Complete Phase-out Research Articles

Forever Pesticides: A Growing Source of PFAS Contamination in the Environment.

Environmental contamination by fluorinated chemicals, in particular chemicals from the per- and polyfluoroalkyl substances (PFAS) class, has raised concerns around the globe because of documented adverse impacts on human health, wildlife, and ecosystem quality. Recent studies have indicated that pesticide products may contain a variety of chemicals that meet the PFAS definition, including the active pesticide ingredients themselves. Given that pesticides are some of the most widely distributed pollutants across the world, the legacy impacts of PFAS addition into pesticide products could be widespread and have wide-ranging implications on agriculture and food and water contamination, as well as the presence of PFAS in rural environments. The purpose of this commentary is to explore different ways that PFAS can be introduced into pesticide products, the extent of PFAS contamination of pesticide products, and the implications this could have for human and environmental health. We submitted multiple public records requests to state and federal agencies in the United States and Canada and extracted relevant data from those records. We also compiled data from publicly accessible databases for our analyses. We found that the biggest contributor to PFAS in pesticide products was active ingredients and their degradates. Nearly a quarter of all US conventional pesticide active ingredients were organofluorines and 14% were PFAS, and for active ingredients approved in the last 10 y, this had increased to 61% organofluorines and 30% PFAS. Another major contributing source was through PFAS leaching from fluorinated containers into pesticide products. Fluorination of adjuvant products and "inert" ingredients appeared to be limited, although this represents a major knowledge gap. We explored aspects of immunotoxicity, persistence, water contamination, and total fluorine load in the environment and conclude that the recent trend of using fluorinated active ingredients in pesticides may be having effects on chemical toxicity and persistence that are not given adequate oversight in the United States. We recommend a more stringent risk assessment approach for fluorinated pesticides, transparent disclosure of "inert" ingredients on pesticide labels, a complete phase-out of post-mold fluorination of plastic containers, and greater monitoring in the United States. https://doi.org/10.1289/EHP13954.

Analysis of refrigerants used in supermarket commercial equipment and the potential for increasing energy efficiency and reducing environmental impact

Refrigerants used in the commercial equipment of supermarkets are the object of the research. The Montreal Protocol calls for a complete phase-out of hydrochlorofluorocarbons (HCFCs) by 2030, and the Kigali Amendment regulates the use of hydrofluorocarbons (HFCs) from 2019. Developed countries began phasing out HFC use in 2019, while developing countries plan to freeze HFC consumption from 2024. These global efforts are aimed at reducing the depletion of the ozone layer and combating climate change. The number of supermarkets in the world varies greatly: in Europe they number from 110 thousand to 115 thousand, and in China – from 65 thousand to 70 thousand, which reflects various needs in refrigeration equipment. Stringent environmental regulations are forcing the commercial refrigeration sector to remain globally competitive. Modernization of supermarkets using natural refrigerants is important for solving emerging challenges. The results of the study show significant improvements in energy efficiency ratio (EER) and coefficient of performance (COP) when using a mixture of hydrocarbons (R290: 85 %, R600a: 15 %) compared to traditional refrigerants R404a, R449a and R502. Specifically, at the evaporation temperature of Tevap=–10 °C, EER increased by 38–44 % and COP by 26–31 % compared to R404a and R449a, respectively. At Tevap=–25 °C, EER increased by 17–34 % and COP by 2–22 % compared to R404a and R449a. Additionally, compared to R502, the hydrocarbon blend showed a 38–44 % increase in EER and 28–31 % COP at Tevap=–10 °C, and a 17–34 % increase in EER and 5–22 % COP at Tevap=–25 °C. These results highlight the advantages of the hydrocarbon mixture at different evaporation temperatures, indicating its potential to improve energy efficiency in refrigeration applications. The obtained data suggest the possibility of a wider application of the mixture of hydrocarbons in commercial refrigeration plants, offering both improved performance and compliance with safety regulations.

