Articles | Volume 17, issue 3
https://doi.org/10.5194/esd-17-451-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/esd-17-451-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
06 May 2026
Research article | Highlight paper |
| 06 May 2026
| 06 May 2026
Quantification of the influence of anthropogenic and natural factors on the record-high temperatures in 2023 and 2024
Endre Z. Farago
CORRESPONDING AUTHOR
Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, 14850, USA
Department of Chemistry and Biochemistry, University of Maryland at College Park, College Park, MD, 20740, USA
Laura A. McBride
Science and Technology Corporation, Columbia, MD, 21046, USA
Brian F. Bennett
Department of Atmospheric and Oceanic Science, University of Maryland at College Park, College Park, MD, 20740, USA
Austin P. Hope
Science and Technology Corporation, Columbia, MD, 21046, USA
Timothy P. Canty
Department of Atmospheric and Oceanic Science, University of Maryland at College Park, College Park, MD, 20740, USA
Ross J. Salawitch
CORRESPONDING AUTHOR
Department of Chemistry and Biochemistry, University of Maryland at College Park, College Park, MD, 20740, USA
Department of Atmospheric and Oceanic Science, University of Maryland at College Park, College Park, MD, 20740, USA
Earth System Science Interdisciplinary Center, University of Maryland at College Park, College Park, MD, 20740, USA
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EGUsphere, https://doi.org/10.5194/egusphere-2025-5261, https://doi.org/10.5194/egusphere-2025-5261, 2025
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Ground-based spectrometers measuring HCHO and NO2 were compared to airborne in situ observations in the Summer 2023. Total column HCHO is within uncertainty, but with high biases near the surface. NO2 results are highly sensitive to the viewing angle of the ground monitor which must be considered during validation studies. Spectrometers in NYC show good agreement with a geostationary satellite on clear-sky days. Further quantified uncertainty for the monitors is necessary.
Endre Z. Farago, Laura A. McBride, Austin P. Hope, Timothy P. Canty, Brian F. Bennett, and Ross J. Salawitch
Earth Syst. Dynam., 16, 1739–1758, https://doi.org/10.5194/esd-16-1739-2025, https://doi.org/10.5194/esd-16-1739-2025, 2025
Short summary
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We show that recent assessed updates to the future abundance and radiative forcing (RF) of greenhouse gases (GHGs) and tropospheric aerosols result in a 0.2 to 0.4 ⁰C rise in global mean surface temperature by the end of the century, relative to prior projections. For society to have confidence in achieving the 2 ⁰C warming limit of the Paris Agreement, the RF due to GHGs and aerosols must be placed close to the primary 2.6 W m−2 Shared Socioeconomic Pathway scenario (SSP1−2.6) over the coming decades.
Megan J. Lickley, John S. Daniel, Laura A. McBride, Ross J. Salawitch, and Guus J. M. Velders
Atmos. Chem. Phys., 24, 13081–13099, https://doi.org/10.5194/acp-24-13081-2024, https://doi.org/10.5194/acp-24-13081-2024, 2024
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The expected ozone recovery date was delayed by 17 years between the 2006 and 2022 international scientific assessments of ozone depletion. We quantify the primary drivers of this delay. Changes in the metric used to estimate ozone recovery explain ca. 5 years of this delay. Of the remaining 12 years, changes in estimated banks, atmospheric lifetimes, and emission projections explain 4, 3.5, and 3 years of this delay, respectively.
Laura A. McBride, Austin P. Hope, Timothy P. Canty, Brian F. Bennett, Walter R. Tribett, and Ross J. Salawitch
Earth Syst. Dynam., 12, 545–579, https://doi.org/10.5194/esd-12-545-2021, https://doi.org/10.5194/esd-12-545-2021, 2021
Short summary
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We use a reduced-complexity climate model trained by observations to show that at the current rate of human release of CO2, total cumulative emissions will pass the 66 % likelihood of limiting warming to 1.5° or 2°C in about 10 and 35 years, respectively. We also show that complex climate models often used to guide policy tend to warm faster than observed over the past few decades. To achieve the Paris Climate Agreement, CO2 and CH4 emissions must be severely curtailed in the next decade.
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Editorial statement
This is a topic of strong interest to the general public, with several explanations for the warm conditions having been suggested. The paper makes a very useful and novel contribution through its attribution of much of the warm anomaly to a combination of individual anthropogenic and natural factors and the suggestion of a significant contribution from the Indian Ocean Dipole.
This is a topic of strong interest to the general public, with several explanations for the warm...
Short summary
Global mean surface temperature anomalies in 2023 and 2024 were the highest on the modern record. We quantify contributions to these anomalies from human activity, including the steep reduction in sulfur emissions from ships that began in 2020, and numerous natural factors. We attribute about 92% of the observed anomalies to a combination of various human-induced and natural factors, including important contributions from the reduction in marine sulfur emissions and the Indian Ocean Dipole.
Global mean surface temperature anomalies in 2023 and 2024 were the highest on the modern...
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