Deep Decarbonization Research Articles

A machine-learning assisted multi-cluster assessment for decarbonization in the chemical fiber industry toward net-zero: A case study in a Chinese province

China has pledged to achieve carbon neutrality by 2060, requiring deep decarbonization in its manufacturing sector, aligning with sustainable development goals such as climate action and responsible production. Notably, China's chemical fiber industry contributes over 70% of global production, facing challenges in net-zero transition due to differences in enterprise scale and energy efficiency. This study proposed an assessment framework for the decarbonization pathway for this type of manufacturing industries, use the chemical fiber industry as a case study. A hybrid model based on machine learning was introduced to predict the industry's energy consumption, while multiple-cluster standards were established to assess energy efficiency improvement potential. Monte Carlo simulation was employed to analyze the carbon trading impact on industry decarbonization. Using a Chinese province's chemical fiber industry as a case, results suggest its carbon emissions could reach 1.58 × 107 tCO2 by 2030, and energy efficiency enhancements could reduce emissions by approximately 22.6%. Achieving carbon neutrality would cause the industry to reduce profits by approximately 10%∼15% on higher-priced emissions trading system (ETS), unless additional carbon reduction techniques are adopted. This assessment framework can be applied to study decarbonization transitions in other manufacturing industries.

A systematic literature review on the decarbonisation of the building sector—a case for Nigeria

The buildings sector is responsible for over 36% of total global end-use energy utilization and nearly 40% of the total indirect and direct carbon emissions. Low-carbon or zero-energy buildings remain the only option to lessen the sector’s energy consumption and CO2 emissions. The current systematic study examines low-carbon buildings under deep decarbonization scenarios in selected global south regions from 2010 to 2021. The study was channelled by the PRISMA (“Preferred Reporting Items for Systematic reviews and Meta-Analyses”) review process, which identified 29 related articles from Scopus, Web of Science., and Google Scholar databases. The identified critical drivers of emissions were population, gross domestic product, dwelling characteristics, and urbanization. The dwelling characteristics contributed about 12% and 27% to the total CO2 emissions in the selected regions. The population varies between 23% and 27% across the areas. Specific findings were made for inclusion in the Nigeria model while the general results were observed and further studies proposed. Total investment from the private and public sectors was identified as key to achieving the transition process of decarbonization in the building sector.

China’s bulk material loops can be closed but deep decarbonization requires demand reduction

China’s bulk material loops can be closed but deep decarbonization requires demand reduction

(Best Student Presentation) Extending the NaCl-AlCl3 Phase Diagram to Enable Low-Cost, Long-Duration Na-Al Batteries for the Grid

Achieving deep grid decarbonization via intermittent renewable power sources requires extensive grid-scale energy storage technologies to deliver stable power during periods of low generation. Doing so at scale and at low cost further adds to this challenge, as current solutions generally rely on geographically limited solutions such as pumped hydro storage, or costly battery chemistries focusing primarily on Li-ion technologies. As an alternative, battery systems based on lower cost materials such as sodium offer an attractive alternative for low-cost, scalable, and non-geographically limited electrochemical energy storage.This work combines an abundant and inexpensive molten sodium metal anode with a cost-effective aluminum cathode to provide a proof-of-concept alternative for grid-scale energy storage. Building on prior work utilizing the high reversibility of the neutral sodium chloroaluminate (NaAlCl4) molten salt electrolyte commonly used for classic molten sodium batteries, this work demonstrates greater capacity utilization of the NaCl-AlCl3 binary system by ‘overcharging’ this Na-Al battery to form an acidic chloroaluminate catholyte, NaAl2Cl7. Leveraging the reaction between NaAlCl4 and NaAl2Cl7 in conjunction with that between Al/NaCl and NaAlCl4 advantageously utilizes the majority of Na available in the cathode for capacity, in addition to providing a higher discharge voltage (~ 2 V compared to ~ 1.6 V for the NaAlCl4 reaction), thereby adding ~ 119 Wh kg-1 additional specific energy, on top of the 493 Wh kg-1 theoretical specific energy of the neutral Na-Al battery reaction between Al/NaCl and NaAlCl4.Fundamental aspects of the acidic chloroaluminate reaction are investigated, showing that cells using only the acidic reaction are able to cycle for hundreds of cycles. The acidic reaction between NaAlCl4 and NaAl2Cl7 occurs via a solution-phase reaction, unlike the two-phase neutral reaction between NaCl/Al and NaAlCl4, and we confirm via Raman and NMR spectroscopies that complete conversion to NaAl2Cl7 occurs at end of charge. Na-Al batteries utilizing both reactions demonstrate high areal capacity (~ 46 mAh cm-2) and excellent reversibility. Enabled by the rapid mass transfer and solid-liquid reaction mechanism of the chloroaluminate catholyte, a higher areal capacity cell with ~ 132 mAh cm-2 is demonstrated, allowing a discharge duration of 28.2 h, implying that this Na-Al battery chemistry may be suitable for long-duration energy storage for grid applications. Finally, the raw active materials cost of this battery is estimated to be only ~ $7 kWh-1, which is promising for enabling low-cost renewable power utilization for the grid. Figure 1

