{"id":348355,"date":"2024-10-22T11:40:24","date_gmt":"2024-10-22T09:40:24","guid":{"rendered":"https:\/\/climatescience.press\/?p=348355"},"modified":"2024-10-22T11:40:27","modified_gmt":"2024-10-22T09:40:27","slug":"naturally-hot-exaggeration-not","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=348355","title":{"rendered":"Naturally Hot, Exaggeration Not"},"content":{"rendered":"\n
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From Master Resource<\/a><\/p>\n\n\n\n

By Kennedy Maize<\/em><\/p>\n\n\n\n

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\u201cWhat has come to be known as \u2018weather attribution,\u2019 research assigning causation to observed weather events, is fraught with methodological problems. Veteran climate scientist Roger A. Pielke Jr. in his Substack publication The Honest Broker<\/a> calls it \u2018weather attribution alchemy\u2019.\u201d<\/p>\n<\/blockquote>\n\n\n\n

Last year was hot, unusually so. The global temperature was almost 0.3\u00b0C above 2022 levels, so much higher that even conventional analyses of global warming didn\u2019t appear to explain it. As a recent article in Science<\/a> magazine notes, iconic climate scientist James Hansen was suggesting that a new, air-pollution-driven warming mechanism might be at work. NASA\u2019s Gavin Schmidt posited that a novel, unknown force could be involved.<\/p>\n\n\n\n

Wrong, says a team of six climate scientists led by Shiv Priyam Raghuraman (University of Illinois, Champaign-Urbana). The culprit is more likely the familiar climate confounder, El Ni\u00f1o (technically, the El Ni\u00f1o-Southern Oscillation or ENSO).<\/p>\n\n\n\n

Writing in the journal Atmospheric Chemistry and Physics<\/a>, published by the European Geosciences Union, the scientific team writes,<\/p>\n\n\n\n

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our results underscore the importance of the El Ni\u00f1o\u2013Southern 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.<\/p>\n<\/blockquote>\n\n\n\n

They add:<\/p>\n\n\n\n

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Global-mean surface temperature rapidly increased 0.29\u2009\u00b1\u20090.04\u2009K from 2022 to 2023. Such a large interannual global warming spike is not unprecedented in the observational record, with a previous instance occurring in 1976\u20131977. However, why such large global warming spikes occur is unknown, and the rapid global warming of 2023 has led to concerns that it could have been externally driven.<\/p>\n<\/blockquote>\n\n\n\n

And:<\/p>\n\n\n\n

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Here we show that climate models that are subject only to internal variability can generate such spikes, but they are an uncommon occurrence (p<\/em>\u2009=\u20091.6\u2009%\u2009\u00b1\u20090.1\u2009%). However, when a prolonged La Ni\u00f1a immediately precedes an El Ni\u00f1o in the simulations, as occurred in nature in 1976\u20131977 and 2022\u20132023, such spikes become much more common (p<\/em>\u2009=\u200910.3\u2009%\u2009\u00b1\u20090.4\u2009%). Furthermore, we find that nearly all simulated spikes (p<\/em>\u2009=\u200988.5\u2009%\u2009\u00b1\u20090.3\u2009%) are associated with El Ni\u00f1o occurring that year.<\/p>\n<\/blockquote>\n\n\n\n

The University of Illinois research fits with an August paper<\/a> by four researchers from CICERO Center for International Climate Research in Oslo, Norway. Published in the Communications Earth & Environment journal, Bj\u00f8rn H. Samset<\/a> et al. wrote:<\/p>\n\n\n\n

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2023 was the warmest year on record, influenced by multiple warm ocean basins. This has prompted speculation of an acceleration in surface warming, or a stronger than expected influence from loss of aerosol induced cooling\u2026. We show that the strong deviation from recent warming trends is consistent with previously observed sea surface temperature influences, and regional forcing.<\/p>\n<\/blockquote>\n\n\n\n

\u201cWeather Attribution\u201d Alchemy<\/strong><\/p>\n\n\n\n

What has come to be known as \u201cweather attribution,\u201d research assigning causation to observed weather events, is fraught with methodological problems. Veteran climate scientist Roger A. Pielke Jr. in his Substack publication The Honest Broker<\/a> calls it \u201cweather attribution alchemy.\u201d<\/p>\n\n\n\n

Pielke notes that the U.N.\u2019s Intergovernmental Panel on Climate Change (IPPC) describes weather attribution research as seeking \u201cto attribute aspects of specific extreme weather and climate events to certain causes.\u201d The IPCC adds:<\/p>\n\n\n\n

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Scientists cannot answer directly whether a particular event was caused by climate change, as extremes do occur naturally, and any specific weather and climate event is the result of a complex mix of human and natural factors. Instead, scientists quantify the relative importance of human and natural influences on the magnitude and\/or probability of specific extreme weather events.<\/p>\n<\/blockquote>\n\n\n\n

Pielke offers three important aspects of weather attribution.<\/p>\n\n\n\n