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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]

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]

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]

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]

Wood use is expanding to new markets, driven by the need to substitute fossil-intensive products and energy. Wood products can contribute to climate change mitigation, if they have a lower fossil footprint than alternative products serving the same function. However, the climate change mitigation potential is contingent on the net fossil and biogenic emissions over time, as well as the realism of the counterfactual scenario and market assumptions. This study aims to improve the consistency of assessing the avoided fossil emissions attributed to changes in wood use, and to estimate the additional mitigation potential of increased wood use in construction and textile markets based on wood harvested in Finland. The results show that, compared to baseline, an increase in the market share of wood leads to an increase in atmospheric CO 2 concentration by 2050. Thus, the substitution impacts of wood use are not large enough to compensate for the reduction in forest carbon sinks in the short and medium term. This outcome is further aggravated, considering the decarbonization of the energy sector driven by the Paris Agreement, which lowers the fossil emissions of competing sectors more than those of the forest sector. The expected decarbonization is a highly desirable trend, but it will further lengthen the carbon parity period associated with an increase in wood harvest. This creates a strong motive to pursue shifts in wood uses instead of merely expanding all wood uses. [Display omitted] • Increase in wood use for construction or textiles increases net emissions by 2050 • Substitution impacts will fall remarkably by 2050 due to decarbonization • Results motivate shifts in wood uses as opposed to expanding all wood uses • Substitution assumptions remain oversimplified which causes great uncertainty [ABSTRACT FROM AUTHOR]

Despite the recognition of carbon capture and sequestration (CCS) as a credible technology for reducing emissions, its implementation has been stalled, partly due to the public's perception of the technology. The literature on CCS technology diffusion points to negative public perception of the technology as a barrier to implementation, and the role of media in that framing. Yet, there remains a gap in the knowledge of media framing of a successful CCS project. This study analyzes the Saskatchewan case, the first successful commercial scale CCS technology deployment in the world and finds that the media framing of CCS technology in Saskatchewan applied a narrative/storytelling approach by deploying metaphors that connected to local values, beliefs, and norms. Also, it notes certain conditions in Saskatchewan made it possible for some frames to be advanced while others were minimized, discounted, or absent altogether in the discussion. Applying the Socio-Political Evaluation of Energy Deployment (SPEED) framework, the study highlights the role of authoritative voices, mostly within Saskatchewan's political system in reframing CCS technology from uncertainty and risk into opportunity; minimizing and sometimes discounting or ignoring the negative frames that have been identified in previous studies as a barrier. It concludes that in Saskatchewan there was a trade-off in framing, where opportunities to advance frames that emphasize how CCS technology can support long term low carbon energy transition and climate change mitigation were missed. This study adds to the literature in that it analyzes a successful case of CCS technology deployment. • The social context shaping technology deployment is created, shaped, and reinforced through communicative practices that are channeled through the media. • Compared to the literature on the social context of CCS technology deployment, this study found similar themes with different articulation and synthesis (communicative practices). • Two major frames found in this study to have enabled the successful deployment of CCS technology in Saskatchewan are: 'World Energy Leader' and 'Managed Risks'. • An effort to understand the key role of actors as they engage in communicative practices that frame innovative and contentious technology is critical to understanding how social context informs technology deployment. [ABSTRACT FROM AUTHOR]

The United Nations Sustainable Development Goal target 7.1, to provide universal access to affordable, reliable and modern energy by 2030, must be achieved in the context of rapid reductions in global greenhouse gas (GHG) emissions. While replacing solid cooking fuels with liquid petroleum gas (LPG) opens questions about the compatibility of energy access and climate mitigation objectives, the environmental impact of 2.6 billion people continuing to rely on solid fuel for cooking and heating is significant. However, models used to map deep decarbonization pathways typically do not feature a granular pathway for universal clean cooking access, which limits the representation of these two interconnected transitions, mitigating climate change and achieving universal energy access. Here, we present a novel methodology for representing residential cooking pathways within the TIMES energy systems optimization model (ESOM) framework. The methodology is demonstrated using India as a proof-of-concept case study, where scenario analysis explores solutions that reach universal clean cooking access in the context of GHG emissions reductions. The model presented here is published and publicly available to access. • Sustainable Development Goal 7.1 targets universal access to clean cooking facilities by 2030. • Energy access and climate mitigation interconnection is underrepresented in energy systems modelling. • The Clean Cooking Model (CCM) represents energy access options in an energy systems optimization framework. • CCM maps cost-optimal, granular pathways to energy access and climate mitigation goals. [ABSTRACT FROM AUTHOR]