Promoting Hydrogen Evolution and Oxidation by Reconstructing Hydrogen-Bonding Network of Interfacial Water

The hydrogen evolution and oxidation reactions (HER/HOR) at the electrode-water control the performance of water electrolyzers and hydrogen fuel cells, two important devices for deep decarbonization of our economy (1). Platinum (Pt) catalyzes the HER/HOR with exceptional activity and stability across a wide pH range. However, its activity progressively decreases by about two orders of magnitude as the pH increases from 0 to 13 (2, 3). The lack of understanding of this pH dependence reflects our fundamental knowledge gaps in electrochemistry and has hindered the advancement of alkaline electrolyzers and fuel cells.Herein, we promoted the HER/HOR of Pt in base by introducing N-methylimidazoles in the Pt-water interface. In situ spectroscopic characterization of the interface together with computations showed that the N-methylimidazoles form strong hydrogen-bonding with neighboring water molecules thereby reconstructing the H-bond network of interfacial water. We accordingly established a unified mechanism by which the HER/HOR in acid and base proceeds via diffusion of protons and hydroxides, respectively through the H-bond network of interfacial water by the Grotthuss mechanism. This mechanism accounts for the pH-dependent HER/HOR kinetics of platinum, a long-standing puzzle. Utilization of N-methylimidazoles as the HER/HOR probes and promoters not only leads to the elucidation of the HER/HOR mechanism but also holds great promise for applications. We have demonstrated 40% performance improvement of an anion exchange membrane water electrolyzer by adding 10-5 M 1,2-dimethylimidazole into the 0.1 M potassium hydroxide solution fed into its Pt cathode. Acknowledgements This work was supported by the Office of Naval Research (ONR) grant N000141712608 (Q.J.)This research used beamline 7-BM (QAS) of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory Contract DE-SC0012704. Beamline operations were supported in part by the Synchrotron Catalysis Consortium Grant DE-SC0012335. V. R. Stamenkovic, D. Strmcnik, P. P. Lopes and N. M. Markovic, Nat. Mater., 16, 57 (2017). J. Durst, A. Siebel, C. Simon, F. Hasché, J. Herranz and H. A. Gasteiger, Energy Environ. Sci., 7, 2255 (2014). W. Sheng, Z. Zhuang, M. Gao, J. Zheng, J. G. Chen and Y. Yan, Nat. Commun., 6 (2015). Figure 1

(Invited) In-Situ/Operando Monitoring of Mechanisms of Catalytic Reaction Using X-Rays

Global climate warming and environment pollution have spurred scientists to develop new high-efficient and environmental-friendly energy technologies. Hydrogen plays a key role in deep decarbonization for realization of net-zero carbon dioxide emission by 2050. Presently, the most popular and economical commercial process for H2 production is steam–methane reforming, which uses fossil fuels as the raw material and produces comparable amounts of CO2 as the by–product. It is definitely an environmental unfriendly and a non–sustainable H2 production process, and development of green H2 production is in urgent need. Sunlight is a clean, renewable and abundant energy source on the earth. Its conversion to hydrogen has been considered an ideal solution to counter the depletion and environmental problems of fossil fuels. Hydrogen is an ideal fuel for fuel cell applications. Hydrogen has to be produced from renewable and carbon-free resources using nature energies such as sunlight if one thinks of clean energy and environmental issues. In this regard, a photoelectrochemical cell consisting of semiconductor photoelectrodes that can harvest light and use this energy directly for splitting water is a more promising way for hydrogen generation. Photocatalysis utilizes the energy delivered by light and enables chemical reactions that otherwise cannot take place. When used to power thermodynamically uphill reactions, photocatalysis offers a solution to large-scale solar energy storage. Despite over four decades of intense research, however, photocatalysis remains either too expensive or too inefficient or both. Poor understanding of the mechanisms behind the low performance is a key reason that limits the progress of this important field. To address this critical challenge, I will overview a number of the experimental studies that successfully revealed the catalytic reactions at solid/liquid interfaces in real time, e.g. electrochemical interface of photocatalysis and electrocatalysis. The experimental results demonstrate that the operando X-ray characterization provides the unique information for understanding the real reaction mechanism.

