Search

Limiting climate change to within the 2 °C limit requires net zero emissions of CO2 by 2050. However, the window of opportunity is closing fast. Geoengineering as the intentional and large-scale manipulation of the environment and the climate is increasingly discussed as a complement to ongoing mitigation efforts. As a particular geoengineering approach, space-based geoengineering proposes blocking or dissipating a fraction of incoming sunlight via a large number of occulting membranes, located close to the Lagrange 1 point between the Sun and the Earth. However, the mass of these sunshades, around 107–108 tons, and their deployment cost and effort render them about 10³ times more costly than terrestrial geoengineering alternatives. In this article, affordable sunshades, to be positioned close to L1 of the Earth-Sun system, are proposed, which are between 102 to 10³ times lighter than the lightest existing sunshade concepts. This is achieved via a nearly zero-radiation pressure design based on transparent refractive surfaces manufactured with ultra-thin polymeric films and SiO 2 nanotubes. The lightest sunshade proposed in this article has a total mass of approximately 5.5 × 105 tons and its deployment requires between 859 and 399 annual launches during a ten year period. [ABSTRACT FROM AUTHOR]

The climate crisis and related events are often in the headline in recent years. The climate agreements reflected these concerns and called the researchers' attention to the urgent need for climate mitigation and adaptation policies. Many countries made new commitments during the latest United Nations Climate Conference (COP26) in November 2021 in Glasgow. In turn, scientists and experts worry that new pledges are not ambitious enough. The first environmental regulation was ratified in Great Britain in 1863. Later, the industrial and agricultural revolution stimulated pollution and brought about the emergence of environmental issues. The first agreement aiming to mitigate environmental pollution and stabilize greenhouse gas concentrations in the atmosphere was the United Nations Framework Convention on Climate Change (UNFCCC), adopted at the Rio Earth Summit in 1992. Behind the European Union, the contribution of the biggest polluter countries to climate change is also significant. The objective of the paper is to investigate the explanatory factors of CO 2 emission, focusing on the contribution of economic growth, agriculture, and trade along with free trade and climate agreements on climate change in Non-European Union member states, including the biggest emitters in the past two decades. In addition, it investigates the role of specific free trade agreements in emission cuts. The results showed an increase in CO 2 emissions in third countries, the reduction in the impact of agricultural export on greenhouse gas emissions, underlining the potential hidden effect of trade-related emissions between 2000 and 2018. NAFTA was encouraged while EFTA, ASEAN and MERCOSUR reduced emission growth. The USA, China, and Russia have the highest responsibility in controlling climate change. The findings reflect the limited progress and implementation of climate and trade policies and agricultural-related emissions in Non-EU countries. • Confirmed the validity of the U-shaped EKC curve in Non-EU countries. • Economic development stimulates while agricultural development reduces CO 2 emission. • Agricultural export has a sinking impact on GHGs in the rest of the world. • NAFTA encouraged while EFTA, MERCOSUR and ASEAN hindered CO 2 emission. • The USA, China, Russia have the highest responsibility in controlling emission. [ABSTRACT FROM AUTHOR]

Bauxite residue or Red Mud (RM) is a by-product from alumina refineries. It has a high pH of 11–13 and accumulates globally at 200 million tons yearly, totalling about 4.6 billion tons. Being an alkaline anthropogenic geomaterial, its adsorption properties and reactivity with acidic gases make it a potential sink for CO 2 and SO X emissions from the aluminium industry. It offers both research challenges and opportunities for its utilisation at an industrial scale. In particular, carbon capture and mineralisation (CCM) within RM has been demonstrated in situ and waste disposal areas through direct air trapping of atmospheric CO 2. The RM-CO 2 system is also operated in ex-situ conditions in various physical states, such as powder, wet cakes, and slurry, with yields of carbonates as CaCO 3 , Na 2 CO 3 , and FeCO 3. Our contribution as a review illuminates significant advancements made and challenges for enhancing the mineral carbonation potential of RM, thereby delineating areas necessitating further exploration. Although, researchers have primarily focused on accelerating the CCM process in RM through slurry carbonation techniques. Recent advancements in filter press technologies have favoured soda recycling and wet cake disposal of RM, creating artificial mountains of RM stacks. With changing disposal trends for RM, it is vital to understand the mechanisms that govern long-term atmospheric CO 2 trapping in RM disposal areas. Recent investigations of techniques, hydrothermal treatment and dual-stage calcification-carbonation methods have expanded the domain of CCM in RM. Given the global need to reduce CO 2 emissions, CCM using RM does offer promising insights on account of its unique physicochemical and mineralogical properties. We, although presume that RM alone will not fully offset the CO 2 emissions of the aluminium industry. Enhanced weathering and mineral carbonation could reduce over 50% of refinery emissions. Uncertainties persist regarding methods of CO 2 sequestration potential and techno-economic feasibility when tested at a field scale. Moreover, contrasting results are revealed, primarily regarding changing disposal trends, variabilities in mineralogy, and limited knowledge of micro-mechanisms of the CCM process in RM. This work elucidates existing knowledge on synthesising CO 2 mineralisation, pathways, and mechanisms under various states associated with leveraging RM as a significant carbon sink in current and future climate change mitigation efforts. [Display omitted] • Illustrates RM mineral carbonation process and mechanistic models for CCM methods (slurry, semi-dry, atmospheric). • CCM potential is studied along with mechanisms using hydrothermal treatment, siderite formation and calcification-carbonation method. • Guidelines for RM sample extraction methods based on its physico-geochemical changes in BRDA with atmospheric CO 2. • Current and future research directions are discussed. [ABSTRACT FROM AUTHOR]

Straw application is an effective and common measure to improve soil quality but generally increases greenhouse gas (GHG) emissions. The combined application of biochar and straw has been proposed to mitigate these emissions. However, the effects of the combined application of biochar and maize straw, particularly at different proportions, on GHG emissions remain inadequately understood. In this study, an incubation experiment was conducted with five treatments: soil only (CK), 1 % maize straw application (TS), 0.7 % maize straw +0.3 % biochar application (S7B3), 0.5 % maize straw +0.5 % biochar application (S5B5) and 0.3 % maize straw +0.7 % biochar application (S3B7). The study also considered the effect of 1 % biochar application (TB) from our previous study with the same soil type and incubation condition. Carbon isotope technology was utilized to trace CO 2 sources and assess the priming effects on soil organic carbon (SOC) mineralization. The results showed that TB reduced CO 2 emission, while TS increased CO 2 emission due to maize straw decomposition and its positive priming effect on native SOC mineralization. S7B3, S5B5 and S3B7 also increased CO 2 emissions, but with significantly lower emissions than TS, in the order of TS > S7B3 > S5B5 ≥ S3B7. The positive priming effects of S7B3, S5B5 and S3B7 on native SOC mineralization weakened over time and eventually turned negative. TB, TS and combined applications reduced N 2 O emission due to decreased substrates (NH 4 + and NO 3 −) for nitrification and denitrification, induced by promoting microbial fixation of inorganic nitrogen. The reduction effects on N 2 O emission of combined applications were superior to those of TS and TB, with S5B5 demonstrating the best efficacy. TS increased CH 4 emission, while S7B3, S5B5 and S3B7 reduced CH 4 emission. The reduction effects of CH 4 emission with combined applications were superior to that of TB, and S5B5 exhibited the lowest CH 4 emission. Unlike soils with higher nitrogen content, where N 2 O emission dominated the global warming potential (GWP), CO 2 emission dominated the GWP in this study, resulting in increased GWP in TS, S7B3, S5B5 and S3B7, but with significantly lower values for S7B3, S5B5 and S3B7 compared to TS. In conclusion, our study suggests that the combined application of biochar and maize straw, especially S5B5, could effectively mitigate GHG emissions promoted by maize straw application, especially in soils with higher nitrogen content. [Display omitted] • Biochar and maize straw co-application reduced CO 2 emission promoted by maize straw application. • The priming effect of co-application on SOC shifted from positive to negative over time. • Co-application reduced stimulation of CH 4 emission caused by maize straw application. • Co-application exhibited superior efficacy in reducing N 2 O emissions. • The optimal co-application ratio for mitigating greenhouse gas emissions was 1:1. [ABSTRACT FROM AUTHOR]