Energy Transition: The Impact of Increasing Energy Production from Renewable Sources on the Commercial Optimization Process of Conventional Power Generation Assets

Abstract Changing the way electricity is produced, as part of the energy transition process, brings new challenges to the energy industry and in particular to the power generation practices. The switch from energy systems based on fossil fuels to generation technologies based on renewable sources is proving to be much more complex than expected. Multiple recent studies have shown that the intermittency in renewable production processes is putting pressure on the system and increasing balancing and maintenance costs of the grid, calling for an efficient management of the electricity produced. Therefore, a complete phase-out of conventional power generation units (e.g. coal, gas and nuclear) is still difficult to imagine in practice, mainly because of their role in balancing the system during the hours when renewables are not available (e.g. no wind, no sun or reduced hydraulicity). From the perspective of technical and commercial management aspects, the operation of conventional assets involves the consideration of multiple constraints (such as a longer operating time before they are shut down, or a longer preparation time before they can be restarted) in order to avoid financial loss and further damages. Therefore, the aim of this is to: 1. study the impact brought by the large installed capacity of renewable assets on the energy system; 2. analyse the options for gradual phase-out of conventional assets, from the perspective of system stability; 3. draw conclusions on how the commercial optimization of the production assets should develop as the energy transition advances. The novelty of this paper lies in the fact that it makes a business study of this transition process, which does not really exist yet, and case and simulation studies, along with statistical and time series analysis were used as a methodological approach for the research.

The place of the climate agenda in modern global communications

The subject of our research is the climate agenda as part of the environmental policies of states. The author's attention to this issue is due to the instability of the international system, which is influenced by current crises and conflict relations between countries. It was important for us to consider how strongly the processes of instability affect the fulfillment of their obligations by global players. We also identified key factors influencing the adoption of current strategic documents. We analyzed the main documents approved at the UN on climate change, adopted in 2021-2023. Scientific novelty manifests itself in several key aspects. First of all, decisions are considered from the point of view of making political decisions and building communication processes. The second aspect is related to the identification of factors influencing the implementation of environmental policy. And finally, we looked at how global crises affected the climate agenda and whether it was transformed on a global scale. The result of the study is the conclusion that the problem of climate change remains key. Moreover, attempts are being made to strengthen the “natural resources – climate change – responsibility” link, which is reflected in plans to introduce a complete phase-out of fossil fuels. Serious steps are being taken to involve developing countries in this process through the provision of financial and other support. Young people have been identified as the main driver of the fight against climate change, which indicates the long-term nature of key decisions. Moreover, international agreements involve further transformation of the existing system through adjustments to national goals, diversification of the energy sector, economic reforms and changes to existing financial systems aimed at achieving climate goals.

Participatory development of Shared Socioeconomic Pathways for Austria’s agriculture and food systems

Agriculture and food systems are central to managing biodiversity loss and climate change. Future changes in agriculture and food systems are highly uncertain and depend on underlying socio-economic developments. Scenarios allow scientists, policy and industry decision-makers to consider such uncertainties and describe a spectrum of plausible futures. The Shared Socioeconomic Pathways for European agriculture and food systems (Eur-Agri-SSPs) semi-quantitatively describe pathways along future challenges for climate change mitigation and adaptation. However, additional or adapted drivers (i.e. scenario elements), like national policies or adaptations of European policies, are relevant to frame plausible future developments at national scales. We aim to set the standard for developing country and sector-specific SSPs in a participatory process by developing and applying an eleven-step protocol and engaging a diverse group of stakeholders throughout the whole research process. By downscaling the Eu-Agri-SSPs to a national level, we contribute to improve their usability in academia, governments and industry. This is achieved by matching qualitative pathways with the needs of integrated land use models (used to simulate land use scenarios), and by quantifying selected drivers for future developments together with stakeholders. In particular, we estimate 20-year trends (2000–2019) and apply fuzzy set theory to quantify ten scenario elements, which are typically required in integrated land use models. The final scenarios describe the semi-quantitative development for 79 scenario elements along the five topics “Population and urbanization”, “Economy”, “Policy and institutions”, “Technology”, and “Environment and natural resources” for the five AT-Agri-SSPs. Exemplary results reveal that stakeholders expect payments for agri-environment-climate measures to increase to 1200 million € in AT-Agri-SSP1 or to decline to 267 million € in AT-Agri-SSP3, 4 and 5. For direct payments, a complete phase-out was specified for AT-Agri-SSP1 and an increase to 711 million € in AT-Agri-SSP3. We discuss 14 lessons learnt and recommendations for future scenario processes and participatory quantification. Recommendations include: tailoring the assignment of scenario elements for quantification to stakeholders’ expertise, keeping survey complexity low, providing historical and relevant SSP data, and encouraging stakeholders to jointly quantify interdependent elements. The AT-Agri-SSPs can inform policy-making, decision-making in industry, and research on the agriculture and food systems.