Biochar amendment has been proposed as a promising solution to mitigate greenhouse gas (GHG) emissions from agriculture and sustainably enhance crop yield. However, the net GHG mitigation potential of biochar remains uncertain, especially the controversial results from field and laboratory experiments. Using 9970 published observational data derived from 592 peer-reviewed papers, this study highlighted the effects of biochar in field experiments on crop yield, soil organic carbon (SOC) stocks, carbon dioxide (CO 2) and methane (CH 4) fluxes, and soil nitrogen (N) dynamics (i.e., soil inorganic N stocks, nitrous oxide [N 2 O] emissions, ammonia [NH 3 ] volatilization, and inorganic N leaching). Overall, field data indicated that biochar significantly increased gross SOC stocks (26.6%) and crop yield (15.7%), reduced soil CH 4 (−14.8%) and N 2 O (−23.1%) emissions, and ammonium (−24.9%) and total inorganic N leaching (−23.2%) but had no effect on soil CO 2 emissions. Whereas laboratory data generally showed greater effect sizes of biochar on these indictors. Global warming potential was decreased only in field experiments, but both experiments showed similar reductions in GHG intensity. Both experiments suggested that soil and biochar cation exchange capacity, pH, biochar application rate, and nitrogen fertilization interactively regulated biochar effects on crop yield and GHG emissions. The unrealistically high rates of biochar in laboratory experiments may overestimate its benefit on soil C sequestration and/or underestimate its mitigation potential. These findings provide a comprehensive view that biochar amendment may serve as a viable climate-smart agricultural practice that can help in partial achievement of multiple sustainable development goals. • Biochar is an effective strategy for climate-smart agriculture. • Biochar added to field (∼20 Mg ha−1) can increase gross SOC stock by ∼27%. • Biochar can decrease global warming potential and greenhouse gas intensity. • Unrealistically high biochar rates in lab overestimated soil carbon sequestration. [ABSTRACT FROM AUTHOR]

Despite the technical maturity and substantial potential cost reduction of BIPV technologies, there are still challenges to overcome for the expansion of BIPV applications and their wider adaptation at global level. Among these, the alignment of PV integration with particular climate and environmental conditions of the local solar architecture is crucial. This will facilitate the transition to sustainable buildings and the mitigation of climate change. In this context, this study proposes for the first time, a novel BIPV climatic design framework for PV buildings positioning and adaptation to local climate towards the minimization of energy expenditure and use of resources. With the review and analysis of a large numbers of BIPV studies globally for seventy parameters grouped in eight main categories of an open-access database, the global horizontal irradiation (GHI) value is selected as an additional index to the Köppen-Geiger classification scheme. The extension accounts for the urban suitability and vulnerability and prioritize the building integration of photovoltaics. Four zones of cold (low GHI), moderate (medium GHI), warm (high GHI) and hot (very high GHI) climatic regions are considered and applied for 127 cities globally. In this framework, the sequence of PV building component integration is proposed according to local climate of each zone and the energy performance of buildings is maximized towards their positive energy contributions and sharing in local, district and city grids. Barriers and limitations of the BIPV implementation at a larger scale are discussed and the emerging research needs are revealed. [Display omitted] • Literature on BIPV studies globally was reviewed and analyzed for seventy parameters grouped in eight main categories. • Global horizontal irradiation was considered as a new Köppen-Geiger climate classification index for BIPV. • A sequence of PV building integration component was obtained for one-hundred twenty-seven cities globally. • A BIPV climatic design framework for positive energy buildings was proposed towards carbon-neutral cities. • Main barriers and future research directions for widespread acceptance of BIPV technology were discussed. [ABSTRACT FROM AUTHOR]

The deep decarbonization of the power systems is pivotal to the efforts of global energy transition and climate mitigation. The small modular reactor (SMR) is a decarbonized, reliable and secure generating technology that can bring new possibilities for global power-sector transition. However, such a transition involves a variety of complexities even beyond conventional systems. We comprehensively explore the SMR deployment and the decarbonization pathway in a number of diversified power and jurisdictional systems under various complexities associated with multiple variables, objectives, criteria and constraints that have dynamic and interactive relationships. This effort is based on the development of an SMR-embedded multi-region power system management model (SMPM). Using Canada as an example, here we show that SMRs would play different roles in diversified power systems, particularly for fossil-fuel dependent, highly variable renewable energy-penetrated and off-grid. The introduction of SMRs to Canada would result in up to 71% (/48%) emission reduction from 2005 (/2018) level in the country by 2045. Our results would help show the significance of SMRs for supporting the global energy transition. [Display omitted] • An SMPM model is developed to analyze low-carbon power system transition in Canada. • Multiple complexities and uncertainties in power systems are reflected. • SMR development issue is investigated within a power-system optimization framework. • The regional development of Canada is analyzed by a holistic optimization method. • GHG emissions from Canada's power sector would be 48% lower in 2045 than in 2018. [ABSTRACT FROM AUTHOR]

