PCLM-D-25-00103

Shifting horizons: Significant life events and pro-environmental behaviour change in early adulthood

PLOS Climate

Dear Dr. Mitev,

Thank you for submitting your manuscript to PLOS Climate. After careful consideration, we feel that it has merit but does not fully meet PLOS Climate’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by 14 August 2025. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at climate@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pclm/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

We look forward to receiving your revised manuscript.

Kind regards,

Wahid Murad, Ph.D.

Academic Editor

PLOS Climate

Journal Requirements:

1. Please provide additional details regarding participant consent. In the ethics statement in the Methods and online submission information, please ensure that you have specified (1) whether consent was informed and (2) what type you obtained (for instance, written or verbal, and if verbal, how it was documented and witnessed). If your study included minors, state whether you obtained consent from parents or guardians. If the need for consent was waived by the ethics committee, please include this information.

If you are reporting a retrospective study of medical records or archived samples, please ensure that you have discussed whether all data were fully anonymized before you accessed them and/or whether the IRB or ethics committee waived the requirement for informed consent. If patients provided informed written consent to have data from their medical records used in research, please include this information.

2. We notice that your supplementary figures are uploaded with the file type 'Figure'. Please amend the file type to 'Supporting Information'. Please ensure that each Supporting Information file has a legend listed in the manuscript after the references list.

Editor Comments:

First of all, I agree with the comments provided by the other reviewer and recommend that the authors address all of those comments in their revision and resubmit the manuscript for further consideration.

Due to the lack of available and appropriate reviewers, I have taken the role of a second reviewer myself. This decision was made after several unsuccessful attempts to secure a sufficient number of external reviewers.

Overall, the manuscript presents an interesting and timely investigation into the role of pro-environmental behaviours (PEBs) and lifestyle changes in addressing climate change. The authors have conducted two studies to examine how PEBs change following moments of change (MoCs), and whether these changes are mediated by values and attitudes (i.e., ‘self-activation’). I find the manuscript promising and recommend the authors address the following comments to strengthen its quality and clarity:

1. Abstract: The abstract should be restructured to clearly and concisely state:

a) What motivated the research,

b) The tools and analytical methods used,

c) Key findings,

d) Specific implications of the results,

e) The unique contribution to the literature, and

f) Any noteworthy limitations.

2. Rationale and Context: While the manuscript states that the research investigates the effects of two MoCs—COVID-19 and starting university—on young people’s PEBs, values, and attitudes, the rationale for selecting these events and their anticipated implications should be made more explicit. While the final paragraph of the section “Habits and Moments of Change” touches on this, further clarity and justification are needed.

3. Discussion of Results (Tables 4–6): The demographic data (Table 4), paired-sample t-tests (Table 5), and linear regression results (Table 6) are clearly presented. However, the discussion of these results is relatively weak. The authors should interpret the findings in the context of existing literature, highlighting similarities, differences, and the unique contribution of the present study.

4. Structural Equation Modelling (SEM): I had difficulty understanding the SEM analyses in both studies. The nine figures provided in the appendix resemble simple cause-and-effect diagrams and do not include parameter estimates (e.g., regression coefficients), standard errors, or p-values. Standard SEM diagrams are more comprehensive and typically depict multidirectional paths and latent constructs. The figures provided seem more akin to regression outputs with limited explanatory power. It is unclear whether these diagrams are based on linear regression models or SEM. The authors are strongly encouraged to consult existing publications that use SEM and present their findings in accordance with established reporting standards.

5. Appendix SEM Files: The two Word files in the appendix contain statistical outputs, but they do not clearly present full SEM results. The manuscript would benefit greatly from clearer and more complete SEM reporting, including model fit indices, factor loadings, and path coefficients in the main texts.

6. References: Many of the references are outdated, with only a few recent citations (e.g., from 2021). The reference list should be updated to include more current literature, ideally from the past 3–5 years.

Aside from the issues listed above, the other sections of the manuscript appear to be in good shape. I therefore strongly recommend that the authors address all the comments raised—both by the other reviewer and myself—and resubmit the revised manuscript for further consideration.

[Note: HTML markup is below. Please do not edit.]

=================================================================

First reviewer's comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does this manuscript meet PLOS Climate’s publication criteria ? Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe methodologically and ethically rigorous research with conclusions that are appropriately drawn based on the data presented.

Reviewer #1: Partly

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

**********

3. Have the authors made all data underlying the findings in their manuscript fully available (please refer to the Data Availability Statement at the start of the manuscript PDF file)?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception. The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS Climate does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: General Evaluation

This manuscript reports on two longitudinal studies examining whether “Moments of Change” (MoCs) affect pro-environmental behaviours (PEBs) among youth in the United Kingdom. Study 1 investigates COVID-19 as a singular MoC, and Study 2 explores composite MoCs (starting university and experiencing COVID-19 simultaneously). The manuscript also tests whether self-transcendence values and environmental attitudes mediate these effects. The manuscript is generally well-written, with clear and fluent academic English that effectively communicates the research aims, methods, and findings.

