Building stock growth around the world drives extensive material consumption and environmental impacts. Future impacts will be dependent on the level and rate of socioeconomic development, along with ...material use and supply strategies. Here we evaluate material-related greenhouse gas (GHG) emissions for residential and commercial buildings along with their reduction potentials in 26 global regions by 2060. For a middle-of-the-road baseline scenario, building material-related emissions see an increase of 3.5 to 4.6 Gt CO2eq yr-1 between 2020-2060. Low- and lower-middle-income regions see rapid emission increase from 750 Mt (22% globally) in 2020 and 2.4 Gt (51%) in 2060, while higher-income regions shrink in both absolute and relative terms. Implementing several material efficiency strategies together in a High Efficiency (HE) scenario could almost half the baseline emissions. Yet, even in this scenario, the building material sector would require double its current proportional share of emissions to meet a 1.5 °C-compatible target.
Cobalt is considered a key metal in the energy transition, and demand is expected to increase substantially by 2050. This demand is for an important part because of cobalt use in (electric vehicle) ...batteries. This study investigated the environmental impacts of the production of cobalt and how these could change in the future. We modeled possible future developments in the cobalt supply chain using four variables: (v1) ore grade, (v2) primary market shares, (v3) secondary market shares, and (v4) energy transition. These variables are driven by two metal‐demand scenarios, which we derived from scenarios from the shared socioeconomic pathways, a “business as usual” (BAU) and a “sustainable development” (SD) scenario. We estimated future environmental impacts of cobalt supply by 2050 under these two scenarios using prospective life cycle assessment. We found that the environmental impacts of cobalt production could likely increase and are strongly dependent on the recycling market share and the overall energy transition. The results showed that under the BAU scenario, climate change impacts per unit of cobalt production could increase by 9% by 2050 compared to 2010, while they decreased by 28% under the SD scenario. This comes at a trade‐off to other impacts like human toxicity, which could strongly increase in the SD scenario (112% increase) compared to the BAU scenario (71% increase). Furthermore, we found that the energy transition could offset most of the increase of climate change impacts induced by a near doubling in cobalt demand in 2050 between the two scenarios.
The environmental benefits of low‐carbon technologies, such as photovoltaic modules, have been under debate because their large‐scale deployment will require a drastic increase in metal production. ...This is of concern because higher metal demand may induce ore grade decline and can thereby further intensify the environmental footprint of metal supply. To account for this interlinkage known as the “energy‐resource nexus”, energy and metal supply scenarios need to be assessed in conjunction. We investigate the trends of future impacts of metal supplies and low‐carbon technologies, considering both metal and electricity supply scenarios. We develop metal supply scenarios for copper, nickel, zinc, and lead, extending previous work. Our scenarios consider developments such as ore grade decline, energy‐efficiency improvements, and secondary production shares. We also include two future electricity supply scenarios from the IMAGE model using a recently published methodology. Both scenarios are incorporated into the background database of ecoinvent to realize an integrated modeling approach, that is, future metal supply chains make use of future electricity and vice versa. We find that impacts of the modeled metal supplies and low‐carbon technologies may decrease in the future. Key drivers for impact reductions are the electricity transition and increasing secondary production shares. Considering both metal and electricity scenarios has proven valuable because they drive impact reductions in different categories, namely human toxicity (up to −43%) and climate change (up to −63%), respectively. Thus, compensating for lower ore grades and reducing impacts beyond climate change requires both greener electricity and also sustainable metal supply. This article met the requirements for a Gold‐Gold JIE data openness badge described at http://jie.click/badges