While identifying the drivers of global CO 2 emission is crucial for climate change mitigation, the heterogeneous technology-related drivers (e.g., technological change and efficiency of energy and CO 2 emission) were ignored to a large extent at a global scale, hindering to formulate heterogenous climate policies. Moreover, the projection of CO 2 emission was also not well compared for countries. Here, the study investigated the heterogeneous technology-related drivers of CO 2 emissions in time and space simultaneously in 42 major emitter countries over 1998–2020 by extending the spatiotemporal production-theoretical decomposition models, and compared the different performances for forecasting CO 2 emission by traditional time-series models and several machine learning models. Key findings as follows: first, drivers of CO 2 emissions exhibit significant heterogeneity across countries where the effects of energy usage technology gap and CO 2 emission technology gap were negative drivers for USA, South Korea, and the Czech Republic and potential energy intensity effect was the negative driver in countries like China, Russia, Japan, and India. Second, the effects of within-GDP per capita and within- population size were the important drivers affecting global CO 2 emission difference. Third, general regression neural network achieved the best forecasting performance on average compared with other models in the study. The study highlights the importance of formulating climate policies based on heterogeneous technology and emission forecast modeling. • Heterogeneous technology-induced global CO 2 emission reduction was analyzed. • Two spatial production-theoretical decomposition models were proposed. • Forecasting models including machine learning were compared for projecting. [ABSTRACT FROM AUTHOR]

Previous empirical research suggests that the characteristics of individuals in the board of directors or peak management teams should be examined. There is a significant gap related to the role of women in the upper level of management and disclosure of carbon emissions. Therefore, this study aims to review the impact of women in top management positions on carbon emission disclosure in the ASEAN banking sector. We analyzed data from 146 banks throughout ASEAN from 2018 to 2022, comprising 719 data of observation. Sample selection employed purposive sampling. Statistical analysis was conducted using Stata MP 17 software, with the fixed effect model identified as the appropriate regression model through Chow, LM, and Hausman tests. Our empirical findings reveal a significant influence of women in upper management, specifically on carbon emission disclosure, as assessed through both Board of Directors (BOD) and audit committee perspectives. These findings have implications for investors and policymakers which support ASEAN countries in achieving net zero pledge, so that sustainability goals related to climate change can be achieved. [ABSTRACT FROM AUTHOR]

As China actively fulfills its emissions reduction obligations to meet the Paris climate goals, it is crucial to explore carbon reduction policies at the city level, given the important role and potential of cities in China's emissions reduction efforts. In this study, a comprehensive assessment and prediction of carbon emission patterns in the Pearl River Delta urban agglomeration was conducted by developing an integrated model that incorporates graph representation learning, factorial analysis, and random forest methods. The main findings are (1) there is significant heterogeneity in carbon emissions across industries and across time and space; (2) carbon clusters can more accurately characterize the flow of carbon emissions than carbon supply chains; (3) the nonmetallic manufacture, electricity supply and transportation industries play a decisive role in carbon emission reduction; and (4) the prediction results show that the carbon emissions of the Pearl River Delta urban agglomeration will reach 349.2 million tons in 2021, and will then show a declining trend year by year, dropping to a projected 179.8 million tons in 2035. Based on the above findings, it is recommended that the monitoring of key carbon emission clusters should be strengthened, and the monitoring data should be utilized to establish a cross-city and cross-industry cooperation mechanism for emission reduction. In addition, a clear set of action plans and strategies should be formulated and implemented to ensure that the carbon emission targets for 2035 are realized. [Display omitted] • ►A graph-factor-based random forest model (GRFM) is developed. • ►Carbon emissions have significant sectoral and spatial-temporal heterogeneity. • ►Electricity supply is the largest carbon emitter. • ►Developed economies such as Guangzhou, Dongguan, Foshan dominate carbon emissions. [ABSTRACT FROM AUTHOR]

Air pollution control measures play a crucial role in reducing air pollution and climate change, but researches on co-benefits of Total Control of Major Air Pollutants (TCMAP) in China is limited. This study quantifies synergistic benefits of TCMAP in reducing pollutant and carbon emissions by constructing a project-level emission reduction database, and further modelling safeguard strategy of emission reduction to achieve dual carbon target. Results revealed that TCMAP has facilitated a shift in the focus of air pollutant management from energy restructuring to deeper industrial and transportation restructuring. Synergistic benefits of TCMAP surpassed Carbon dioxide (CO 2) emissions from end-of-pipe treatment measures. As a result of rigorous implementation of TCMAP, approximately 0.12 GtCO 2 emissions were projected to be avoided in 2022. Synergistic reductions of 5,161 kt pollutants need to be achieved by 2030, and this commitment should be further strengthened to achieve 11,352 kt pollutants by 2060 to achieve dual-carbon target. [Display omitted] • Atmospheric control turned to transportation and industrial structure adjustment. • TCMAP pathway achieved synergistic carbon reduction 0.12 GtCO 2 in 2022. • Synergistic benefits of TCMAP far outweigh the end-treat measures that produce CO 2. • More ambitious TCMAP target safeguards needed for climate change mitigation. [ABSTRACT FROM AUTHOR]

Assessment of carbon stock (CS) in various land use/land cover (LULC) types is essential for environmental policies focused on reducing CO 2 emissions and mitigating climate change. This study utilized the CA-Markov model to simulate future LULC scenarios and the InVEST model to evaluate CS changes in Pakistan from 2001 to 2030. The study employed two decades of yearly composite land cover data from MODIS, achieving high accuracy with a kappa value of 0.856. The results indicate that an increase of 38.1 × 103 km2 in cultivated land could lead to an increment of 13.5 Tg in Pakistan's total CS. In comparison, an increase in forest area can be the reason for raising above-ground carbon (AGC) by 16.8 Tg. These findings enhance the understanding of long-term LULC and CS changes in Pakistan. The study provides valuable insights for governments to refine land use strategies, adjust carbon emission reduction policies, and design better regulations based on the study's findings. Key recommendations include promoting vertical urban development to preserve carbon sequestration areas, implementing strict agricultural zoning laws, expanding afforestation initiatives like the Billion Tree Tsunami and Green Pakistan, and establishing a national LULC and CS monitoring program. Integrating data from various sources will create a comprehensive database to inform policy decisions and land management practices, contributing to global climate change mitigation efforts. [Display omitted] • First national scale assessment (2000−2020) and forecast (2030) of carbon stock and land use/land cover changes in Pakistan. • Barren lands contain 63% of Pakistan, responsible for 56% of total CS. • An increase of 45% area of forest (LC with a high density of CS) will increase (16.8 Tg) above-ground carbon (AGC) by 2030. • Pakistan's total CS will be increased by 0.5% by 2030. [ABSTRACT FROM AUTHOR]

Carbon emissions elimination in the rapid urbanization areas contributes to regional sustainable development and global climate change mitigation. With the target of carbon neutrality, the global top-class Beijing-Tianjin-Hebei Urban Agglomeration which confronts with the dual pressure of excess carbon emissions and shrink ecological space has increased its carbon reduction coordination cooperation, among which energy consumption carbon emission control and natural resource sink maintenance have been recognized as the key strategy. However, the study on carbon balance prediction is lack and the amount of energy consumption carbon emissions in the future can be offset by the ecological carbon sink is still unknown. To estimate the gap to carbon neutrality, this study proposes a framework for carbon offset analysis and prediction which takes various carbon emission scenarios and the potential of natural resource on carbon reduction into consideration. After the framework conduction in the agglomeration, it is revealed that the regional least carbon emissions of 29.51 Mt mainly derive from the population and economic growth brought by urbanization process, while the carbon sink predicted to be 2552.31 Kt is still far to cover the emissions. With the regional carbon offset rate decline from 0.68% to 0.63%, the ecological carbon sink in Beijing will offset 1.21% of its carbon emission, while the least ecological space keep city Tianjin is predicted to suffer the lowest offset rate of 0.09%. The research results contribute to recognize the key factors on carbon emission control and key areas for carbon maintenance in following years, as well as narrowing the gap to neutrality with both consideration of carbon emission reduction and sink maintenance. [Display omitted] • Framework on energy consumption carbon offset analysis was established. • Regional carbon emissions, sinks and offset rate were predicted. • Drop from 0.68% in 2020 to 0.63% in 2030, the declining offset rate indicates the gap to neutrality is still large. • Implications for each area's carbon emission offset rate improvement were discussed. [ABSTRACT FROM AUTHOR]

We perform an ex-ante life cycle assessment, integrating cradle-to-gate greenhouse gas emissions into an off-grid energy system model. By applying a multi-objective optimization, minimizing both costs and carbon dioxide equivalent (CO 2 e) emissions, we find the Pareto boundary between these two goals. As a case study, we chose the power supply to an astronomical observatory in Chile, using mostly solar power and energy storage in batteries and hydrogen. We compare the ex-ante study to a prior ex-post life cycle assessment, and furthermore dive into sensitivities of our model regarding component lifetimes and costs. We find (i) low-hanging fruit in lowering emissions with small cost increases, (ii) ex-ante life cycle assessments' possibility to find less CO 2 e intensive power systems compared to ex-post conducted studies, (iii) a pronounced sensitivity of the optimization model on assumed lifetimes of energy storage components. This study shows the importance of including life cycle CO 2 e emissions into the optimization objective of energy system models. This method uncovers the environmental and economic trade-offs associated with high shares of renewable energies in off-grid energy systems. • We integrate life cycle assessment (LCA) into an off-grid energy system optimization. • The applied case study powers a remote astronomical telescope in Chile. • A multi-objective optimization finds Pareto curves at varying costs and lifetimes. • Low-hanging fruit shows low additional system costs to reduce CO 2 e impacts. • In contrast, a separate LCA did not find such trade-offs in costs and CO 2 e emissions. [ABSTRACT FROM AUTHOR]