Application of fuel cell and alternative fuel for the decarbonization of China's road freight sector towards carbon neutral

The deployment of new energy trucks is a crucial national strategy in China to achieve deep decarbonization in road transport. Although fuel cell trucks and electric tucks are regarded as alternatives to conventional fuel trucks due to the advantage of zero usage emissions, their applicability for each truck type has not been determined.By developing a total cost of ownership analysis, this study dynamically determines the most economical alternative fuel type for each truck type and identifies when the large-scale deployment of new energy trucks is economically achievable. Then, by conducting a life cycle analysis with a localized database, this study quantitively evaluates the green gashouse emission intensities and their possible changes of different types of trucks. Finally, the emission reduction potential in the truck fleet by applying fuel cell and alternative fuel during 2020–2050 is comprehensively evaluated.The main results suggest that electric trucks are economically suitable for mini and light-duty trucks by 2031 and 2026, while fuel cell trucks suit medium-duty and heavy-duty trucks by 2027 and 2032. The application of alternative fuels in the truck fleet could achieve 28% carbon emissions in 2030 and up to 80% in 2050.

Modelling governance for a successful electricity sector decarbonisation

Early and deep electricity decarbonisation is critical to achieve the overall energy transition target of net-zero emissions by 2050. This paper extends an electricity agent based model to capture the inter-dependence of consistent governance with underpinning societal pressure and resultant investment strategies. Results show only with the strongest level of governance – reflected in the range of national/local policy mechanisms used, and their strength/timing when interim targets are met/missed – can near-zero electricity emissions be met well before 2050. Strong governance can also ensure a stable electricity system, with consistent policies mitigating the intensity of any investment cycles. Strong governance entails higher capital investments, but these can deliver lower electricity prices in the long-term. And strong governance means that a successful electricity decarbonisation does not need to be built solely on existing incumbents, but also via local cooperatives to aggregate household financing and demand side management. However, with inconsistent governance, a vicious cycle ensues with a weak rationale to enact ambitious policies at both the local and national levels, significant inertia in new electricity investments, and hence “failure” scenarios of decarbonisation. This challenges the prior findings of optimistic achievement of electricity decarbonisation scenarios by standard techno-economic optimisation models.

Green manufacturing facilities – Meeting CO2 emission targets considering power and heat supply

To achieve carbon neutrality in the industrial sector, variable low-carbon and low-cost electricity sources, together with a variety of storage technologies, maybe the only viable path. Here, we investigate the diverse scenarios for manufacturing facilities (MF) under different emission reduction targets to determine the least-cost decarbonization pathway. This study developed a multi-energy model to assess emission reduction versus cost ratio and gave a technology roadmap for MF, i.e., cost-effectiveness of each technology at a given decarbonization level. We optimized the dispatch of each scenario with the least cost objective and step-wise reduced the emissions of selected exemplar European MF from current levels until the solution came out as infeasible due to the lifecycle emissions of considered technologies. Results showed that electrical boiler became key technology from 10% emission reduction target (ERT), while battery storage is cost-effective for medium ERT and H2 facility remains a critical part of achieving deep decarbonization targets (>80%). This analysis reveals a basic understanding of a given technology's economic viability to target a certain decarbonization goal and would help guide MF that are more inclined to invest in having their green energy distributed system. Sensitivity analysis of key parameter values (i.e., grid electricity/gas prices, technology costs) reveals that the H2 facility will play a critical role in deep decarbonization and high gas prices made the expensive heat pumps cost-effective in all scenarios. Furthermore, the future costs of electrolyzer, fuel cell, heat pump, and battery storage will decide the technological transformation speed for the industrial sector.

