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More than 130 countries and regions have put forward various climate goals, which makes carbon-oriented energy system planning a heated topic. However, these planning studies do not consider the carbon fixation role played by forest carbon sinks (FCSs). To take advantage of the carbon fixation role of FCSs, this paper will develop a carbon-cycle integrated energy hub (CC-EH) model to quantify the economic advantages of FCSs in planning a zero-carbon energy system, where energy flow and carbon flow are both analyzed. A total planning and operating costs minimization with the constraints of CO 2 emissions is proposed as a mixed integer nonlinear programming (MINLP) optimization model and the overall problem is solved based on commercial solver. The proposed model is validated by case studies on six medium to large-size cities in different geographical locations in China. Results indicate that the typical cities in China can fulfill their carbon-neutral commitments by 2060. Throughout the entire planning period, FCSs can offset up to 55.31 % of the total carbon dioxide emissions from urban energy systems. Besides, FCSs achieved by forestation will help the energy system to reduce up to 36 % of the planning cost compared to the case without using FCSs. [Display omitted] • Forest carbon sink (FCS) is modeled considering CO 2 absorption and biomass growth. • FCS is applied to planning through a carbon-cycle integrated energy hub (CC-EH) model. • Coupling of energy system operation and FCS process on an hourly scale is realized. • A power function is introduced to characterize the transition path, and determine the optimal capacity of the CC-EH. • Typical cities in China are taken for case studies to analyze the impact of FCSs on the carbon neutral. [ABSTRACT FROM AUTHOR]

Urban areas have key roles in climate mitigation, including increasing renewable energy penetration in smart energy systems. The potential of urban areas in limiting global warming, however, is not quantified. This research work develops a new framework to analyse urban emissions and land use efficiency scenarios with coupling to the transient climate response to cumulative carbon dioxide emissions. Two new parameters that quantify contributions to and avoidance of increments of global warming from urban areas are formulated and applied to twelve scenario combinations. The results for 465 urban areas indicate that a green-growth scenario with lower ambition in reducing urban emissions can lead up to a 0.13 °C additional increment of global warming in 2050 based on the best estimate of the transient climate response to cumulative carbon dioxide emissions. Those of the most ambitious urban emissions scenario with green-growth and renewable energy are limited to 0.06 °C. When combined with the most ambitious land use efficiency scenario for 135 urban areas, it is possible to avoid more than double or 2.09 times additional increments of global warming in comparison to other integrated urban scenarios. The mean and 5–95th percentile range of the results are compared based on 10,000 Monte Carlo simulations. Informing on the urgency to ensure ambitious mitigation action in urban areas can support a climate future that remains within critical thresholds and tipping elements of the planet. [Display omitted] • A new framework couples urban scenarios and increments of additional global warming. • Cumulative urban emissions of 465 urban areas can be 291.04 GtCO 2 eq in 30 years. • A green-growth oriented renewable energy scenario can avoid up to 0.09 °C in 2050. • Cumulative sequestration penalties of 135 urban areas are up to 2.01 GtCO 2 in 30 years. • Joint ambitious mitigation and land use efficiency in this case averts 0.039 ± 0.016 °C. [ABSTRACT FROM AUTHOR]

Achieving decarbonisation of the heating sector is a major challenge, especially in Ireland, which has the lowest proportion of renewable heat in Europe. In economically pursuing ambitious and equitable climate targets, Ireland's Climate Action Plan 2023 set a goal of reaching 2.5 TWh of district heating by 2030, starting from a limited existing capacity. This pioneering study explores supply sources and heat density demand cohorts to develop a model to understand district heating in a low-deployment region, using Ireland as a case study. We also conduct a sensitivity analysis considering different connection rates. Our research demonstrates that district heating is pivotal in achieving optimal decarbonisation pathways. Incorporating district heating reduces marginal CO 2 emission prices by 13%–25%. Additionally, with feasible growth limits applied, total savings for the energy system are anticipated to reach €17.2 billion by 2050. This reduction of emissions in the building sector, facilitated by district heating, allows for greater emissions allowances in other sectors and reduces reliance on electricity while meeting climate targets. These insights highlight the need for spatial energy policies and deepen our understanding of integrating district heating within an energy system optimisation model. • District heating in Ireland can reduce marginal CO 2 emission prices by 13%–25%. • District heating can cumulatively save €17.2 billion compared to no district heating. • Regional energy policy is needed to align with cost-optimal pathways. • Regional supply and demand quantified sensitivity analysis strengthens insights. [ABSTRACT FROM AUTHOR]