Global climate action is the grand challenge of the 21st century. Large reductions in greenhouse gas emissions are needed, with net-zero CO 2 emissions by mid-century a requirement for many scenarios that restrain global warming below 1.5 °C by 2100. This will require massive deployment of renewables such as ground-based solar and wind, increased long-distance grid transmission capacity, and electrification of much of the global economy. Increased electrification, coupled with rising standards of living in developing countries, will drive ever-larger electricity demand to 2050 and beyond. And the intermittency, land-use, and transmission requirements of ground-based solar and wind present challenges to large-scale deployment to meet Net Zero targets. Space-based solar power (SSP) presents an enticing alternative, and with full reusability of upcoming heavy launch vehicles and modular SSP architectures, the economics of deployment are expected to become favorable in the coming decades. Efforts exist today to deploy demonstrators this decade, with initial production systems by 2050. However, deploying SSP at the scale required to address rising, global electricity demand will itself require orders-of-magnitude greater launch frequencies. If heavy launch frequency does not increase quickly enough, due to environmental concerns, launch site competition, or other bottlenecks, the dropping cost of launch will not be sufficient to enable SSP for global impact this century. A space elevator (SE) development program like that proposed by the International Space Elevator Consortium (ISEC) offers an alternative delivery mechanism for scaling SSP beyond 2050, hedging the risk of reliance on a single delivery system while reducing the time required for large-scale SSP deployment. To de-risk possible futures in which SSP is a major part of the global energy mix this century, a dual space access architecture is proposed, leveraging the strengths of heavy launch and SEs together. Such an architecture would secure the future for green energy on Earth, in 2050 and beyond. • Net-zero CO 2 emissions by 2050 required for many climate scenarios with < 1. 5 °C warming. • Massive deployment of renewables and scale-ups of long-distance transmission required. • Space-based solar power (SSP) is becoming economically viable as an enticing alternative. • Reusable heavy launch must scale-up rapidly to deploy SSP at scale for net-zero. • A space elevator development program would de-risk delivery of SSP at scale. [ABSTRACT FROM AUTHOR]

Climate change poses a significant threat to humanity and human activity is largely responsible for it. Clinical microbiology laboratories have their unintended shares in carbon dioxide (CO 2) emissions. The aim of this study is to estimate CO 2 emission of a clinical microbiology laboratory and to propose initiatives to reduce the emissions. CO 2 emission of instruments was estimated based on their electricity consumption. CO 2 emitted in producing consumables was estimated by weighing the consumables needed to perform major tests in a large academic hospital. A systematic literature review was performed to identify studies on the impact of clinical microbiology laboratories on the environment. A short survey was sent to four major manufacturers of agar plates on initiatives to reduce the environmental impact of their products. Opinion was given on activities that can reduce CO 2 emission in laboratories. The study shows that the largest amount of CO 2 emission in the microbiological laboratories comes from consumables and personnel commuting. For example, the production and transportation of agar plates needed to culture samples for a year in a hospital with 1320 beds result in 16 590 kg CO 2 is emitted. All survey participants mentioned that they were committed to reduce environmental impact of their products. The initiatives to reduce CO 2 emission can be performed at the laboratory and at policy level, such as reducing the number of tests to only the necessary amount to reduce consumables. The calculations contribute to map CO 2 -related emissions in clinical microbiology laboratory activities, and the proposed initiatives to reduce the CO 2 may serve as starting point for further discussions. [ABSTRACT FROM AUTHOR]

Efforts to enhance greenhouse gas (GHG) emission reduction in East Asia play a pivotal role on both global and regional scales in advancing climate mitigation strategies. This study aimed to better constrain anthropogenic CO 2 emission estimates by expanding the network of near-surface in-situ stations for CO 2 observations across South Korea. To achieve an optimal CO 2 network design, we conducted an Observing System Simulation Experiment (OSSE) coupled with the Stochastic Lagrangian Transport model (STILT), utilizing meteorological data from the Korean Integrated Model (KIM). Our inversion setup incorporated two CO 2 emission datasets with a 0.1o resolution: EDGAR v6 for prior emissions and GRACED for truth emissions. A uniform model-mismatch error of 3 ppm was introduced across sites. The effectiveness of the existing five in-situ stations, termed the base network, in South Korea was evaluated to gauge their ability to constrain CO 2 surface flux estimates. However, the findings revealed a reduction in flux uncertainty of only 29.2%, which fell short of the desired uncertainty reduction goal. In this base network, the Lotte World Tower (LWT: 37.5126°E, 127.1025°E) in Seoul and the Anmyeondo (AMY: 36.538576° N, 126.330071° E) site in Taean county stood as major contributors, with estimated reductions of 17.48% and 6.35%, respectively. Consequently, we proposed and developed an extended network, identifying seven candidate sites based on consideration of logistical factors, existing infrastructures, and proximity to the emission source regions. An incremental optimization scheme ranked their contributions, resulting in an additional 25% reduction, bringing the total to 54.13%. However, it is noteworthy that diminishing returns (ranging from 13% to less than 0.1%) were observed with an increase in station count mainly due to the possibility that adding a station earlier in the sequence might render subsequent stations redundant. Despite this, the proposed CO 2 network successfully reduced uncertainty in emissions, narrowing the gap with the objectives of the Global Greenhouse Gas Watch (G3W). • Designing CO 2 near-surface observation network over South Korea. • New stations selected considering logistic factors, existing infrastructures, and proximity to emission sources. • The base network was able to reduce 29.18% of the uncertainty in CO 2 emissions. • Extending network, by adding new seven candidate sites, led to a total uncertainty reduction of 54.13%. [ABSTRACT FROM AUTHOR]

• Implementation costs are a more relevant constraint to afforestation than opportunity costs. • Financial incentives for afforestation are constrained by market access and market prices. • Carbon-neutral and food multi-oriented land policies need further exploration. • Collaboration among global carbon markets can enhance CO 2 removal efficiency. Afforestation is a promising nature-based climate solution for mitigating climate change, but it is subject to a complex web of biophysical, cost-benefit, market, and policy processes. Although its biophysical feasibility has been established, the cost, market, and policy constraints that affect climate change mitigation through afforestation are still unclear. Here, we estimate such cost, market, and policy constraints on the basis of biophysical feasibility. Our findings reveal that implementation costs are a more relevant constraint than opportunity costs on mitigating climate change through afforestation. The China Certified Emission Reduction market currently provides only a 0.308 % incentive for climate change mitigation through afforestation, due to market access constraints. The current market prices of China Certified Emission Reduction, China Carbon Emissions Trading Exchange, and Nature Based Carbon Offset in Voluntary Carbon Market constrain 88.15 %, 87.95 %, and 85.75 % of CO 2 removal actions through afforestation, compared to the carbon price scenario (US$62.97 tCO 2 -1) of the EU Emissions Trading System. Moreover, land policy under the scenarios of prohibiting conversion of cultivated land to forest and forest restoration in degraded areas exhibit 8.87–29.59 % and 65.16–74.10 % constraints, respectively, on mitigating climate change through afforestation compared to land-use freedom conversion scenarios from 2020 to 2060. Thus, enhancing the incentive price of CO 2 removal, addressing the market access barrier, strengthening cooperation between global carbon markets, and exploring carbon–neutral and food multi-oriented land policies can be valuable sources of mitigation efforts over the next 40 years. [ABSTRACT FROM AUTHOR]