Switchgrass is a promising feedstock for cellulosic biorefineries, due to its ability to maintain comparatively high biomass yields across a wide range of soil and climatic conditions. However, there is an incomplete understanding of the economic and environmental tradeoffs associated with cultivating switchgrass on low-productivity land for conversion to biofuels. This study surveys prior literature and demonstrates a new integrated assessment framework, including agroecosystem, ecosystem services valuation, technoeconomic, and life-cycle assessment models, to quantify and contextualize the economic and environmental impacts of switchgrass cultivation on marginal land with downstream conversion to biofuels. Monetizing and incorporating the value of ecosystem services, such as improved water quality benefits from nitrate and sediment reductions, climate change mitigation benefits from CO 2 emission reduction, and recreational and pollination benefits from increased biodiversity, the modeled multifunctional landscape reduces the ethanol production cost by 33.3–58.9 cents/ l -gasoline-equivalent ($1.3–2.2/gge). Planting switchgrass in low productivity land improves soil health, resulting in the carbon footprint reduction credit of 12.8–20.2 gCO 2e /MJ. For an improved switchgrass-to-ethanol conversion pathway with the maximum benefits from ecosystem services, the minimum ethanol selling price and carbon footprint of ethanol, respectively, could reach to 31 cents/ l -gasoline-equivalent (47% reduction relative to average gasoline price) and 3 gCO 2e /MJ (97% reduction relative to gasoline). This low carbon renewable ethanol leads to substantial State and/or Federal policy incentives (∼$1/ l -gasoline-equivalent) providing a large benefit to biorefinery operators, farmers, and the public as a whole. • Ecosystem services benefits reduced the delivered switchgrass cost by $29–104/bdt. • Switchgrass grown on marginal land increased carbon sequestration by 0.1–0.36 MgC/ha. • Ecosystem services benefits reduced ethanol selling price reduced by 20–55%. • Carbon footprint of ethanol reduced by 44–81% with ecosystem services benefits. • Biorefinery operators could make profit of 28 cents/ l -gasoline-equivalent. [ABSTRACT FROM AUTHOR]

Carbon Capture and Storage is a technology of paramount importance for the fulfillment of the Sustainable Development Goal 7 (Affordable and Clean Energy) and the Sustainable Development Goal 5 (Climate Action). The European Union is moving rapidly towards low carbon technologies, for instance via the Energy Union Strategy. Coupling biofuels and carbon capture and storage to decarbonize the power and the industrial sector can be done through the development of BECCS (Bioenergy with Carbon Capture and Storage). Chemical Looping combustion is one of the cheapest way to capture CO 2. A Chemical Looping Combustion (CLC) plant can be coupled with a turbo expander to convert energy to power, but it has to work in pressurised conditions. The effect of pressure on the chemical reactions and on fluidised bed hydrodynamics, at the moment, is not completely clear. The aim of this review is to summarize the most important highlights in this field and also provide an original method to optimize power plant efficiency. The main objective of our research is that to design a pressurised Chemical Looping Combustion plant which can be coupled to a turbo expander. To achieve this we need to start from the characteristics of the turbo expander itself (eg. the Turbine Inlet Temperature and the compression ratio) and then design the chemical looping combustor with a top down approach. Once the air and the fuel reactor have been dimensioned and the oxygen carrier inventory and circulation rate have been identified, the paper proposes a final optimization procedure based on two energy balances applied to the two reactors. The results of this work propose an optimization methodology and guidelines to be used for the design of pressurised chemical looping reactors to be coupled with turbo expanders for the production of power with carbon negative emissions. • BECCS technology can be developed by coupling PCLC with a gas turbine. • Efficiency of a chemical looping combined cycle plant can range between 42.1% and 52.4%. • Pressure can affect minimum fluidization velocity in the fluidised bed reactor. • The influence of pressure is dependent on the type of bed particles and their dimension. • Circulation rate is one of the most critical factors in PCLC design. [ABSTRACT FROM AUTHOR]

The OECD countries are failing to fulfil their obligation towards the implementation of the objectives of SDG 7 and SDG 13. The failure of OECD countries is major constraint concerning global progress on curbing GHG emissions and mitigation of climatic changes as it provides rationale for developing countries to avoid their commitments. Therefore, the major focus of COP26 was to explore policy options for sustainable transition of energy from fossil fuel to clean renewables. This study analyzes the impact of innovation in environmental technology along with various policy regimes on energy transition in OECD countries from 2000 to 2019. The driving factors of energy transition in OECD countries are analyzed, under moderation of environmental governance regimes. This objective is realized by constructing an Energy Transition Index that accounts for the movement along the energy ladder. This index is developed using the Energy Ladder Hypothesis. Using two-step system-GMM and segregating the sample across level of emissions, the results show that the regional authority augments the energy transition, while enforecement of the climate change laws shows mixed results. Based on the study outcomes, a policy framework is recommended for attaining the SDG objectives by realigning the climate change adaptation and mitigation policies. • Study aims at analyzing the energy transition drivers in the OECD countries. • Moderation of environmental governance is analyzed. • Energy Transition Index is developed. • Climate change adaptation policies are less effective than mitigation policies. • An SDG-oriented policy framework is recommended. [ABSTRACT FROM AUTHOR]

