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• Many local authorities are preparing climate actions plans. • Policies to increase distributed energy generation such as PV are likely. • As capacities increase, PV can dominate system variability and predictability. • Predictive demand side response (DSR) may be too coarse to address this. • More granular techniques such as using system frequency may be required. Since 2018, over three quarters of UK local governments have signed climate emergency declarations signalling a new phase in local climate action. Many areas are developing climate action plans and considering what policies could be adopted to increase the use of distributed energy resources, such as building-integrated photo-voltaic (PV) generation. In this paper we demonstrate how city-scale backcasting can be used as a tool to go beyond technical feasibility and explore the policy, market and governance implications of decarbonisation pathways across the local and nation scales. Using urban PV as an example we model three scenarios for increasing installed capacity in the UK city of Bristol and demonstrate how, in each case, PV switches from being a minor 'negative load' on the energy system to being the dominant factor determining the volatility and predictability of the energy demand during daylight hours. Current approaches to integrating distributed energy resources into the wider system tend to focus on predictive modelling and half-hourly pricing to drive demand-side response. Our analysis indicates the risks of relying on these non-real time methods and suggests that more granular techniques such as triggering local DSR based on changes in electricity system frequency could better manage the variability of high levels of PV deployment at the local scale. We also demonstrate the importance of developing new local approaches to system integration that bring together network operators, local authorities and other local actors to deploy renewable generation and flexibility assets in coordination. [ABSTRACT FROM AUTHOR]

• Localized socioeconomic and natural narratives are applied on the regional scale. • Propose ecological zoning management in mountainous agglomerations. • POP, GDP, DEM, and Slope have an inverted U-shaped relationship with carbon storage. • Urbanization expands into the western mountainous under the localized SSP5–8.5 narrative. Ecological carbon storage is critical to climate change mitigation by absorbing CO 2 from the atmosphere. Mountainous ecosystems, crucial carbon reservoirs, are experiencing persistent carbon storage declines, yet management mechanisms targeting such complex terrains remain challenging. Focusing on the Sichuan-Chongqing urban agglomeration, interwoven as mountains and basins, we employed the MPI-coupled (Improved Markov-PLUS-InVEST) model and localized "socio-economic-climatic" narratives to simulate the dynamic evolution of carbon storage over extended periods. Diverse impacts and gradient effects of social, economic, and natural (incl. terrain, climate) drivers on carbon storage are further examined. The findings revealed that: (1) The most carbon storage growth projected from 2030 to 2060 reaches 1.53 %, but of which localized SSP5–8.5 narrative the urbanization encroached upon the undeveloped mountainous, severely impairing carbon sequestration by 81.5Tg. (2) In addition to landscape types, carbon storage exhibits complex spatial responses to economic development, population size, and terrain with an inverted U-shaped relationship. The proposed methodology offers more accurate carbon storage estimates and assists policy-makers in similar terrains to effectively manage the spatial heterogeneity of carbon storage. This study facilitates the implementation of tailored ecological conservation through urban zoning, thus contributing to enhanced subregional climate change mitigation efforts globally. [ABSTRACT FROM AUTHOR]

From a global perspective, climate change mitigation requires countries to consider Low-Carbon Development (LCD) policies, including "Low-Carbon Transport (LCT)" and decarbonization options, which should be ideally developed within a place-based scope. Due to the complex structure of the transportation sector, mitigation actions require not only technological but also behavioral shifts, which can be challenged by the existing legislative and socio-economic structure of a region. Therefore, it is essential to identify and assess barriers and opportunities (B&Os) as a necessary initial phase in the development of national mitigation strategies. Turkey voluntarily started climate change mitigation by preparing the legislative and political infrastructure as a part of the European Union Harmonization Process. Detection of B&Os in other dimensions required an in-depth evaluation of existing LCT barriers and instruments (B&Is) in the IPCC literature in terms of their applicability and priority for Turkey. A focus group study with transport sector representatives was conducted to evaluate 15 barriers and 19 instruments (proposing 285 B&I matrix combinations), followed by a brain-writing exercise that revealed 12 main barriers (i.e., a lack of measurable targets, an imbalanced modal split, a lack of institutional coordination and data archiving, etc.). Various opportunities have been identified, such as the increased utilization of Intelligent Transportation Systems and the timely adoption of vehicle and fuel technologies in the EU region. These opportunities would not only contribute to the development of a national climate change mitigation strategy but also facilitate the implementation of place-based action plans, including climate change action plans and sustainable urban mobility plans at the city level. • Detection of barriers and opportunities is crucial for decarbonization in countries. • A five-step methodology was developed. • Survey, brain-writing and roundtable discussions were performed. • Major barriers included lack of measurable targets, imbalanced modal split and lack of coordination. • Intelligent transportation systems, new vehicle and fuel technologies were major opportunities. [ABSTRACT FROM AUTHOR]

• Just low-carbon transition in food systems needs conceptualisation. • We introduce principles and criteria as a guiding framework for the conceptualisation. • We establish a conceptual framework for clarifying justice in food system low-carbon transition. • The framework is suitable for application in different contexts. • The principles of the framework suit conceptualizing justice in any transition sector. In this article, we propose a framework of principles and criteria for just transitions in food systems. Climate mitigation activities are urgently needed in food systems, but can have damaging social, environmental, economic, and health impacts. Consequently, food system transitions can cause significant side effects across and beyond food systems, aggravating existing inequalities and unsustainabilities, causing new ones, or hampering equal engagement in the transition itself. Thus, justice questions stand at the core of assessing decarbonization pathways and policies and must link to other sectors as well: Who bears the costs and who enjoys the benefits of the transitions? Can transitions be inclusive, leaving no one behind? We examine the establishment and purpose of general principles and food system-specific criteria for just transition, present the framework – standards for judging, evaluating, and deliberating justice in food system transitions – and reflect upon the uses of the framework and future developments. [ABSTRACT FROM AUTHOR]

This study aims to unveil the heterogeneous impacts of import product diversification and institutional factors for achieving energy efficiency in Organization for Economic Co-operation and Development (OECD) countries. In doing so, the study employs robust econometric techniques such as Fully modified ordinary least squares (FMOLS) co-integration, pooled Ordinary Least Squares (OLS), Feasible Generalized Least Squares (FGLS), pool mean group regressions, fixed effects, and random effects for panel data from 1990 to 2015 for selected OECD countries. The detailed empirical outcomes suggest that import product diversification is conducive to reducing the energy and carbon intensity (improvement in energy efficiency) in OECD countries. The empirical conclusions provide various guidelines to achieve cleaner and greener growth and align with various Sustainable Development Goals (SDG 7: Affordable and clean energy, SDG 9: Industry, innovation, and infrastructure, and SDG 13: Climate action) of OECD countries. The paper elaborates fruitful policy suggestions regarding the diversification of imports and energy use-carbon emission-nexus for the OECD member nations. Based on the findings, policymakers and environmental scientists should strengthen the trade-energy and import portfolio policies to attain energy efficiency. [ABSTRACT FROM AUTHOR]

Approximately 172 million rural households in China in 2022, will still rely on traditional biofuels instead of electricity. This study explores the feasibility of achieving rural electrification in China utilization various Energy origins and assesses its potential impact on climate change mitigation. To do so, we employ the Regional Energy Model (REM) to formulate hypotheses for rural power distribution. Covering the era from 2020 until 2050. We evaluate consequences in terms of greenhouse gas discharges, principal energy consumption, associated expenses by comparing these possibilities with a Business- as -Usual (BU) scenario. Our findings reveal that diesel-based arrangements tend to produce 'the maximum Carbon Dioxide (CO2) emissions, trailed by network-based solutions. Electrification focused on renewable energy-driven applications has the potential to reduce total CO2 emissions by up to 97 % and primary energy consumption by 43 % in 2050 compared to the BU scenario. We also find that electrification through decentralized diesel systems tends to be the priciest choice. Rural electrification utilizing renewable energy emerges as a cost-effective choice when the majority of end-use applications rely on renewable energy sources. However, it becomes less economical than network expansions when electric end-user appliances are predominant. In summary, this study investigates the viability of renewable energy for rural power distribution and its role in climate change abatement in rural China, offering policy suggestions. • Analyzes six energy-based scenarios for China's rural electrification until 2050. • Evaluates GHG emissions, energy use, and costs impacts with regional energy model. • Provides policy insights and uncertainties for China's sustainability goals. • An oil price and distance-based analysis also is done with extra 6 scenarios. [ABSTRACT FROM AUTHOR]