Designing a circular carbon and plastics economy for a sustainable future.

The linear production and consumption of plastics today is unsustainable. It creates large amounts of unnecessary and mismanaged waste, pollution and carbon dioxide emissions, undermining global climate targets and theSustainable Development Goals. This Perspective provides an integrated technological, economic and legal view on how to deliver a circular carbon and plastics economy that minimizes carbon dioxide emissions. Different pathways that maximize recirculation of carbon (dioxide) between plastics waste and feedstocks are outlined, including mechanical, chemical and biological recycling, and those involving the use of biomass and carbon dioxide. Four future scenarios are described, only one of which achieves sufficient greenhouse gas savings in line with global climate targets. Such a bold system change requires 50% reduction in future plastic demand, complete phase-out of fossil-derived plastics, 95% recycling rates of retrievable plastics and use of renewable energy. It is hard to overstate the challenge of achieving this goal. We therefore present a roadmap outlining the scale and timing of the economic and legal interventions that could possibly support this. Assessing the service lifespan and recoverability of plastic products, along with considerations of sufficiency and smart design, canmoreoverprovide design principles to guide future manufacturing, use and disposal of plastics.

Improvised Freon Extractor as an Innovative Trainer

The decade of the 1990's has been a challenging time for the Heating, Ventilation, Air Conditioning, and Refrigeration (HVAC&R) industry worldwide. Due to its vital role in the destruction of the stratospheric ozone layer, provisions of the Montreal Protocol and its various amendments required the complete phase-out of chlorine-containing refrigerant such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). Appliances such as window type air-conditioners, motor vehicle air-conditioners, and refrigerators, rely on ozone depleting refrigerants and their substitutes. In this case, the regulation of the Environmental Protection Agency (EPA) which prohibits the venting of refrigerants compounds to the atmosphere must be followed. Along this line of concern, educational institutions need to be aware of this technological gap specifically in developing programs in Heating, Ventilation, Air-conditioning and Refrigeration for environmental protection against incorrect disposal of refrigerant. The aim of this study was to develop an Improvised Freon Extractor as an Innovative Trainer to help students and instructors in the Bachelor of Industrial Technology and
 Bachelor of Science in Mechanical Engineering courses in their effective teaching-learning of lessons in Refrigeration and Air-conditioning subjects. The results of the study revealed that the developed innovative trainer contains the following parts: electrical parts - includes the dual capacitor, banana plug, compressor, fan motor, air swing motor, air swing motor switch, thermostat switch, and selector switch; nonelectrical parts - frame housing, frame cover, suction and discharge valve, caster wheels, filter receiver drier assembly and condenser. The Improvised Freon Extractor as an Innovative Trainer was also found to be suitable to serve as an alternative learning material that assists the learning of Refrigeration and Air-conditioning subjects in the Bachelor of Industrial Technology and Bachelor of Science in Mechanical Engineering courses

Impacts of coal use phase-out in China on the atmospheric environment: (2) public health and global radiative forcing