The cost-competitiveness of concentrated solar power with thermal energy storage in power systems with high solar penetration levels

In this paper, we show that concentrated solar power (CSP) with thermal storage is an economically attractive technology to achieve high solar penetration levels. To this end, we utilize an alternative framework of net levelized cost of electricity (net-LCOE), which captures the projected curtailment rate, to economically compare PV with batteries to CSP in power systems with high levels of solar penetration. We also explore potential benefits enabled by hybrid PV-CSP configuration, which are unattainable by either technology independently. We show the existence of a turning point in power systems with 20%–30% solar penetration levels, after which it is cheaper to supply electricity by CSP with thermal storage by up to 16%. It is demonstrated that storing excess PV electricity in low-cost thermal storage is valuable, enabling CSP configuration with solar multiple as low as 0.5 to operate with a high capacity factor. Furthermore, we show that converting green hydrogen to electricity using CSP power block is cost-effective when seasonal storage is required, thus enabling deep decarbonization based on solar electricity. In these high solar penetration levels, using CSP resulted in a reduction of up to 65% in the net-LCOE. The results may enable researchers and policymakers to evaluate CSP with thermal energy storage as a cost-effective solution for achieving high penetration levels of solar electricity.

International governance of technological carbon removal: Surfacing questions, exploring solutions

This paper examines questions about governing technological carbon removal methods, proposes potential avenues for resolving emerging challenges, and explores the role that existing international bodies and processes may be able to play in resolution. It aims to inform research and orient civil society, academic, and other groups focused on supporting responsible scale-up of technological carbon removal, as well as international bodies able to implement guidance that countries may use as they develop plans for technological CDR deployment. Key questions and proposed solutions were informed by a literature review; a series of consultations with experts in carbon removal, international climate governance, and deep decarbonization; plus an expert stakeholder meeting. The goal of this work is to spur discussion among stakeholders interested in, or supporting development of, carbon removal policy, including those working with or in international bodies responsible for guiding and overseeing international climate planning. It is important to note that carbon removal approaches traditionally known as “nature-based” or “natural,” including tree restoration and forest management, are not within the scope of this paper, as they have long been included in climate plans.

Thoughts on the development of CO2-EGR under the background of carbon peak and carbon neutrality

In September 2020, the Chinese government proposed the goals to reach carbon dioxide emissions peak by 2030 and achieve carbon neutrality by 2060 (“two-carbon goals”). This brings opportunities to the development and application of CO2-enhanced gas recovery (CO2-EGR) in China. To obtain an overall understanding of the development of CO2-EGR under the two-carbon goals, this paper analyzes the significance, potential, status quo and challenges of CO2-EGR, and makes suggestions on the development of CO2-EGR in China. The research results are obtained as follows. First, the development of CO2-EGR plays a crucial role in ensuring China's energy security, accelerating the construction of the clean energy system to promote energy transition and realizing the two-carbon goals as early as possible. Second, China should clarify a path for CO2-EGR development, build a spatial layout of CO2-EGR, and promote digital inclusion in CO2-EGR, enhance the emission reduction role of CO2-EGR in the multi-energy complementary system, boost large scale application of renewable energy and deep decarbonization in the traditional coal industry, which is difficult to reduce carbon emissions. Third, China should draw lessons from European and American tax credit and innovation funds policies to accelerate the construction of a CO2-EGR policy support system. Fourth, China should carry out research on key CO2-EGR technologies to accelerate the construction of a CO2-EGR methodology and standard system and promote rapid and standardized development of the CO2-EGR industry. It is suggested to establish a CO2-EGR demonstration area in the Sichuan Basin and popularize it across China, so as to improve comprehensive economic benefits through the establishment of large-scale industrial clusters. It is concluded that the two-carbon goals bring opportunities to the development of CO2-EGR in China, which will promote gas production and demonstration of CO2 sequestration in gas reservoirs and have positive significance in ensuring energy security and realizing carbon peak and carbon neutrality in China.

On the Electrification of Winter Season in Cold Climate Megacities—The Case of New York City

Abstract Cities are accelerating policies to electrify their energy sectors as a key strategy for reducing greenhouse gas emissions. In densely populated cities with cold climates, the building sector often accounts for over 70% of total energy consumption during winter seasons. In such cold climate megacities, the common practice for heating building spaces involves burning oil or gas. A major shift from this conventional approach toward electric-based heating technologies could have far-reaching implications. In this work, we focus on New York City (NYC), where buildings account for over 75% of the total energy consumption used during winter seasons. The city has adopted policies aimed at achieving deep decarbonization by targeting buildings as a primary source of emissions. We evaluate the potential energy infrastructure and environmental impacts of such major shifts by focusing on the adoption of air-source heat pumps from natural gas boilers. The Weather Research and Forecasting model, coupled with a multilayer building environment parameterization and building energy model, is used to perform this analysis. A city-scale case study was performed over the winter month of January 2021. Simulation results show good agreement with surface weather stations. We show that a shift of heating systems from gas to electricity results in an equivalent peak energy demand from 21,500 MW to 5800 MW, while reducing the peak urban heat island (UHI) by 2.5–3 °C. Results highlight potential trade-offs in adaptation strategies for cities, which may be necessary in the context of increasing decarbonization policies.