Planning power system (PS) towards renewable energy is crucial for reducing carbon dioxide (CO 2) emission as well as mitigating climate change. However, the inherent uncertainty and hierarchical structure of PS pose intractable challenges to the planning process. This study develops a multi-GCM-based interval bi-level programming (MIBP) method that can balance two-level decision-making conflict between CO 2 -emisison reduction and system cost minimization. MIBP can also deal with uncertainties expressed as interval values in objective functions and constraints. Then, a MIBP-PS model is formulated to plan PS for China (2021–2050), where the upper-level objective is to minimize CO 2 emission and the lower-level objective is to minimize the system cost. The major findings are: (i) the CO 2 emission for PS would reach peak value before 2030 and then reduce by [10.2, 20.4]% in 2050, which is mainly owing to the curtailment of fossil fuel; (ii) compared with the conventional model, CO 2 emission from MIBP-PS model could decrease by [3.1, 4.8]%, which shows the superiority of the developed model; (iii) the fossil-fuel power would be gradually replaced by renewable energy, and the proportion of coal-fired power would decrease by 38.8% by 2050, especially small coal-fired facilities (i.e., below 0.3 GW) should be gradually phased down. [Display omitted] [ABSTRACT FROM AUTHOR]

Nudge-based decarbonization policies possess significant potential to foster low-carbon lifestyles and contribute to the mitigation of climate change. However, securing public support for such policies is a complex endeavor. The pivotal role of policy narratives in molding public perceptions and garnering support underscores the necessity for a strategic approach in the crafting and deployment of these narratives to strengthen public endorsement of nudge-based decarbonization strategies. This study examines the influence of victim framing on the potency of policy narratives to bolster public support for nudge-based decarbonization policies. The study elucidates that narratives portraying climate change victims as humans rather than wildlife more effectively bolster support for policies. Furthermore, policy narratives featuring a lesser number of victims prove more efficacious in augmenting support for these policies. Moreover, the relationship between the number of victims and the narrative's impact on policy support transitions from negative to positive in the context of high narrativity. These disparities in narrative effectiveness can be attributed to their varying abilities to evoke compassion. These insights offer valuable guidance for enhancing public support for nudge-based decarbonization policies, highlighting the strategic use of policy narrative as a key tool in policy promotion. • Policy narratives portraying climate change victims as humans rather than wildlife more effectively bolster public support for nudge-based decarbonization policies. • Policy narratives featuring a lesser number of victims prove more efficacious in augmenting public support for these policies. • In the context of high narrativity, the relationship between the number of victims and the policy narrative's impact on public support for these policies transitions from negative to positive. [ABSTRACT FROM AUTHOR]

The environmental impact of battery electric vehicles (BEVs), which are an integral part of climate change mitigation measures, depends on charging strategies, such as uncontrolled charging, controlled charging (V1G), and discharging (V2G). However, the impact is unclear because power system operation involves the cost of carbon dioxide (CO 2) emissions and flexibility requirements for imbalances caused by renewable energies. To clarify the robustness of the environmental impact of BEVs, we assessed the interactions between CO 2 prices and flexibility requirements in Japan in 2030 using a production cost model. The results showed that uncontrolled charging increases CO 2 emissions, whereas V1G or V2G reduces them. Further, the impact of BEVs was non-monotonic with respect to CO 2 prices, implying that policymakers should carefully evaluate CO 2 prices to achieve decarbonization as BEVs do not always reduce CO 2 emissions. This study provides useful insights for policymakers in countries with low-cost, inflexible, and high-emission power plants. [ABSTRACT FROM AUTHOR]

In 2018, Costa Rica demonstrated its commitment to the Paris Agreement and published its Decarbonization Plan for achieving zero net emissions by the year 2050. We evaluate the impacts of the country's strategy for decarbonizing its Agriculture, Forestry and Other Land Uses (AFOLU) sectors by coupling the Integrated Economic-Environmental Modeling framework with high-resolution spatial land use-land cover change and ecosystem services modeling (IEEM+ESM). Our results show that decarbonization of AFOLU would simultaneously enhance carbon storage, water purification, water regulation and erosion mitigation ecosystem services. Moreover, the positive cumulative wealth impact of decarbonization would be approximately US$7.27 billion by 2050 while lifting an additional 3810 individuals out of poverty. From a public investment perspective, decarbonization would have a fiscally neutral impact with the economic benefits sufficient in magnitude to off-set policy implementation costs and generate economic returns of over US$852 million when changes in natural capital stocks and environmental quality are considered. This application to Costa Rica is the first integrated economy-wide analysis of a growing number of decarbonization plans globally. The IEEM+ESM approach provides an integrated framework for analyzing decarbonization plans and can be used to refine AFOLU mitigation strategies to capitalize on synergies and minimize negative trade-offs across the three dimensions of wealth and sustainable economic development, namely economy, society and the environment. • Decarbonization of Costa Rica's AFOLU will generate US$7.3 billion in wealth. • AFOLU decarbonization will be fiscally neutral and generate returns of US$852 million. • The methods can be applied to integrated analysis of decarbonization globally. [ABSTRACT FROM AUTHOR]

The Chinese government has announced ambitious carbon reduction goals to address climate change, however, there has been limited scientific attention to the achievement of deep decarbonization in regions with insufficient economic development. Moreover, the complex impacts of climate change mitigation on energy system, environment and economic development remain unclear in Northwest China. Here we construct a comprehensive evaluation model system to evaluate the effects of different climate mitigation pathways in Qinghai, Ningxia, Gansu and Xinjiang provinces. Results show that the four provinces need to vigorously increase the share of electricity that consumed in final energy to 53.1–60.0% and 52.9–62.0% for 2 °C and 1.5 °C target, respectively, and reduce total energy demand to 11.6–44.4 Mtoe and 8.2–34.1 Mtoe in 2050. Meanwhile, the CO 2 emissions for their energy systems will reach peak by 2025 at lower values. Moreover, the synergies of CO 2 reduction are most conducive to abating SO 2 pollution and also contributing to decreasing PM 2.5 concentrations. Additionally, the GDP losses in 2050 fluctuate from 5.0 to 21.7 billion USD in the 2 °C scenario to 11.5–52.7 billion USD in the 1.5 °C scenario. Our study provides practical guidance on achieving carbon reductions in less developed regions of China and lays foundations to promote decarbonization of energy systems in other provinces. • Realizing climate goals requires low-carbon energy systems led by electricity. • Energy-related carbon emissions in Northwest China will peak by 2025. • More ambitious climate and clean air policies are needed for air quality improvement. • Economic loss shows an upward trend in the future under climate targets. [ABSTRACT FROM AUTHOR]

In the quest for carbon neutrality, the cement industry employs various CO 2 mitigation strategies, including material efficiency, cement plant technologies, and clinker-to-cement ratio reductions. This study reviews the past decade's Life Cycle Assessment (LCA) literature on cement production to assess the feasibility of modeling these strategies. Heating energy is the predominant factor in energy consumption, benefiting from energy efficiency measures. Allocation consistently favors cement in evaluations of secondary fuel-related impacts, leading to significant reductions in energy consumption and Greenhouse Gas (GHG) emissions. However, transparency improvements are necessary to clarify the origin and calculation of combustion-related emissions. Challenges arise from limited data availability when assessing grinding energy, especially for high-quality cement aligned with a material efficiency strategy. In our examination of Ground Granulated Blast Furnace Slag (GGBS) as Supplementary Cementitious Materials (SCMs), we have observed that production process variations and allocation assumptions significantly influence LCA models, while highlighting the absence of waste availability consideration in current substitution-focused LCA methods for both secondary fuels and SCMs. • Cement functionalities are generally not described and should be based on strength. • Existing models overlook impacts of increased cement quality due to grinding energy. • Allocation method choice affects climate change impacts of slag-blended cement. • Excluding allocation methods, slag recovery shows climate change impacts variability. • Substantial variability is also found for heating energy for clinkerization. [ABSTRACT FROM AUTHOR]

