Guest Post by Willis Eschenbach.
With all the recent interest in rare or extreme weather events, I got to wondering … what makes a weather event rare or extreme?
With that in mind, here’s a thought experiment whose relevance will be made clear shortly.
Imagine some woman works in the Tennessee Valley plant of a big corporation. It’s a 24/7/365 operation. The Regional Manager likes to visit each plant, spend a day or more there, and stir things up. So the woman decides to record the comings and goings of the Regional Manager. At the end of the year, she graphs it up and it looks like this:
Figure 1. Dates of visits of the Manager to the plant.
When she runs the numbers, she finds out that the Regional Manager’s been visiting the Tennessee Valley plant about one day in five.
So here are two questions.
In Figure 1, is a visit by the Regional Manager a “rare event”?
In Figure 1, are these visits “extreme events”?
Obviously, no. Something that happens about one time out of five is neither rare nor extreme.
Why is this a relevant thought experiment? Well, like I said, I was wondering what makes an event “rare” or “extreme”. So I went to “THE SCIENCE”, which in this case are the Glossaries of the two latest IPCC Assessment Reports. Here are the definitions from the Fifth (AR5) and Sixth (AR6) Assessment Reports.
Extreme weather event
An extreme weather event is an event that is rare at a particular place and time of year. Definitions of rare vary, but an extreme weather event would normally be as rare as or rarer than the 10th or 90th percentile of a probability density function estimated from observations.
and
Extreme weather event
An event that is rare at a particular place and time of year. Definitions of ‘rare’ vary, but an extreme weather event would normally be as rare as or rarer than the 10th or 90th percentile of a probability density function estimated from observations. By definition, the characteristics of what is called extreme weather may vary from place to place in an absolute sense.
I cracked up when I saw those definitions.
Why?
Well, because on average, one observation out of every five is “as rare or rarer than the 10th or 90th percentile of a probability density function estimated from observations”.
So the IPCC is claiming that one weather observation in five is “rare” … here’s how that plays out for a few years of daily Chicago Midway Airport temperatures. This shows the IPCC-defined “extreme Chicago temperatures”.
Figure 2. Daily average temperatures at Midway Airport, Chicago. Horizontal red lines show the 10th and 90th percentiles of the observed temperatures. Yellow area shows the one in five temperature records that exceed those percentiles. Middle white area encompasses the 80% of the data between the 10th and the 90th percentiles.
I swear, the inmates are in charge of the IPCC asylum.
CODA: This post is about extreme weather events. About a month ago, in a post called “The IPCC Says No Climate Crisis” I highlighted that the IPCC agreed with a recent study pointing out how little change there’s been in extreme weather events.
The study was entitled “A critical assessment of extreme events trends in times of global warming“, and the conclusion says:
In conclusion on the basis of observational data, the climate crisis that, according to many sources, we are experiencing today, is not evident yet.
Can’t say it any better than that. And the IPCC itself agrees. Here, shown as white squares in the first data column, are the areas of the weather where the IPCC says there is no significant change in frequency or strength.
Figure 3. IPCC AR6 Table 12.12. The column entitled “Already Emerged In Historical Period” shows climate phenomena that the IPCC says have or haven’t changed due to “global warming”.
Let’s be clear about this. The following are the areas where the IPCC itself, in the graphic above, says there is low scientific confidence in the existence of any visible “global warming” effects in the form of weather extremes:
- Air Pollution Weather (temperature inversions)
- Aridity
- Avalanche (snow)
- Average rain
- Average Wind Speed
- Coastal Flood
- Drought Affecting Crops (agricultural drought)
- Drought From Lack Of Rain (hydrological drought)
- Erosion of Coastlines
- Fire Weather (hot and windy)
- Flooding From Heavy Rain (pluvial floods)
- Frost
- Hail
- Heavy Rain
- Heavy Snowfall and Ice Storms
- Landslides
- Marine Heatwaves
- Ocean Alkalinity
- Radiation at the Earth’s Surface
- River/Lake Floods
- Sand and Dust Storms
- Sea Level
- Severe Wind Storms
- Snow, Glacier, and Ice Sheets
- Tropical Cyclones
So when folks claim things like “We’re already seeing the effects of global warming in storms/cyclones/floods/coastal erosion/fire weather/sea level/etc.”, feel free to tell them that the IPCC and reality itself both beg to disagree.