In the second of two companion papers, we quantify the potential ultimate benefits for public health and radiative forcing from the phase-out of coal use in China. With the baseline year of 2015, we estimate that the premature deaths and disability-adjusted life years (DALYs) in China will be reduced by 375,000 persons and 8.90 × 106 years (GEMM model), which is 41.7% and 54.5% of the total number of premature deaths and DALYs caused by PM2.5 from anthropogenic sources, effectively improving the health of the population. The provinces with the most significant decreases in fatalities and disabilities are concentrated in large coal-consuming provinces. Regarding age distribution, the phase-out of coal use will effectively extend the life expectancy of the elderly, especially in the age group of 65–89 years. Health benefits’ growth rate upsurges notably once more than half of coal is phased out. Based on the Parallel Offline Radiative Transfer (PORT) model, the global annual average radiative forcing due to changes in short-lived climate pollutants (SLCPs), including sulfate, black carbon, organic carbon, and O3 associated with the phase-out of coal use, is 0.34 W m−2, -0.048 W m−2, 0.00064 W m−2, and 0.00055 W m−2, respectively. The complete phase-out of coal use in China also reduces the emission of long-lived climate pollutants (LLCPs) and causes negative radiative forcing. Among them, the global annual average radiative forcing of CO2, CH4, and N2O is −0.0073 W m−2, -5.48 × 10−5 W m−2, -1.60 × 10−5 W m−2. If the lifetimes of pollutants are considered, the total global reduction in heat uptake is −2.29 × 107 J m−2 over 100 years, dominated by the decrease of CO2, which will slow the rate of global warming and thus may reduce the probability of extreme weather events. This report will incentivize relevant policymakers to remove coal significantly to achieve carbon neutrality.

Air pollution deaths attributable to fossil fuels: observational and modelling study

ObjectivesTo estimate all cause and cause specific deaths that are attributable to fossil fuel related air pollution and to assess potential health benefits from policies that replace fossil fuels with...

Aerosol demasking enhances climate warming over South Asia

Anthropogenic aerosols mask the climate warming caused by greenhouse gases (GHGs). In the absence of observational constraints, large uncertainties plague the estimates of this masking effect. Here we used the abrupt reduction in anthropogenic emissions observed during the COVID-19 societal slow-down to characterize the aerosol masking effect over South Asia. During this period, the aerosol loading decreased substantially and our observations reveal that the magnitude of this aerosol demasking corresponds to nearly three-fourths of the CO2-induced radiative forcing over South Asia. Concurrent measurements over the northern Indian Ocean unveiled a ~7% increase in the earth’s surface-reaching solar radiation (surface brightening). Aerosol-induced atmospheric solar heating decreased by ~0.4 K d−1. Our results reveal that under clear sky conditions, anthropogenic emissions over South Asia lead to nearly 1.4 W m−2 heating at the top of the atmosphere during the period March–May. A complete phase-out of today’s fossil fuel combustion to zero-emission renewables would result in rapid aerosol demasking, while the GHGs linger on.

Exchange of Pb from Indian to Atlantic Ocean is driven by Agulhas current and atmospheric Pb input from South Africa

Using a spatiotemporal dataset of dissolved lead (dPb) from the subtropical oceans surrounding South Africa, this study quantifies the exchange of dPb between the Indian and Atlantic Oceans. Despite the absence of a major Pb source within the South Atlantic sector and the complete phase-out of leaded petroleum in Southern Africa, the ecologically important southeast Cape Basin shows an elevated surface dPb concentration (21–30 pmol kg−1). We estimated up to 90% of the measured dPb in surface waters of the Cape Basin was delivered from the Indian Ocean via the Agulhas Current (AC). Eddy dynamics and leakage at Agulhas retroflection result in an increased Pb flux from winter to summer, while a long-term (2008–2019) temporal change in dPb in the AC-derived water of Cape Basin was contemporaneous to a change in atmospheric Pb emissions from South Africa. The South African-origin atmospheric Pb, however, contributes first to the Agulhas waters in the West Indian Ocean, which is then transported to the South Atlantic, thereby regulating the dPb inventory of the Cape Basin. This indirect mechanism of Pb transfer emphasizes the importance of regulating Pb emissions from Southern Africa to protect rich fishing grounds associated with the Benguela marine ecosystem.