The green energy transition is aimed at mitigating the impact of climate change. Yet, the current emphasis on 'green' is narrowly centred around decarbonisation, or CO 2 reduction, often side-lining the roles of other gases, such as sulphur hexafluoride (SF 6) and PCF-14 (CF 4), which have a respective 24,300- and 7380-times higher global warming potential than CO 2 on a time horizon of a century. In addition, any energy transition is a complex affair that simultaneously impacts the environmental, economic and social systems, with significant system-level interactions. For example, the material requirement for renewable energy is known to be substantial, at a factor of 15 times greater than natural gas-based energy for offshore wind generation, and almost 7 times greater for solar. The resulting increased competition for materials is reducing the appetite for global collaboration. In addition, the global capacity to deploy renewable energy technology or participate in climate change mitigation is geographically variable and no single solution is universally viable. This study examines an expanded definition of 'green' energy and proposes a beyond-decarbonisation approach that is more comprehensive and globally inclusive, in pursuit for a sustainable transition. The increased diversity of our approach promises advantages such as heightened global collaboration, diminished geopolitical tension, improved energy access, expanded market opportunities, and socio-environmental co-benefits. Strategies pivotal to this approach involve understanding the role of carbon-based energy systems in the transition, amplifying renewable resources, augmenting cross-sector energy efficiency, implementing effective carbon markets, and integrating nature-based as well as carbon removal technologies. Moreover, it is imperative to implement all-cost and all-benefit monitoring and evaluation systems to optimise existing decarbonisation methods systematically. This could entail the use of composite metrics that normalise the gain in climate change mitigation against economic, social or environmental metrics. Addressing societal apprehensions requires a focus on pragmatic and fair outcomes, geopolitical stability, market impacts, developmental objectives, effective public engagement, and recognition of the role of enterprises. Policymakers are important in fostering global synergy by implementing policies that encourage international collaboration, investment, enterprise engagement, institution fortification, and cross-sector policy integration. • The green energy transition is currently mainly decarb-centric. • We propose a beyond-decarbonisation approach that is multi-faceted and inclusive. • Realistic strategies and achievable targets will ensure a sustainable transition. • Inclusion supports developing nations, facilitates knowledge and technology transfer. [ABSTRACT FROM AUTHOR]

• Accelerated systemic decarbonization will become a defining feature of climate action planning. • City CAPs fail to adequately address scope 3 greenhouse gas emissions. • Economic case for climate mitigation at the city level is often weak or missing. • Recent innovations in terms of local climate budgeting are yet to be adopted widely. • Decarbonization pace shaped by political enabling environment and extent of public engagement. Globally, many cities have pledged to reach net zero emissions by mid-century and formulated climate action plans (CAPs) to pursue this goal. Attainment of net zero requires accelerated systemic decarbonization measures to catalyze fundamental changes across multiple societal systems simultaneously. Yet the extant literature has not conceptually clarified conditions leading to accelerated systemic decarbonization in cities. This research therefore aims to: (1) conceptualize strategies that contribute to accelerated systemic decarbonization at the sub-national level and develop a framework for empirically identifying these; and (2) assess the extent to which CAPs in cities known for progressive climate policies embody these characteristics. This involved examination of evidence from CAPs and related documents in six cities: Copenhagen, Leeds, Oslo, San Francisco, Australian Capital Territory and Kyoto. Findings show that San Francisco's climate actions are the most indicative of accelerated systemic decarbonization. In other cities, although many ingredients for accelerated systemic decarbonization are in place, several missed opportunities to achieve more rapid and transformative decarbonization outcomes were identified. These include lack of consideration of scope 3 emissions and limited participatory governance measures as well as absence of economic planning, climate budgets and financial indicators to estimate the benefits or costs of various climate-mitigation actions. [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 International Panel on Climate Change (IPCC) recommended more stringent climate mitigation strategies compared to the updated nationally determined contributions (NDC) presented by nations at COP27 to keep global warming temperatures below 2 °C. Given the unique geographical, political, and socioeconomic factors in different regions, it is imperative to evaluate diverse mitigation scenarios required to achieve global climate objectives. This study focuses on the Latin America and Caribbean region due to its vulnerability to global climate adversities and deteriorating climate conditions, notwithstanding its minor contribution to global emissions. Despite facing distinct climate changes, Latin America remains significantly understudied in the broader context of global climate research. The deployment of negative emission technology (NET) is crucial for achieving the end-of-century global climate goal of limiting global mean temperature to 1.5 °C and realizing regional net-zero greenhouse gas (GHG) emission targets. Most countries in Latin America have established such targets for 2050. Among various NETs, Direct Air Carbon Capture and Storage (DACCS) has recently gained research interests. This study examines the strategic implementation of NETs across the five socio-economic pathways (SSPs) to provide a comprehensive understanding of the uncertainties in regional mitigation actions and impacts on the intricate climate-energy-land-food-water nexus. In the scenario where emissions decrease by 56 % by 2030 compared to 2020 levels (NDC-56 %) on a net-zero trajectory, energy consumption under DACCS deployment is 13.1–36.2 % higher than without DACCS (between 2040 and 2100, across all SSPs). The energy demands of DACCS, especially in the aggressive NDC-56 % scenario place significant strain on energy resources, which is offset by fossil fuels. Under a globally co-ordinated climate policy and co-deployment of DACCS and Bioenergy with Carbon Capture and Storage (BECCS), the NDC-56 % scenario restricts global warming temperatures to 1.81–1.96 °C by 2100. • IAM analysis is used in assessing scenarios of net-zero goal of Latin America. • The deployment of DACCS under aggressive decarbonization is analysed. • The deployment of DACCS reduces the demand on BECCS requirements. • DACCS deployment will reach 88 MtCO 2 /year in the NDC-SSP1 scenario by 2100. [ABSTRACT FROM AUTHOR]

• UCCS research, initiated in the 1990s, is following a sigmoidal growth pattern. • No highly active research group has been identified in UCCS research. • USA and China are currently leading countries in UCCS research. • More systematic studies are required to promote UCCS for real applications. • Findings can be used by stakeholders such as governments, among others. In this study, a scientometric comprehensive analysis has been executed in order to explore the scientific situation of research efforts performed previously with regard underground CO 2 sequestration and encapsulation. To this end, a total of 1280 bibliographic records from the Web of Science (WoS) database were extracted and analysed to report the analysis of scientific state of the authors, journals, countries, and categories. Eventually, geospatial maps of the progress in this field are created and presented. As per the results obtained, efforts on this subject have been initiated significantly since 1990s. Scientific articles and proceeding papers share nearly 63% and 31% of the documents published. The results indicate that USA and China are the most contributing countries. Among the active journals, international journal of greenhouse gas control impact is the most active journal. It may be concluded that no highly active research group has yet been emerged. Hence, more supports and scientific efforts are needed to promote carbon dioxide capture and storage technologies. [ABSTRACT FROM AUTHOR]

Deep decarbonization scenarios indicate a decline in fossil oil usage in the coming decades, meaning that oil refineries must adapt. This work evaluates the refining sector in deep decarbonization pathways using Brazil as a case study. BLUES – a national integrated assessment model – is employed to investigate the evolution of the sector in mitigation scenarios until 2050. The production of feedstocks for the petrochemical industry, of fuels for the aviation and maritime sectors, and biomass co-processing are analyzed. These strategies may bring resilience to the sector. The potential for avoiding emissions in refineries' operations is also explored. Findings show that the refining sector operates at 70% and 74% of its nameplate capacity in decarbonization scenarios. These results are used as the starting point for a detailed analysis of Brazilian refineries. Results show that the employment of refineries' assets for purposes aligned with decarbonization targets, along with emissions mitigation in the sector, reduces risks of carbon lock-in and of asset stranding. To our knowledge, this is the first study that evaluates emissions mitigation in the refining sector and also uses an integrated assessment model to investigate oil refining repurposing and co-processing options in the context of decarbonization. • The refining sector is evaluated using an integrated assessment model for Brazil. • A comparison is made between business- as -usual and decarbonization scenarios. • Opportunities for refineries' assets and mitigation measures are explored. • Opportunities for refineries depend on their location and type of processing units. • Risks of carbon lock-in and asset stranding can be reduced. [ABSTRACT FROM AUTHOR]