Achieving net zero emissions is a crucial challenge in the global climate change policy. It requires a substantial reduction in unabated fossil fuel use, the deployment of renewable energy sources, and the development of carbon capture, utilisation and storage technologies. The aim of this study was to investigate and compare two CO 2 capture retrofits for natural gas combined cycle (NGCC). First one, amine absorption, is already mature and characterised as commercial technology, whereas second one, calcium looping is a promising method but still under pilot studies. Energy required for capture process yields net efficiency penalty, which in conducted research totalled 8.4% points for amine unit and 7.4–15.5% points in calcium-looping units. The economic evaluation was performed to analyse the impact of both concepts on their profitability. Moreover, the climate change mitigation potential was assessed and indicated that carbon capture can lower the emissivity of a conventional power plant by 82–87% or even contribute to achieving negative emissions when biofuels are used. Carbon dioxide capture is one of the key elements of ongoing energy transition and its integration with NGCC power units could be determined as essential for maintaining energy security with net zero emissions. • The work provides the comparison between amine scrubbing and calcium-looping CO 2 capture for Natural Gas Combined Cycle. • CCS retrofit causes a net efficiency penalty between 7.4 and 15.5%p for analysed configurations. • Calcium-looping retrofit placed after the gas turbine yield lower SPECCA and higher unit power due to new steam cycle. • Using biogas as a feedstock to calciner of calcium-looping unit leads to negative CO 2 emissions. • Amine scrubbing retrofit has much lower CAPEX and OPEX than CaL units, yet they reach higher ΔNPV within 25 years. [ABSTRACT FROM AUTHOR]

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

Limiting global warming well below 2 °C requires substantial increase in the installation of low-carbon electricity generation technologies (EGTs). EGTs however require several critical materials and materials associated with considerable energy, water and CO 2 emissions. This paper assesses the implications of materials and energy efficiencies for climate change mitigation potential of global energy transition scenarios (GETS). The analysis is carried out using a dynamic material flow-stock model for 21 materials and 15 scenarios combining GETS developed by international organizations including International Energy Agency (IEA) and Greenpeace (GP), materials scenarios, and energy, water, and emissions intensities scenarios. Materials related CO 2 emissions are expected to constitute between 4% and 14% the emissions reported in the IEA Sustainable Development scenario, while expected to be between 10% and 28% in GP Advanced Revolution scenario. Increasing material efficiency and reducing emissions intensities (driven by increasing energy efficiency, renewable technologies in energy supply mix, and recycling) reduce cumulative emissions by 73.2% and 26.3% respectively, while both reduce emissions by 79.5%. Increasing materials efficiency in EGT, energy and water efficiency in mining activities mainly for iron, aluminium, and nickel, and recycling, combined with careful selection of EGTs are significant to realize the full potential of GETS in climate change mitigation. • Materials and energy efficiencies implications for climate change mitigation potential of energy scenarios are assessed. • Dynamic material flow-stock model for 21 materials and 15 combined materials and energy scenarios are used. • Materials related CO 2 emissions constitute between 4% and 14% of emissions reported in IEA Sustainable Development scenario. • Increasing material efficiency and reducing emission intensities reduce cumulative emissions by 79.5%. • Increasing materials efficiency and recycling, and careful selection of EGT are significant for climate change mitigation. [ABSTRACT FROM AUTHOR]

Due to frequent natural disasters, it is required for the energy systems to be more resilient and affordable. Numerous investigations can be found in the publications that proposed renewable energy systems to deliver power to localities. Nevertheless, researchers have yet to explore the resiliency benefits of renewable energy systems in refugee camps. Therefore, in this study, we modelled the performance of a PV/battery system for hypothetical health care centres located in the Rohingya refugee camp, Bangladesh. A 24-h grid outage was assigned to the REopt software to observe the survival possibility of the system. An optimized mixed-integer linear programming model is used as it considers several practical parameters such as reducing total cost sufficiently robust to handle the simulated outages perfectly. The optimum system consists of a 643 kW PV and a 102 kW battery. The potential life cycle savings of the system are $27,212, and the system can successfully handle a 24-h duration outage. The system also reduces CO 2 emissions by 69% in resilient mode compared to 44% in financial mode. Therefore, it can contribute to climate change mitigation. • First study to address the resiliency benefits of a PV/Battery System in Refugee Camp. • REopt software is used to study and simulate the outage impact in the camp. • The system can successfully handle a 24-h duration outage. • The optimum system consists of a 643 kW PV and a 102 kW battery. • The system also reduces CO 2 emission by 69% in resilient mode. [ABSTRACT FROM AUTHOR]