Politics of climate change and energy policy in Japan: Is green transformation likely?

While being proud of comparatively high levels of energy efficiency and having experienced the Fukushima nuclear disaster, it may be presumed that Japan would become a leader in the global energy transition. On the contrary, however, Japan has demonstrated a degree of intransigence around deep decarbonization. Why does Japan not take leadership in the energy transition and arrest climate change? What is the context for Japanese climate/energy policymaking? What is the context for the 2050 net-zero target, what are the obstacles, and which actors could assist effectively in accelerating this transition? This article considers new drivers for national policy as well as the influence of exogenous domestic and international forces. This leads to the question of whether the 2050 carbon neutrality policy goal could deliver a rapid shift away from fossil fuels. It presents an analytical framework to explain Japan’s evolving climate-energy nexus, illuminating core variables hampering and enabling the attainment of the net-zero 2050 target.

The role of technical change in low-carbon transformation and crises in the electricity market: A CGE analysis with R&D investment

The Russia–Ukraine conflict has exacerbated the global energy and electricity crisis. Considering China's carbon neutrality target, predicting the power market's response to the mandate of energy transformation and the impact of the energy crisis is particularly critical. Technical change is essential for the power sector to solve these crises; however, limited studies have systematically evaluated the role of endogenous technical change in low-carbon transformation of the power sector from an economy-wide perspective. Therefore, applying a multi-sector computable general equilibrium model, this study examines the potential trajectory of research and development (R&D)-based endogenous technical change, investigating the impact of different technical changes on China's power sector, the overall socio-economy, and the energy environment. The relevant results are threefold. First, carbon pricing combined with subsidising renewable electricity is an effective way to reduce emissions to achieve low-carbon transformation in the power sector. This approach can cause relatively moderate losses for the macro-economy and households' welfare. It can also significantly improve the renewable share, electrification rate and synergistic abatement effects on sulphur dioxide and nitrogen oxides. Second, shifting R&D inputs from fossil fuel power generation technology to renewable power technologies should be considered to advance the deep decarbonisation of the power sector. This approach can further improve the renewable share and electrification rate and enhance synergistic abatement effects; however, it can also slightly increase the macro-economic loss. Third, to alleviate the negative impacts to the macro-economy, it is advisable to consider increasing the R&D inputs of various sectors extensively, rather than only increasing that in the power sector. This approach can effectively alleviate the negative impacts on the socio-economy while improving the renewable share with the best synergistic abatement effects.

Analysis of electrification and its greenhouse gas reduction potential in the industrial sector of Korea using mixed methods

Carbon neutrality has heightened the necessity for deep decarbonization in the industrial sector, emphasizing the significance of ambitious mitigation measures, including system-level energy and material efficiency, carbon capture and utilization, electrification, and green hydrogen utilization. Electrification, particularly in the hard-to-abate industrial sector, emerges as a critical tool assuming the power sector's decarbonization. This study aims to evaluate Korea's industrial sector electrification potential and its greenhouse gas (GHG) reduction potential by 2050. To achieve this, we employ a mixed-method approach, integrating quantitative methods, such as the Iterative Proportional Fitting Procedure (IPFP) for data consistency, energy forecast, and elasticity of substitution models, along with a qualitative method involving energy experts through the Delphi technique. The results indicate an estimated 41% electrification potential for Korea's industrial sector by 2050, with a potential GHG reduction of approximately 26.3% compared to the Business-as-Usual emissions.

Institutional Drivers of Voluntary Carbon Reduction Target Setting—Evidence from Poland and Hungary