The renewal of old bridges is sometimes restricted to avoid the high carbon emissions caused by materials and construction, which however might not be conductive to climate change mitigation due to their insufficient functions. In order to facilitate the optimization of renewal timing and strategy from the perspective of reducing the comprehensive global warming impacts, we put forward the low-carbon bridge renewal decision method referring to the ideas of consequential life cycle assessment (LCA) and dynamic LCA. In the proposed method, a comparative system boundary matching the bridge renewal characteristics is constructed, where the carbon emission reduction owing to the traffic efficiency improvement by functional updating is incorporated as the low-carbon benefits of renewal, and three types of time-dependent factors, i.e., time-dependent characterization factor, trend factors and changes of traffic demands, are introduced to characterize the influence of renewal timing. The proposed method provided guidance for the renewal of Maogang Bridge, the first long-span cable-stayed bridge in Shanghai. Results illustrate that the global warming impacts of renewal construction activities and the low-carbon benefits from functional updating decrease with the renewal timing. For Maogang Bridge, the rapidly increasing traffic demands inevitably advocated renewal in advance, and the reduction of global warming impacts from emission reduction or carbon uptake could be manifested for renewal in advance. Adopting material recycling in the disposal of old bridge helped reconstructing a new bridge while deconstructing the old one in 2019 becoming the finally selected low-carbon renewal strategy, which is expected to reduce 15.04 kt CO 2 e-2019 compared to the essential renewal in 2050 with the landfill disposal method. The robustness of the strategy choice has been justified, given the variations of analytical time horizon, expected emission trends and repair emissions. In this way, the low-carbon renewal decision method could build a quantitative basis for judging the urgency of functional updating and verifying the low-carbon benefits of immediate concrete recycling in up-coming urban renewals. • Low-carbon bridge renewal decision optimizes renewal timing and strategy. • System boundary is expanded for quantifying benefits from functional updating. • Emission trends and time-dependent characterization factors are explored. [ABSTRACT FROM AUTHOR]

The ever-increasing challenges related to water security and climate mitigation underscore the pressing need for forward-thinking systems planning tools to drive urban sustainability transitions. In this study, we propose a novel city-level multi-objective planning framework that explores the nexus between carbon trading and water management, with the aim of facilitating water-efficient urban industrial restructuring. The framework integrates cap-and-trade mechanisms into a two-layered optimization model, creating an integrated approach to optimizing carbon emissions and generating economic opportunities for improving water efficiency. To illustrate the potential application of this framework, we conducted a case study focusing on Dongguan City, a water-stressed industrial metropolis in southern China. The results illustrate potential synergies between water planning strategies and carbon trading schemes, which could be harnessed to enable targeted reductions in water usage and carbon emissions. Furthermore, our findings identify the textile, apparel, and paper products manufacturing industries as primary candidates for strategic production scale reduction, emphasizing the importance of sustained support for the development of the computer and electronic manufacturing sector as a catalyst for urban sustainability transitions. By pioneering this new nexus-based perspective, our study offers valuable insights into long-term strategic planning for a low-carbon and resource-efficient urban economy. • Synergizing carbon trading and water management within a novel integrated planning framework. • Implementing resource-efficiency-driven optimization for water- and carbon-intensive manufacturing sectors. • Gaining insights into the specific roles of key manufacturing sectors in water management and carbon trading. • Introducing carbon trading systems may help in promoting water-efficient industrial restructuring. [Display omitted] [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]

Efforts to avoid the acceleration of global warming have tended to focus on countries with high CO 2 emissions levels and large populations, with a high level of economic development or industrialization. African countries, which often do not conform to such criteria, are more vulnerable to climate change due to their dependence on climate-sensitive industries and their limited infrastructure and technological capacity to cope with its impacts. The long-term economic growth rates projected for Africa's rapid development period will, further, make Africa a potential emission hotspot in the near future. Here, for the first time, we built an energy-related emissions inventory for 19 African countries for 2010–2019, which addresses emissions from 47 economic sectors and 5 energy types, making it the most comprehensive of its kind. The degree of decoupling of economy and emissions, and drivers of CO 2 emission changes are also examined. Most African countries experienced rapid growth in CO 2 emissions, with an average annual growth rate of 5.5% for fossil fuel-related CO 2 emissions and 6.0% for unsustainable biomass-related CO 2 emissions. Only two countries, South Africa and Tanzania, have achieved a strong decoupling of economic growth from CO 2 emissions. Economic and population are the most important drivers of emissions, while energy intensity has been identified as a key factor in mitigating CO 2 emissions, especially for those countries that have reached strong or weak decoupling. The findings from this study provide essential insights that could guide the development of low-carbon policies and strategies in Africa. • We provide energy-related emission inventories for 19 African countries from 2010 to 2019. • African countries experienced rapid growth in CO2 emissions. • Two countries achieved strong decoupling of GDP from CO2 emissions. • Economic and population growth are the most important drivers of emissions. [ABSTRACT FROM AUTHOR]

Decarbonizing the passenger transportation sector is critical for climate change mitigation. Existing studies on net-zero scenarios using Energy System Optimization Models (ESOM) often overlook non-monetary aspects of consumers' mobility choices but primarily focus on cost aspects. This study incorporates consumers' travel time duration and valuation, and an endogenous modal shift option into the Swiss TIMES Energy system Model (STEM). STEM is applied in a multi-objective optimization framework to quantify the impacts of faster Public Transport (PT) and slower car speeds on modal shifts in the transport sector's transformation. Similarly, we assess scenarios where consumers weigh travel time less, reflecting improved travel productivity. The results show that speed variations on medium- and long-distance trips, which can be interpreted as policies for highway speed limits and more efficient PT, can induce modal shifts towards 5–10% higher PT demand. Its implied secondary effects across the energy system include a reduced need for electrification of heavy-duty trucks by 11% and a decrease in hydrogen demand in road transportation by 34% by 2050. If travelers weigh costs over travel time, PT becomes less competitive against cars. Thus, electric vehicles (EVs) need to play a more dominant role in decarbonization, with a demand increase of 13% in 2040 (+9.2 billion passenger kilometer (bpkm)) and 6% in 2050 (+5.0 bpkm), along with the need for additional 45,000 public chargers of 22 kW size. Policy implications include the emphasis on improved PT speeds, speed limits on highways, needs to achieve more widespread EV adoption, and the need for balancing travelers' decision factors when aiming for reduced transport CO 2 emissions. • Non-monetary aspects relevant for modal shift incorporated in the Swiss TIMES model. • Multi-objective optimization to quantify net-zero impacts of non-monetary aspects. • Travel speed measures induce a 5–10% demand uptake of public transport. • Weighing travel time less makes electric cars more critical for decarbonization. • Secondary energy system effects are quantified & policy implications are drawn. [ABSTRACT FROM AUTHOR]

• The network structure characteristics of land-use carbon emissions (LUCE) are explored. • The problems of synergistic CO 2 reduction in Jiangxi province were identified. • The LUCE network structure in study areas becomes increasingly intricate and stable. • The LUCE spatial correlation network exhibited pronounced spatial spillover effects. • The study combines new relevant indicators to conduct carbon balance zoning. Exploring the spatial network structure of land-use carbon emissions (LUCE) and the carbon balance in developing regions is pivotal for climate change mitigation in these areas. Using socio-economic and land-use data from 2000 to 2020, this study focused on Jiangxi Province as a representative case to elucidate the spatial network structure of LUCE and conduct carbon balance zoning. The primary findings were as follows: (1) The LUCE distribution in Jiangxi Province demonstrated a spatial pattern with high values in the northwest and low values in the southeast. An increasing trend was observed in the total amount of LUCE. Furthermore, there were evident regional differences in the Ecological Support Coefficient (ESC), indicating a weakening regional carbon sink capacity. (2) The spatial network structure of LUCE was intricate but stable. Although the gravitational interactions of LUCE between cities have intensified, overall network connectivity remained moderately correlated, indicating a prominent regional development imbalance. (3) There was a pronounced "core-periphery" structure in the LUCE spatial correlation network. Northern Jiangxi was the "core" of the network, taking an "initiator" role, whereas most cities in southern Jiangxi played a "passive" role, and resided at the "periphery" of the network. The inter-regional LUCE network exhibited pronounced spatial spillover, with inter-block correlations surpassing those within blocks. (4) By leveraging empirical data and spatial metrics, we categorized Jiangxi Province into five distinct carbon balance zoning types and subsequently proposed land-use optimization strategies. From the perspective of social network analysis (SNA), this study offers methodological insights into low-carbon development and synergistic emission reduction in developing regions. [ABSTRACT FROM AUTHOR]

