It is unclear if any of the authors listed are Indigenous. In the Introduction, the authors include statistics about "lack of minority groups" in the STEM field. They do address the gender imbalance. There is a saying among Indigenous scholars, "Nothing about us, without us." In their Ethical Statement, there are a number of ethical guidelines even for privately owned non-profit organisations (see https://www.arcus.org/resources/northern-communities). 

Scientific significance: The four key projects sponsored by Arctic Frontiers include audiences as outlined in the authors introductions (gender and minorities): Science for Kids, Science for Schools, Student Forum, and Emerging Leaders (please note the serial comma as adopted by many writing style guides);

Scientific quality: the authors provide quantitative data and translated qualitative data to support their article; 

Presentation quality: the article is clearly written without jargon and reads well for its intended audience.

Minor corrections:

"Sámi" should include the accent throughout the paper (see https://samas.no/) and Line 268 should be "...Sámi University of Applied Sciences."

While this is an important societal topic (STEM, technical labour challenges of Arctic regions, education), and the Arctic Frontiers approach is worthwhile evaluating in this regard, in its current form the academic rigour is not up to standards to be accepted for publication. The paper generally is well written and structured. The paper contains interesting insights with regards to the various educational programmes that Arctic Frontiers has been running over the last 10 years. 

The key weakness of the current version of the manuscript is its lack of methodological explanation. Half-way the paper in the results section it is mentioned suddenly that the programmes are evaluated based on different types of performance criteria. What these criteria are, and how they have been determined, remains largely hidden. To be acceptable for publication the paper would require a solid methodological section in which the various steps of the evaluation methodology, the choice for particular criteria, should be clearly presented

In its current form the discussion section of the paper fails to link the results of the paper to the existing literature on the topic, to conceptual choices made in the study, or to the methodology chosen for evaluation. To be acceptable for publication a more serious attempt should be made to discus the research results to clarify what is common or distinctive about these results. 

Page 3, like 69-71: explains the main objective of the paper ("highlight the importance of E&O projects"), which sounds more like an advocacy objective than an academic research paper objective (i.e. understand, assess, evaluate, etc). It could be that the analysis could lead to a greater appreciation of such E&O projects, but it sounds too preconceived to assume that they are before evaluation. Since the authors of the paper seem to be strongly affiliated with Arctic Frontiers and their programmes, they would have to be very careful with mixing academic independence/neutrality and rigour with their interests in the success of their programmes. In the acknowledgement of the paper it is stated that the authors or Arctic Frontiers as a private company have no interests in the outcomes of the research. I find this not convincing at all. The authors are advised to not shy away from their interests in this issue, and to be more clear on how the methodology has enabled them to produce reliable, valid outcomes on this issue regardless. 

Page 3, line 76: It is mentioned that Arctic Frontiers is a private company. Please make this more clear in the introduction of the paper, what Arctic Frontiers is, what its mission is, and why as a private entity it engages with public educational institutions.  

This paper outlines a very large outreach program run through the Arctic Frontiers organization out of Tromsø, Norway. The authors have investigated who the program reaches, and assessed whether the program is meeting its objectives. The paper reads rather like a prospectus for the outreach program and the impressive number of persons and educational institutions involved, as well as some next steps the organization is taking. There are some missed opportunities to discuss key issues in reaching local Arctic residents in these kinds of programs, in recruiting local and Indigenous researchers more generally, and what the stakes are for Arctic representation in research and policy. As the authors mention, it is a challenge securing local and Indigenous participants in the lower levels, as well as participants from Norway in the higher levels of the Arctic Frontiers program. What is the significance of this on the impacts of the Arctic Frontiers program? What is the significance of this for Arctic research more generally? The program has expanded over recent years, reaching even more participants, showing an impressive effort at outreach, but the paper could show more clearly whether this has helped the program reach their objectives.  Overall, more critical reflection on the program and study could help contextualize the efforts better. A suggestion might be structuring the paper more around the objectives of the program, spending less time describing the program, detailing the methods used and their limitations, and to return to the references outlined in the introduction in the discussion of the results. The conclusion would be improved by referring back to the objectives.

