a state-of-the-art investigation on technical options for capture (including direct air capture), transportation (including pipelines, ships, and rail), storage (including biotic and abiotic), and utilization (including enhanced oil recovery and biochar). The Review also investigates the evidence base within the literature on enablers and barriers to CCUS, policy mechanisms, and international frameworks as well as themes such as geopolitics, trade, and future research gaps. We conclude with insights about future CCUS pathways and sociotechnical systems dynamics. [Display omitted] • Carbon Capture Utilization and Storage can play a critical role in climate change mitigation. • Ample emerging technologies are available with adequate capture capacities and biotic and abiotic forms of storage. • Utilization processes include enhanced oil recovery and biochar. • Carbon Capture Utilization and Storage deployment has been largely limited by social and economic barriers. • Policy driven solutions may help drive costs down, engender social acceptance, and increase CCUS deployment. [ABSTRACT FROM AUTHOR]

Even though oil, gas, and coal resources might be unavailable after 2040, 2042, and 2112, respectively; 81.7% of the energy is produced from fossil fuels. Experts have established that this level of non-renewable resource use is unsustainable, ecologically unsafe, and critically changing climate patterns. Whereas climate change and biodiversity loss have subjected mankind to significant systemic risks, policymakers have recommended a switch from fossil fuel-based to a biobased economy and reconnecting humans with the biosphere as a way to mitigate these risks. A circular bioeconomy has been suggested as an efficient approach to utilize environmentally safe ecosystem services for socio-ecological development and transformation towards sustainability. The circular bioeconomy provides significant opportunities to achieve 17 SDGs and 134 targets of the Sustainable Development Agenda 2030, and address numerous national and international challenges caused by climate action. In this review, we have highlighted links between circular bioeconomy and internationally agreed SDG targets [particularly SDG 13 (climate action)]; and assessed ecosystem services in a circular biobased economy. A critical synthesis vis-à-vis climate action through circular bioeconomy to assure the sustainability of bioeconomy programmes is herein presented. [Display omitted] • Switching to a biobased circular economy is a perfect strategy for climate action. • Ecosystem services are valuable for the execution of circular bioeconomy policies. • Circular bioeconomy framework involves living feedstock conversion into useful products. • Linking bioeconomy programmes to SDGs assure their sustainability. [ABSTRACT FROM AUTHOR]

The residential sector has been targeted as the one with a huge potential for reducing carbon emissions. In order to determine the present carbon footprint and the potential for achieving carbon neutrality, the study examines electricity consumption in average households, whose electricity is supplied by their national power grids. 31 European countries (27 EU and 4 non-EU countries) were included in this analysis. Our results indicate that the annual carbon emissions of these average households range from 0.09 to 6.44 tCO 2 e (1.36 tCO 2 e on average), depending on a country. In addition, the calculated electricity costs per tCO 2 e emission for an average household vary significantly (from 94 to 10,135 EUR/tCO 2 e).Carbon offsetting is a mechanism which enables households to achieve carbon neutrality, i.e. households can compensate for the emissions caused by their electricity consumption by purchasing voluntary carbon offsets. This study also analyses the financial implications of purchasing voluntary carbon offsets. The results indicate that voluntary carbon offsets do not burden household budgets significantly because their share in total electricity costs is small. European households, particularly those in countries where electricity is more expensive, can comfortably achieve carbon neutrality with voluntary carbon offsets. In this way, they can contribute to global sustainable development. [Display omitted] • Average carbon footprint of grid-connected household in Europe is less than 2 tCO2e. • The cost of electricity per CO2 emissions varies from 94 to 10,135 EUR/tCO2. • Voluntary carbon offset costs in electricity costs vary widely across Europe. • Carbon offsetting is a practical solution for achieving a carbon-neutral household. [ABSTRACT FROM AUTHOR]