With the aim to meet customers diverse energy needs by an economical and ecological means, integrated energy system has become a popular choice. Amongst various integrated energy system coupling configurations, individual heating infrastructure entails painstaking attention due to rapid expansion. Individual heating network plays a massive role in carbonizing the atmosphere as traditionally individual heating demands are fulfilled by fossil fuel-fired (natural gas and coal) boilers. Recently, trend is heading towards the integration of energy efficient technologies like micro combined heat and power and heat pumps to replace fossil fuel boilers. However, individual heating performance evaluation is generally investigated by energy analysis that employs only the first law of thermodynamics, thereby exergy analysis assessment and its comparison with energy analysis become noteworthy to measure actual performance. In this work, energy and exergy analysis of the individual heating network of China for the year 2030 is performed under the framework of both laws of thermodynamics. The proposed work includes various technological options like Hydrogen fired micro combined heat and power, natural gas fired micro combined heat and power and heat pumps to replace the fossil fuel boilers intending to attain an economically viable and carbon-free environment. At first, energy and exergy efficiencies of the aforementioned heat producing components are computed and afterwards EnergyPLAN technical simulation strategy is employed to evaluate performance in terms of costs, CO 2 emissions and primary energy supply. Subsequently, a comparison of both analysis is provided in order to present the difference between the two analysis which substantiates that exergy analysis provides inferior results than energy analysis as depicted in case 3 where heat pumps inclusion appears to be the most decarbonized alternative for energy analysis but corroborates vice versa for exergy analysis. However, exergy analysis complements the energy analysis that helps evaluating the actual performance of system in relation to climate change mitigation and cost-effectiveness. • Energy and exergy analysis of individual heating network of China is performed. • Economical and decarbonized environment is proposed. • Exergy analysis results are inferior to energy analysis. • Heat Pump is considered worse alternative according to exergy analysis. [ABSTRACT FROM AUTHOR]

Since the role of fiscal decentralization cannot be overlooked in tracking sustainable development goals targets of a clean environment and climate mitigation, it is inevitable to understand the comprehensive picture of its link with environmental quality. Unlike past studies, this study investigates the combined influence of energy prices and non-linear fiscal decentralization on carbon emissions in the presence of institutional quality and gross domestic product in the model. It employed advanced econometric panel techniques on data from 1990 to 2018 for the top seven fiscally decentralized Organisation for Economic Co-operation and Development (OECD) nations, including Spain, Belgium, Austria, Switzerland, Germany, Australia, and Canada. The main outcomes are as follows: first, a cointegrating equilibrium link is existent among the study variables. Second, the linear term of fiscal decentralization promotes carbon emissions, while the non-linear term mitigates it. It verified the inverted U-shaped curve between fiscal decentralization and carbon emissions. Third, increasing energy prices for non-renewable energy decrease carbon emission due to a substitution effect. Among other explanatory variables, improvement in the quality of institutions decreases carbon emissions, while the gross domestic product increases it. These findings suggest strengthening fiscal decentralization, lowering non-renewable energy prices, and improving institutional quality to check the deteriorating environmental quality in the study sample and other worldwide regions. • Employed Westerlund cointegration and found long-run equilibrium association. • Applied CS-ARDL and AMG techniques to obtain the influence estimates. • Linear (non-linear) fiscal decentralization promoted (reduced) carbon emissions. • Fiscal decentralization presented an inverted U-shaped association with carbon emissions. • Energy prices and institutional quality mitigated carbon emissions. [ABSTRACT FROM AUTHOR]

In this paper we evaluate whether the US states have been able to achieve convergence in their carbon emission cycles which may be a key factor in taking a leap as regards the development of a US climate change policy. The use of a dynamic unobserved component approach and a time-varying parameter model enable estimation of the short run dynamics of energy convergence over the extended period 1960–2017. To date, this type of analysis has not received enough attention in the literature. The results reveal the existence of cross-state links in the fluctuations of CO 2 emissions, although the degree to which a good part of the states are co-moving is weak. We also find that cyclical convergence patterns differ considerably in both the level and trajectories across the US states. The difficulties in increasing synchronization of the US CO 2 emissions highlight the importance of the states to lead climate change mitigation actions. The present study presents valuable information of interest regarding the short-run characteristics in carbon dioxide emissions, for better understanding of factors affecting CO 2 mitigation policies. Image 1 • Short run characteristics of CO2 emissions convergence at state-level are studied. • We rank US states by the level of cross-state links in CO2 fluctuations. • Cyclical convergence patterns are distinctively different across states. • National environmental initiatives only have transitory effects on CO2 emissions. • Dataset of CO2 emissions covering 1960–2017 at state level is provided. [ABSTRACT FROM AUTHOR]