Energy saving in buildings is an important measure for mitigation of climate change. There exists a large potential for energy saving in buildings by improving the thermal performance of windows. For decisions on energy saving window retrofits, accurate estimation of the energy saved and its uncertainty is of importance. The ISO 15099 standard, which is normative for thermal modelling of windows within the building sector, does not give uncertainty estimates. The main novelty of this study was to provide uncertainty analysis for model prediction of the thermal transmittance of windows, in the perspective of decisions on window retrofits. For this purpose, we proposed a new simplified model, which facilitated uncertainty analysis, and still was similar to the ISO 15099 window model. The model was validated by application of a benchmark validation procedure to a set of previously performed validation experiments. Main conclusions were: (i) The model was accurate within a prediction uncertainty equal to 0.20 Wm−2K−1; (ii) The domain where the model is valid was described using existing well-documented validation experiments. This domain was restricted to windows with glazing thermal transmittance corresponding to 2-layer glazing, and to windows where the frame area is a minor part of the total window area. (iii) The prediction uncertainty was mainly determined by the measurement uncertainty in the validation experiments; (iv) If a window retrofit is based on reduction of window thermal transmittance, then this reduction has to be larger than 0.56 Wm−2K−1 in order to yield energy savings above the uncertainty limit. • New simplified model was proposed for prediction of window thermal transmittance. • Main novelty consists of estimation of prediction uncertainty for window model. • Benchmark validation was performed and domain of model validity was defined. • Measurement uncertainty was the major contributor to prediction uncertainty. • Criteria was given for window retrofit energy saving above the uncertainty limit. [ABSTRACT FROM AUTHOR]

There are critical mitigation opportunities in urban areas that can be better understood through urban level analyses in the context of climate scenarios. This research work develops an approach for emissions scenarios for specific urban areas based on Shared Socioeconomic and Representative Concentration Pathways with a focus on the green growth paradigm at the lowest radiative forcing outcomes. The scenario characteristic for compact urban form is further complemented with improvements in existing land use efficiencies that are based on the Global Human Settlement Layer. Urban emissions scenarios for 420 urban areas among those with the highest emissions footprint totaling about 10.7 GtCO 2 eq in 2020 and land use efficiency scenarios for the top 10 urban areas in 9 regions are analysed. The 90 urban areas that represent about 6.2 GtCO 2 eq of urban emissions and 83.3 thousand km2 of built-up area in 2020 are then compared in a two-dimensional scenario space. Co-benefits are quantified for a new 100% renewable energy scenario that represents electrification combined with sector coupling. Based on Monte Carlo simulations, random performances that near the most stringent emissions pathways in a range of ±10% can still approach net-zero emissions by 2050 in alignment with the temperature goal of the Paris Agreement. Yet there is a penalty of about 0.95 GtCO 2 even in the best land use efficiency scenario due to possible impacts of urban land expansion on the sequestration potential of local biomes. The results have widespread ramifications for guiding urban areas towards integrated action for reducing emissions, limiting the growth in urban extent, and providing co-benefits for urban inhabitants when effective action is needed urgently. • Urban emissions scenarios for 420 urban areas with the largest emissions footprint. • Scenarios consider green growth contexts and lowest radiative forcing outcomes. • Co-benefits are quantified for 90 urban areas in a 100% renewable energy scenario. • Future urban built-up area is projected based on land use efficiency improvements. • An integrated framework to compare urban emissions and built-up area is developed. [ABSTRACT FROM AUTHOR]

This review analyzed 75 studies published 2017–2021 investigating future wind resource evolution. It provides comprehensive information on the studies' specifications and globally summarizes the reported wind resource changes. The studies show substantial differences in design, limiting their comparability. Most studies evaluated a small number of regional climate models driven by general circulation models from CMIP5 under the worst-case scenario RCP8.5. The use of worst-case scenarios can be justified, intending to study climate change impacts for the most significant climate change signal. To quantify the differences between present and future resources, very short evaluation periods with average durations of 23.8 and 24.9 years were used. Our analysis reveals that the availability and distribution of wind resources would likely change in the future. The changes' magnitudes are usually greatest under the most pessimistic climate change scenarios. The direction of the changes varies spatially. The strongest wind resource decline was observed in the Western United States. Declining wind resources are likely in most parts of the northern hemisphere. For southern Brazil, a distinct wind resource increase is projected. For the design of future studies, it is recommended to use (1) the more realistic climate change scenarios SSP245, SSP460, and SSP370, (2) multi-model ensembles, which allow testing the statistical significance of the detected changes, (3) longer investigation periods (≥30 years) to reinforce the climate change relevance of the statements made. • State-of-the-art overview of 75 studies published between 2017 and 2021. • Validation of Coupled Model Intercomparison Project Phase 5 and 6 models. • Declining wind resource is likely in most parts of the northern hemisphere. • Increasing wind resource is likely in most parts of the southern hemisphere. [ABSTRACT FROM AUTHOR]