While feeding 20% of global population, China's agriculture is a large greenhouse gas (GHG) emitter, posing a major challenge to the country's carbon neutrality target. However, the pathways of agriculture towards carbon neutrality remain unclear. To address this knowledge gap, we conduct a comprehensive life-cycle assessment and show that valorization of sustainable biomass wastes (crop residues, forest residues, livestock manure, food waste, and sewage sludge) into biochar can contribute importantly towards agricultural carbon neutrality in China. The maximum potential of biochar production from these waste resources in 2018 is 145 Mt yr−1 with a corresponding GHG mitigation potential of 455.7 (405.5–572.4) Mt CO 2 -eq yr−1. This can fully offset the total CH 4 and N 2 O emissions from China's croplands (∼400 Mt CO 2 -eq yr−1), which are difficult to be entirely eliminated due to rice paddy irrigation and intensive use of fertilizers. Distribution of biomass waste varies across regions, and at the national level , crop residues (48.8%) and livestock manure (25.4%) and food waste (15.6%) are the main sources of biochar feedstocks and should be prioritized in biochar development. Forest residues have a marginal contribution due to competing uses from other sectors, and sewage sludge derived biochar is a net source of GHG emissions due to the large energy consumption required for sludge drying. The total GHG mitigation potential of biochar is greatly affected by pyrolysis temperature and the highest mitigation effect is observed under 300–500 °C. These results underscore the benefit of sustainable biochar production to agricultural carbon neutrality, and to maximize the climate benefit requires differential policies and pyrolysis technologies tailored to regional availability of biomass resources. • The GHG mitigation potential of sustainable biochar in China was analyzed. • The maximum mitigation potential can offset all CH 4 and N 2 O emission from croplands. • Biochar GHG mitigation potential is affected significantly by pyrolysis temperature. • Sustainable biochar can contribute toward agricultural carbon neutrality. [ABSTRACT FROM AUTHOR]

In addition to carbon capture and storage, efforts are also being focussed on using captured CO 2 , both directly as a working fluid and in chemical conversion processes, as a key strategy for mitigating climate change and achieving resource efficiency. These processes require large amounts of energy, which should come from sustainable and, ideally, renewable sources. A strong value chain is required to support the production of valuable products from CO 2 . A value chain is a network of technologies and infrastructures (such as conversion, transportation, storage) along with its associated activities (such as sourcing raw materials, processing, logistics, inventory management, waste management) required to convert low-value resources to high-value products and energy services, and deliver them to customers. A CO 2 value chain involves production of CO 2 (involving capture and purification), technologies that convert CO 2 and other materials into valuable products, sourcing of low-carbon energy to drive all of the transformation processes required to convert CO 2 to products (including production of hydrogen, syngas, methane etc.), transport of energy and materials to where they are needed, managing inventory levels of resources, and delivering the products to customers, all in order to create value (economic, environmental, social etc.). Technologies underpinning future CO 2 value chains were examined. CO 2 conversion technologies, such as urea production, Sabatier synthesis, Fischer-Tropsch synthesis, hydrogenation to methanol, dry reforming, hydrogenation to formic acid and electrochemical reduction, were assessed and compared based on key performance indicators such as: CAPEX, OPEX, electricity consumption, TRL, product price, net CO 2 consumption etc. Technologies for transport and storage of key resources are also discussed. This work lays the foundation for a comprehensive whole-system value chain analysis, modelling and optimisation. [ABSTRACT FROM AUTHOR]

The European Union launched a set of policies as part of its 2020 climate and energy package aimed at meeting its 20/20/20 headline targets for smart, sustainable and inclusive growth. This paper evaluates how successful new-to-the-market climate change mitigation technologies (CCMT) are in helping EU member states (MS) reach these goals and, furthermore, whether there are differences between sectors subject to EU-wide polices. To do so, we relate CCMT patent counts to two specific headline targets: (1) achieving 20% of gross final energy consumption from renewables, and (2) achieving a 20% increase in energy efficiency. Our results provide the first ex-post evaluation of the effectiveness of these technologies for combating climate change. Moreover, our sectoral impact assessment points to significant differences in the way in which these technologies contribute to policy goals across the sectors. [ABSTRACT FROM AUTHOR]