CO2 emissions from global steel production may jeopardize climate goals of 1.5 °C unless current steel production practices will be rapidly decarbonized. At present, primary iron and steel production ...is still heavily dependent on fossil fuels, primarily coke. This study aims to determine which decarbonization pathways can achieve the strongest emission reductions of the iron and steel industry in Germany by 2050. Moreover, we estimate whether the German iron and steel industry will be able to stay within its sectoral carbon budgets for a 1.5 °C or 1.75 °C target. We developed three decarbonization scenarios for German steel production: an electrification, coal-exit, and a carbon capture and storage (CCS) scenario. They describe a phase-out of coal-fired production plants and an introduction of electricity-based, low-carbon iron production technologies, i.e. hydrogen-based direct reduction and electrowinning of iron ore. The scenarios consider the age and lifetimes of existing coal-based furnaces, the maturity of emerging technologies, and increasing recycling shares. Based on specific energy requirements and reaction-related emissions per technology, we calculated future CO2 emissions of future steel production in Germany. We found that under the decarbonization scenarios, annual CO2 emissions decrease by up to 83% in 2050 relative to 2020. The reductions of cumulative emissions by 2050 range from 24% (360 Mt CO2) under the electrification scenario up to the maximum of 46% (677 Mt CO2) under the CCS scenario compared to a reference scenario. This clearly demonstrates that the technology pathway matters. Nevertheless, the German steel sector will exceed its sectoral CO2 budget for a 1.5 °C warming scenario between 2023 and 2037. Thus, drastic measures are required very soon to sufficiently limit future CO2 emissions from German steel production, such as, a rapid decarbonization of the electricity mix, the construction of a hydrogen and CCS infrastructure, or early shutdowns of current coal-based furnaces.
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•Scenarios for iron and steel production in Germany until 2050•Adopting new technologies: hydrogen-based direct reduction and electrowinning•Comparison of CO2 emissions with sectoral carbon budgets for the steel industry•Carbon budget for climate goal of 1.5 °C likely to be exceeded between 2023 and 2037•Carbon capture scenario achieves lowest CO2 emissions but has higher energy demand
•We present a prospective life cycle assessment model for lithium-ion battery cell production for 8 battery chemistries and 3 production regions during 2020–2050.•GHG emissions per kWh of lithium-ion ...battery cell production could reduce by over 50% during 2020–2050, mainly due to expected low-carbon electricity transition.•Cathode component is, with 46%−70% for NCM/NCA cells and 33%−46% for LFP cells, the biggest contributor to GHG emissions of lithium-ion battery cell production until 2050.
Understanding the future environmental impacts of lithium-ion batteries is crucial for a sustainable transition to electric vehicles. Here, we build a prospective life cycle assessment (pLCA) model for lithium-ion battery cell production for 8 battery chemistries and 3 production regions (China, US, and EU). The pLCA model includes scenarios for future life cycle inventory data for energy and key materials used in battery cell production. We find that greenhouse gas (GHG) emissions per kWh of lithium-ion battery cell production could be reduced from 41 to 89 kg CO2-Eq in 2020 to 10–45 kg CO2-Eq in 2050, mainly due to the effect of a low-carbon electricity transition. The Cathode is the biggest contributor (33%-70%) of cell GHG emissions in the period between 2020 and 2050. In 2050, LiOH will be the main contributor to GHG emissions of LFP cathodes, and Ni2SO4 for NCM/NCA cathodes. These results promote discussion on how to reduce battery GHG emissions.
