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.

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.