Environmental deterioration brought on by the top ten greenhouse gas emitters is a critical worldwide issue with far-reaching ramifications for global economic sustainability. The main purpose of this research is to explore the link between economic growth, energy consumption, trade openness, and environmental factors with a focus on achieving carbon neutrality without compromising economic growth in the top ten emitting countries by employing a dynamic STIRPAT modeling technique. The data used in this research was taken from various sources, such as the International Energy Agency and the World Bank. The research found a robust association between energy consumption and economic growth, with a correlation coefficient of 0.87. The results revealed that carbon emissions (CO 2) are positively related to per capita gross domestic product (PGDP), cubic GDP (G D P 3 ), international tourism arrivals (Tour) and energy consumption (EC), while negatively related to trade openness (TO) and squared GDP (G D P 2 ) in the top ten emitting countries, confirming the N shaped Kuznets curve hypothesis. Trade liberalization also impacted emissions with a coefficient of 0.65 (p < 0.01). The findings suggest that in order to simultaneously achieve carbon neutrality and continue economic development, it is imperative for the major polluting countries to embrace renewable energy sources and enact environmentally beneficial trade and economic measures. [Display omitted] • The study highlights collaboration for carbon neutrality and economic growth. • Results suggest a balance between carbon neutrality & economic vitality. • Renewable energy can drive economic growth while reducing emissions. • Results are policy relevant in achieving carbon neutrality. • The study validates the N shape Kuznets curve hypothesis. [ABSTRACT FROM AUTHOR]

The depth and breadth of the climate crisis is well known, all sectors, industry, government and the individual have the potential to reduce emissions to slow or stop catastrophic climate change. To determine and evaluate the (revealed) preferences of the public in reducing their personal carbon emissions, a conjoint analysis survey, using the PAPRIKA (Potentially All Pairwise RanKings of all possible Alternatives) method, was distributed to the public in a city in the south of England (Southampton). Knowledge of the deep-seated preferences of the public makes a fundamental contribution to future climate actions because it enables publicly acceptable system change to be developed. Results showed the public were unwilling to make large-scale lifestyle changes, even if they would cause large emission reductions. There was a clear preference for making relatively easy, convenient changes to behaviour rather than making more difficult personal lifestyle changes involving diet and transportation. A significant value-action gap is evident, with the public showing high awareness of the seriousness of climate change but showing an unwillingness to make deep cuts to their personal emissions. Demography and personal factors had a relatively low influence over preferences with trends generally staying the same across demographic groups, aside from income brackets. Participants believed that reductions in emissions should come from a 'group effort' from all levels of government, business, environmental groups and individuals. Few participants placed themselves as individual drivers of carbon emission reduction. In order to reduce emissions some form of intervention needs to be made, as the public are not personally willing to make large-scale reductions in carbon emissions, regardless of their environmental awareness or demography. • Public's views on approaches to carbon reduction investigated via conjoint analysis. • Preference for low intensity, 'easy' behaviours not challenging lifestyle changes. • Demographic & personal factors have low influence on carbon reduction preferences. • High awareness of severity of climate change, impacts/priority; also high anxiety. • Desire to consume & "carry on as normal" outweighs self-reported concerns/attitudes. [ABSTRACT FROM AUTHOR]

Micro-level concerns about climate change can not only affect individual low-carbon behaviors but also exert intense pressure on carbon emission reduction strategies and policy design. However, whether public concern about climate change can affect per capita carbon emission is still unclear. Based on panel data from 30 provinces in China and 188,943 climate change-related blogs from 2012 to 2019, this research investigates the impact of public concern on per capita carbon emissions. Results show that, in general, public concern about climate change has a significant negative impact on per capita carbon emissions in China, indicating that climate crisis awareness has a supervisory effect on greenhouse gas emissions. Nevertheless, the effects of different public concerns on per capita carbon emissions are different, with the topics of "low-carbon appeal" and "concern for future" have significant positive impacts on per capita carbon emissions, while the topics of "carbon governance performance" and "climate change mitigation strategies" have significant negative impacts on per capita carbon emissions. The findings yield new opportunities to delve into the relationship between the externality of people's will and governmental behaviors and provide in-depth insights for decision-makers to develop tailor-made solutions towards carbon reduction and sustainable development. [Display omitted] [ABSTRACT FROM AUTHOR]

The climate crisis is recognized as one of the world's most serious concerns, posing a threat to environmental, social, and economic growth. However, previous work has failed to address the dynamic effects through which economic growth may affect green growth and climate crisis. In this research, we take a closer look at the impact of carbon emissions, eco-innovation adoption, and international collaboration on economic growth and the influence of economic growth on green growth. This paper used the generalized method of moments (GMM) for 54 African countries from 2010 to 2019, allied with an imbalanced panel of 540 observations. This paper finds a positive relationship between carbon emissions, eco-innovation international cooperation, and economic growth with p-values lower than 0.047. Our study discovers economic growth's robust and positive impact on green growth with a p-value of 0.009. This research finds a three-pronged mediating effect of economic growth between its driving factors and green growth. Lastly, this paper furnishes new visions into the argument over economic growth versus green growth. It informs policymakers of the need to pay attention to the growing effect of eco-innovation driving factors on attaining sustainable and greener growth and climate crisis mitigation. [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]

The contribution of municipal solid waste incineration (MSWI) to anthropogenic mercury and CO 2 emissions have become increasingly important over the past decade. This study developed an inventory of anthropogenic mercury emissions and CO 2 emissions during the period of 2014–2020, of MSWI process in China using a bottom-up inventory at the plant level. Overall, national MSWI anthropogenic mercury emissions increased from 2014 to 2020 by province. It was estimated that total 8321.09 kg of anthropogenic mercury emissions from 548 MSWI plants were scattered in 31 provinces of mainland China in 2020. The average intensity of mercury emission in China was 0.06 g·t−1 in 2020, which was much lower than the pre-2010 level. Furthermore, the increased CO 2 emission generated by MSWI from 2014 to 2020 is 1.97 times. Anthropogenic mercury emissions and CO 2 emissions were concentrated mainly in developed coastal provinces and cities. The general uncertainty of national mercury emissions and CO 2 emissions was estimated to be −123% to 323% and −130% to 335%, respectively. Furthermore, future emissions were predicted from 2030 to 2060 based on different scenarios of the independent and collaborative effects of control proposals, the results indicate that the enhancement of advanced air pollution control technologies and effective management of MSWI represent pivotal factors in realizing future reductions in CO 2 and mercury emissions. The findings will supplement those for mercury and CO 2 emissions, and be useful for relevant policy-making and to improve urban air quality, as well as human health. [ABSTRACT FROM AUTHOR]

The global energy landscape is experiencing substantial transformations, and the energy policies of various countries are also evolving under the influence of economic development and climate change mitigation. The Policies and Measures Database of the International Energy Agency assembles over 7000 pieces of information on energy policy from around the world and classifies them into four categories based on their objectives: addressing climate change policy, renewable energy policy, energy efficiency policy, and building energy efficiency policy. This paper aims to analyze the status quo of global energy policy development from these four aspects and examine the effectiveness of both aggregate and individual instruments utilizing an econometric model based on panel data analysis. Moreover, this paper analyzes the energy policy paths of six leading countries and compares the effectiveness of their policies. The results revealed that global climate policy plays a significant role in reducing carbon emission, while the performance of policies varies among different countries. Based on these findings, this paper provides reference for policymakers to formulate energy policies aligned with global and domestic requirements. [Display omitted] • Characterizing a full picture of global climate policy inventories. • Different policy instruments have varying performances in reducing carbon dioxide emissions. • The policy effectiveness varies across countries, better in developing countries. [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]

This study seeks to identify the change points, tendencies, and trends in climatic parameters and to investigate their relationship with forest cover loss and carbon dioxide (CO 2) emission in the Garo Hills region of Northeast India.This study is based on secondary data on Precipitation, Maximum Temperature, Minimum Temperature, Relative Humidity, Tree cover loss, and CO 2 emission in Garo Hills from 1984 to 2019. Mann-Kendall's and Sen's slopes were employed to calculate the trend of monthly and seasonal climatic parameters, and Pettitt's test was used to estimate the breakpoints.We further attempted to identify the relationship between the variables under consideration using Pearson's correlation and regression analysis. The results indicate that precipitation levels were generally decreasing over the majority of months and seasons.The maximum temperature showed a marked increase, while the minimum temperature experienced a decrease in all seasons after 2008. From 1999 onwards, the relative humidity has been on the rise in all seasons except monsoon. Regression analysis reveals that the relative humidity and maximum temperature contributed negatively to precipitation. The maximum temperature was positively correlated with both forest cover loss (r = +0.58) and CO 2 emission (r = +0.59), while the minimum temperature was negatively correlated with both (r = −0.59 and r = −0.59). This study will provide stakeholders with an understanding of how weather factors vary over time, how forest cover loss and CO 2 emissions affect weather patterns in the region, and how to develop climate mitigation strategies. • Change Point detection of climatic parameters of Garo hills of Meghalaya. • Trend analysis for Annual, Seasonal, Monthly climatic parameters during 1984–2019. • Analysis of trend for climatic parameters before and after the change points. • Establishing relationship between forest cover loss and CO 2 emission and climatic parameters. [ABSTRACT FROM AUTHOR]

