Review of 'A virtual global carbon price enabling engineers to drive essential and rapid decarbonization'

Global carbon pricing has been recognized as a cost-effective way to reduce carbon emissions and support the achievement of the Net Zero goal. The proposed method of assigning a price based on carbon intensity weighting from an LCA perspective is attractive and could be useful in accelerating the technology transition. Therefore, the article could contribute to the scientific debate by providing a method for evaluating technologies and driving decarbonization based on differentiated carbon pricing.  However, in its current form, it has many shortcomings that limit its usefulness and clarity as explained in the following.

The abstract should better focus on the objective of the study and briefly explain the application and main conclusions, so as to provide the reader with the essential context, highlight the objectives and key findings.

The introduction is vague and does not focus the topic of the paper. Carbon pricing/carbon tax is a widely discussed topic and a thorough evaluation of the existing literature is necessary to frame the study and improve its innovative contribution to the scientific debate. Some opinions not substantiated by recent studies and legislative measures are also reported.  For example, the authors report that "Energy efficiency, resource utilization, local pollution abatement, and cost reduction have enabled mass access to affordable transportation, technology, and food. But this has come at the expense of the global environment."  Related to this statement, it should be noted that according to the "energy efficiency first" principle, energy efficiency is considered by the EU to be the "first fuel" to achieve climate mitigation (e.g. European Green Deal Package, Commission Recommendation (EU) 2021/1749, Energy Efficiency Directive 2018/2002), and as outlined by the recent IEA Energy Efficiency 2022 report. This concept should be appropriately emphasized in the context of the document, taking into account the significant contribution to the reduction of CO2 and other emissions from anthropogenic activities.

In addition, as underlined by the authors, a holistic approach is certainly useful in addressing complex issues such as climate change mitigation and "planetary health". This is what energy modelers have been doing by for many decades, developing complex models based on optimizing resource use and performing in-depth scenario analyses widely used for policy assessment at different spatial scales (e.g., the E3M Lab http://www.e3mlab.eu/e3mlab/; IEA-ETSAP https://iea-etsap.org/index.php). Therefore, in light of these studies, the authors should review the possible implications of their analysis, which can certainly support technology assessment in a complex modeling environment.

The section on Data should be moved after Methods and more extensive comments are needed to better understand how these data were processed and further used in the application of the method proposed by the authors.  In fact, the presentation of the application of the method is unclear and should be reworded to highlight its usefulness and the main results obtained in terms of promoting clean technologies and fuels that can accelerate the energy transition as well as policy indications.

The conclusions are also vague, non-explanatory and not supported by the results and/or scientific evidence.

Taking into account the above comments, the authors should improve the manuscript accordingly, including a thorough analysis of the state of the art, highlighting the scientific content and the importance of the study in the context of climate change mitigation and energy system transformation.