Now, you can clearly see above that the IPCC itself agrees wholeheartedly with the paper “A critical assessment of extreme events trends in times of global warming”. Both the paper and the IPCC Table 12.2 above say that to date there is very little sign of any change in almost all measures of extreme events.
Since my earlier post, however, there’s been a disturbing development. Despite the paper agreeing with the IPCC, in an act of venal scientific malfeasance, the usual alarmist “scientists” including the serial liar Dr. Michael Mann have intimidated the publisher of the paper into withdrawing the paper.
I cannot find any report of any specific statement that these underhanded “scientists” found to be false. They just claimed unspecified problems with “the selection of the data, the analysis, and the resulting conclusions” … yeah, right. There’s an excellent discussion of the issues here.
Climate cowards. They can’t defeat an argument, so they try to censor it. Here’s the most subversive part of the paper they’ve censored …
Can’t have scientists saying things like that … it’s just not done.
But the good news is, you know these climate thugs are running scared when they have to illicitly prevent the publication of ideas that might do significant damage to their to-date-endless climate money gravy train …
My very best to all,
w.
USUAL CAVEAT: When you comment, please quote the exact words you are discussing. This avoids endless misunderstandings.
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fitting qualitative words like rare and extreme to quantitative phenomena is a nasty business.
when i saw the hurricane hitting long beach
i thought thats weird. i spent 15 years there and no extreme weather or rare events
next up China
https://www.aljazeera.com/news/2023/8/2/chinas-heaviest-rains-in-140-years-kill-at-least-20-leave-27-missing
140 years is nothing. Given Qing Dynsty records, that timeline could be pushed back hundreds of years.
anyway looks like the Mandate of Heaven is challenging the CCP rule.
https://en.wikipedia.org/wiki/Mandate_of_Heaven
in any case Willis here is my question.
forget the words rare and extreme.
look:
https://www.youtube.com/watch?v=84RYl1ogQBo
heres my question:
how does so much water end up in the sky?
how does the air hold that much water.
I mean seriously
Actually, air doesn’t “hold” water. When you grasp this concept
you will be on the way to enlightenment.
Are you worried that the sky really is falling Mosh? 🙂
Plasma is a contiguous mass of ions. English: A volume containing charged particles. The definition cares not for densities or composition. It is a common misconception that lightning originates in clouds, it is a geoelectrical phenomenon, and a lightning bolt may equalise charges to the point where “the water falls out”. May equalise, consider the total spectrum of possibilities positive and negative.
Almost all weather is electrix at work, and that electricity comes not only from inside the surface, but also the heavenly bodies, most notably the sun. Climate is at least 90% solar electrix. Then there’s Jupiter…
Or so sayeth the unlettered (unencumbered by status and the possible loss thereof) oberver…
China floods every 2 or 3 years in different areas of the country, this is not a rare or even unusual event – the Chinese people have lived with monsoon floods for centuries, as have many countries in Asia. As far as major floods go (loss of life, damage) this was not a major flood. The Beijing area floods of the 1960’s killed thousands of chinese people, displaced millions and caused huge amounts of damage, the one alluded to in your comment, 140 years before, killed over 3 million people and displaced over 20 million with devastating damage. This flood killed less than a hundred people and damages, due to flood management, has been less than in previous years – like many in the moronic alarmist cult, you appear to be unable to grasp anything that happened in the past.
Mosher writes “how does the air hold that much water. I mean seriously”
The “amount of water the air holds” is greater with increasing temperatures but since half or more of the “increase” is at the minimum daily temperature, the increase of “water in the air” is only half what you might expect.
