Guest Post by Willis Eschenbach
So I was wandering through the marvelous KNMI website, and I came across data for the Palmer Self-Correcting Drought Severity Index. This is an index that measures the drought conditions in some given area. The source website says:
The scPDSI (self-correcting Palmer Drought Severity Index) is a variant on the original PDSI of Palmer (1965), with the aim to make results from different climate regimes more comparable. As with the PDSI, the scPDSI is calculated from time series of precipitation and temperature, together with fixed parameters related to the soil/surface characteristics at each location.
Now, the KNMI site only offers linear trends of data. But if you look at the bottom of the KNMI page linked above, or other pages at that level of inquiry, you’ll find that there is an option to download the NetCDF version of the data. As in this case, this NetCDF data is often gridded.
And using that NetCDF gridded file lets me make a graphic showing the average scPDSI for the globe.
Figure 1. Yes, indeed, Australia is a dry country
Note that the long-term averages range from minus 2.5 (very dry) to 1.9 (pretty wet). Here, to the same scale, is the monthly global average scPDSI.
Figure 2. Monthly global average self-correcting Palmer Drought Severity Index (scPDSI).
No overall change in the scPDSI over the last 120 years—droughts are not becoming either more or less frequent or intense … go figure.
Having gotten that far, I thought I’d see what the IPCC Sixth Assessment Report (AR6) has to say about droughts. Here are couple of quotes:
It is an established fact that human-induced greenhouse gas emissions have led to an increased frequency and/or intensity of some weather and climate extremes since pre-industrial time, in particular for temperature extremes. Evidence of observed changes in extremes and their attribution to human influence (including greenhouse gas and aerosol emissions and landuse changes) has strengthened since AR5, in particular for extreme precipitation, droughts, tropical cyclones and compound extremes (including dry/hot events and fire weather).
SOURCE
My rule of thumb is that most of the time when the IPCC says something is an “established fact” … it isn’t. Here’s another of their claims:
In summary, there is high confidence that concurrent heatwaves and droughts have increased in frequency over the last century at the global scale due to human influence.
SOURCE
Both of those made me say “Hmmm”, so I thought I’d take a look to see what they are calling “heatwaves”, “droughts”, and “high confidence”. From the glossary of the Working Group where those quotes are found, we have:
Heatwave: A period of abnormally hot weather, often defined with reference to a relative temperature threshold, lasting from two days to months. Heatwaves and warm spells have various and, in some cases, overlapping definitions.
Drought: An exceptional period of water shortage for existing ecosystems and the human population (due to low rainfall, high temperature, and/or wind).
SOURCE
I suppose it might be possible for definitions of measurable phenomena to be more vague, but you’d have to work at it. How on earth can you have “high confidence” in claims involving totally undefined terms? And a two-day “heatwave”? Say what? That’s not a wave, that’s a tiny ripple.
Next, here’s how they assign “high confidence”. Not with mathematics or statistics, as you might imagine, but by squinting at it from across the room and making a value judgment based on “evidence” and “agreement”.
Figure 3. IPCC matrix for making value judgments regarding “confidence”.
So how can they have “high confidence” that ” concurrent heatwaves and droughts have increased in frequency” over the last century when they haven’t even bothered to establish clear, bright-line definitions for either heatwaves or droughts? This is fast approaching simply throwing darts at the above confidence matrix …
Having seen that the IPCC is merely issuing its usual meaningless pabulum, I continued my investigation of the scPDSI. I moved on to looking at the 120-year trends by geographical areas. Here’s that graph:
Figure 4. Century-long trends in the self-correcting Palmer Drought Severity Index.
Some points of note. First, there’s no overall trend. Next, almost nowhere has there been a change of more than ± 0.1 units per century. Next, the southwestern US has gotten wetter and the rest has gotten drier. And Australia, as usual … drier. But again, not much.
Seeing that graphic made me wonder about the oft-repeated claim that wet areas are getting wetter and dry areas are getting drier. For example, a study in Nature magazine says:
The “dry gets drier, wet gets wetter” (DGDWGW) paradigm is widely accepted in global moisture change.
To determine if this is true, we can use a scatterplot of the trend in scPDSI levels (Fig. 4) versus the average scPDSI levels. This gives us the following:
Figure 5. Scatterplot, trend vs average, self-correcting Palmer Drought Severity Index.
Interesting. Most of the world has an average scPDSI between -1 and +1 (bottom scale). There’s little trend in there. But in the dry areas, less than -1, the dryer it is, the wetter it’s getting. And the same is true above +1, the wetter it is, the dryer it’s getting.
Finally, I made a video of the annual changes in scPDSI around the globe. Here’s that graphic:
Figure 6. Video, changes in annual average scPDSI.
My conclusion from that? Ignore the hype about droughts. There’s almost always a hair-raising drought going on somewhere on this lovely planet.
In closing, to show there’s nothing new under the sun, here’s a long-term look at drought conditions in the American west …
Good thing that the now-ubiquitous Climate Snowflakes weren’t around during the 200-year drought, the folks back then would never have heard the end of their whining …
My very best to everyone,
w.
Heard It Before Note: When you comment please quote the exact words you’re discussing. It avoids endless problems and misunderstanding.