Nationwide assessment of atmospheric organochlorine pesticides over a decade during 2008–2017 in South Korea

Long-term nationwide atmospheric monitoring of organochlorine pesticides (OCPs) was performed in South Korea during 2008–2017. Their occurrences, seasonal and temporal variability, sources, and effect of ambient temperature were investigated. The OCPs are pronounced with a mean concentration of total OCPs ranging from 5.2 to 256 pg/Sm3. However, a decrease of 54 % was observed in the mean concentration of total OCPs from 2008 to 2017 associated with regulatory actions. OCP concentrations did not show any variations between the different site types, and OCPs were ubiquitously present at all site types. The mean concentration of total OCPs in summer was two-fold higher than in winter. The concentrations of DRINs, DDTs, ENDOs, and HCHs were significantly higher in summer, but the concentrations of chlordane and heptachlor were higher in winter. The diagnostic ratios identified major sources as ongoing sources, past use, and atmospheric transport. Clausius Clapeyron plots strongly suggested the re-emission of α-endosulfan, β-endosulfan, α-HCH, and β-HCH, and ΔHsa (enthalpy of surface air exchange) values suggested the influence of the transport and/or new sources on aldrin, dieldrin, and chlordane. The occurrence of OCPs due to re-emissions, ongoing sources, and long-range atmospheric transport could be a challenge towards the complete phase-out of OCPs in South Korea.

Decarbonization, population disruption and resource inventories in the global energy transition

We develop a novel approach to analysing decarbonisation strategies by linking global resource inventories with demographic systems. Our ‘mine-town systems’ approach establishes an empirical basis for examining the spatial extent of the transition and demographic effects of changing energy systems. The research highlights an urgent need for targeted macro-level planning as global markets see a decline in thermal coal and a ramp up of other mining commodities. Our findings suggest that ramping up energy transition metals (ETM) could be more disruptive to demographic systems than ramping down coal. The data shows asymmetry in the distribution of risks: mine-town systems within the United States are most sensitive to coal phase-out, while systems in Australia and Canada are most sensitive to ETM phase-in. A complete phase-out of coal could disrupt demographic systems with a minimum of 33.5 million people, and another 115.7 million people if all available ETM projects enter production.

Identification of key influencing factors to Chinese coal power enterprises transition in the context of carbon neutrality: A modified fuzzy DEMATEL approach

Coal power is the major force behind the flexible peaking of China's power system. Its complete phaseout is unrealistic and may cause multiple problems related to social stability. Therefore, how to guarantee a steady and orderly transition of coal power is critical. To promote coal power to transform smoothly, this study applies a modified fuzzy Decision-making Trial and Evaluation Laboratory (DEMATEL) approach to identify key influencing factors and their influence-influenced connection in Chinese coal power transition, basing on a state-owned coal-fired plant. Firstly, by surveying literatures and consulting experts, an index system of 12 main factors is identified, which includes 4 dimensions (management capability, market price, resource allocation, society environment). Then, the Interval Type-2 Fuzzy Sets (IT2FSs), Ordered Weighted Average (OWA) operator, and K-means clustering algorithm are used to optimize the approach. Six factors are judged as key influencing factors in coal power plant's transition according to the findings, among which policy, units' configuration, and market prices are included with high scores. Finally, political solutions are proposed to facilitate the efficient transition of coal plant.

Phasing out an embedded technology: Insights from banning the incandescent light bulb in Europe

Opening up the dynamics of phase-outs is important to advance the knowledge about how to navigate phase-outs, how to speed them up and how to ensure justice, all pressing topics in energy transitions. I revisit the case of the incandescent light bulb phase-out in Europe and investigate what processes were involved after the phase-out regulation entered into force (2000–2020). The present study deviates in approach and analytical focus from prior studies of the light bulb phase-out. I use ‘technologies-in-practice’ as heuristic to trace technology as a processual phenomenon, i.e. as an outcome of processes of co-evolving materiality, meanings, activities and skills integral to them.I find that intentional push for a destabilising meaning (energy inefficiency) of the light bulb, resonant with powerful larger discourse (climate change), and imitation of existing technology by a group of stakeholders was key in the process of light bulb’s downscaling. The attachment of new, reinforcing the stability of the configuration, meanings to the light bulb (nostalgic lamp, rough-service lamp) by another group of stakeholders prevented a complete phase-out. I contribute to the existing theoretical literature by offering to put more emphasis on studying the later stages of the technological trajectory, and discussing the winners and losers of the phasing-out.

