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• Substitution factors for forest products for the Canadian context were developed. • Substitution factors ranging from 0.51 to 0.91 tC/tC were found. • They will lead to more accurate assessments of the forest GHG mitigation potential. • These factors will help governments to manage forest and fight climate change. Evaluating the climate change mitigation potential of the forest sector requires a holistic approach based on forest carbon (C) sequestration, C storage in harvested wood products (HWP) and substitution on markets. High uncertainty is associated with substitution factors, that express avoided fossil greenhouse gas (GHG) emissions from the use of forest-based products in replacement of GHG-intensive materials and fossil fuels. Few studies have focused on the development of substitution factors in Canada, resulting in the use of unrepresentative generic data. Here, we provide a framework to reduce uncertainties related to substitution factors for primary wood products in a Canadian context. A life cycle assessment framework is used to quantify fossil GHG emissions for a baseline and a wood-intensive scenario. For solid product substitution, we focused on the construction sector and analyzed a range of innovative wood buildings with steel and reinforced concrete as alternative materials. We found non-weighted averages of 0.80 tC/tC for sawnwood and 0.81 tC/tC for panels. For energy substitution, we analyzed cases with different specifications on biomass product, facility type and alternative fossil fuel source in non-residential heat production and biofuel transportation sectors. We found a non-weighted average of 0.80 tC/tC for non-residential heat production and 0.51 tC/tC for biofuel transportation, that can be interpreted as 0.91 tC/tC for heavy fuel oil, 0.69 tC/tC for light fuel oil and 0.68 tC/tC for natural gas substitution. These results provide a benchmark for substitution factors in Canada, to help guide forest management strategies for climate change mitigation. [ABSTRACT FROM AUTHOR]

• Provide an in-depth analysis of the recent advances, challenges, and future perspectives in HPTSU technologies. • Discusses various methods of hydrogen production and highlights the developments in transportation and storage solutions. • Explores the potential applications of hydrogen across different sectors, and identifies the key research areas for further improvement and large-scale deployment of hydrogen technologies. Hydrogen has been recognized as a promising alternative energy carrier due to its high energy density, low emissions, and potential to decarbonize various sectors. This review paper aims to provide an in-depth analysis of the recent advances, challenges, and future perspectives in hydrogen production, transportation, storage, and utilization (HPTSU) technologies. The paper discusses various methods of hydrogen production, highlights the developments in transportation and storage solutions, explores the potential applications of hydrogen across different sectors, and identifies the key research areas for further improvement and large-scale deployment of hydrogen technologies. This review provides a valuable resource for researchers, engineers, policymakers, and industry stakeholders seeking to understand the latest technical advancements in HPTSU technologies, and their potential to accelerate the transition to a sustainable energy future. [ABSTRACT FROM AUTHOR]

This paper investigates the potential pathways and associated requirements to meet a goal of net-zero greenhouse gas (GHG) emissions from the US commercial aviation sector by 2050 as outlined in the US 2021 Aviation Climate Action Plan. Aviation traffic (RTK) is projected to grow at an average of 2.0% per annum between 2019 and 2050, suggesting that a progressive and ultimately total decoupling of emissions from traffic growth will be required to meet the US aviation sector goal. Aircraft technology advancements, operational efficiency improvements, sustainable aviation fuels, and market-based measures (MBM) are considered as emissions reductions measures towards the goal. A parametric analysis framework is used to develop low, medium, and high emission reduction scenarios for each of these emissions reduction measures. If aircraft technology, operations, and fuels were frozen at 2019 levels, the aviation sector is projected to emit ≈430 million tonnes of CO 2 (MtCO 2) in 2050. Retirements of older aircraft, replaced by current-generation alternatives, may contribute 17% of the total 2050 emissions reduction goal. Further introduction of advanced aircraft technologies may contribute an additional system-level 11% emissions reductions towards the goal. Operational improvements may contribute ≈2% with a range from 1.5 to 4%. The remaining 70% of emissions in 2050 will be addressed through a combination of sustainable fuels and MBM, where appropriate. The level of contribution from fuels will be dependent on continued production ramp-up to meet aviation demand as well as improvements in lifecycle emissions reduction factor (ERF) for current and future fuel feedstock and production pathways, ranging from 0% for current petroleum-based fuels to 100% for sustainable aviation fuels with zero life-cycle emissions. Meeting a net-zero emissions goal by 2050 with SAF would require an increase in SAF production by 57% annually from 2022 to 2030 and 13% per year thereafter, reaching 100% emissions reductions factor by 2050. MBM may fill the gap between residual lifecycle emissions after accounting for all other in-sector improvement opportunities and the goal. [ABSTRACT FROM AUTHOR]