Climate change mitigation by reducing greenhouse gas emissions is one of the major challenges for existing electric power systems. This study presents a multi-stage joint-probabilistic left-hand-side chance-constrained fractional programming (MJCFP) approach to help tackle various uncertainties involved in typical electric power systems and thus facilitate risk-based management for climate change mitigation. The MJCFP approach is capable of solving ratio optimization problems associated with left-hand-side random information by integrating multi-stage programming method, joint-probabilistic chance-constrained programming, fractional programming into a general framework. It can balance dual-objectives of two aspects reflecting system optimal ratio and analyze many of possible scenarios due to various end-user demand situations during different periods. The MJCFP approach is implemented and applied to the provincial electric power system of Saskatchewan, Canada to demonstrate its effectiveness in dealing with the tradeoff between economic development and climate change mitigation. Potential solutions under various risk levels are obtained to help identify appropriate strategies to meet different power demands and emission targets to the maximum extent. The results indicate that the MJCFP approach is effective for regional electric power system planning in support of long-term climate change mitigation policies; it can also generate more alternatives through risk-based management, which allows in-depth analysis of the interrelationships among system efficiency, system profit and system-failure risk. [ABSTRACT FROM AUTHOR]

Malaysia has a plethora of biomass that can be utilized in a sustainable manner to produce bio-products for circular green economy. At the 15th Conference of Parties in Copenhagen, Malaysia stated to voluntarily reduce its emissions intensity of gross domestic product by upto 40% by 2020 from 2005 level. Natural resources e.g. forestry and agricultural resources will attribute in achieving these goals. This paper investigates optimum bio-based systems, such as bioenergy and biorefinery, and their prospects in sustainable development in Malaysia, while analyzing comparable cases globally. Palm oil industry will continue to play a major role in deriving products and contributing to gross national income in Malaysia. Based on the current processing capacity, one tonne of crude palm oil (CPO) production is associated with nine tonnes of biomass generation. Local businesses tend to focus on products with low-risk that enjoy subsidies, e.g. Feed-in-Tariff, such as bioenergy, biogas, etc. CPO biomass is utilized to produce biogas, pellets, dried long fibre and bio-fertilizer and recycle water. It is envisaged that co-production of bio-based products, food and pharmaceutical ingredients, fine, specialty and platform chemicals, polymers, alongside biofuel and bioenergy from biomass is possible to achieve overall sustainability by the replacement of fossil resources. Inception of process integration gives prominent innovative biorefinery configurations, an example demonstrated recently, via extraction of recyclable, metal, high value chemical (levulinic acid), fuel, electricity and bio-fertilizer from municipal solid waste or urban waste. Levulinic acid yield by only 5 wt% of waste feedstock gives 1.5 fold increase in profitability and eliminates the need for subsidies such as gate fees paid by local authority to waste processor. Unsustainable practices include consumable food wastage, end-of-pipe cleaning and linear economy that must be replaced by sustainable production and consumption, source segregation and process integration, and product longevity and circular economy. [ABSTRACT FROM AUTHOR]

Offshore wind power technology holds the potential for tackling major problems associated with energy and climate change as well as triggering economic growth and providing employment opportunities. Offshore wind power has the potential to play a key role for Turkey in achieving stated 2023 energy targets due to the country's favourable geographic location and coastline. However, there are currently no offshore wind farm projects in Turkey. The aim of this study is to determine the feasibility of an offshore wind farm in the Turkish seas. Prior to that, offshore wind market in the EU is reviewed, and the current status regarding the wind power market and supporting mechanisms are reviewed regarding the situation in Turkey. A location is proposed in the Aegean Sea, based on consideration of wind speeds and other factors. Technical analysis is conducted with the use of windPro software, and potential annual energy production of the proposed project is calculated. Combined with the economic analysis, feasibility of such an offshore wind farm is discussed. Issues with the current supporting mechanism are identified, and solutions are proposed for the future development of offshore wind farms in Turkey. [ABSTRACT FROM AUTHOR]