Biochar has received increasing attention in agricultural and environmental fields as an integrated solution to agricultural waste recycling, soil amendment, carbon sequestration, and greenhouse gas (GHG) reduction. However, obtaining the environmental benefits of biochar is limited by an inadequate number of soil applications. Currently, the willingness to use biochar in soil management is relatively low, which results from the insufficient understanding and promotion of the roles of biochar in soil management and climate change mitigation. This review article presents biochar applications based on carbon-neutral strategies in agricultural soil systems. The primary roles of biochar in soil improvement and remediation are discussed and the main soil application methods are introduced. The focus of this article is on biochar-based soil management strategies for contributing to carbon neutrality. Carbon sequestration using biochar is an application-dependent strategy, as the key to obtaining this ecological benefit is to store biochar products in soil via effective agricultural management. This article offers insights into biochar-based soil management strategies and their contribution to carbon neutrality in agricultural soil systems, with recommendations for appropriate government involvement in promoting biochar-based soil management and for incorporating biochar into the carbon trading market. • The non-CO 2 GHGs account for the majority of carbon emission via agricultural soil. • Incorporating biochar into the global carbon trading market is recommended. • Using biochar to help achieve carbon neutrality is an application-dependent strategy. [ABSTRACT FROM AUTHOR]

Wind energy is a mature and cost-effective solution to greenhouse gas emission reduction and climate change mitigation. Wind resource assessment is the most pivotal activity before wind farm development since it determines the bankability of the wind project. Based on the joint use of a Doppler wind sodar (sonic detection and ranging) system and a microwave radiometer, this paper investigates the wind and thermal characteristics and wind energy resources in a coastal region of Hong Kong. First, wind climatology and variability, as well as their correlation with large-scale and local meteorological and geographical conditions, are analyzed and discussed. Then, statistical distributions of wind speed are evaluated, and the goodness-of-fit of the Weibull, Kappa, Wakeby, Normal-Weibull mixture, and Weibull-Weibull mixture distributions is assessed. Subsequently, the probability distribution and variation of atmospheric stability are examined, and their effects on vertical wind shear, wind profile, and wind speed at turbine hub height are revealed. Lastly, the spatiotemporal variation of wind power density is investigated with attention paid to air density. The results presented in this paper are expected to offer insights into coastal wind and thermal characteristics, provide references for vertical extrapolation of wind speed and wind turbine load evaluation, and facilitate wind farm development in coastal regions. • Investigation of coastal wind climatology and variability in Hong Kong. • Evaluation of statistical distributions of wind speed, gradient Richardson number, and air density. • Exploration of vertical variation of wind speed, air density, and wind power density. • Analysis of wind shear coefficient under different atmospheric stability conditions. • First known study of wind resources that jointly uses sodar and microwave radiometer. [ABSTRACT FROM AUTHOR]

Achieving sustainable urban development requires a reorientation in the planning, management, and design of cities based on the use of cross-cutting solutions that can systematically address urban problems. The implementation of Nature-based Solutions (NBS) such as green walls in cities contributes to reducing the effects of a systemic issue: climate change. This field of research is constantly evolving, and there is a growing need for systematic analysis to understand the current scenario, identify gaps, and accelerate new lines of research. This review aims to demonstrate the impact of green walls on urban comfort by providing a systematic review of the state of the art in the field of temperature reduction and acoustic absorption, identifying the factors that influence urban comfort through the use of vegetation, and highlighting research gaps that can be further explored. The most relevant results have shown that the temperature reduction is mainly influenced by the shading capacity of the selected vegetation type, the evapotranspiration process of the plants, and the presence of substrate. Also, the acoustic absorption capacity is influenced to a greater extent by the system's configuration, the substrate's characteristics, and the vegetation's density. In both cases, the environmental conditions in which they are found can vary the impact to a greater or lesser extent. The results of this research are relevant for the implementation of green walls as a climate change mitigation tool in cities and the development of new research approaches. • Green walls have a positive impact on thermal and acoustic urban comfort. • Shading and evapotranspiration reduce from 0.8 °C to 31 °C depending on the system configuration. • 80% of the noise absorbed by a green wall is due to the presence of the substrate. • For dense vegetation, the absorption coefficient can increase by 0.2–0.3. • The evapotranspiration impacts temperature reduction if irrigation of 2.5 L/m2/day is ensured. [ABSTRACT FROM AUTHOR]

Pyrolysis can be used to produce renewable energy and offset greenhouse gas emissions. While the biopower potential of pyrolysis has been widely analyzed, agronomic and environmental benefits under competing pyrolysis modes have not been investigated and compared. This study reviews the properties and characteristics of major pyrolysis technologies including fast, intermediate, slow, gasification, and torrefaction, and then investigates and compares their biopower potential and the biochar-induced agronomic and environmental benefits so that the fundamental figures for future large-scale biopower development can be explored. The results indicate that (1) revenues from energy sale generally outweigh the agronomic and environmental benefits, but the extent depends on the commodity price and emission price; (2) if biochar is not used as an energy source, 10.58%–26.73% of biopower generation is decreased for fast pyrolysis and a 90%–97.44% decrease would occur for torrefaction; (3) biochar-induced agronomic benefits and emission offsets from torrefaction can greatly recover the loss of energy sales; and (4) with torrefaction the emission offset can be up to 2.82–3.19 tonnes carbon dioxide, on a per tonne biomass basis. We also discuss how biochar application might alleviate surface water eutrophication and groundwater pollution. • Mitigation potential of torrefaction is up to 3.19 MT per ton feedstock. • Without the use of biochar, power generation of fast pyrolysis declines by 26.73%. • Torrefaction benefits agronomic mostly but yields least biopower. • Changes in energy and emission prices would cause technology transitions. • Slow pyrolysis balances biopower production and mitigation effects. [ABSTRACT FROM AUTHOR]

