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The use of carbon dioxide as a feedstock for a broad range of products can help mitigate the effects of climate change through long‐term removal of carbon or as part of a circular carbon economy. Research on capture and conversion technologies has intensified in recent years, and the interest in deploying these technologies is growing fast. However, sound understanding of the environmental and economic impacts of these technologies is required to drive fast deployment and avoid unintended consequences. Life cycle assessments (LCAs) and techno‐economic assessments (TEAs) are useful tools to quantify environmental and economic metrics; however, these tools can be very flexible in how they are applied, with the potential to produce significantly different results depending on how the boundaries and assumptions are defined. Built on ISO standards for generic LCAs, several guidance documents have emerged recently from the Global CO2 Initiative, the National Energy Technology Laboratory, and the National Renewable Energy Laboratory that further define assessment specifications for carbon capture and utilization. Overall agreement in the approaches is noted with differences largely based on the intended use cases. However, further guidance is needed for assessments of early‐stage technologies, reporting details, and reporting for policymakers and nontechnical decision‐makers.

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Technologies that valorize carbon dioxide are becoming an increasingly relevant component of the portfolio of solutions necessary to mitigate and reverse climate change. Assessing the environmental and economic characteristics of these technologies early in their developmental trajectories can help technologists either efficiently accelerate emissions reductions and commercialization or realize potential infeasibility and direct resources toward better opportunities. To aid in such assessments, this article constructs a typology of carbon removal and utilization technologies and identifies specific pathways in need of early-stage life cycle assessment (LCA) and techno-economic assessment (TEA) templates. Based on published literature and project experience, example LCA and TEA templates are developed for high-priority pathways with relatively low technology readiness levels including direct air capture, chemical synthesis, algae products, carbonated concrete, and carbonated aggregates. The templates attempt to capture the most important elements of early-stage LCA and TEA in an easily understandable and usable manner that still allows for reliable, order-of-magnitude estimations and hotspot analysis. Opportunities for other practitioners to use and build upon the templates are also discussed.

Comparisons of emerging carbon capture and utilization (CCU) technologies with equivalent incumbent technologies are necessary to support technology developers and to help policy-makers design appropriate long-term incentives to mitigate climate change through the deployment of CCU. In particular, early-stage CCU technologies must prove their economic viability and environmental reduction potential compared to already-deployed technologies. These comparisons can be misleading, as emerging technologies typically experience a drastic increase in performance and decrease in cost and greenhouse gas emissions as they develop from research to mass-market deployment due to various forms of learning. These changes complicate the interpretation of early techno-economic assessments (TEAs) and life cycle assessments (LCAs) of emerging CCU technologies. The effects of learning over time or cumulative production themselves can be quantitatively described using technology learning curves (TLCs). While learning curve approaches have been developed for various technologies, a harmonized methodology for using TLCs in TEA and LCA for CCU in particular is required. To address this, we describe a methodology that incorporates TLCs into TEA and LCA to forecast the environmental and economic performance of emerging CCU technologies. This methodology is based on both an evaluation of the state of the art of learning curve assessment and a literature review of TLC approaches developed in various manufacturing and energy generation sectors. Additionally, we demonstrate how to implement this methodology using a case study on a CO2 mineralization pathway. Finally, commentary is provided on how researchers, technology developers, and LCA and TEA practitioners can advance the use of TLCs to allow for consistent, high-resolution modeling of technological learning for CCU going forward and enable holistic assessments and fairer comparisons with other climate technologies.