The sustainability of air transport is increasingly studied in relation to climate issues. The objective of this paper is to provide the key elements for assessing whether a given transition scenario for aviation could be considered as sustainable in the context of the Paris Agreement. Addressing this question relies on a broad range of concepts which are reviewed. First, ethical considerations related to effort-sharing mitigation principles and physical considerations on climate impacts of aviation are introduced. Then, the technological levers of action for mitigating CO 2 and non-CO 2 effects are detailed. Concerning CO 2 emissions, low-carbon alternative energy carriers represent the main lever, with a wide range of solutions with varying degrees of maturity and decarbonization potentials. Other significant CO 2 levers include improving aircraft architecture efficiency and accelerating fleet renewal. Concerning non-CO 2 effects, contrail effect mitigation through operational strategies is one of the most promising lever. Aviation transition scenarios are then reviewed, with a particular focus on scenario simulation and sustainability assessment methodologies. Prospective scenarios are a useful framework for assessing the impacts of technological levers on the achievement of climate objectives. This review leads to the conclusion that technological levers have an important role to play in making aviation sustainable; however, significant uncertainties weigh on their feasibility, particularly for the most ambitious scenarios which rely on strong technological and political trade-off assumptions. The paper ends by raising the question about the meaning of sustainable aviation, which must be based on technological but also, for instance, social, economic and ethical considerations. • Prospective scenarios help assessing climate mitigation and sustainability potentials. • Technological levers can help to make aviation compliant with the Paris Agreement. • Low-carbon alternative energy carriers are the main lever for reducing CO2 emissions. • Contrails mitigation strategies seem promising to reduce aviation climate impact. • Technological and political assumptions of most ambitious scenarios remain uncertain. [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]

The environmental problems brought by the shipping industry have drawn the attention of all parties, making it critical to select a fuel system that combines economic and environmental benefits when ordering new ships. This paper narrows down a list of fuels to four high-potential options: LNG, methanol, hydrogen, and ammonia. Based on the dual perspectives of shipowners and the public, this study takes different-sized ships as the object, establishes mathematical models throughout their life cycle, and selects a variety of indicators to evaluate alternative fuels. The findings demonstrate that, in the short term, heavy fuel oil with scrubbers is the most economically advantageous option for all sizes of container ships, but methanol is a desirable alternative when taking into account the social cost of pollutants. Hydrogen might be the ultimate fuel to reduce emissions in the long run when the price gap closes. [ABSTRACT FROM AUTHOR]

Diesel vehicles are one of many sources of black carbon (BC) emissions in Europe; nevertheless, due to recent changes in fuel composition towards renewable fuel such as biodiesel, advances in engine design and pollution control technology, BC and organic carbon (OC) emissions may worsen air quality and encourage global warming. As there are no regulatory terms on BC mass concentration levels, assessment of pollution sources is crucial for air quality improvement policies and mitigation of climate change. BC mass concentration and aerosol optical absorption were derived using 7-wavelenght Aethalometer during 3 measurement campaigns in 2014, 2017, and 2020. BC source apportionment analysis was performed using 18 combinations of absorption Ångström exponent (AAE) values for assessing BC to fossil fuel combustion and biomass burning. The choice of the most suitable AAE combination (0.9 and 2.2, respectively) was supported by organic aerosol (OA) source apportionment results. AAE value for transport exhaust emission (0.95) from locally available diesel fuel was established using (CI) 1.9 TDI engine with different engine torque regimes and 7-wavelenght Aethalometer. Statistically and experimentally obtained values were compared and showed great agreement. Subsequently, a statistically obtained AAE tr value was used for BC source apportionment and long-term analysis. A significant increase in the contribution of transport-related BC contribution was observed between years 2014 and 2020 (from 51% to 65%) which was associated with a boost in the use of diesel vehicles (by 83.9% of diesel passenger cars comparing 2014 and 2020) and growing diesel fuel consumption. These findings underline the diesel transport-induced problem for local air quality together with its impact on atmospheric radiative balance and raise concerns for public health. • The choice of AAE combination was supported by OA source apportionment results. • BC source apportionment revealed increasing trend of transport-related pollution. • A significant increase in BC tr light absorption was observed during 2014–2020. [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]