Governments worldwide have launched climate policies to mitigate greenhouse gas emissions (GHG). These policies aim to enhance businesses to be active actors in the process of decarbonisation. Therefore, the main objective of this paper is to identify the drivers of voluntary corporate decarbonisation illustrated by climate target-setting practices. In particular, this paper aims at diagnosing whether European Union (EU)-wide and country-level policies foster material corporate commitment to mitigating the carbon footprint in two countries that are exceptionally heavily dependent on fossil fuels: Poland and Hungary, which are characterised by a specific political-economic situation. This analysis focuses on policies related to the EU sustainable finance initiative that enhances companies to voluntarily reduce their GHG emissions: (1) sustainable financial sector, (2) corporate disclosure, and (3) corporate governance policy. At the country level, the national policies for state-owned enterprises (SOEs) are analysed. The empirical research is conducted based on the financial and economic data for a group of Polish and Hungarian publicly listed companies exposed to these regulations. The exposure to certain policies is approximated through selected corporate characteristics. Logistic regression analysis is applied to firm-level data gathered from Refinitive and corporate reports. The dataset covers the period 2014 to 2021, with 214 data-points. The response variable is a binary indicator of whether a company sets emission targets. The empirical research proved that state ownership, belonging to the financial sector, and performance-oriented corporate governance factors have a significantly negative impact on the probability of a company setting target emissions. On the other hand, the company’s size and leverage have a strong positive impact on the probability of setting emission targets. Also, it was confirmed that after 2020 the frequency of corporate target-setting in Poland and Hungary increased. Additionally, it was observed that Polish firms are more willing to set climate targets than Hungarian ones. Therefore, from the analysed policies, only the corporate sustainability disclosure policy proved to have a positive impact on the practices of setting climate targets in Polish and Hungarian firms. The policies related to the sustainable financial sector and to state-owned enterprises proved to have a negative impact on the probability of setting climate targets, while for the corporate governance policy, the results are mixed. In this vein, it was shown that, by a majority, policies to stimulate voluntary corporate commitment to decarbonisation are counter-effective in countries characterised by exceptional fossil fuel dependence and particular institutional features. The original value of this study stems from the applied methodology focusing on a mix of policies addressing the deep decarbonisation process in the specific country settings. The presented research contributes to an on-going debate on the drivers of voluntary corporate decarbonisation, in particular the impact that policy mixes framed under the sustainable finance agenda may have on material commitments to GHG emission reduction targets. In this context, the main findings are important for policymakers who are responsible for creating and implementing policy measures devoted to the deep decarbonisation process. It is recommended that policymakers should consider national specificities while designing policies for a Europe-wide net-zero transition and account for potential tensions arising from different goals as they may have impact on the effectiveness of the decarbonisation process. Future research may focus on the verification of the observed relationships between variables on a larger sample of the European firms to identify the key drivers of deep corporate decarbonisation.

Repurposing, co-processing and greenhouse gas mitigation – The Brazilian refining sector under deep decarbonization scenarios: A case study using integrated assessment modeling

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

Impacts on manufacturing workers as part of a whole-system energy transition

Providing access to good employment opportunities has become a key area of focus to ensure a just energy transition and to ensure that there is sufficient support for the technology transitions necessary for deep decarbonization. However, a societal transition to a decarbonized energy system will impact workers beyond those involved in energy resource extraction and energy production. Workers involved in manufacturing, especially those working in manufacturing industries that are energy- and emissions-intensive may face additional changes as those industries undergo technological changes. While discussions of the quality of jobs have focused on things like compensation, employment terms, and representation, other job dimensions, like the intrinsic characteristics of the work, health and safety, and work–life balance, stand to be directly impacted by technology change and are largely excluded from consideration. As these new technologies are developed and new energy sources are introduced to support manufacturing, we should also consider sociotechnical solutions that balance worker quality of life among other considerations like the utilization of new capital resources. Incorporating considerations across a wider definition of job quality dimensions will help to ensure that there is a sufficient workforce available to meet the demands of a decarbonization transition.

Deep decarbonisation pathways of the energy system in times of unprecedented uncertainty in the energy sector

Unprecedented investments in clean energy technology are required for a net-zero carbon energy system before temperatures breach the Paris Agreement goals. By performing a Monte-Carlo Analysis with the detailed ETSAP-TIAM Integrated Assessment Model and by generating 4000 scenarios of the world's energy system, climate and economy, we find that the uncertainty surrounding technology costs, resource potentials, climate sensitivity and the level of decoupling between energy demands and economic growth influence the efficiency of climate policies and accentuate investment risks in clean energy technologies. Contrary to other studies relying on exploring the uncertainty space via model intercomparison, we find that the CO2 emissions and CO2 prices vary convexly and nonlinearly with the discount rate and climate sensitivity over time. Accounting for this uncertainty is important for designing climate policies and carbon prices to accelerate the transition. In 70% of the scenarios, a 1.5 °C temperature overshoot was within this decade, calling for immediate policy action. Delaying this action by ten years may result in 2 °C mitigation costs being similar to those required to reach the 1.5 °C target if started today, with an immediate peak in emissions, a larger uncertainty in the medium-term horizon and a higher effort for net-zero emissions.