Bioenergy aims to reduce greenhouse gas (GHG) emissions and contribute to meeting global climate change mitigation targets. Nevertheless, several sustainability concerns are associated with bioenergy, especially related to the impacts of using land for dedicated energy crop production. Cultivating energy crops can result in synergies or trade-offs between GHG emission reductions and other sustainability effects depending on context-specific conditions. Using the United Nations Sustainable Development Goals (SDGs) framework, the main synergies and trade-offs associated with land use for dedicated energy crop production were identified. Furthermore, the context-specific conditions (i.e., biomass feedstock, previous land use, climate, soil type and agricultural management) which affect those synergies and trade-offs were also identified. The most recent literature was reviewed and a pairwise comparison between GHG emission reduction (SDG 13) and other SDGs was carried out. A total of 427 observations were classified as either synergy (170), trade-off (176), or no effect (81). Most synergies with environmentally-related SDGs, such as water quality and biodiversity conservation, were observed when perennial crops were produced on arable land, pasture or marginal land in the 'cool temperate moist' climate zone and 'high activity clay' soils. Most trade-offs were related to food security and water availability. Previous land use and feedstock type are more impactful in determining synergies and trade-offs than climatic zone and soil type. This study highlights the importance of considering context-specific conditions in evaluating synergies and trade-offs and their relevance for developing appropriate policies and practices to meet worldwide demand for bioenergy in a sustainable manner. • Synergies and trade-offs between SDGs from land use for bioenergy. • Synergies are related to water quality, soil quality and biodiversity conservation. • Trade-offs are related to water availability, food security and revenue. • Previous land use and feedstock are more relevant than other context conditions. [ABSTRACT FROM AUTHOR]

Prospective Life Cycle Assessment (pLCA) is useful to evaluate the environmental performance of current and emerging technologies in the future. Yet, as energy systems and industries are rapidly shifting towards cleaner means of production, pLCA requires an inventory database that encapsulates the expected changes in technologies and the environment at a given point in time, following specific socio-techno-economic pathways. To this end, this study introduces premise , a tool to streamline the generation of prospective inventory databases for pLCA by integrating scenarios generated by Integrated Assessment Models (IAM). More precisely, premise applies a number of transformations on energy-intensive activities found in the inventory database ecoinvent according to projections provided by the IAM. Unsurprisingly, the study shows that, within a given socio-economic narrative, the climate change mitigation target chosen affects the performance of nearly all activities in the database. This is illustrated by focusing on the effects observed on a few activities, such as systems for direct air capture of CO 2 , lithium-ion batteries, electricity and clinker production as well as freight transport by road, in relation to the applied sector-based transformation and the chosen climate change mitigation target. This work also discusses the limitations and challenges faced when coupling IAM and LCA databases and what improvements are to be brought in to further facilitate the development of pLCA. [Display omitted] • Prospective LCA can benefit from projections of models such as IAM. • Premise streamlines the production of LCA databases based on prospective scenarios. • Emissions and energy efficiencies of major industries are aligned with IAM scenarios. • Stricter greenhouse gas targets result in larger transformations in the LCA database. • However, such targets result in increased LCA impacts other than global warming. [ABSTRACT FROM AUTHOR]

Space-based geoengineering is gaining attention, if not necessarily traction, as a possible "break the glass" solution to mitigate the worst impacts of climate change and facilitate the transition to a low-carbon future. Though still on the periphery of discussions around climate mitigation and geoengineering, space-based methods that would deflect or block incoming sunlight, and thereby diminish how much radiation ultimately reaches the Earth, could offer advantages, notably, by avoiding the need for difficult trade-offs and decisions in terms of land and resource use on Earth. Aside from a few specialist-oriented studies, the literature on space-based geoengineering remains limited. In this study, we utilize a large and diverse expert-interview exercise (N = 125) to provide a first critical examination of the promise and relevance of space-based geoengineering for tackling climate change, including perhaps as a source of renewable energy, its feasibility and prospective risks, as well as key actors and issues related to commercialization and governance. To our knowledge, no other study has employed empirical data of any kind to examine perceptions of space-based geoengineering, let alone in relation to other kinds of climate-intervention technologies. Not only does the current research represent the first of its kind, it also provides a foundation for more informed, comprehensive deliberations around this interesting, possibly even necessary solution to climate change. • Space-based solar geoengineering is a radical proposal for tackling climate change. • No study has so far employed empirical data to explore perceptions of space-based proposals. • Our data is derived from a diverse set of 125 original interviews with key experts. • The promise, feasibility, and risks for climate mitigation are critically examined. • We also engage with the potential of sunshades to provide significant amounts of renewable energy. [ABSTRACT FROM AUTHOR]