This paper combines stakeholder assessments of potential scenarios for radical decarbonisation in shipping with scenario simulations with the MATISSE-SHIP model. It advances previous scenario work in low carbon shipping by combining qualitative and quantitative analysis in a 'reality' check of transitions scenarios with stakeholders. Stakeholders identified the critical factors covering society, technology, economics, environmental and legislation/policy. The MATISSE-SHIP model applied these factors and assumptions to model the decision process for shipowners in ordering new ships and propulsion technologies. Four scenarios were developed. With strong climate policy, technological growth with power to liquid/gas (PtL/PtG) fuels (e.g. ammonia) and wind technologies come to dominate. In business as usual, continuing emphasis on local air emissions results in the growth of LNG. Weak policies lead to severe impacts of climate change in the medium term. Eventually, cost savings from wind systems and technology development enable alternative fuel technologies to start to develop. If society moves towards sustainable lifestyles, very strong climate mitigation policies lead to a rapid substitution of fossil fuels by PtL/PtG and, in the tanker and bulker sectors, wind. • The paper shows conditions for a wide range of futures in ship propulsion. • The paper combines a qualitative scenario analysis with simulation modelling with the MATISSE model. • Regulation driven technological innovation can achieve low carbon shipping. • A change in global culture enables organisational as well as technological change. • A transition happens in all scenarios, but very slowly without policy support. [ABSTRACT FROM AUTHOR]

• Hydrogen accounts for 5–10% of total energy in 2050 under 2 °C scenarios. • Hydrogen share increases for a 1.5 °C goal and reaches 15% if CCS is limited. • Transport is the largest consumer of hydrogen, followed by industry and power. • Synthetic hydrocarbons based on hydrogen and direct air capture are an option. • Holistic energy policy design is needed rather than heavy dependence on hydrogen. Hydrogen-based energy carriers, including hydrogen, ammonia and synthetic hydrocarbons, are expected to help reduce residual carbon dioxide emissions in the context of the Paris Agreement goals, although their potential has not yet been fully clarified in light of their competitiveness and complementarity with other mitigation options such as electricity, biofuels and carbon capture and storage (CCS). This study aimed to explore the role of hydrogen in the global energy system under various mitigation scenarios and technology portfolios using a detailed energy system model that considers various energy technologies including the conversion and use of hydrogen-based energy carriers. The results indicate that the share of hydrogen-based energy carriers generally remains less than 5% of global final energy demand by 2050 in the 2 °C scenarios. Nevertheless, such carriers contribute to removal of residual emissions from the industry and transport sectors under specific conditions. Their share increases to 10–15% under stringent mitigation scenarios corresponding to 1.5 °C warming and scenarios without CCS. The transport sector is the largest consumer, accounting for half or more of hydrogen production, followed by the industry and power sectors. In addition to direct usage of hydrogen and ammonia, synthetic hydrocarbons converted from hydrogen and carbon captured from biomass or direct air capture are attractive transport fuels, growing to half of all hydrogen-based energy carriers. Upscaling of electrification and biofuels is another common cost-effective strategy, revealing the importance of holistic policy design rather than heavy reliance on hydrogen. [ABSTRACT FROM AUTHOR]

In the context of modern science, there is a growing interest in the creation of novel porous materials capable of acting as sorbefacients for small gas molecules. This is critical in terms of innovative energy alternatives as well as a healthier environment. In an effort to overcome the consequences of global industrialization, one of humanity's most severe problems, intensive attempts have been made to prevent CO 2 from entering the carbon cycle, as the ever-increasing CO 2 pollution in the earth's atmosphere. Owing to their high porosity, presence of ultra-small pores, structural diversity, high stability, and excellent recyclability, researchers claim that zeolite–an inexpensively accessible sorbent–could be an excellent prototype for CO 2 sorption. Here, we provide an exhaustive review of re-engineered zeolites as a sustainable material for selective CO 2 capture and storage; the progress so far indicates fast removal of CO 2 , and more work conforming to simple scalability, energy and time efficiency application can be done to improve the challenges. [Display omitted] • Discussed the importance of size change from micro to nano level and their proficiency in Carbon capture and storage. • Role of reshaping changes and site selectivity enhancement in CO 2 monetization. • Role of biomass-based material on CO 2 sequestration has also been illustrated. • Strategies to promote circular economics by using wastes as precursors in synthesis of zeolites. • Discussed novel green technologies in constructing reshaped zeolite. [ABSTRACT FROM AUTHOR]