The manuscript 'From Five to Thirty-Five: Fostering the Next Generation of Arctic Scientists’ aims to address the challenge of out-of-classroom education and outreach (E&O) initiatives in Arctic science by analyzing Arctic Frontiers’ framework and programs since 2012. The project include four projects, targeting a wide range of audiences from children to early-career professionals. The paper is well-presented, aligned with the scope of the GC journal, and will be of benefit to readers interested in conducting similar activities in and beyond the Arctic. The paper also emphasizes the importance of raising public awareness of scientific outreach activities within Arctic and beyond, which is a valuable contribution. However, I concur with other reviewers that the manuscript currently reads like a project report rather than a research paper, and requires improvement in several areas. Below, I provide detailed feedback.

Major Comments:

1. There needs to be a clear separation between methods, results and discussions. There is no clear method section, and some discussion content is in the results section. For example, I suggest moving some of the content from Part 3: Impact and Evaluation (e.g., lines 244, 260, and 276) into Part 4: Discussion. This includes explaining why data availability is poor, why participant numbers have decreased, and addressing the need for continued funding and marketing efforts. These points could lead to interesting discussions and provide deeper insights into the program’s successes and challenges.

2. The data and analysis supporting the results should be strengthened, especially to bolster claims of program success. For example, the quotes from attendees used in Table 2 are minimal, which may raise concerns about the credibility and robustness of the conclusions. I recommend that the authors classify the quotes and consider applying some form of text-analysis, such as keyword frequency, to lend more rigor to the findings. Including both positive and negative feedback could make the analysis more balanced and informative.

3. Some of the more descriptive sections can be shortened to make them easier to read. This includes, for example, the introduction of the company. Some content, such as the detailed feedback in tables, could be moved to supplementary materials and only referred to in the manuscript text. Additionally, it would be helpful to readers to see what a typical schedule or activity arrangement (as templates perhaps) looks like. Adding sub-sections to Part 3: Impact and Evaluation would enhance understanding. Sub-sections could include topics like “Factors for Success of E&O Activities” or “Gender-related Issues,” allowing the reader to navigate the manuscript more easily.

Minor Comments:

1. Line 69: The manuscript highlights the importance of E&O initiatives to inspire Arctic scientists. However, it may serve a broader purpose by offering insights into conducting E&O activities in non-Arctic regions. This could be further emphasized.

2. Line 200: The manuscript mentions that participants from over 15 countries joined in 2023. Can the authors give a specific number? Providing precise figures would increase accuracy and clarity.

3. Line 234: The number “550 children” is questionable, as summing the values from Figure 4 results in a higher total. Please verify this figure.

4. Line 299: The reference to “Figures 4b and 5” may be incorrect. Is this intended to be “Figure 7b and 8” instead? Please check the numbering.

5. Part 3 (Impact and Evaluation): While the paper assesses the programs’ success through participant growth and feedback, the figures show a decline in participation. I recommend explaining this discrepancy in the discussion and enriching the overall analysis.

6. Line 316: The average satisfaction score dropped from 86/100 in 2023 to 71/100 in 2024. As a reader, I would like to know the reasons behind this decline. A deeper analysis of the factors influencing participant satisfaction is warranted.

7. Line 329: The manuscript claims to assess the impact on participants’ study and career choices, but this is difficult to discern from the data in Table 2. Clarifying how this table supports aims 1 and 3 would strengthen the argument.

8. Line 331: The activity of following participants on social media is mentioned in the discussion without prior reference in the results section. Social media data should be introduced in Part 3 and elaborated upon in Part 4 to maintain consistency.

Technical Comments:

1. Line 229: The section number should be 3.1, not 3.3.

2. Line 271 : “Note held in 2022 due to…” should read “Not held in 2022…”.