As a key component in mitigating global warming and achieving sustainable development strategies, wind power has received widespread attention and support from governments around the world. Numerous countries are engineering ambitious programs to map and project the mitigation potential of wind energy expansion to combat future global warming. Here, using the global installed wind capacity data, we identity that a total of 837 GW of wind energy installed capacity (WEIC) in 31 countries generated about 2186 TWh of electricity, that is 1311 Mt of CO 2 mitigation, in 2021. Considering power mix transformation, wind power could account for more than 30% of total global electricity generation by the mid-21st century, when many countries expect to realize carbon neutrality, and could reduce CO 2 emission up to 14871 Mt by 2050 and 32864 Mt by 2100. Meanwhile, the global phenomenon of the future southward shift of wind energy resources makes the wind energy development in low-latitude countries, such as Brazil, Vietnam, and Central African, more confident. Combined with the Shared Socio-economic Pathways (SSPs), we find that the mitigation benefits of wind energy expansion are significant and will directly reduce global warming by up to 0.64 °C by the end of the century (NZE deployment scenario, SSP3-7.0). For China and the United States, the share of renewable energy will reach 78% and 84% by 2050 (APS scenario) and the cumulative climate mitigation by wind power will be 0.12 °C and 0.11 °C during 2020–2100, respectively. The findings strongly support the development and practice of global climate mitigation energy solutions. • This study quantifies wind energy's impact on CO 2 and temperatures reduction. • Global wind energy can currently mitigate 1311 Mt CO 2 , up to 32864 Mt by 2100. • Wind energy expansion could mitigate global warming by up to 0.64 °C in 2100. • China and the U.S. lead global CO 2 reductions in wind power. [ABSTRACT FROM AUTHOR]

[Display omitted] • A total of 95 papers systematically reviewed cool material as a mitigation strategy for urban heat island (UHI). • Based on the type of reflection and the spectral range, the analysis found 7 material technologies (UV–Vis-NIR). • Optical properties such as reflectance (ρ), absorptance (α), and emittance (ε) are key factors in cool materials design. • Technological setbacks constitute a key limitation to scale cool material technologies and low-cost alternatives. • DRC and super cool materials represent the most efficient innovations amongst current technologies. The challenging urban expansion represents a pressing need to implement climate mitigation strategies for the urban heat island (UHI) effects and significant threats to the environmental quality, energy consumption, and human health. Thus, this manuscript systematically evaluates 95 relevant studies through a robust evidence-based analysis centered on the latest advances in cool materials, their potential, technological innovation, and global trends. The results showed studies in 21 countries, 81 cities, and 16 climate zones, of which the majority belong to Humid subtropical climates (Csa) including 29 % of studies, Oceanic climates (Cfb) with 15 %, and Mediterranean climates (Cfa) with 13 %. Spectrophotometry analysis is used in 48 % of the studies, while the most studied technologies are the Daytime Radiative Cooling (DRC); 22 %, followed by Thermochromics (TC); 19 %, Cool-Colored (CC); 17 %, Phase Change Materials (PCM); 17 %, Retroreflectives (RR); 11 %, Light-colored (LC); 5 % and Fluorescents (FL); 5 %. Finally, DRC reported the highest cooling power of up to 136 W/m2, however, the latest developments advocate for climate-dependent dynamic modulation techniques of Super Cool Materials (SCM) with Passive Daytime Radiative Cooling (PDRC) attributes and engineered spectral properties to dissipate urban heat to outer space in different meteorological conditions and wavelengths levels of the atmospheric window (8–13 μm). [ABSTRACT FROM AUTHOR]

[Display omitted] Major efforts are still needed to decarbonize passenger transport. To do so, a combination of improved technologies, a shift towards public transport, cycling and walking and the avoidance of trips is crucial. However, to ensure successful implementation, we need to better understand how these strategies affect the overall costs to society. Therefore, we assess the social costs of a decarbonized ground-based passenger transport system in 2040, covering vehicle costs, costs for externalities and travel time costs across travel modes. Our results show that social costs decline with the introduction of decarbonization strategies. Specific effects include a reduction of vehicle costs and external costs, a rise in external benefits due to positive health effects of active mobility that overcompensate remaining external costs, and possibly increased travel time costs. [ABSTRACT FROM AUTHOR]

Abstract Amine-based CO 2 capture (ACC) has become one cost-effective method for reducing carbon emissions in order to mitigate climate changes. The amine-rich wastewater (ARWW) generated from ACC may contain a series of degradation products of amine-based solvents (ABSs). These products are harmful for ecological environment and human health. Effective and reliable ARWW treatment methods are highly required for mitigating the harmfulness. However, there is a lack of a comprehensive review of the existing limited methods that can guide ARWW-related technological advancements and treatment practices. To fill this gap, the review is achieved in this study. All available technologies for treating the ARWW from washwater, condenser, and reclaimer units in ACC are examined based on clarification of degradation mechanisms and ARWW compounds. A series of significant findings and recommendations are revealed through this review. For instance, ARWW treatment methods should be selected according to degradation conditions and pollution concentrations. UV light can be only used for treating wastewater from washwater and condenser units in ACC. Biological activated carbon is feasible for removing nitrosamines from washwater and condenser units. Sequence batch reactors, microbial fuel cells, and the other techniques for removing amines and similar degradation products are applicable for treating ARWW. This review provides scientific support for the selection and improvement of ARWW treatment techniques, the mitigation of ACC's consequences in environment, health and other aspects, and the extensive development and applications of ACC systems. Highlights • Investigation of degradation mechanisms and hazardousness of amine-rich wastewater. • Analyzing techniques for treating wastewater generated from washwater, condenser, and reclaimer units. • Providing support for the selection and improvement of wastewater treatment techniques. • Mitigation of wastewater has consequences in the environment and health during CO 2 capture. [ABSTRACT FROM AUTHOR]

Sub-national and regional greenhouse gas (GHG) mitigation policies are being stimulated by the Paris Agreement. Several low carbon studies have been conducted for important emitters such as California State in the US and Chinese provinces. At the same time, carbon mitigation studies have focused on the industrial sector, especially in developing countries. In comparison to the national scenario, the Sao Paulo state in Brazil shows a distinct emission profile. The industry in Sao Paulo is responsible for 14.7% of the total emissions, and this share increases to 31.5% considering energy indirect emissions. Therefore, Sao Paulo mitigation efforts depend on industry’s leadership such as in other parts of the world. The present study has evaluated the Sao Paulo state’s industry mitigation potential between 2014 and 2030 based on a Marginal Abatement Cost (MAC) curve. In contrast to previous MAC studies, the MAC-SP study has also considered cement related emissions released outside its jurisdictions but that are driven by industrial choices within its boundary. Nine out of seventeen technologies show a negative MAC value, and energy efficiency technologies yield the lowest cost with a weighted average value of -$122/metric ton of CO 2 . Considering only the territorial based approach, the Sao Paulo state’s Industry would avoid 78.4 million metric ton of CO 2 until 2030. Although emissions under Sao Paulo’s responsibility increase 27%, if the consumption-based approach is adopted, the assessed mitigation potential enhances 83% and entails US$ 2.3 billion savings until 2030. In conclusion, the mitigation potential for São Paulo state’s industry is sizeable and consumption-based strategies are worthwhile, especially when regional policies are considered. Results can assist in formulating climate change policies and innovative incentive mechanisms to maximize the regional mitigation potential. [ABSTRACT FROM AUTHOR]

The iron and steel industry plays an important role in mitigating global climate change. As the largest steel producer and consumer, China bears the primary responsibility for energy savings and CO 2 emission reduction in the iron and steel industry. In this study, taking China as the empirical context, we analyze the effectiveness of the following four strategies on the potential of energy savings and emission reduction: phasing out backward production capacity in accordance with the current major policies, adjusting the production structure to increase electric arc furnace steelmaking, promoting low-carbon technologies, and switching to clean fuels. Under the principle of cost minimization, the mitigation potential of different strategies until 2030 and the technological development paths for reducing energy and CO 2 emissions in China’s iron and steel industry are identified via an established National Energy Technology model. The results show that promoting low-carbon technologies is the most effective strategy for energy savings and emission reduction alongside cost minimization. Compared with existing policies, these strategies could lead to a cumulative reduction of 818.3 MtCO 2 (4.1%) during the period 2015–2030. Therefore, policy makers should provide financial or administrative support to promote the development of specific production and low-carbon technologies such as non-blast furnace iron-making and endless strip production. [ABSTRACT FROM AUTHOR]