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In the race to achieve global climate neutrality, carbon intensive industries like the clinker and cement industry are required to decarbonize rapidly. The environmental impacts related to potential ...transition pathways to low-carbon systems can be evaluated using prospective life cycle assessment (pLCA). This study conducts a pLCA for future global clinker production, integrating long-term transition pathways from the IMAGE integrated assessment model (IAM) to maintain global consistency. It systematically modifies the ecoinvent v3.9.1 database using the Python library premise to create future database versions representing future clinker production embedded in a future economy according to a 3.5°C-baseline, a 2°C-compliant and a 1.5°C-compliant scenario. Our study indicates that climate change impacts of clinker production may decrease from about 1.03 kg CO2-eq/kg clinker in 2020 to 0.94 (3.5°C-baseline), 0.20 (2°C-compliant), and 0.16 (1.5°C-compliant) kg CO2-eq/kg clinker in 2060 for the global average. This corresponds to a 10% (3.5°C-baseline), 81% (2°C-compliant) and 84% (1.5°C-compliant) decrease by 2060 compared to 2020. Under these scenarios, global clinker production alone would require 5%–11% of the remaining end-of-century carbon budget for the 2 °C and 1.5 °C-target, respectively. While the climate change impacts are substantially reduced, our study also indicates that the transition pathways shift the burden towards other impact categories, such as ionizing radiation, ozone depletion, material resources and land use. Developing IAM-compatible scenarios for more product groups helps to increase the coherence of pLCA studies. As this study is based on an IAM heavily reliant on carbon capture and storage and bioenergy, future research should explore the effects of different technology pathways and alternative mitigation strategies.
•This study assesses environmental impacts of global clinker production scenarios.•We introduce a new prospective LCA set-up using IMAGE global transition pathways.•Novel life cycle inventories are compiled for clinker kilns with carbon capture.•Optimizing for climate impacts leads to burden shift to other environmental impacts.•Decarbonization scenarios require a rapid uptake of CCS and bio-based fuels.
•Metal production causes severe environmental impacts, that may increase in the future when demand for metals may rise.•We found that, e.g., greener electricity, higher recycling shares, or novel ...technologies may reduce impacts per kg metal.•Yet, this is probably insufficient to compensate for rising demand. Thus, demand-related impacts are likely to increase.•Knowledge is lacking about future impacts of many metals, especially minor metals essential for the energy transition.•Better understanding of future impacts of metals is needed, considering rising demand and impacts beyond GHG emissions.
With the energy transition, the future demand for many metals is expected to sharply increase. We systematically reviewed studies which assessed future environmental impacts of metal supply chains. We evaluated their results regarding future impact trends, and their methods, i.e., modelling approaches, scenario variables, and data sources.
Our review yielded 40 publications covering 15 metals: copper, iron, aluminium, nickel, zinc, lead, cobalt, lithium, gold, manganese, neodymium, dysprosium, praseodymium, terbium, and titanium. Metals crucial for the energy transition, e.g., lithium or neodymium, are rarely addressed, unlike major metals. Results for future environmental impacts of metals strongly depend on scenario narratives and assumptions. We found that specific impacts (per kg) may decrease driven by, e.g., greener electricity, higher recycling shares, or novel technologies. Nevertheless, this is probably insufficient to compensate for surging demand. Thus, future demand-related impacts are still likely to increase. We identified 15 scenario variables. The most common variables are background electricity mix, ore grade, recycling shares, demand, and energy efficiency.
It is crucial to better understand future impacts of more metals, considering also rising demand and impacts beyond GHG emissions. We recommend improving research practices towards open and collaborative research, to enable more harmonised, reusable and accurate scenario assessments.
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We present an energy transition pathway constrained by a total CO2 budget of 7 Gt allocated to the German energy system after 2020, the Budget Scenario (BS). We apply a normative backcasting approach ...for scenario building based on historical data and assumptions from existing scenario studies. The modeling approach combines a comprehensive energy system model (ESM) with REMix—a cost optimization model for power and heat that explicitly incorporates sector coupling. To achieve the necessary CO2 reduction, the scenario focuses on electrifying all end use sectors until 2030, adding 1.5–2 million electric vehicles to the road per year. In buildings, 400,000–500,000 heat pumps would be installed annually by 2030, and the share of district heating would double until 2050. In the scenario, coal needs to be phased out by 2030. Wind and Photovoltaic (PV) capacities would need to more than double to 290 GW by 2030 and reach 500 GW by 2050. The BS results indicate that a significant acceleration of the energy transition is necessary before 2030 and that this higher pace must be maintained thereafter until 2050.
