Rising atmospheric CO<sub>2</sub> concentrations: the overlooked factor promoting SW Iberian Forest development across the LGM and the last deglaciation?

Gomes, Sandra Domingues; Fletcher, William; Stone, Abi; Rodrigues, Teresa; Rebotim, Andreia; Oliveira, Dulce; Sánchez Goñi, Maria; Abrantes, Fátima; Naughton, Filipa

doi:10.5194/bg-22-6631-2025

Articles | Volume 22, issue 21

https://doi.org/10.5194/bg-22-6631-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/bg-22-6631-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 22, issue 21

Research article

|

07 Nov 2025

Research article |

| 07 Nov 2025

Rising atmospheric CO₂ concentrations: the overlooked factor promoting SW Iberian Forest development across the LGM and the last deglaciation?

Sandra Domingues Gomes, William Fletcher, Abi Stone, Teresa Rodrigues, Andreia Rebotim, Dulce Oliveira, Maria Sánchez Goñi, Fátima Abrantes, and Filipa Naughton

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Final revised paper (published on 07 Nov 2025)
Supplement to the final revised paper
Preprint (discussion started on 06 Nov 2024)
Supplement to the preprint

Interactive discussion

Status: closed

RC1:
'Comment on egusphere-2024-3334', Anonymous Referee #1, 08 Jan 2025

Please find my review in the attached pdf.

Citation: https://doi.org/10.5194/egusphere-2024-3334-RC1
- CC1: 'Reply on RC1', Sandra Gomes, 27 Feb 2025
  
  Publisher’s note: the content of this comment was removed on 20 March 2025 since the comment was posted by mistake.
  
  Citation: https://doi.org/10.5194/egusphere-2024-3334-CC1
- CC2: 'Reply on RC1', Sandra Gomes, 27 Feb 2025
  
  Publisher’s note: the content of this comment was removed on 20 March 2025 since the comment was posted by mistake.
  
  Citation: https://doi.org/10.5194/egusphere-2024-3334-CC2
- AC1: 'Reply on RC1', Sandra Gomes, 20 Mar 2025
  
  To the Reviewer1,
  Thank you for taking the time to review the submitted manuscript.
  Please find our responses to your questions and suggestions in the attached PDF file.
  Kind regards,
  
  Sandra Gomes
  
  Citation: https://doi.org/10.5194/egusphere-2024-3334-AC1
RC2:
'Comment on egusphere-2024-3334', Anonymous Referee #2, 19 Feb 2025

My comments are attached as a PDF.

Citation: https://doi.org/10.5194/egusphere-2024-3334-RC2
- CC3: 'Reply on RC2', Sandra Gomes, 27 Feb 2025
  
  Publisher’s note: the content of this comment was removed on 20 March 2025 since the comment was posted by mistake.
  
  Citation: https://doi.org/10.5194/egusphere-2024-3334-CC3
- AC2: 'Reply on RC2', Sandra Gomes, 20 Mar 2025
  
  To the Reviewer2,
  Thank you for taking the time to review the submitted manuscript.
  Please find our responses to your questions and suggestions in the attached PDF file.
  Kind regards,
  
  Sandra Gomes
  
  Citation: https://doi.org/10.5194/egusphere-2024-3334-AC2

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload

ED: Reconsider after major revisions (02 Apr 2025) by Petr Kuneš

AR by Sandra Gomes on behalf of the Authors (30 Jun 2025) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (01 Jul 2025) by Petr Kuneš

RR by Anonymous Referee #1 (16 Jul 2025)

Suggestions for revision or reasons for rejection

The authors did a solid job revising the manuscript according to the reviewer comments and I only have a few remaining minor comments:
- The revised manuscript distinguishes more clearly between climatological moisture availability and perceived dryness by plants (due to either changes in climatological moisture availability or changes in water use efficiency in response to different atmospheric CO2 concentrations). However, in my opinion, the term moisture availability should refer only to a climate variable (a function of precipitation, soil moisture, evapotranspiration and/or potential evapotranspiration) and not the perceived dryness by plants. Therefore, I would recommend to not use ”moisture availability” when referring to the perceived moisture availability by plants (e.g., in Fig. 4), but either ”perceived dryness” or ”perceived moisture availability”.
- l. 62-66: The last two sentences of the abstract are rather difficult to understand. Maybe you can reformulate them to convey a clearer message.
- l. 75-76: A ”global mean temperature increase of 5-10°C” is not in line with recent studies by Annan et al. (2022), Osman et al. (2021), and Tierney et al. (2020). Please update the provided range accordingly.
- l. 77-79: It should be noted that the warming/cooling during HS1/BA/YD refers mainly to the North Atlantic region (or the Northern Hemisphere). In the Southern Hemisphere, the changes during these periods are (partly) different.
- l. 294: ”basis” instead of ”basin”.
- l. 363: Consider using ”the modern environmental space” instead of ”the environmental space”
- l. 473: I suggest to use ”reconstructed” instead of ”modelled”.
- l. 1229: In the brackets, it should be ”perceived moisture availability” or ”perceived dryness” instead of ”precipitation”

References:
- Annan, J. D., Hargreaves, J. C., and Mauritsen, T.: A new global surface temperature reconstruction for the Last Glacial Maximum, Climate of the Past, 18, 1883–1896, https://doi.org/10.5194/cp-18-1883-2022, 2022.
- Osman, M. B., Tierney, J. E., Zhu, J., Tardif, R., Hakim, G. J., King, J., and Poulsen, C. J.: Globally resolved surface temperatures since the Last Glacial Maximum, Nature, 599, 239–244, https://doi.org/10.1038/s41586-021-03984-4, 2021.
- Tierney, J. E., Zhu, J., King, J., Malevich, S. B., Hakim, G. J., and Poulsen, C. J.: Glacial cooling and climate sensitivity revisited, Nature, 584, 569–573, https://doi.org/10.1038/s41586-020-2617-x, 2020.

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RR by Anonymous Referee #2 (18 Jul 2025)

ED: Reconsider after major revisions (29 Jul 2025) by Petr Kuneš

AR by Sandra Gomes on behalf of the Authors (02 Sep 2025) Author's response Author's tracked changes Manuscript

ED: Publish as is (11 Sep 2025) by Petr Kuneš

AR by Sandra Gomes on behalf of the Authors (24 Sep 2025)

Post-review adjustments

AA: Author's adjustment | EA: Editor approval

AA by Sandra Gomes on behalf of the Authors (30 Oct 2025) Author's adjustment Manuscript

EA: Adjustments approved (31 Oct 2025) by Petr Kuneš

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Short summary

Our study explores how rising CO₂ at the end of the last ice age impacted vegetation in the Iberian Peninsula. By analyzing pollen and ocean temperatures in marine sediments, we found that higher CO₂ helped forests expand, even in cool or dry conditions. This shows that CO₂ played a key role in shaping ecosystems during climate shifts. Understanding this past response helps us see how different factors interact and provides insights into how today’s ecosystems might adapt to rapidly rising CO₂.

Rising atmospheric CO2 concentrations: the overlooked factor promoting SW Iberian Forest development across the LGM and the last deglaciation?

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Interactive discussion

Peer review completion

Suggestions for revision or reasons for rejection

Suggestions for revision or reasons for rejection

Post-review adjustments

Rising atmospheric CO₂ concentrations: the overlooked factor promoting SW Iberian Forest development across the LGM and the last deglaciation?