The Sustainable Development Goals (SDGs) allow global economies to establish nationally determined plans to track ecological and economic sustainability at regional and international levels. While renewables are proven effective ecological sustainability tools, they might not comprehensively achieve climate change mitigation without emissions control regulations available in the combined policy toolbox, largely ignored by mainstream research. Therefore, we empirically assess the combined effect of renewable electricity output, stringent environmental regulations, and coal consumption in an attempt to acquire sustainable ecosystems via employing second-generation methodological approaches to ten selected OECD members' data during 1990–2015. We revealed long-term equilibrium among our study variables, implying that our variables maintain inherent stability. Also, the environmental Kuznets Curve notion is verified in the long term. Notably, we found that renewable energy output and stringent environmental regulations effectively mitigate ecological footprint and carbon emissions, whereas coal consumption boosts them. However, as the degree of coal consumption-driven carbon emissions promotion impact exceeded that of the emissions reduction impact of renewable energy output, simply ramping up the deployment of renewable energy solutions would be insufficient for climate change mitigation targets. Instead, a comprehensive climate policy inclusive of energy transformation and environmental regulations would be indispensable. While all the under-analysis variables unveil significant impacts merely in the long term, their respective short-term policies would be ineffective. We suggest implementing marketable and non-marketable environmental laws and deploying renewable solutions for achieving SDGs involving climate action and universal access to affordable alternative energy to guide a green and sustainable future. [Display omitted] • Applied advanced methods robust to cross-section dependency and slope heterogeneity. • Renewable electricity output improves ecological sustainability in the long term. • Stringent environmental regulations drove long-term ecological sustainability. • Coal consumption impeded the ecological quality. • EKC notion is found valid from the long-term perspective. [ABSTRACT FROM AUTHOR]

Cities are the major contributors to global carbon dioxide emissions; however, the carbon transfers embodied in cities' domestic and foreign trade have not been fully discussed. As carbon emissions from different domestic and foreign trade partners have not been distinguished, and since China's four municipalities (Beijing, Tianjin, Shanghai and Chongqing) carry an increasingly significant responsibility for carbon reduction in China, a multi-scale and multi-regional carbon emission assessment is applied to identify their emission transfers to and from 26 domestic provinces and 184 foreign economies. The results show that the intensities of the four municipalities are mainly above the international standard (0.14 kg/CNY) but beneath the Chinese average (0.24 kg/CNY). 71.72%, 55.35%, 65.34% and 33.65% of their emissions are imported from other regions. Generally, the four municipalities are net recipients of domestic carbon transfers and suppliers of foreign carbon transfers. Carbon transfers from Hebei to Beijing and Tianjin, Zhejiang to Shanghai, and Sichuan to Chongqing as well as from Beijing and Tianjin to Japan and South Korea and from Shanghai and Chongqing to the United States and Germany are identified in domestic and foreign supply chains. The multi-scale and multi-regional simulation and assessment in this work allows us to identify the carbon emissions not only within a city's boundaries but also via inter- and intra-national trade, providing a solid foundation for the carbon emission assessments of Chinese mega cities from an embodied perspective. [ABSTRACT FROM AUTHOR]

Maritime emission regulations set limits for SOx and NOx emissions for health and environmental reasons, and for CO 2, through the Energy Efficiency Design Index (EEDI), with the general aim of mitigating global warming. EEDI verification is performed at the vessel's design speed and design loads, under calm-water conditions. This, although calm seas are the exception in shipping, and that even with calm-water conditions, ships usually operate at lower speeds than their design speed. A major challenge, if greenhouse gases (GHG) reduction targets are to be met through the EEDI, will be to identify EEDI-compliant solutions that reduce energy consumption and GHG emissions under realistic operational conditions, from lying idle at berth in port to when full power is required in critical situations at sea. In view of all the above, we use the Aframax tanker class to illustrate how such an assessment can be performed, and to display the differences in costs and benefits of options, all of which meet the requirements of the EEDI. [ABSTRACT FROM AUTHOR]

To mitigate climate change, many studies have been conducted to identify the determinants of CO 2 emissions. However, a consensus has not been reached yet on the issue because past work has often not considered the unobserved individual heterogeneity across countries. Therefore, this study revisits the environment-energy-growth nexus by employing a panel quantile regression to incorporate the effects of renewable energy consumption and technological innovation within the research background of global 30 countries over the period 1980–2014. The advantage of this method is considering the distributional heterogeneity to provide a detailed description of linkage between the CO 2 emissions and driving factors at different emissions levels. The results show that the effects of determinants on CO 2 emissions are heterogeneous. For high-emissions countries, the function of renewable energy consumption is limited in reducing CO 2 emissions due to the smaller proportion of renewable energy use. Moreover, technological innovation greatly affects countries with relatively higher CO 2 emissions. Therefore, one option is to financially support and apply technological innovations to generate renewable energy at lower costs as well as increase energy efficiency. Moreover, transforming the economic growth mode is helpful to transfer from non-renewable to renewable sources of energy to meet energy demand. [ABSTRACT FROM AUTHOR]

This study combined the input-output clustering analysis and structural path betweenness analysis, and identified critical sectors belonging to important emission clusters in the global supply chain networks associated with final demand of transport equipment in five countries (United States, China, Germany, Japan, and France). Clustering analysis can divide the groups constructing the strong connecting supply chain with large emissions from the global supply chain network, and structural path betweenness represents how much CO 2 emissions from the supply chain paths a sector has in global supply chain network. I applied the combined method to the EORA database which covers 189 countries and focused on the whole global supply chain networks in detail. The results demonstrate that the global supply chain networks of transport equipment were well separated into emission clusters with higher emissions that consist of sectors with higher structural path betweenness. Chinese emission clusters were identified from the global supply chain networks for the five countries in question and the betweenness of Chinese sectors tend to be higher values in the supply chain networks. In this study, I suggested supply chain management of high priority sectors for a reduction in CO 2 emissions of transport equipment in the producing countries. [ABSTRACT FROM AUTHOR]

Building sector accounts for nearly 30% of global final energy usage, and its energy demand is expected to keep growing with the increasing population and expanding tertiary industry in the coming decades. To achieve global climate mitigation goal, building sector will need to fully tap its potential on energy conservation and CO 2 reduction. This paper simulated the transformation pathways of global energy system under 2-degree and 1.5-degree climate targets with Global TIMES model, classified the 14 model regions into high, middle and low income region, and analyzed the main features and key challenges of each region’s building sector transition pathways. Modeling results show that: (1) For global building sector, 32 Gt of CO 2 emissions reduction is required between 2010 and 2050 by 2-degree target, additional 28 Gt of reduction would be essential to achieve 1.5-degree target; (2) High income region would take the lead in building sector’s CO 2 mitigation, while low income region may be increasingly important when the carbon constraint gets more stringent; (3) Electrification is a critical approach in building sector’s low carbon transition, by 2050, the share of electricity in final energy consumption is expected to reach 44%, 54% and 59% in reference, 2-degree and 1.5-degree scenarios respectively. [ABSTRACT FROM AUTHOR]

This paper examines the social costs and benefits of potential configurations of electric vehicle deployment, including and excluding vehicle-to-grid. To fully explore the benefits and costs of different electric vehicle pathways, four different scenarios are devised with both today's and 2030 electricity grid in Denmark. These scenarios combine different levels of electric vehicle implementation and communication ability, i.e. smart charging or full bi-directionality, and then paired with different levels of future renewable energy implementation. Then, the societal costs of all scenarios are calculated, including carbon and health externalities to find the least-cost mix of electric vehicles for society. The most cost-effective penetration of electric vehicles in the near future is found to be 27%, increasing to 75% by 2030. This would equate to a $34 billion reduction to societal costs in 2030, a decrease of 30% compared to business as usual. This represents a projected annual savings per vehicle of $1200 in 2030. However, current vehicle capital cost differences, a lack of willingness to pay for electric vehicles, and consumer discount rates are substantial barriers to electric vehicle deployment in Denmark in the near term. [ABSTRACT FROM AUTHOR]

CO 2 emissions caused by private motorized traffic for the city of Graz, a typical European inland city with about 320 000 citizens, are investigated. The main methodology is a newly developed agent-based model that incorporates empirical data about the mobility behavior of the citizens in order to calculate the traveled routes, the resulting traffic and subsequent emissions. To assess the impact of different policies on CO 2 emissions, different scenarios are simulated and their results are compared to a base line scenario. The model features a local and temporal resolution, effects like congestion and stop-and-go traffic as well as commuters to and from other regions. In addition to the evaluation of certain policies (like a focus on electric cars, telecommuting or an improvement of the road infrastructure), a method is provided, that makes it possible to compare many diverse scenarios, featuring technological changes, societal changes or changes in the road network, all within the same framework. The findings suggest that one of the most promising strategies to decrease urban CO 2 emissions is to focus on the use of electric cars, especially if it is combined with offering alternatives to private car traffic and incentives for telecommuting. Banning the use of old cars only yields a significant result if a large amount of cars is affected, which would make such a policy difficult to implement. Expanding the road network has no significant positive effect and may even encourage using cars, therefore leading to even more CO 2 emissions. Due to its flexible structure the presented model can be used to evaluate policies beyond what is presented in this study. It can easily be adapted to other conditions and geographical regions. [ABSTRACT FROM AUTHOR]

