[Posted this earlier but somehow the URL went missing.]
"Here we show that climate change made 213 historical heatwaves reported over 2000–2023 more likely and more intense, to which each of the 180 carbon majors (fossil fuel and cement producers) substantially contributed… Overall, one-quarter of these events were virtually impossible without climate change. The emissions of the carbon majors contribute to half the increase in heatwave intensity since 1850–1900.
I don’t understand the discrepancy between the US, Canada, and Mexico. Is it mostly driven by Hawaii or something? or is it the Midwest?
If you’re referring to the global map (fig. a) the darkness of the purple corresponds to the “The number of heatwaves reported per country” over 24 years (not from 1800-on).
This is a very long, complex analysis. I’m not familiar enough with this science to follow it. Going by the math, the authors don’t seem to be trying to communicate their conclusions to the general public … probably looking for some helpful critiques of their reasoning.
I get that part, what I dont understand is why thr US would be reporting so many more heatwaves than its direct neighbors, even though the parts of the country hilighted in the graphic directly boarder Canada and Mexico. One would think those countries would have experienced the same heatwaves at least a portion of the time, yet there is a wide discrepancy in the number of heat waves reported between them.
Don’t know. Certainly Mexico and Canada have had some extremely high temps in recent years.
https://www.visualcapitalist.com/cp/mapped-the-worlds-record-heat-waves/
But a high temp is not a ‘heatwave’, (The authors of that page certainly don’t understand what a ‘heatwave’ is.)
I didn’t see that the authors of our article defined their use of that term. There must be a standard definition within the climate discipline.
According to WPedia, "The IPCC defines heatwave as “a period of abnormally hot weather, often defined with reference to a relative temperature threshold, lasting from two days to months.” It also notes that "In the United States, definitions also vary by region. "
So I guess you’d have to write the authors to suggest that they define the terms they’re flinging around. The article also has a huge bibliography; maybe some of the older entries discuss the question.
Brittanica says: “No formal, standardized definition of a heat wave exists. The World Meteorological Organization defines it as five or more consecutive days during which the daily maximum temperature surpasses the average maximum temperature by 5 °C (9 °F) or more. Some countries have adopted their own standards … whereas the U.S. National Weather Service defines a heat wave as a spell of “abnormally and uncomfortably hot and unusually humid weather” spanning two days or more.” - https://www.britannica.com/science/heat-wave-meteorology
Maybe it’s in one of the references in the Wikipedia article: https://en.wikipedia.org/wiki/Extreme_event_attribution (that’s the EEA term they keep using).