Role of Hydrogen in n-Hexane Hydroisomerisation as a Model Reaction for Gasoline Quality Valorization

Consequent to the current global environmental legislations that enforced the phase-out of dangerous fuel additives with associated pollution problems, other research alternatives for improving fuels quality are investigated. Previously, lead and oxygenates have posed emission dangers that accounted for their complete phase-out in many regions. The emergence of hydroisomerisation as an option presents an opportunity for improving gasoline octane features while eliminating the environmental dangers. We prepared and characterized a noble and cheap catalyst based on β-Mo2C/sulfated zirconia that completely upgraded n-hexane into mono- and di-branched isomers at milder reaction conditions (1 atm, 400oC). The catalyst was 100% selective to n-hexanes at high hydrogen flow rates and recyclable and stable. This way, cheap opportunity for gasoline feed valorization via the hydroisomerisation process became possible.

A plant-by-plant strategy for high-ambition coal power phaseout in China

More than half of current coal power capacity is in China. A key strategy for meeting China’s 2060 carbon neutrality goal and the global 1.5 °C climate goal is to rapidly shift away from unabated coal use. Here we detail how to structure a high-ambition coal phaseout in China while balancing multiple national needs. We evaluate the 1037 currently operating coal plants based on comprehensive technical, economic and environmental criteria and develop a metric for prioritizing plants for early retirement. We find that 18% of plants consistently score poorly across all three criteria and are thus low-hanging fruits for rapid retirement. We develop plant-by-plant phaseout strategies for each province by combining our retirement algorithm with an integrated assessment model. With rapid retirement of the low-hanging fruits, other existing plants can operate with a 20- or 30-year minimum lifetime and gradually reduced utilization to achieve the 1.5 °C or well-below 2 °C climate goals, respectively, with complete phaseout by 2045 and 2055.

Estimate of Hydrochlorofluorocarbons (HCFCs) Emission Variations During 2011-2018 in the Yangtze River Delta, China

Hydrochlorofluorocarbons (HCFCs) with reduced ozone depletion potentials (ODPs) and high global warming potentials (GWPs) are used as temporal substitutes of chlorofluorocarbons, and were regulated by the Montreal Protocol and its adjustment with the 2013 cap and until a complete phase-out by 2030 in Article 5 (developing) countries. Weekly flask measurements for four HCFCs (HCFC-22, HCFC-141b, HCFC-142b, and HCFC-124) were conducted at Lin’an regional background station in the Yangtze River Delta (YRD) over the period of 2011-2018 and the measurements of HCFC-132b and HCFC-133a were started in 2018. The HCFCs emissions in YRD were estimated based on the tracer ratio method using CO and HFC-134a as multi-tracers and the estimated emissions of HCFCs based on CO and HFC-134a agreed well within the uncertainties of each other. The YRD’s HCFC emissions based on CO tracer were 28.8 ± 14.1 kt yr-1 for HCFC-22, 5.8 ± 3.4 kt yr-1 for HCFC-141b, 1.3 ± 0.6 kt yr-1 for HCFC-142b, 0.14 ± 0.11 kt yr-1 for HCFC-124, 0.025 ± 0.022 kt yr-1 for HCFC-132b, and 0.40 ± 0.35 kt yr-1 for HCFC-133a in 2018. HCFC-141b, HCFC-142b, and HCFC-124 emissions have reached peaks during the period of freezing consumption (2013-2014) or the period without emission control (2011-2012) and have all recently undergone substantial declines of 18%, 45%, and 30% in 2018 compared with those for 2011-2012. HCFC-22 emissions showed steadily increased during 2011-2018, but the rate of increase in 2018 was obviously slower than the two previous periods. The YRD’s cumulative emissions, ODP-weighted and CO2-equivalent emissions of the four HCFCs accounted for 20%, 23%, and 18% of the national totals, respectively, for 2011-2017, and the HCFC-133a emissions in the YRD provided 70% to the eastern China emissions and 18% to the global emissions in 2018, thus are important contribution to China’s total emissions and even worldwide.