In the face of a changing climate, a growing number of construction firms are adopting carbon reduction targets on individual projects and across their portfolios. In the wake of the Paris Agreement, some firms are seeking a means of aligning their targets with sectoral, national and international mitigation commitments. There are numerous ways by which such an alignment can be achieved, each requiring different assumptions. Using data from the UK construction industry, this paper reviews current company commitments and progress in carbon mitigation; analyses the unique challenges in aligning construction targets, and presents a series of possible sectoral decarbonisation trajectories. The results highlight the disparity between current company targets and the range of possible trajectories. It is clear that a cross-industry dialogue is urgently required to establish an appropriate response that delivers both a widely-accepted target trajectory and a plan for its delivery. This paper is intended to stimulate and support this necessary debate by illustrating the impact of different methodological assumptions and highlighting the critical features of an appropriate response. [ABSTRACT FROM AUTHOR]

The decarbonisation of membrane desalination is a grand challenge due to the competing demands of more water for a thirsty world and the urgent need to reduce carbon emissions to mitigate climate change. This paper is a review of some developing strategies that could lead to lower energy use and thereby reduce the carbon foot print of desalination. Each strategy brings benefits along with technical challenges that are research opportunities. The use of very low energy ‘engineered biofilms’ coupled with biomimicry control of biofouling could almost eliminate pretreatment energy. Improved membranes based on ‘water channels’ could contribute to reduced energy demand but high flux operation will need novel mass transfer control and will be constrained by module engineering. Significant energy benefits could come from combining seawater RO with wastewater reclamation using forward osmosis and pressure-retarded osmosis (PRO), although fouling by the wastewater stream requires special attention. The overall potential of the novel pretreatments, membranes and post-treatments is to more than halve the net energy of RO desalination. However there would be significant trade-offs to achieve this level of decarbonisation. The application of renewable energy is considered in the context of a membrane-enabled osmotic battery using PRO for discharge and advanced RO for recharge. Finally, low energy desalination for agriculture is being developed using novel applications of forward osmosis. [ABSTRACT FROM AUTHOR]

Spatial planning plays an increasingly significant role in climate change mitigation by providing energy efficient settlements and promoting the utilization of renewable energy resources. However, the effect of urban spatial planning on spatial pattern of carbon dioxide emissions in cities is rarely discussed. The relationships between the changes in urban zoning plans and carbon dioxide emissions of major economic sectors has yet to be investigated on a scale smaller than an entire city. Using the Taipei metropolitan area as a case study, this study hypothesizes that: (1) carbon dioxide emissions have a spatial dimension within the city due mainly to the heterogeneous nature of land use activities and urbanization, and (2) changes in spatial planning can influence the urban form, and consequentially affect carbon dioxide emissions through changes in traffic demand and energy consumption. A downscaling analysis approach was used to estimate carbon dioxide emissions of different sectors for each administrative district in the Taipei metropolitan area. The analytical results reveal that the total carbon dioxide emissions of the four sectors in the Taipei metropolitan area increased with the increases in the growth of urban planned zones during the period 1981–2011.The carbon dioxide emission increases were correlated with the distribution of land uses in each administrative district. A negative correlation was found between the population density and the per-capita carbon dioxide emissions in the transportation sector. The compact development and planning of urban transit systems are believed to be the source of decreasing per -capita carbon dioxide emissions. While many studies have emphasized that spatial planning is important addressing climate change, this work demonstrates understanding the historic links between spatial planning and carbon dioxide is equally valuable. [ABSTRACT FROM AUTHOR]

In 2008, the European Commission (EC) launched the Covenant of Mayors (CoM), a voluntary agreement under which local governments commit to reduce CO 2 emissions by at least 20% within 2020, in order to reinforce local authorities in designing strategies to mitigate climate change in coherence with the European Union’s climate policy. The CoM may be defined as a coordinated collection of experiments based on common rules established by the EC. Cities signing the CoM commit to follow guidelines and standardized methodologies in setting CO 2 emission reduction targets and in designing and implementing policies and measures to reach them, through the definition of key tools such as the Baseline Emission Inventory (BEI) and the Sustainable Energy Action Plan (SEAP). The present study analyses the emission reduction strategies of a sample of 124 cities with more than 100,000 inhabitants, signatories of the CoM, which delivered a SEAP by February 2014. More than 5500 actions planned by the sample cities were analysed and categorized. The most relevant actions in terms of recurrence and mitigation impact were assessed. Finally a set of variables was tested through a regression so as to determine their influence on emission reductions strategies. The main results of this study show that the sample cities accounted for a total of 370 million tons of CO 2 emissions in selected baseline years and 94 million tons of intended emission reductions per year. The total emission reductions planned by cities reached 25% of the baseline emissions. Buildings and Transport stood out as the sectors where cities intend to deliver the largest emission reductions. Furthermore the analysis showed that cities’ administrations attribute higher potential to actions in subsectors under their direct control (municipal buildings, public transport, municipal fleet and public lighting) compared to actions in subsectors managed by private actors (households and firms). In the Building sector, the category of action delivering the highest share of CO 2 emission reductions was represented by integrated actions, which combine several types of intervention so as to maximise the energy efficiency of buildings. In the transport sector, it was the modal shift, which implies a transition from private transport to public and cleaner transport modes. In both the Building and Transport sectors, cities plan to reduce the major amount of CO 2 emissions through the implementation of management and organization, infrastructure construction and awareness-raising policy levers. Our results may be useful to urban policy makers to shape their mitigation strategies in coherence with cities’ commitments and plans and to replicate policies and actions on the basis of CoM signatories’ experiences. [ABSTRACT FROM AUTHOR]

Understanding provincial-level driving mechanisms of carbon emissions is critical for achieving China's national action targets on climate change mitigation. The paper combines two-layer logarithmic mean divisia index (LMDI) decomposition with Q-type hierarchical clustering to systematically evaluate the contributions of related drivers from 30 provinces to the growths in China's national carbon emissions, and accordingly puts forward more targeted emissions reduction strategies for each cluster of provinces based on the features of CO 2 emissions and underlying emissions driving forces. It was concluded that the contributions of various provinces to national CO 2 emissions growths and their respective driving mechanisms differed considerably and changed dynamically over time. From 1996 to 2013, Shandong, Hebei, Inner Mongolia, Jiangsu and Guangdong were the top five provincial drivers behind carbon emissions growths in China, and provincial economic expansion and energy intensity reduction played dominant roles, respectively, in raising and abating carbon emissions. Across the sub-periods, the driving effects of economic activity, energy intensity and energy structure changes on carbon emissions and their evolving trends clearly varied by province. Certain provinces, such as Beijing and Shanghai, have presented significantly decreased contributions to national carbon emissions growths and even became negative contributors; while other provinces, such as Hebei, Shanxi and Anhui, have made increased contributions. Therefore, the formulation of China's emissions reduction strategies should consider both the features of provincial carbon emissions and the underlying causes shaping them, and should be adjusted in a timely manner to respond to different development stages. [ABSTRACT FROM AUTHOR]

Urban policy plays an important role in urbanization and urban sprawl, which in turn affect changes in CO 2 emissions from urban areas. However, urban planning policies that consider climate change mitigation have not been widely adopted, despite the issue's importance. To promote the consideration of climate change policies in urban planning, it is useful to identify the key determinants of effective climate change mitigation for policy makers. The objective of this study is therefore to identify the determining factors that affect changes in urban CO 2 emissions based on city type using a dataset of metropolitan areas. We obtained data on 276 cities in 26 countries for the years 2000, 2005, and 2008. We divided the data into five regional groups and four clusters to control for the characteristics of metropolitan areas. The dataset includes urban CO 2 emissions, GDP, and population. Three variables related to urban characteristics are subjected to determinants analysis using an econometric approach. The results show that the determinants of changes in urban CO 2 emissions differ by city type and region. These results contribute to a better understanding of urban policies that can improve the effects of these driving factors by considering the characteristics of each city type. [ABSTRACT FROM AUTHOR]

