Kennedy Corn
“So-called 'weather attribution,' the study of assigning cause and effect to observed weather events, is fraught with methodological problems,” senior climate scientist Roger A. Pielke Jr. said in his Substack publication The Honest Broker It is the “alchemy of weather attribution”.
Last year it was extremely hot. Global temperatures are nearly 0.3°C above 2022 levels, so much higher that even traditional analyzes of global warming seem unable to explain the phenomenon. As a recent article in Science notes, iconic climate scientist James Hansen suggests that a new, air pollution-driven warming mechanism may be at work. NASA's Gavin Schmidt believes a novel, unknown force may be involved.
A team of six climate scientists led by Shiv Priyam Raghuraman (University of Illinois at Urbana-Champaign) says this is wrong. The culprit is more likely to be a familiar climate confounder called El Niño (technically, the El Niño Southern Oscillation, or ENSO).
The scientific team wrote in the journal Atmospheric Chemistry and Physics published by the European Geosciences Union,
Our results highlight the importance of the El Niño-Southern Oscillation in driving global warming peaks, such as the one in 2023, without invoking anthropogenic forcing (such as changes in atmospheric greenhouse gas or aerosol concentrations) as an explanation .
They added:
From 2022 to 2023, the global average surface temperature increased rapidly by 0.29 ± 0.04 K. However, why such a massive global warming spike occurred is unclear, and the rapid pace of global warming in 2023 has raised concerns that it may be externally driven.
and:
Here we show that climate models subject only to internal variability can produce such peaks, but this is uncommon (p= 1.6% ± 0.1%). However, when El Niño events in simulations are preceded by longer La Niña events, as happened in nature in 1976-1977 and 2022-2023, such spikes become more common (p= 10.3% ± 0.4%). Furthermore, we found that almost all simulated spikes (p= 88.5 % ± 0.3 %) is related to the phenomenon of the Holy Child that occurred that year.
The University of Illinois study is consistent with a paper published in August by four researchers at the CICERO International Climate Research Center in Oslo, Norway. Published in the journal Communications Earth & Environment , Bjørn H. Samset et al. wrote:
2023 is the warmest year on record, affected by multiple warm ocean basins. This has led to speculation that surface warming is accelerating, or that the effects of aerosol-induced cooling losses are stronger than expected…. We show that strong deviations from recent warming trends are consistent with previously observed effects on sea surface temperature and regional forcing.
“Weather Attribution” Alchemy
So-called “weather attribution,” the study of assigning causality to observed weather events, is fraught with methodological problems. Veteran climate scientist Roger A. Pielke Jr. calls it “the alchemy of weather attribution” in his Substack publication The Honest Broker.
Pielke noted that the United Nations Intergovernmental Panel on Climate Change (IPPC) describes weather attribution research as seeking to “attribute aspects of specific extreme weather and climate events to certain causes.” The IPCC added:
Scientists cannot directly answer whether a specific event is caused by climate change because extreme events do occur naturally, and any given 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.
Pielke proposed three important aspects of weather attribution.
- It is “tactical,” meaning political, “research conducted expressly to serve legal and political purposes.” He pointed out that a key motivation for the UK's World Weather Attribution (WWA) project work is to “increase the 'immediacy' of climate change, thereby increasing support for climate change mitigation.” WWA founder Frederike Otto said: “With climate science “Unlike every other branch of science in general, event attribution was actually originally proposed with the courts in mind,” Pielke said. “Tactical science is not necessarily bad science, but it should enhance the scrutiny such analyzes face.” extent, especially when they are not typically subject to independent peer review.”
- Weather attribution reflects the IPPC's inability to detect with a high degree of confidence “trends in increasing frequency or intensity of most types of influential extreme events – in particular hurricanes, floods, droughts and cyclones.” He writes: “For example, The Intergovernmental Panel on Climate Change reported increases in heatwaves and heavy precipitation, but not tropical cyclones (including hurricanes), floods, tornadoes or droughts, an issue that climate activists see as a political impediment to their policy agenda. This can be corrected by the invention of extreme event attribution.”
- The weakness of weather attribution should not overshadow the importance of climate issues, but it does not excuse scientific integrity. “We live in an age where calls for scientific integrity are often criticized by political activists (including scientists),” he argued, “and where certain scientific understandings are not entirely consistent with this or that political agenda.”
“Some people outright deny the possibility of human-caused climate change,” Pielke writes, “while others are quick to claim that every weather event is becoming more extreme or more common due to climate change. These extreme positions are in contrast to those of the far right. Much in line with the far left – discussions of climate science and policy have long been dominated by these extreme views.
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