Can the 1.5 ℃ warming target be met in a global transition to 100% renewable energy?

<abstract> <p>First, we recognize the valuable previous studies which model renewable energy growth with complete termination of fossil fuels along with assumptions of the remaining carbon budgets to reach IPCC warming targets. However, these studies use very complex combined economic/physical modeling and commonly lack transparency regarding the sensitivity to assumed inputs. Moreover, it is not clear that energy poverty with its big present impact in the global South has been eliminated in their scenarios. Further, their CO<sub>2</sub>-equivalent natural gas emission factors are underestimated, which will have significant impact on the computed greenhouse gas emissions. Therefore, we address this question in a transparent modeling study: can the 1.5 ℃ warming target still be met with an aggressive phaseout of fossil fuels coupled with a 100% replacement by renewable energy? We compute the continuous generation of global wind/solar energy power along with the cumulative carbon dioxide equivalent emissions in a complete phaseout of fossil fuels over a 20 year period. We compare these computed emissions with the state-of-the-science estimates for the remaining carbon budget of carbon dioxide emissions consistent with the 1.5 ℃ warming target, concluding that it is still possible to meet this warming target if the creation of a global 100% renewable energy transition of sufficient capacity begins very soon which will likely be needed to power aggressive negative carbon emission technology. The latter is focused on direct air capture for crustal storage. More efficient renewable technologies in the near future will make this transition easier and promote the implementation of a global circular economy. Taking into account technological improvements in 2<sup>nd</sup> law (exergy) efficiencies reducing the necessary global energy demand, the renewable supply should likely be no more than 1.5 times the present level, with the capacity to eliminate global energy poverty, for climate mitigation and adaptation.</p> </abstract>

Fossil Natural Gas Exit – A New Narrative for the European Energy Transformation towards Decarbonization

This paper discusses the potential role of fossil natural gas (and other gases) in the process of the energy transformation in Europe on its way to complete decarbonization. Mainstream conventional wisdom has it that natural gas, perhaps in combination with other gases, should maintain an important role in the energy mix, first, as a “bridge fuel”, and then through a gradual transition toward decarbonized gases. This is most comprehensively rolled out in three consecutive discussion papers by Jonathan Stern from the Oxford Institute for Energy Studies (2017b, 2017a, 2019). Based on an in- depth assessment of the ambitious climate targets of the EU and the subsequent need for far-reaching decarbonization, as well as on results from energy system modeling, a contrasting result emerges, where the disappearance of fossil natural gas and its corresponding infrastructure is the next logical step of the transformation process in Europe. The lack of an economic perspective for nuclear power and the absence of a plausible deployment of large-scale carbon-dioxide removal technologies (CDR) imply that natural gas has no “sweet spot” any longer in the decarbonization process. In other words: Fossil natural gas is no longer part of the solution to the challenge of climate change, but has become part of the problem. Over the last years, the phasing out of natural gas in Europe has already started, and will continue until its complete phase-out, most likely in the 2040s, i.e. only two decades from now. The decline of natural gas in Europe has implications for the short- and longer-term aggregate and sectoral energy mix, but also for the future of the lumpy infrastructure, that has been developed over the last decades for a growing market. Today, investments into natural gas infrastructure are likely to produce stranded assets, as we show in three concrete cases: The € 10 bn. investment into the North Stream 2 pipeline are not necessary to assure European supply security, nor to make a return on investment; projects of new LNG terminals on the shore of the German North Sea (Brunsbuettel, Stade, Wilhelmshaven) lack a business case; and new natural gas power plants are likely to be unprofitable. The paper proposes to replace the dominant narrative (“natural gas in decarbonizing European energy markets“) with what we consider a more coherent narrative in the context of decarbonization: Fossil natural gas exit.