Reducing local and global emissions is one of the drivers behind the promotion of renewable energy technologies (RETs). Some RET projects (e.g. solar, marine power, and some biomass and wind) usually require supplemental income from carbon credits in order to make them economically viable. This paper presents the mathematical development of nodal marginal CO 2 emission metrics for hydrothermal systems. These metrics are obtained from optimal power flow and hydrothermal dispatch models considering hydro uncertainty. The proposed model allows a more accurate assessment of the emission reduction effect of RET projects and the provision of efficient carbon signals to the system. Modeling of hydro reservoirs and intertemporal constraints also allows incorporating the emission mitigation potential of water storage. The concepts of marginal CO 2 emissions for hydrothermal systems are first exemplified using a small test system, and then simulations on a real hydrothermal system illustrate how these metrics can inform investment and operational decisions. Theoretical and simulation results show that transmission and hydro storage constraints neglect may provide wrong signals for RET investors, missing the incentives to install in areas where the potential for emissions reduction is higher (where renewable energy displaces a larger amount of coal or diesel). Policy makers can use the proposed model to assess the cost-effectiveness of emission reduction policies. [ABSTRACT FROM AUTHOR]

China is the world's largest energy consumer and CO 2 emitter. Cities contribute 85% of the total CO 2 emissions in China and thus are considered as the key areas for implementing policies designed for climate change adaption and CO 2 emission mitigation. However, the emission inventory construction of Chinese cities has not been well researched, mainly owing to the lack of systematic statistics and poor data quality. Focusing on this research gap, we developed a set of methods for constructing CO 2 emissions inventories for Chinese cities based on energy balance table. The newly constructed emission inventory is compiled in terms of the definition provided by the IPCC territorial emission accounting approach and covers 47 socioeconomic sectors, 17 fossil fuels and 9 primary industry products, which is corresponding with the national and provincial inventory. In the study, we applied the methods to compile CO 2 emissions inventories for 24 common Chinese cities and examined uncertainties of the inventories. Understanding the emissions sources in Chinese cities is the basis for many climate policy and goal research in the future. [ABSTRACT FROM AUTHOR]

Tourism needs to reduce emissions in line with other economic sectors, if the international community's objective of staying global warming at 1.5°-2.0 °C is to be achieved. This will require the industry to half emissions to 2030, and to reach net-zero by mid-century. Mitigation requires consideration of four dimensions, the Scales, Scopes, Stakeholders and Strategies of carbon management. The paper provides a systematic review of these dimensions and their interrelationships, with a focus on emission inventory comprehensiveness; allocation principles at different scales; clearly defined responsibilities for decarbonization; and the identification of significant mitigation strategies. The paper concludes that without mitigation efforts, tourism will deplete 40% of the world's remaining carbon budget to 1.5 °C. Yet, the most powerful decarbonization measures face major corporate, political and technical barriers. Without worldwide policy efforts at the national scale to manage the sector's emissions, tourism will turn into one of the major drivers of climate change. [ABSTRACT FROM AUTHOR]

In later years the potential contribution of forest bioenergy to mitigate climate change has been increasingly questioned due to temporal displacement between CO 2 emissions when forest biomass is used for energy and subsequent sequestration of carbon in new biomass. Also disturbance of natural decay of dead biomass when used for energy affect the carbon dynamics of forest ecosystems. These perturbations of forest ecosystems are summarized under the concept of carbon debt and its payback time. Narrative reviews demonstrate that the payback time of apparently comparable forest bioenergy supply scenarios vary by up to 200 years allowing amble room for confusion and dispute about the climate benefits of forest bioenergy. This meta-analysis confirm that the outcome of carbon debt studies lie in the assumptions and find that methodological rather than ecosystem and management related assumptions determine the findings. The study implies that at the current development of carbon debt methodologies and their lack of consensus the concept in it-self is inadequate for informing and guiding policy development. At the management level the carbon debt concept may provide valuable information directing management principles in a more climate benign directions. [ABSTRACT FROM AUTHOR]

Global climate change and energy crises have increasingly impeded the sustainable development of society and economy. With an accelerated process of urbanization and improved standards of living, China has become the largest carbon emitter in the world and therefore has great responsibility and great potential to mitigate global carbon emissions. Accordingly, as the largest source of emissions in China, Chinese buildings should also decrease carbon emissions towards this goal. However, until now, there has been no clear and comprehensive understanding of the carbon emissions in this sector. To fill this gap, we survey the current and future situation. Firstly, we estimate the controlled ceiling of building carbon emission, splitting from the overall reduction goal in China. Then we develop a comprehensive carbon-calculating methodology, the China Building Carbon Emissions Model, using a bottom-up approach, and assess the building carbon emissions based on official statistics. On the basis of that, scenario analysis is used to predict the future trend of carbon emissions in China's building sector. According to our analysis, it is critical to simultaneously control floor space, energy consumption and energy structure to limit the growth of carbon emissions in the building sector. Finally, some relative policy suggestions are also discussed. [ABSTRACT FROM AUTHOR]

The concept of “pathways” has increasingly come to frame the challenge of transitioning to low-carbon societies. It also shows promise as a bridging concept, encouraging constructive dialogue among the diverse perspectives and constituencies evoking its use. However, its interpretations and attributes are rarely explicit and have yet to be subject to serious scrutiny. This raises important questions for both theory and governance as the way in which a problem is framed shapes how it is understood and addressed, structuring the possibilities considered and privileging certain responses. Therefore, this study explores the concept of pathways in the context of low-carbon transitions, exposing its conceptions, maturation, and implications. Based on a survey of the relevant climate change mitigation literature, this analysis uncovers three core conceptions of pathways in the context of low-carbon transitions: (1) biophysical, (2) techno-economic, and (3) socio-technical. Constituted by diverse perspectives and approaches, each of these three core conceptions emphasize different yet interconnected dimensions of the decarbonization challenge. This analysis also points to several key attributes and functions of the concept of pathways. Yet, while the concept may possess a variety of features that recommend its use as a critical problem frame for low-carbon transitions, it also raises issues that suggest a need for further reflexivity. If the concept is cast too strongly in terms of individual core conceptions, there may be a tendency to emphasize certain dynamics while paying somewhat less attention to others, inadvertently diminishing the complexity of the decarbonization challenge. Beyond this, there are other facets of the concept that have to date received more limited attention, including the implications of choices at critical junctures and the evolving character of social practices. So, there is room for the concept of pathways to engage more fully with the range of complexities embodied by low-carbon transitions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Phase equilibria of CO 2 + DIOX hydrate for C DIOX between 0.05 mol% and 5.56 mol% • The kinetics of CO 2 + DIOX hydrate is quantified with morphology observation. • Phase separation of DIOX/H 2 O above 3.1 MPa weakens the promotion effect of DIOX. • A comprehensive evaluation of DIOX in the application of hydrate-based CO 2 storage. To reduce anthropogenic CO 2 emissions for the mitigation of climate change require novel CCUS solutions. Hydrate-based CO 2 sequestration (HCS) is a novel carbon-neutrality technology that aims to store CO 2 in solid hydrate form with long-term stability. However, imminent issues exist for the application of HCS in terms of demanding thermodynamic conditions, slow formation kinetics, and low CO 2 gas uptake. These challenges necessitate the quest for an efficient and eco-friendly CO 2 hydrate promoter. In this study, 1,3-dioxolane (DIOX) as a low-toxicity CO 2 hydrate promoter was systematically examined. The phase equilibria, cage occupancy, and the kinetics of binary CO 2 + DIOX hydrate were measured for DIOX concentrations (C DIOX) varying from 0.05 mol% to 5.56 mol%. It was confirmed that DIOX is a dual-function promoter for CO 2 hydrate, but its promotion effect is weakened for C DIOX between 0.60 mol% and 1.00 mol% and for all C DIOX at relatively high pressure. The CO 2 uptake in the hydrate phase increases with C DIOX above 2.00 mol% and is the highest for C DIOX = 5.56 mol% (57.08 ± 6.39 mmol/mol). Based on the morphology observation, hydrate transits from ice-like to slurry to mushy-like and finally to snow-like with increasing C DIOX. Interestingly, we observed that the aqueous phase separates into two phases (i.e., DIOX-rich and H 2 O-rich) at pressure above 3.09 MPa, which explains the gradual loss of the promotion effect. The results of our study provide a comprehensive evaluation on DIOX as a possible promoter for CO 2 hydrate in HCS application. [ABSTRACT FROM AUTHOR]

