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https://doi.org/10.5194/egusphere-2024-1937
https://doi.org/10.5194/egusphere-2024-1937
08 Jul 2024
 | 08 Jul 2024

The 2023 global warming spike was driven by El Niño/Southern Oscillation

Shiv Priyam Raghuraman, Brian Soden, Amy Clement, Gabriel Vecchi, Sofia Menemenlis, and Wenchang Yang

Abstract. Global-mean surface temperature rapidly increased 0.27 ± 0.05 K from 2022 to 2023. Such an interannual global warming spike is not unprecedented in the observational record with previous instances occurring in 1956–57 and 1976–77. However, why global warming spikes occur is unknown and the rapid global warming of 2023 has led to concerns that it could have been externally driven. Here we show that climate models that are subject only to internal variability can generate such spikes, but they are an uncommon occurrence (𝑝 = 2.6 ± 0.1 %). However, when a prolonged La Niña immediately precedes an El Niño in the simulations, as occurred in nature in 1956–57, 1976–77, 2022–23, such spikes become much more common (𝑝 = 16.5 ± 0.6 %). Furthermore, we find that nearly all simulated spikes (94 %) are associated with El Niño occurring that year. Thus, our results underscore the importance of El Niño/Southern Oscillation in driving the occurrence of global warming spikes such as the one in 2023, without needing to invoke anthropogenic forcing, such as changes in atmospheric concentrations of greenhouse gases or aerosols, as an explanation.

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Journal article(s) based on this preprint

10 Oct 2024
| ACP Letters
| Highlight paper
The 2023 global warming spike was driven by the El Niño–Southern Oscillation
Shiv Priyam Raghuraman, Brian Soden, Amy Clement, Gabriel Vecchi, Sofia Menemenlis, and Wenchang Yang
Atmos. Chem. Phys., 24, 11275–11283, https://doi.org/10.5194/acp-24-11275-2024,https://doi.org/10.5194/acp-24-11275-2024, 2024
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The rapid increase in global warming in 2023 has sparked fears that Earth has entered a new warm...
Short summary
The rapid global warming of 2023 has led to concerns that it could be externally driven. Models...
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