Space-based geoengineering is gaining attention, if not necessarily traction, as a possible "break the glass" solution to mitigate the worst impacts of climate change and facilitate the transition to a low-carbon future. Though still on the periphery of discussions around climate mitigation and geoengineering, space-based methods that would deflect or block incoming sunlight, and thereby diminish how much radiation ultimately reaches the Earth, could offer advantages, notably, by avoiding the need for difficult trade-offs and decisions in terms of land and resource use on Earth. Aside from a few specialist-oriented studies, the literature on space-based geoengineering remains limited. In this study, we utilize a large and diverse expert-interview exercise (N = 125) to provide a first critical examination of the promise and relevance of space-based geoengineering for tackling climate change, including perhaps as a source of renewable energy, its feasibility and prospective risks, as well as key actors and issues related to commercialization and governance. To our knowledge, no other study has employed empirical data of any kind to examine perceptions of space-based geoengineering, let alone in relation to other kinds of climate-intervention technologies. Not only does the current research represent the first of its kind, it also provides a foundation for more informed, comprehensive deliberations around this interesting, possibly even necessary solution to climate change. • Space-based solar geoengineering is a radical proposal for tackling climate change. • No study has so far employed empirical data to explore perceptions of space-based proposals. • Our data is derived from a diverse set of 125 original interviews with key experts. • The promise, feasibility, and risks for climate mitigation are critically examined. • We also engage with the potential of sunshades to provide significant amounts of renewable energy. [ABSTRACT FROM AUTHOR]

Crop residue management remains a major problem in the Indian agriculture sector. The in-situ firing of crop residues has been linked to air pollution, global warming, soil fertility decline and others. Biochar conversion through slow pyrolysis could be one of the techniques for the safe disposal of crop residues. 212.04 ± 44.27 MT biochar could be produced from 517.82 MT crop residues in India. Biochar conversion of crop residues can address agriculture production, safe drinking water, livelihood, energy security and environmental protection. Soil amendment with biochar sequestrate about 376.11 ± 78.52 MT CO 2 e carbon and help retain about 1.66 ± 0.46 MT of soil nutrients. Also, crop residues derived biochar has an estimated market value of approximately $500 billion in India. Biochar applications in the cosmetics, pharma and chemical industries offer market and employment opportunities. This review discusses the impact of in-situ crop residue burning and its biochar conversion through slow pyrolysis as part of sustainable crop residue management. Also, biochar applications and socio-economic aspects of crop residues – biochar system has been deliberated to fulfil several sustainable development goals (SDGs). [Display omitted] • Impacts of crop residues in-situ firing in India were quantified and discussed. • Biochar conversion of crop residues for its strategic management was discussed. • Impact of pyrolysis process parameters on biochar yield & properties was reviewed. • Biochar as a conventional & upcoming value-added product was comprehensively analysed. • Crop residues – biochar system for the attainment of SDGs has been mapped. [ABSTRACT FROM AUTHOR]

Air-to-water heat pumps are regarded as a fundamental part of many proposed climate action plans in heating dominated climates. However, individual studies have concluded that this technology generally underperforms in practice when compared to its rated performance. This study aims to harmonise these conclusions and propose reasons for this reported underperformance. The European standards used to rate the performance of heat pumps are first reviewed and deconstructed, a review and analysis of all past research that report air-to-water heat pump performance is then conducted. Finally, a novel in-situ monitoring study of an air-to-water heat pump in Ireland is presented. Of the 378 heat pumps reviewed, it was found that the average seasonal performance was 2.59, significantly lower than typical product rated performances. Three reasons for this underperformance include, misrepresentative weather data for certain locations, unaccounted for losses in the distribution pipes and unaccounted for effects of cycling. The measured seasonal performance factor of the case study heat pump monitored in this paper was 2.49 for space heating. This 40% reduction in performance, when compared to the product rated performance of 4.12, was attributed to the three reasons identified. Because these reasons are largely due to inadequate installation practice, environmental policy should focus not just on the quantity of these technologies to be installed but critically also on the quality of the installation itself. • Review of heat pump field studies evidences consistent underperformance. • Heat pump rating in the EU and heat pump in-use performance are analysed. • Heat pump performance metrics are defined, compared and evaluated. • A case study analysis reports ∼40% lower performance in-use than product rating. • The difference is primarily due to losses in the pipe run and unaccounted for cycling. [ABSTRACT FROM AUTHOR]