But at any rate, the additional water in the atmosphere due to that warming isn’t the difference between a flood plain destroying homes or not. That’s weather.
I’ve noticed that the Clausius-Claperyon equation has been updated with an extra coefficient, Bs.
Bs is a coefficient whose sign and magnitude depend on if the region is in a 10th percentile rainfall event or a dodgy dam is about to break.
Years ago I used to know what the Clausius-Claperyon equation was. Now it’s a distant memory–along with most of the climate change nonsense.
I have no idea what you’re talking about, so I enjoyed what I think is very clever sarcasm…
…in which case we can add another important parameter to any climastrological equation, possibly the most important driver of climate catastrophe: Tv.
Just a reference to dumb arguments for why floods were worse due to climate change.
Over on Cliff Mass’s blog he gave a prediction of an atmospheric river event on the near
horizon. Rainfall in the 10″ish range. Sounds extreme to me, but it’s what the 3rd such year
in a row for those on the west coast? The media will go down the climate change path when it hits..
It is my recollection that the atmospheric rivers usually arrive in December or January.
[ Editorial note, to those suffering from “déjà vu” : The following is adapted from a comment I made under the “The Wolf and the Lamb” WUWT article 5 days ago. ]
_ _ _ _ _
The IPCC is capable of “rewriting the dictionary” within a single (long) document.
On page 169 of the AR6 WG-I report you will find “Box 1.1 : Treatment of uncertainty and calibrated uncertainty language in AR6”, where the IPCC wrote the following “definition” for what the term “low confidence” is, and is not, supposed to mean for the AR6 assessment reports :
By the time the IPCC’s “coalface worker / grunt” scientists had got to chapter 12, however, their outlook had subtly shifted.
Look carefully at the caption at the top of Table 12.12 copied in the ATL article (from page 1856 of the self-same AR6 WG-I report), especially the sub-clause after the colon, which reads :
“white cells indicate where evidence is lacking or the signal is not present, leading to overall low confidence of an emerging signal”
This means that by the penultimate chapter of AR6 WG-I the IPCC’s scientists had determined that “low confidence” actually meant either :
1) There is no data, or
2) There is some (limited or patchy) data, but there is no trend, or
3) Mathematically there is a non-zero trend, but it is not statistically significant.
NB : Both Alimonti et al and Roger Pielke Jr. highlighted that all of the white cells in Table 12.12 were equivalent to my summary (though they obviously did not use my exact wording).
In just 1687 pages the IPCC scientists went from
“low confidence = the best conclusion based on currently available knowledge”
to
“low confidence = either there is no data or there is no trend”.
Generally, in science, engineering, and business the 95% probability is the generally understood confidence level in assessing the probability of an event of some defined nature. So 90th percentile is much lower than 95% confidence.
Secondly, the thing with weather is that the media and the desk pounders for climate action always focus only on extraordinary events, because there is no ability to attract mouse clicks with headlines that read something like, “Today most people experienced an average day where nothing really changed.” That’s not news.
The old saying in the print media was “If it bleeds, it leads”.
So by constantly reporting a stream of events claimed to be rare and/or extreme that affect only a tiny sliver of the population, it creates a sense that everybody is at extreme risk every day. Which of course is nonsense.
And of course most non-engineers don’t understand weather related statistics at all.
For example, people mistakenly believe that a 100 year storm event is (1) a single defined event, and (2) is supposed to happen only once every 100 years.
Engineers and hydrologists understand well that the 100 year event is strictly a probabilistic definition of specific circumstances based upon a long record of daily weather data. So for rainstorms, it is not only necessary to define the return period (the 100 year part) but also the specific event, such as a 5 minute storm, a 30 minute storm, a 1 hour storm, a 12 hour storm, a 24 hour storm, and a 72 hour storm. The US government publishes a graphic atlas of the entire United states with contour lines showing in areal terms a given rainfall volume (in inches) results from a given return period for every single defined storm duration.
This atlas is referred to as the USGS rainfall intensity-duration-frequency map.