Climate change poses economic, social, and environmental challenges to humanity. Through the Kyoto Protocol and Paris Agreement (PA), World leaders are obliged to identify climate solutions. In 2015, within the United Nations Framework Convention on Climate Challenge (UNFCCC), 197 countries negotiated the PA on climate change mitigation and adaptation. This study examines Africa's Nationally Determined Contributions (NDCs) pledges: 47 African countries provided such pledges in 2016, while 7 countries did not ratify the PA at the time. This study hereafter examines the PA treatment effect by designing a difference-in-differences technique between (2015) and (2018). The results reveal that 47 African countries that ratified the PA together have reduced carbon emissions intensity (CE) by about 80.76% of the pledge. The implication is that based on the NDCs' pledge to reduce emissions by 32% in 2030, African countries avoided emissions by approximately 26% by 2018. The study also analyses which policy measures assisted in CE reduction, showing renewable and clean energy. This suggests that African countries to the PA ratification have not over-ambitiously increased CE in their pursuit of economic growth and development. We further estimate carbon efficiency (CEE) as a total-factor analysis. It indicates that the 47 African countries' ratification of the PA has contributed to improving CEE. Thus, the economic productivity of the factor inputs relative to those which did not ratify at the time. The results suggest that the countries that ratified the PA have a carbon efficiency reduction potential of 23.47%, while those that declined have a wider gap of 77.77%. The inferred conclusions is that countries which declined the PA ratification or later withdrawal will increase emissions and hence leading to climate consequences. The authors propose insightful, targeted policies toward achieving efficient climate goals in Africa via integrated economic and environmental measures. • Africa is a committed actor in Paris Agreement toward emissions mitigation. • NDC pledges of African countries are presently consistent with emissions targets. • Quasi-experiment on climate change policy shows reduction in carbon emissions. • NDCs contribute to carbon emission reductions of African countries • NDCs provide opportunities for socioeconomic and environmental co-benefits. [ABSTRACT FROM AUTHOR]

In this study, claims and counterclaims that fossil fuel subsidies removal yields benefits in terms of budget deficits, energy efficiency and mitigation are assessed. In order to do this, a global computable general equilibrium (CGE) model has been estimated to evaluate the impact of subsidies removal on imported refined oil in Ghana on prices, carbon dioxide (CO 2 ) emissions, households' demand, firm's production and real GDP. The simulation experiment points to evidence that subsidy removal raises prices, increases the rate of CO 2 emissions, reduces households' demand, reduces aggregate output and affects various sectors differently. The increased rate of CO 2 emissions due to the removal of subsidies is indicative of the existence of the so-called ‘green paradox’. These results underscore the fact that a removal of subsidies on fossil fuels may win in some regards but fail in others. A general implication from the applied model, therefore, is one which supports the assertion that removal of subsidies on fossil fuels removal on energy should be implemented along with policies aimed at stimulating economic activities and reducing the level of CO 2 emissions, especially where there is evidence of the ‘green paradox’. [ABSTRACT FROM AUTHOR]

Carbon-dioxide (CO 2 ) is the main contributor to anthropogenic global warming, and the timing of its peak concentration in the atmosphere is likely to be the major factor in the timing of maximum radiative forcing. Other forcers such as aerosols and non-CO 2 greenhouse gases may also influence the timing of maximum radiative forcing. This paper approximates solutions to a linear model of atmospheric CO 2 dynamics with four time-constants to identify factors governing the timing of its concentration peak. The most important emissions-related factor is the ratio between average rates at which emissions increase and decrease, which in turn is related to the rate at which the emissions intensity of CO 2 is reduced. Rapid decarbonization of CO 2 can not only limit global warming but also achieve an early CO 2 concentration peak. The most important carbon cycle parameters are the long multi-century time-constant of atmospheric CO 2 , and the ratio of contributions to the impulse response function of atmospheric CO 2 from the infinitely long lived and the multi-century contributions respectively. Reducing uncertainties in these parameters can reduce uncertainty in forecasts of the radiative forcing peak. A simple approximation for peak CO 2 concentration, valid especially if decarbonization is slow, is developed. Peak concentration is approximated as a function of cumulative emissions and emissions at the time of the concentration peak. Furthermore peak concentration is directly proportional to cumulative CO 2 emissions for a wide range of emissions scenarios. Therefore, limiting the peak CO 2 concentration is equivalent to limiting cumulative emissions. These relationships need to be verified using more complex models of Earth system's carbon cycle. [ABSTRACT FROM AUTHOR]

Climate change mitigation is a key issue in formulating global environmental policies. Energy production and consumption are the main sources of greenhouse gas (GHG) emissions in Europe. Energy consumption and energy-related GHG emissions from agriculture are an important concern for policymakers, as the agricultural activities should meet food security goals along with proper economic, environmental, and social impacts. Carbon dioxide (CO 2 ) emission is the most significant among energy-related GHG emissions. This paper analyses the main drivers behind energy-related CO 2 emission across agricultural sectors of European countries. The analysis is based on aggregate data from the World Input-Output Database. The research explores two main directions. Firstly, Index Decomposition Analysis (IDA), facilitated by the Shapley index, is used to identify the main drivers of CO 2 emission. Secondly, the Slack-based Model (SBM) is applied to gauge the environmental efficiency of European agricultural sectors. By applying frontier techniques, we also derive the measures of environmental efficiency and shadow prices, thereby contributing to a discussion on CO 2 emission mitigation in agriculture. Therefore, the paper devises an integrated approach towards analysis of CO 2 emission based upon advanced decomposition and efficiency analysis models. The research covers eighteen European countries and the applied methodology decomposes contributions to CO 2 emission across of regions and factors. Results of IDA suggest that decreasing energy intensity is the main factor behind declines in CO 2 emission. According to the SBM, the lowest carbon shadow prices are observed in France, Finland, Sweden, Denmark, the Netherlands, Poland, and Belgium. These countries thus have the highest potential for reduction in CO 2 emission. The results imply that measures to increase energy efficiency are a more effective means to reduce CO 2 emissions than are changes in the fuel-mix. [ABSTRACT FROM AUTHOR]

CO 2 emissions from global steel production may jeopardize climate goals of 1.5 °C unless current steel production practices will be rapidly decarbonized. At present, primary iron and steel production is still heavily dependent on fossil fuels, primarily coke. This study aims to determine which decarbonization pathways can achieve the strongest emission reductions of the iron and steel industry in Germany by 2050. Moreover, we estimate whether the German iron and steel industry will be able to stay within its sectoral carbon budgets for a 1.5 °C or 1.75 °C target. We developed three decarbonization scenarios for German steel production: an electrification, coal-exit, and a carbon capture and storage (CCS) scenario. They describe a phase-out of coal-fired production plants and an introduction of electricity-based, low-carbon iron production technologies, i.e. hydrogen-based direct reduction and electrowinning of iron ore. The scenarios consider the age and lifetimes of existing coal-based furnaces, the maturity of emerging technologies, and increasing recycling shares. Based on specific energy requirements and reaction-related emissions per technology, we calculated future CO 2 emissions of future steel production in Germany. We found that under the decarbonization scenarios, annual CO 2 emissions decrease by up to 83% in 2050 relative to 2020. The reductions of cumulative emissions by 2050 range from 24% (360 Mt CO 2) under the electrification scenario up to the maximum of 46% (677 Mt CO 2) under the CCS scenario compared to a reference scenario. This clearly demonstrates that the technology pathway matters. Nevertheless, the German steel sector will exceed its sectoral CO 2 budget for a 1.5 °C warming scenario between 2023 and 2037. Thus, drastic measures are required very soon to sufficiently limit future CO 2 emissions from German steel production, such as, a rapid decarbonization of the electricity mix, the construction of a hydrogen and CCS infrastructure, or early shutdowns of current coal-based furnaces. [Display omitted] • Scenarios for iron and steel production in Germany until 2050 • Adopting new technologies: hydrogen-based direct reduction and electrowinning • Comparison of CO 2 emissions with sectoral carbon budgets for the steel industry • Carbon budget for climate goal of 1.5 °C likely to be exceeded between 2023 and 2037 • Carbon capture scenario achieves lowest CO 2 emissions but has higher energy demand [ABSTRACT FROM AUTHOR]