The authors wish to make two small amendments to the published text.

On page 6, the following sentence includes an inaccuracy: “The probability of the observed exceptional global exceedance assuming a steady linear warming trend has been shown to be low (about 1 in 500 years (Terhaar et al. 2025)).”

It should read instead: “The probability of the observed exceptional global exceedance has been shown to be low (about 1 in 500 years (Terhaar et al. 2025)).

On page 22, the wording of the following paragraph could be interpreted in a way that is not directly supported by the cited references:

“The sustained inadequacy of global mitigation efforts is now reflected in what appears to be an acceleration of global warming, which implies that even larger efforts will be required to minimise the magnitude and duration of overshoot of the + 1.5°C limit goal (Bustamante et al. 2023). Climate models face significant challenges in reconciling the 2023-2024 warming surge, reflecting both well-documented limitations in representing aerosol-cloud interactions and the extreme statistical rarity of the observed temperature anomalies (Terhaar et al. 2025; Rantanen and Laaksonen 2024). While updated model experiments incorporating recent forcings are still emerging, the magnitude of the warming suggests that either known feedback processes are stronger than currently modeled, or additional mechanisms may be contributing to accelerated warming.”

It should read instead:

“The sustained inadequacy of global mitigation efforts is now reflected in what appears to be an acceleration of global warming, which implies that even larger efforts will be required to minimise the magnitude and duration of overshoot of the + 1.5°C limit goal (Bustamante et al. 2023). The extreme statistical rarity of the 2023-2024 warming surge is consistent between observation-based temperature anomalies and model-based estimates (Terhaar et al. 2025; Rantanen and Laaksonen 2024). This agreement, however, neither indicates that current models adequately capture the relevant physical mechanisms nor that the simulated forcings are broadly accurate. While updated model experiments incorporating recent forcings are still emerging, the magnitude of the warming suggests that either known feedback processes may be stronger than currently modeled, or additional mechanisms may be contributing to accelerated warming.”

References

Bustamante, M., Roy, J., Ospina, D., Achakulwisut, P., Aggarwal, A., Bastos, A., Broadgate, W., Canadell, J. G., Carr, E. R., Chen, D., Cleugh, H. A., Ebi, K. L., Edwards, C., Farbotko, C., Fernández-Martínez, M., Frölicher, T. L., Fuss, S., Geden, O., Gruber, N., … Zscheischler, J. (2023). Ten new insights in climate science 2023. Global Sustainability, 7(e19), e19. https://doi.org/10.1017/sus.2023.25

Ospina, D., Mirazo, P., Allan, R. P., Basnett, S., Bastos, A., Bhattarai, N., Broadgate, W., Broekhoff, D. J., Bustamante, M., Chen, D., Choi, Y., Cox, P., Domeignoz-Horta, L. A., Ebi, K., Friedlingstein, P., Frölicher, T. L., Fuss, S., Goessling, H. F., Gruber, N., … Zhu, S. (2026). Ten new insights in climate science 2025. Global Sustainability, 9(e6), 1–73. https://doi.org/10.1017/sus.2025.10043

Rantanen, M., & Laaksonen, A. (2024). The jump in global temperatures in September 2023 is extremely unlikely due to internal climate variability alone. Npj Climate and Atmospheric Science, 7(1), 1–4. https://doi.org/10.1038/s41612-024-00582-9

Terhaar, J., Burger, F. A., Vogt, L., Frölicher, T. L., & Stocker, T. F. (2025). Record sea surface temperature jump in 2023-2024 unlikely but not unexpected. Nature, 639(8056), 942–946. https://doi.org/10.1038/s41586-025-08674-z