Of course, that is vastly more complex an analysis than any media person with the equivalent of maybe an 8th grade earth science education, or any of the claimed “climate scientists” who mostly know nothing of actual weather science.
In any event, a 100 year event can easily happen more often than once in 100 years. Because weather patterns tend to occur across multiple years or even multiple decades of wet spells or dry spells, a given area can experience the 100 year event two years in a row, or three years in five. And then not experience it again for another 250 years.
Finally, at any given point in time, it is guaranteed that at least some tiny sliver of the Earth’s surface is undergoing extreme weather. For a day, or three. And then it’s not. If the media and the warmunsts focus only on where extreme weather is taking place, no matter how small the sliver of population or surface of the planet is undergoing that weather, and report it for everywhere in the world, not just in your local area or region, then it gives the false appearance that everybody is experiencing extreme weather all of the time.
Sorry, Willis, way off topic, but I had a question which might end up being a good base for a future article: given that CO2 levels increase a lot during October to April and then drop rapidly May to September, to a level about 2-3ppm higher than the previous minimum, and given that it seems the biosphere is soaking up half the human emissions, even with those emissions growing the Earth seems to keep up, given that and more – will the Earth eventually catch up to human emissions?
The biosphere has expanded on land 15-20% according to NASA, who knows how much the biosphere has improved under the waves, and if the Earth continues to warm and growing conditions to improve – will we reach a real, natural Net-Zero where our emissions are completely soaked up?
A disturbed dynamic system will attempt to re-equilibrate. But, there is no guarantee that equilibrium will be reached before the next disturbance.
w. => Great Example and great work — you have taken the time to discover exactly what they are really counting.
Almost always a surprise — not only are they not counting what one would expect but the thing they are counting does not have the same significance, the same meaning, the same reality, of what they claim they are counting.
TIP
An Easterly Wave has just been noted off the east coast of Africa.
Compared to barking dogs, such storm seeds are relatively rare. Peak hurricane season has just been passed, but this one is starting at sufficiently low Latitude that my “sharpshooter model” predicts it could, might, maybe reach the USA. 🙂
I confess I was suspicious.
The phrase ‘probability Density Function’ is distinct from ‘probability’.
So, I went researching. Dictionary, Wikipedia, ChatGPT, Google Bard, and you know what? At the end of the day, it turns out that Willis was correct.
On page 10 in AR6 Summary for Policymakers there is a chart entitled “Climate change is already affecting every inhabited region across the globe with human influence contributing to many observed changes in weather and climate extremes.” The “hot extremes” observed change assessment there seems particularly scary, displaying many red hexagons on a map. Is that false? I recall Willis debunking that very chart on Twitter not long ago. Does anyone remember what he said?
The summary is not science, it has nothing to do with the science.
It’s the equivalent of brain injury
Willful brain injury. Like bashing your own head against a bring wall, repeatedly, then trying to say something meaningful.
Thank you Willis; this was very useful.
Now I know what it means when we’re told that peer-reviewed climate research employing doctored data or faulty methodology is “rare”.
Willis writes “Let’s be clear about this. The following are the areas where the IPCC itself, in the graphic above, says there is low scientific confidence in the existence of any visible “global warming” effects in the form of weather extremes:”
It’s also worth noting that future change detection relies on “at least” RCP8.5 which itself is unlikely.
Unlikely for the IPCC, practically impossible for the real world.
here’s how that plays out for a few years of daily Chicago Midway Airport temperatures.
Well.
raw data please, then SHOW every calculation and how it changes the source data.
but in general i agree.
the weather is the same as always, climate is the same as always
nothing rare can happen.
there are no extremes
Steven Mosher
September 21, 2023 6:08 pm
Well.
raw data please, then SHOW every calculation and how it changes the source data.
==========================
If that’s all you’ve got, you’ve got nothing.
w.
Meanwhile even though its hidden on page 1856 of the AR6 WG1 report and quite difficult to find, especially on their web interface, Table 12.12 largely agrees with you and the alarmist climate scientists are hoisted by their own petard with the published science summary.