The circular economy has potential synergies with climate change mitigation, although quantitative evidence for these synergies in the consumer product sector has not yet been systematically evaluated. We conducted a systematic review of existing studies of consumer-oriented product-service systems (PSS) on the lifecycle impacts, focusing on a meta-analysis of global warming potentials. Potential reductions in greenhouse gas emissions and the risk of backfire as a result of 10 types of circular economy strategies were investigated by reviewing 103 studies and more than 1500 scenarios for consumer durable and semi-durable products. As many as three-quarters of the reviewed studies analyse only one circular economy strategy rather than comparing (e.g., reusing, sharing, and renting) or integrating multiple strategies (e.g., leasing combined with remanufacturing). Approximately one-third of the reviewed studies rely on assumptions for set parameters of use, transport, and end-of-life phases, whereas more than half of the studies do not consider service and infrastructure provisions, or imperfect product substitution. Among the reviewed case studies, upgrading, repair, refurbishing, and pooling showed moderate to high improvement potentials with lower risks of backfiring, whereas servitisation, sharing, and reuse were associated with higher backfire risks, but they had high improvement potentials. The risk of backfiring was explained by factors such as transport, number of uses, product substitution and lifetime, maintenance, energy source, and energy efficiency. This meta-analysis revealed the importance of prioritising low-risk strategies, controlling for rebound effects of high-potential strategies, and integrating multiple strategies in order to utilize PSS for climate change mitigation. • More than 1500 consumer-oriented PSS scenarios in 103 studies were reviewed. • Low-risk strategies (upgrading, repair, refurbishing, and pooling) should be prioritised. • High-potential strategies (servitisation, sharing, and reuse) need rebound controls. • Synergies can be expected by integrating multiple circular economy strategies. • Empirical analysis of critical parameters is required for improved PSS assessments. [ABSTRACT FROM AUTHOR]

Increasing demand by the public and shareholders for substantial actions against the climate crisis is forcing organisations of all sectors to manage their greenhouse gas emissions more effectively. One method for organisations to reduce their emissions is Internal Carbon Pricing (ICP). So far, a comprehensive overview on ICP, especially on the impacts and barriers to its implementation, is missing. This paper closes the knowledge gap by summarising the motives for organisations to use ICP, by discussing the different ICP methods and by describing their impacts as well as identifying key implementation barriers. The work condenses the findings into a flow chart for easy identification of promising ICP methods while accounting for implementation barriers. The discussed ICP methods are emissions trading systems, proxy prices, carbon fees and hybrid systems. The review also discusses ICP methods which are not that common such as revenue-neutral carbon fees. The developed flow chart underlines two common barriers for implementing ICP. These are, 1) frequent difficulty allocating emissions to the responsible cost center within an organisation; 2) the challenge cost centers face reacting to the ICP by changing processes, technologies or products. Nevertheless, the results underline a variety of methods that allow the effective use of ICP under different organisation-specific circumstances. The literature review also emphasises the need for more in-depth case studies on the implementation of ICP within organisations. • Concise overview on the motivation, the methods, impacts and implementation barriers of internal carbon pricing. • Review of case studies where the impacts and problems of ICP are described. • Frequently used internal carbon pricing method is proxy prices. • First main implementation barrier is the ability to allocate emissions to the emission-responsible cost center. • Second main implementation barrier is the ability of cost centers to react to the ICP by changing processes or products. [ABSTRACT FROM AUTHOR]

Building stock models (BSMs) are essential for simulating the contributions of regional and national building sectors to climate change under different policy scenarios, and for identifying pathways to climate change mitigation. To date, BSMs have focused on the operational life-cycle impacts of domestic dwellings; there has been less emphasis either on non-domestic buildings (NDBs) or full life-cycle analysis. This paper provides a first review of the theory and practice of NDB stock modelling which considers life-cycle energy, emissions and costs. A meta-analysis of the literature was undertaken involving a structured search of relevant articles in key scientific repositories. 98 in-scope studies were identified and data collected on their aims and objectives, methodologies, data sources, system boundaries, considered impacts, representativeness, uncertainty analysis, validation and verification techniques, further research identified, model transparency and software tools employed. The review necessitated the classification of modelling methodologies. The existing 'bottom-up' and 'top-down' groups were found to be ambiguous and led to confusion. Therefore, an alternative methodology classification is proposed, considering both the modelling technique and model simulation data used. The findings of the analysis indicate that most approaches use engineering models employing archetype data. However, almost all current life-cycle models of NDB stocks are incomplete. Only one study considered the full building life-cycle and most did not include uncertainty analysis. The reproducibility of study results is poor since most do not provide sufficiently-detailed information on the models and data used. Critically, there is a lack of representative input data which limits their usefulness as evidence in policymaking. • Existing stock modelling methodology categories are ambiguous and lead to confusion. • Non-domestic stock modelling is underdeveloped due to data limitations. • Most studies of do not include uncertainty analysis. • Consequently, their usefulness for evidence-based policymaking is limited. • This is a fragmented research field utilizing many diverse methods and tools. [ABSTRACT FROM AUTHOR]