• BLSVM-MFA method is developed for predicting renewable power generation potential. • BLSVM-MFA can reflect nonlinear relationship between CETC factors and WPG & PPG. • Main factors affecting WPG and PPG and their contributions can be identified. • Ensemble predictions reveal that Xiamen's WPG and PPG potentials decrease. • Results are valuable for energy-structure transformation and carbon abatement. In order to reduce fossil-energy carbon emission and mitigate its climate change impact, developing integrated mathematical methods that are capable of predicting renewable power-generation (e.g., wind and photovoltaic power) potential are desired. This study advances an integrated Bayesian least-squares-support-vector-machine based multilevel-factorial-analysis (BLSVM-MFA) method to find out the main factors affecting wind- and photovoltaic-power generations (WPG and PPG), as well as predict WPG and PPG potentials. The BLSVM-MFA method is then applied to a case study of Xiamen (China), where various factors including climate, economic, technological and capacity are investigated and 216 scenarios are analyzed. Results disclose that the main factors affecting WPG are wind power index (contributing 54.04%) > installed capacity (41.45%) > technology (2.60%), and the main factors affecting PPG are installed capacity (60.36%) > solar radiation (19.27%) > technology (9.24%). Results also reveal that WPG and PPG potentials (in 2020–2035) decrease under most scenarios and WPG and PPG show seasonal complementarity. Ensemble predictions under 216 scenarios indicate that WPG and PPG would be 130.21 WMh and 436.51 MWh by 2035. The promotion of high-conversion and high-profit technologies can improve the competitiveness of WPG and PPG in the regional power system. Results are valuable for revealing the impacts of climate change, economic development, and technological improvement on renewable power potentials and providing support for regional energy-structure transformation and carbon-emission abatement. [ABSTRACT FROM AUTHOR]

• Energy use positively affects carbon emission intensity. • Urbanization has positive impact on carbon emission intensity. • Technological innovation negatively affects carbon emission intensity. • Data was analyzed by Quantile-on-quantile model. In recent years, policy experts have engaged in a spirited discussion over the relationship between environmental quality and energy use. This association is critical for the mitigation of climate change and achieving Sustainable Development Goals (SDGs). Furthermore, current studies have not given enough consideration to this relation, notably in the case of the Kingdom of Saudi Arabia (KSA). Therefore, this study examines the KSA case, focuses on the connection of industrialization, foreign direct investments, and technological innovation with carbon emissions intensity (CEI) by also considering urbanization and energy use, examines the period between 1991 and 2020, and uses quantile-on-quantile (QQ) regressionand quantile regression (QR) approaches for empirical examination. The empirical outcomes revealthat (i) urbanization and energy usehave an increasing impact on CEIin all quantiles; (ii) industrialization, foreign direct investments, and technological innovation have a generally decreasing impact on the CEI in most quantiles; (iii) power of the factors' impact on the CEI change according to quantiles; (iv) the robustness the findings is also validated. Hence, theresults highlight the importance of quantile-based analysis and suggest that KSA authorities need to embrace environment-friendly policies while managing environmental pollution to develop industrialization level and technological innovation as well as increase foreign direct investments. [ABSTRACT FROM AUTHOR]

Clean vehicle fleet will greatly benefit air quality and climate change mitigation. Here, we employ an integrated model to systematically investigated the contribution of combined clean vehicle policies to "emissions, exposure, and health benefits" from a regional perspective 2019–2035 in China. We find that driven by clean vehicle polices, the national vehicle CO 2 will likely to peak around 2028 with about 1327 million tons, and then reduce by 7.8% from 2028 to 2035. The developed region will peak CO 2 before 2030, while the developing region probably peak after 2030. In general, most air pollutants emissions from vehicles will decrease, subsequently leading to obvious PM 2.5 and O 3 exposure decrease. About 68 thousand PM 2.5 related and 33 thousand O 3 related deaths will be avoided 2019–2035 nationwide. Note that the health benefits are unequal, with higher PM 2.5 -O 3 related excess deaths be avoided per 100000 in developed region than developing region. Besides, results show that emission standard upgrade contributes largest to emission reduction and related health benefits, followed by electric vehicles, road-to-railways and waterways, and fuel consumption regulation in general. This work is able to provide valuable information for policy makers to collaboratively reduce CO 2 , air pollutants and premature deaths in China and other developing countries. [Display omitted] • Emissions in CO 2 and air pollutants were both investigated based on a dataset with 27 vehicle categories from 338 cities. • The contribution of vehicle clean policies to abated PM 2.5 -O 3 exposure and related deaths was quantified and decomposed. • This work proposed region-specific clean vehicle pathways from a national and regional perspective 2019-2035. [ABSTRACT FROM AUTHOR]

Middle-class expansion has played a crucial role in driving the changes in embodied carbon emissions. However, its driving mechanisms still need to be clarified. In this paper, we compiled novel multiregional input-output tables to capture the rise of the middle class in China in terms of its expansion and consumption pattern changes. Structural path analysis was employed to investigate the critical paths of embodied carbon emissions from middle classes of different regions in China during 2012–2015. Structural path decomposition was further used to explore the driving factors along the paths, including changes in population size, consumption patterns, industrial structure, and carbon intensity. Our results show that, from 2012 to 2015, the role of the middle class in driving carbon emissions through the most critical paths was either enhanced or reduced depending on different factorial changes. Generally, the paths with enhanced roles of the middle class stemmed from the urban and rural middle classes in Central China, Southwestern Coastal, and Northern Coastal regions, and the changes in consumption patterns and population of the urban middle class were the main driving factors. The top 30 paths of carbon emissions growth driven by the urban and rural middle classes approximately increase 19.5 Mt and 8 Mt of carbon emissions, respectively. In contrast, most of the paths with the weakened role of the middle class were intraregional paths in the Southern Coastal and Eastern Coastal regions, and carbon intensity was the dominant factor governing the changes. Our analysis systematically revealed, for the first time, the heterogeneous impacts and driving factors of middle-class expansion in different regions of China on carbon emissions. Therefore, it provides new insights for climate mitigation in the context of China's plan to cultivate a majority middle-class society. • New multiregional input-output tables are compiled for the rise of the middle class in China. • Middle-class expansion has heterogeneous effects on regional carbon emissions. • Urban and rural middle class lead to an incease of 19.5 and 8 Mt CO2 for top 30 paths, respectively. • Four driving factors play different roles in supply chains affecting carbon emissions. • Consumption patterns and urban middle-class size changes were the main driving factors. [ABSTRACT FROM AUTHOR]

In an effort to contribute to climate change mitigation, China has committed to achieving its peak carbon by 2030 and carbon neutrality by 2060. However, reaching these goals will require a massive reduction in carbon emissions. The humans have to consume food to meet their survival needs. Furthermore, the society's demand for food is consistent with the development level of agricultural structures. At present, reducing environmental costs associated with food to adjust the agricultural structure has not received sufficient scientific attention. Because of this, the present study combines food consumption, climate change, and agricultural structure to design future scenarios based on the widely used SSP storyline. Moreover, in order for China to reach its carbon peak in 2030, this study applies a life-cycle approach to uncover the potential carbon reduction of Chinese residents under different dietary structures. From a demand perspective, this study puts forward recommendations for dietary restructuring and guides the direction of future agricultural restructuring in China. It also shows that a diet structure that replaces red meat with plant foods such as vegetables and fruits will have a more significant carbon reduction potential. The traditional agricultural structure consumes a large amount of food and produces a significant amount of greenhouse gases. Reducing meat and high-fat foods consumption may help reduce GHG emissions produced by food consumption. In addition, reducing the proportion of food used for feeding in the agricultural structure will also help achieve peak carbon targets. The shift in diet structure will advance China's agricultural structure and promote green agriculture development. • Food consumption and related carbon emissions within the 2030 scenario will continue to increase, with the highest share of rice consumption. • The carbon emissions of food consumption in the environmentally sustainable scenario will decrease. • Readjusting toward a more balanced diet could significantly contribute to the carbon peak goal. • A shift in dietary structure will promote agricultural restructuring. [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]

Action is needed from all the major emitting economies if we are to achieve global net-zero carbon dioxide emissions. Climate action takes place at various levels of the political system. In this study, we concentrate on cooperation between the major economies on clean energy technologies in the frame of the Clean Energy Ministerial (CEM; initiated in 2010) and Mission Innovation (MI; initiated in 2015). More precisely, building on research on the European Union's (EU) leadership in international climate politics, we concentrate on how the EU Commission and the EU member states have exerted leadership in these two organizations in the period 2013–2022 (for the CEM) and 2017–2022 (for MI), respectively. We use descriptive techniques and cluster analysis to investigate our original dataset. We find that, first, the EU Commission has been more active in MI than in the CEM. Interestingly the EU Commission's leadership in MI even surpasses that of the United States. Second, the EU Commission has been more active than the EU member states in MI but not in the CEM. Third, Germany and the United Kingdom, together with Italy, the Netherlands, and Denmark, stand out as particularly active in terms of (co-)leading workstreams. [ABSTRACT FROM AUTHOR]