Germany 2050: For the first time Germany reached a balance between its sources of anthropogenic CO2 to the atmosphere and newly created anthropogenic sinks. This backcasting study presents a ...fictional future in which this goal was achieved by avoiding (∼645 Mt CO2), reducing (∼50 Mt CO2) and removing (∼60 Mt CO2) carbon emissions. This meant substantial transformation of the energy system, increasing energy efficiency, sector coupling, and electrification, energy storage solutions including synthetic energy carriers, sector‐specific solutions for industry, transport, and agriculture, as well as natural‐sink enhancement and technological carbon dioxide options. All of the above was necessary to achieve a net‐zero CO2 system for Germany by 2050.
Plain Language Summary
Here a net‐zero‐2050 Germany is envisioned by combining analysis from an energy‐system model with insights into approaches that allow for a higher carbon circularity in the German system, and first results from assessments of national carbon dioxide removal potentials. A back‐casting perspective is applied on how net‐zero Germany could look like in 2050. We are looking back from 2050, and analyzing how Germany for the first time reached a balance between its sources of CO2 to the atmosphere and the anthropogenic sinks created. This would consider full decarbonization in the entire energy sector and being entirely emission‐free by 2050 within three priorities identified as being the most useful strategies for achieving net‐zero: (a) Avoiding‐ (b) Reducing‐ (c) Removing emissions. This work is a collaboration of interdisciplinary scientists with the Net‐Zero‐2050 cluster of the Helmholtz Climate Initiative HI‐CAM.
Key Points
The net‐zero system shows that for countries like Germany, avoiding CO2 emissions was the largest contribution to achieve net‐zero CO2
With the three strategies of emissions avoidance, reduction, and removal, Germany has achieved its net‐zero CO2 goal for the first time
In addition, to natural sink enhancement carbon dioxide removal (CDR) options, technological CDR measures combined with geological CO2 storage were necessary to reach net‐zero CO2
Abstract
Germany 2050: For the first time Germany reached a balance between its sources of anthropogenic CO
2
to the atmosphere and newly created anthropogenic sinks. This backcasting study presents ...a fictional future in which this goal was achieved by avoiding (∼645 Mt CO
2
), reducing (∼50 Mt CO
2
) and removing (∼60 Mt CO
2
) carbon emissions. This meant substantial transformation of the energy system, increasing energy efficiency, sector coupling, and electrification, energy storage solutions including synthetic energy carriers, sector‐specific solutions for industry, transport, and agriculture, as well as natural‐sink enhancement and technological carbon dioxide options. All of the above was necessary to achieve a net‐zero CO
2
system for Germany by 2050.
Plain Language Summary
Here a net‐zero‐2050 Germany is envisioned by combining analysis from an energy‐system model with insights into approaches that allow for a higher carbon circularity in the German system, and first results from assessments of national carbon dioxide removal potentials. A back‐casting perspective is applied on how net‐zero Germany could look like in 2050. We are looking back from 2050, and analyzing how Germany for the first time reached a balance between its sources of CO
2
to the atmosphere and the anthropogenic sinks created. This would consider full decarbonization in the entire energy sector and being entirely emission‐free by 2050 within three priorities identified as being the most useful strategies for achieving net‐zero: (a) Avoiding‐ (b) Reducing‐ (c) Removing emissions. This work is a collaboration of interdisciplinary scientists with the Net‐Zero‐2050 cluster of the Helmholtz Climate Initiative HI‐CAM.
Key Points
The net‐zero system shows that for countries like Germany, avoiding CO
2
emissions was the largest contribution to achieve net‐zero CO
2
With the three strategies of emissions avoidance, reduction, and removal, Germany has achieved its net‐zero CO
2
goal for the first time
In addition, to natural sink enhancement carbon dioxide removal (CDR) options, technological CDR measures combined with geological CO
2
storage were necessary to reach net‐zero CO
2
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