While the topic is of importance in informing intervention design for encouraging PEBs, and the statistical analysis itself appears appropriate and competently carried out, several core aspects of the study design and interpretation require more careful treatment. In particular, the central claim that Study 2 captures a “composite MoC” is difficult to support based on the timeline and participant experience. Furthermore, the theoretical justification for the mediation analyses is currently underdeveloped. I outline these and related concerns below.

Interpretation of Study 2 and the Composite MoC Framework (Publication Criteria)

The authors describe Study 2 as capturing a “composite MoC,” under the assumption that participants’ pre-university responses represent a baseline prior to both university transition and COVID-19 disruptions:

“[Line 510]...before starting to university, i.e., September 2020 when there were no COVID-19 restrictions in the UK...”

Students who entered university in September 2020 had already undergone substantial COVID-related disruptions beginning in March 2020, including the first national lockdown, which interrupted their final semester of secondary school. Although many restrictions were relaxed during July and August, this period largely coincided with the summer break and does not appear to have marked a meaningful return to pre-pandemic routines from their perspectives. It is therefore highly unlikely that their retrospective accounts of the “pre-university” period reflect a context uninfluenced by the pandemic.

As a result, Study 2 may not capture a genuinely composite MoC, but rather reflect a single biographical MoC (entering university) occurring within the broader context of another MoC (COVID-19). This distinction significantly weakens the manuscript’s central theoretical contribution concerning the distinctiveness and potential amplifying effects of composite MoCs. I strongly encourage the authors to revise their interpretation of Study 2 accordingly and temper their conclusions to reflect this limitation.

Mediation Analyses: Theoretical Justification and Measurement Reliability (Methodology)

The manuscript includes several structural equation models testing whether environmental attitudes mediate the relationship between self-transcendence values and PEBs. However, the motivation for examining mediation in this context remains unclear. Given the stated goal of identifying windows for behavioural intervention, a moderation analysis (i.e., identifying for whom MoCs predict behaviour change) might have been more directly informative.

Furthermore, the reliability of the environmental attitude scale is notably low in Study 1 (Cronbach’s α = .44), which calls into question the robustness of the SEM results. While the use of well-established scales is acknowledged, the authors should consider and discuss the impact of measurement error on their mediation findings.

Taken together, these issues suggest the need for further justification as to why it was important to conduct mediation analysis using SEM in this context, particularly given the measurement limitations. Clarifying the motivation for the mediation analysis would strengthen the manuscript considerably.

Attrition and Sample Bias in Study 1 (Methodology)

The final analytical sample in Study 1 (N = 146) represents a small subset of the original 829 participants. Although such attrition is not unusual in longitudinal designs, the extent here is considerable. In fact, the study experienced an attrition rate of approximately 82%, which warrants more serious attention. Moreover, the retained sample is highly unbalanced in gender (85.6% female), suggesting the possibility of systematic self-selection bias.

It is plausible that those who completed both surveys are more conscientious, engaged, or pro-environmentally inclined than average. These characteristics could systematically bias the observed behavioural trends and limit the generalizability of the findings. Given the high attrition rate in Study 1, it is important to explicitly consider how non-random dropout may have introduced sampling bias and affected the interpretation of behavioural change over time. I recommend the authors more explicitly acknowledge this limitation and discuss its potential impact on interpretation.

Data Availability

The authors state that their dataset is publicly available via the DOI [https://doi.org/10.15125/BATH-01379]. However, this link does not currently resolve to an accessible repository. Please verify and correct the link to ensure compliance with PLOS Climate’s data sharing policy.

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean? ). If published, this will include your full peer review and any attached files.

Do you want your identity to be public for this peer review? If you choose “no”, your identity will remain anonymous but your review may still be made public.

For information about this choice, including consent withdrawal, please see our Privacy Policy .

Reviewer #1: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Shifting horizons: Significant life events and pro-environmental behaviour change in early adulthood

PCLM-D-25-00103R1

Dear Dr. Mitev,

We're pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you'll receive an e-mail detailing the required amendments. When these have been addressed, you'll receive a formal acceptance letter, and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at https://www.editorialmanager.com/pclm/ click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. For billing related questions, please contact billing support at https://plos.my.site.com/s/.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they'll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact climate@plos.org.

Kind regards,

Wahid Murad, Ph.D.

Academic Editor

PLOS Climate