• Climate change was identified as the main threat for seagrass soil CO 2 emissions. • Direct threats have the highest potential risk for CO 2 emissions at a local scale. • Empirical data on seagrass CO 2 emissions following disturbance is scarce. • Ranking of threats for seagrass CO 2 emissions can aid management and policy. Seagrass meadows are natural carbon storage hotspots at risk from global change threats, and their loss can result in the remineralization of soil carbon stocks and CO 2 emissions fueling climate change. Here we used expert elicitation and empirical evidence to assess the risk of CO 2 emissions from seagrass soils caused by multiple human-induced, biological and climate change threats. Judgments from 41 experts were synthesized into a seagrass CO 2 emission risk score based on vulnerability factors (i.e., spatial scale, frequency, magnitude, resistance and recovery) to seagrass soil organic carbon stocks. Experts perceived that climate change threats (e.g., gradual ocean warming and increased storminess) have the highest risk for CO 2 emissions at global spatial scales, while direct threats (i.e., dredging and building of a marina or jetty) have the largest CO 2 emission risks at local spatial scales. A review of existing peer-reviewed literature showed a scarcity of studies assessing CO 2 emissions following seagrass disturbance, but the limited empirical evidence partly confirmed the opinion of experts. The literature review indicated that direct and long-term disturbances have the greatest negative impact on soil carbon stocks per unit area, highlighting that immediate management actions after disturbances to recover the seagrass canopy can significantly reduce soil CO 2 emissions. We conclude that further empirical evidence assessing global change threats on the seagrass carbon sink capacity is required to aid broader uptake of seagrass into blue carbon policy frameworks. The preliminary findings from this study can be used to estimate the potential risk of CO 2 emissions from seagrass habitats under threat and guide nature-based solutions for climate change mitigation. [ABSTRACT FROM AUTHOR]

This study developed a climatic-economic-technological integrated assessment model named CIECIA-TD-F. Based on model, the implementation effects of low carbon technology financing on climate mitigation, technology promotion, and economic development in the context of climate change cooperation were studied. The results indicate that carbon reduction, under the current pledged climate financing scale, is limited. Global surface warming in 2100 is still around 2.38 °C even when the technologies are globally shared. Low carbon technology financing improves technology R&D and absorptive capacities of the least developed countries. Their carbon reduction rates reach 50 percent under the capacity principle. However, donations impair the R&D inputs of developed countries and delay their advanced technological progress, leading to 1 percent more carbon emissions. This limits the imitations of China and Russia in turn by decreasing their imitation numbers by 1–2 percent. Collecting 800 billion USD per year from 2030 to 2100 is a climatically effective means. It holds global warming to 1.99 °C. However, the donors suffer more than 1 percent of economic losses. That indicates the economic feasibility of this means is weak. On this basis, we proposed a Pareto-improvement scheme which combines financing with technology sharing and national R&D improvements. This policy mix both achieves the 2 °C goal and protect the economic benefits of all countries. Thus, policy mix combining different measures will be more suitable for improving reduction effects and achieving multiple goals. Compared with sole technology financing, it has more significant global carbon governance meanings and is noteworthy in future climate negotiations. • Nine combinations of typical collection and dispensation principles were assessed. • The current scale of climate financing pledge was insufficient. • 2 °C goal can be achieved by improving financing scale dramatically in short term. • Advanced technology innovation was delayed for the economic losses of the funding donors. • A Pareto improving scheme was proposed. [ABSTRACT FROM AUTHOR]

Cities are a major source of greenhouse gas emissions (GHGs), but they can play a significant role in climate change mitigation by adopting and implementing GHG emission reduction plans, policies and measures. Circular economy measures are recognized to contribute significantly to decarbonization. However, in the literature there is a lack of quantitative analyses on circular measures in cities and their impact on urban GHG emissions. The paper aims to contribute to the literature on the relation between circular cities and climate change mitigation by focusing on circular interventions applicable in three high-impact sectors in cities: energy systems, mobility and built environment, in order to investigate their impacts in terms of emission reductions and contribution to decarbonization. The study covers four cities around the world accounting for more than 10 million of inhabitants and 2,000 km2 of metropolitan area: Bogotá, Colombia; Genoa and Milan, Italy; Glasgow, UK. The methodology uses a Global Trade Analysis Project (GTAP) modelling approach to develop production and consumption-based emission baselines for the four cities and to assess impacts of selected circular measures in the three sectors on the baselines. According to the in-depth analysis of the four considered urban contexts, the majority of the emissions generated by activities carried out within the urban borders are emitted outside the borders in the form of emissions scope 3, thus demonstrating how today's cities are large consumers of goods produced outside their borders, requiring the use of a consumption-based approach for emissions inventory. The results on the modelling of the GHG reduction impact of circular measures show that there is a relevant emission reduction potential in Scope 1 and 2 emissions in cities and highlight the need to prioritize decarbonization of electricity supply in order to ensure relevant emission reductions across the three sectors. The results also demonstrate the potential to reduce supply-chain Scope 3 emissions through urban measures. [Display omitted] • Four different urban contexts around the world are taken in account. • Three sectors are investigated: energy, mobility and built environment. • A consumption-based emission accounting method is used to assess the effective impact of cities. • Impacts of different GHG emission reduction interventions are evaluated for each city. [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]

Decarbonization is a process that transforms economies to lower greenhouse gas (GHG) emissions per unit of economic output, aiming towards net-zero GHG emissions. This process could also reduce short-lived climate pollutant (SLCP) emissions, including black carbon and methane. They have relatively short atmospheric lifetimes but have large radiative forcing and impact human health. Therefore, reducing SLCPs can improve air pollution and help mitigate climate change. Costa Rica was one of the first countries to have a decarbonization plan, and many others have stated their goal to reach net-zero emissions by around mid-century. However, reducing SLCP emissions as an economy decarbonizes is not guaranteed, and few examples in the literature have assessed how decarbonization impacts SLCPs. This paper estimates the SLCP emission reductions from Costa Rica's decarbonization plan. Through a value chain analysis and the identification of implementation barriers, the paper also evaluates which policy instruments can advance SLCP mitigation in multiple sectors, creating implementation synergy. We find that mitigation measures, by 2050, in the transport, agricultural, solid waste, and industrial sectors avoid 25.2 kt of black carbon emissions (23 times the 2018 emissions) and 2167 kt of methane (15 times the 2018 emissions). However, the country faces financial and governance challenges in each sector that will need overcoming to implement the intended mitigation measures. We identify a comprehensive environmental tax reform, the overhauling of urban regulatory plans, the strengthening of institutional capabilities, and low-carbon investment with favorable financing as crucial cross-sectoral policy synergies that will advance the implementation of SLCP mitigation. • Decarbonizing can reduce and avoid short-lived climate pollutant (SLCP) emissions. • Black carbon and methane (two SLCPs) cause global warming and poor air quality. • Some policy instruments can reduce SLCPs in multiple sectors, causing synergy. • Improved urban planning can favor the mitigation in transport and waste sectors. • Institutional strength and favorable financing are needed to advance mitigation. [ABSTRACT FROM AUTHOR]

Carbon capture, utilization, and storage (CCUS) is a crucial technology for global climate mitigation. To implement large-scale CCUS, decisions about where and how to build a CO 2 transportation network are urgently required. However, previous studies are limited in proposing the economical transportation network for CCUS that considered comprehensive risks from socio-economic, geographical and geological factors. Here, we develop a pipeline layout planning model to investigate the cost-effective and reliable transportation network for CCUS. Results show that to meet the annual CO 2 emission reduction target of 654 million tons for CCUS in the coal-fired power sector under China's carbon neutral goal, pipelines with a total length of 17,589 km need to be constructed. The emission sources can be transported in pipelines with an average radius of 58 km, and with diameters of 8, 12, and 16 inches. Northeast, north, and northwest China are the main areas suitable for pipeline construction. • Northeast, North, and Northwest in China are vital areas for capture, transport, and storage. • Five large-scale pipeline network groups can be constructed in China. • Pipeline construction is greatly affected by a variety of practical factors. [ABSTRACT FROM AUTHOR]

This study contributed to the environmental research by analyzing the nexus between innovation in climate change mitigation technologies and carbon dioxide emissions in the United States, with the gross domestic product per capita, international collaboration in green technology development, renewable energy consumption, the labor force, and trade openness as control variables from 1990Q1 to 2018Q4. First, the results suggested that renewable energy consumption, innovation in climate change mitigation technologies, and international collaboration in green technology development are significant mitigating and determining factors for carbon dioxide emissions. Second, the findings also indicated that trade openness and gross domestic product per capita were positively associated with carbon dioxide emissions. Third, the Granger causality test results validated the presence of a bidirectional nexus between innovation in climate change mitigation technologies and carbon dioxide emissions, renewable energy consumption and carbon dioxide emissions, and international collaboration in green technology development and carbon dioxide emissions. Fourth, the results validated a one-way causality between gross domestic product per capita and carbon dioxide emissions. [ABSTRACT FROM AUTHOR]

Climate change and CO 2 emissions intertwine corporations and society in current political, social, environmental, and economic debates, specifically in Europe. The climate action plan formulated by the European Commission aims to achieve net zero emissions through eco-innovation by 2050. The objective of this study is to investigate the impact of the European eco-innovation index on CO 2 emissions produced by European firms. Using a dataset of 735 firms from 17 European countries listed during 2010–2018, we found a significant negative association between the country-level eco-innovation index and CO 2 emissions directly produced by the European firms. We also found a significant negative association between the eco-innovation index and indirect CO 2 emissions produced by the value chain of these firms. The results provide evidence that via eco-innovation, supportive steps taken by European countries provide a conducive environment for the European firms to adopt eco-innovative strategies that significantly reduce their direct and indirect CO 2 emissions per dollar of their corporate assets and make their value chains eco-friendly. The results also reveal that financial development brings in some environmental monitoring that cultivates a supportive culture for the corporations to promote corporate efforts to reduce CO 2 emissions. • The first study that uses an eco-innovation index, based on 5 dimensions, developed by the European Commission. • We find a negative impact of country-level eco-innovation on the reduction in direct and indirect corporate CO 2 emissions. • Eco-innovation initiatives taken by the European countries are helping European firms in reducing their CO 2 emissions. [ABSTRACT FROM AUTHOR]

Decarbonization of urban water systems has been increasingly important for addressing the target of climate change mitigation. Yet, little insight has been derived regarding how water use and energy transition policies jointly alter climate impact of water systems in cities. In this study, using 21 cities in Guangdong Province (China) as a case study, we account for the carbon dioxide emissions related to energy use in urban water systems (UWSs) over 2006–2035. By constructing a city-scale water-carbon nexus model, we project future trajectories of electricity-related CO 2 emissions in UWSs by considering dynamics of water demand and varying pathways of energy transition. We show that increasing need of tap water purification is a main contributor to electricity-related CO 2 emissions, followed by tap water distribution and wastewater treatment. The electricity-related CO 2 emissions in most cities could peak before 2030 under a fast-decarbonization energy transition pathway, despite the rise of urban water demand. Fast-urbanizing cities like Foshan, Shantou and Qingyuan may witness a 4–23% increase of emissions between 2020 and 2035. With a more rapid increase of proportion of cleaner energies in electricity mix, the fast-decarbonization pathway could end up with 21% more reduction of emissions on average during 2020–2035, compared to currently-planned energy transition pathway. Under the stringent climate goal of China, cities should foster a joint mechanism between water system and grid companies that leads to a more effective low-carbon governance of water systems. [Display omitted] • We project carbon peaks in UWSs under varying energy transition pathways. • Tap water purification is a main contributor to CO 2 emissions in UWSs. • Fast-urbanizing cities may further increase their emissions during 2020–2035. • Fast-decarbonization pathway would mean 21% more reduction of emissions. [ABSTRACT FROM AUTHOR]

Infrastructure for heat provision in the built environment needs to change remarkably to support lowering carbon emissions and achieving climate mitigation targets before 2050. We propose a computational approach for finding a mix of heat options per neighbourhood that minimises cumulative carbon emissions between 2030 and 2050, referred to as committed emissions, while at the same time adhering to technological constraints at both the household and neighbourhood scales. To establish this approach, we integrated bottom-up heat demand modelling at neighbourhood scale with a mixed-integer non-linear optimisation problem. Nine scenarios with different pathways for the insulation of buildings and the decarbonisation in electricity generation were considered and applied to three neighbourhoods in the city of Amsterdam, the Netherlands. The results show that (i) the committed emissions are ten times lower between 2030 and 2050 in scenarios in which ambitious measures are taken for the insulation of buildings and the decarbonisation in electricity generation, (ii) only in these 'ambitious scenarios' low temperature heat systems, such as heat pumps and low temperature heat networks, are optimal solutions for minimising committed emissions, (iii) if less ambitious insulation and decarbonisation measures are taken, high temperature heat options can be part of the heat mix with lowest committed emissions, and (iv) the minimum heat density for low temperature heat networks is not always achieved, creating risks for carbon lock-ins when applying these heat networks. Our results clearly indicate that pathways for the retrofitting of buildings and the decarbonisation in electricity generation need to be taken into account jointly when designing renewable and low-carbon heat systems to optimally reduce carbon emissions towards 2050 and reduce future carbon lock-ins. • Bottom-up heat demand models enable testing spatial heat system requirements. • Power supply decarbonisation and building insulation characterise ambitious policies. • Hybrid or low temperature heat systems are optimal solutions for ambitious policies. • Ambitious decarbonisation policies can lower committed emissions tenfold. • Heat networks can cause a carbon lock-in due to the needed minimum heat density. [ABSTRACT FROM AUTHOR]

• Pursuing a zero-carbon US electricity system would incur additional cost. • The use of non-renewable low-carbon resources reduces the additional cost. • Negative emission technologies show economic advantage to mitigate the last few percent CO 2 from the US electricity system. Decarbonizing the electricity system to zero-carbon emission is crucial for climate change mitigation. Previous studies have shown that such a transition in the United States (U.S.) may lead to higher system cost compared to a business-as-usual case, but it is not well-known how the cost of electricity generation varies at sub-regional level under the transition, and studies have rarely evaluated the trade-off between the cost and avoided climate damages, as well as the potential roles of negative emission technologies (NETs) in the electricity decarbonization. Here, we present a regionally resolved national model to quantify the cost of decarbonizing the U.S. electricity system under a set of possible scenarios. The results show that, compared to the reference scenario without a decarbonization policy, reaching zero CO 2 emission by 2050 would incur, depending on the scenarios, 335–494 billion USD additional cost to the U.S. electric power sector during 2020–2050. The regional costs of electricity generation ranges from 2.4 to 4.7 cent/kWh, largely due to the generation profiles and renewable resources availability of those regions. The additional costs can be translated to an average CO 2 abatement cost of 29–59 USD/metric ton CO 2 (with 2%–7% discount rates), which are comparable to the social cost of carbon in the literature at around 4% discount rate. The results also show that the cost of mitigating the last few percent CO 2 emission from the U.S. electricity system may exceed the costs of NETs, indicating an opportunity for NETs to contribute to electricity decarbonization. [ABSTRACT FROM AUTHOR]

This study investigates and evaluates the European expert's selection and conjoined degree of willingness to decrease the carbon footprint (WDC) of consuming products and services to mitigate climate change. The survey respondents were segregated into four European regions based on their nationality viz. Nordic, Baltic, and Eastern Europe (NBE), Central and South-eastern Europe (CSE), Western and southern Europe (WSE), and North-western Europe (NWE). The WDC are represented by four index categories viz. low willing, moderate willing, willing, and highly willing. The WDC indicators such as housing, food, energy, waste and transport were used to identify the trend and correlation, gender-specific density distribution, and overall regional comparison analysis. The trend and correlation analysis between energy vs. transport, waste vs. food, and a separate state of housing represented the current global carbon emission situation, where four overlapping clusters indicated the respondent's closest or similar selection at their consumption level. The gender-specific density suggests that the male respondent's average WDC for housing and food index ranges from moderate to highly willing. In contrast, the female average WDC for food, waste, energy and transport index ranges from moderate willing to willing and bimodal for other scenarios. Among the regional comparisons, NBE in housing (moderate willing to willing), CSE in food (willing to highly willing), WSE and CSE in energy and all the regions in waste management (willing to highly willing) presented better indices. In transport, Europe as a whole exhibits poor index. In case of WDC index, the regional comparison indicates that the CSE region exhibited better outcomes than the other regions, except for housing. The findings of this study will be beneficial for the common people, researchers, policymakers, and regulators to enrich their future thoughts and contributes to the development and improvement of the existing carbon reduction policies, especially in the transport sector. • Investigates the European expert's willingness to decrease carbon footprint (WDC). • Nordic, Central, & Western experts exhibited top WDC in housing, food, & energy. • In the WDC of waste, experts from all the regions presented better signs. • In the WDC of transport, all the areas showed poor index. • In general, the central part showed better WDC indices than other areas. [ABSTRACT FROM AUTHOR]