Editor’s note. For general reference on droughts and other topics, visit EveryThingClimate.com
Figure 4 would contradict “established wisdom”.
Models require increased atmospheric water vapor to derive high equilibrium climate sensitivity under increasing CO2. So how can computer gamers predict more drought?
More excellent work sir! Thank you. I will pass this one for sure.
Just in the past couple of years here in Colorado, the prediction was for continuing drought and then this year becomes the wettest ever.
Normally, around the end of June, the irrigation ditches are dry. This year they are still running strong, at least the ones around here just outside of Boulder.
Figure 6 is a stunning show – no dry or wet year predicts the next. It refutes all the “new normal” pontificators.
Easy explanation for <-1 dry getting wetter and >+1 wet getting drier. It is the well known phenomena of ‘regression to the mean over time’. Extremes tend to get statistically less extreme with time.
Conclusion: When you have the MSM in your pocket you can say anything you want without being challenged.
Thanks for your continued good work, Willis. It might be better, however, to use Snowflake rather than Karen. Karen is a pejorative aimed at white middle class women, although everybody seems to be using it.
WE, nice work. I find it amazing that the IPCC repeats alarming stuff that is so easily refuted by publicly available information, as you do here.
A decade ago, in their special SREX study, they concluded there was no or little evidence of increases in weather extremes. Yet in AR6 2023 they say it is now so with high confidence. Trying to have it both ways usually does not end well.
“The long-term averages range from minus 2.5 (very dry) to 1.9 (pretty wet).”
Definitely misleading. I would expect a high drought severity to be a large positive number, not a large negative one. Maybe it is misleading on purpose ..
Willis,
You do realize of course that this is all religious heresy and Orwellian thought-crime, don’t you? What matters here is what real-world Orwellian Big Brother wants us to believe and the truth (and the data) be damned.
When will the thought police come knocking on your door?
I like paleo records for this subject–>
https://news.arizona.edu/story/giant-sequoias-yield-longest-fire-history-from-tree-rings
“The scientists found the years from 800 to 1300, known as the Medieval Warm Period, had the most frequent fires in the 3,000 years studied. Other research has found that the period from 800 to 1300 was warm and dry”
In another related piece it noted that from aprox 1860 to the present the dendro data
was correlated to direct temperature readings, which might give some indications to
earlier data. So yea dry does get drier..
Taxpayers have been sending the UN billions over decades to deal with drought, famine & disease – it’s still there, however, some people have been made very rich
Its like the cure for cancer – multi billions poured into research over decades, still no cure – one wonders whether a cure is good business, or not
Speaking of Drought (gleaned from The Automatic Earth)
Very nice work. This needs wide distribution.
My Mark IV eyeball would put that at more like -1.5 and +1.0
Story tip: National Geographic have published an article stating that Oceans are like a Hot Tub with temperatures upwards of 90degF!
“Is The Dry Getting Drier?”
Certainly not here in the American northeast- been raining for weeks. I seem to recall some years ago when we did have a mild drought here- the climate pitch here was that New England would turn into a desert! Now it seems tropical. Not fun if you want any outdoor activities, but my lawn, my garden, my flower beds, my trees and shrubs never grew so fast or looked so healthy. And all the reservoirs are filled to overflowing, including the Quabbin Reservoir in the center of the state which sends water to Boston. It had been way down for many years.
As CO2 levels continue to increase, plants need less water. Because of this, even if there was a tiny increase in dryness, it wouldn’t make any difference.
From the article: “It is an established fact that human-induced greenhouse gas emissions have led to an increased frequency and/or intensity of some weather and climate extremes since pre-industrial time, in particular for temperature extremes.”
That is just a blatant lie.
These climate change alarmists don’t have one shred of evidence establishing that human-induced greenhouse gases are causing the atmosphere to do anything.
Somebody ought to ask the question: What is this evidence you have?
They don’t have any evidence. I’ve been paying attention. For *many* years. They are lying through their teeth saying something like this.
I used ro enjoy quoting from the “Observations” chapter of AR5 (2013), because measurements showed no global trends for any “extreme weather” events. None. Not a single one. I never bothered with the “Summary for Policymakers” because it was political nonsense written by–you guessed it—politicians, not scientists. The politicians wanted something more hyperbolic than actual science so they doctored it to their liking and would always—always!—refer the media to the Summary for Policymakers not the Observations chapters where the actual science lay.
In Observations I had to skip the summaries and go to the measurements of each weather event like droughts, floods, cyclones, etc. and read carefully to see that they were phrasing their findings in a way to infer to the reader that there was a trend without actually blatantly saying there was. To be scientifically accurate they would very briefly say something like “no global trend” but follow it with equivocation like “there are regional trends” or “not enough data”. Once you discarded the equivocating language it was easy to see they had bupkis. But they would quickly assure the reader that “it’s going to happen, because climate models”. A brief skim of AR6 shows the same tactics. Buried in all the summaries and assurances that global catastrophe is happening and it’s caused by humans are the very brief admissions of the real data which show, once again, bupkis. And I use the word knowing the original Yiddish meaning of the word, which accurately describes their so-called “conclusions”.
FWIW
“Models wrong again: Looks like Climate Change is making rainfall *less* intense globally”
https://joannenova.com.au/2023/07/models-wrong-again-looks-like-climate-change-is-making-rainfall-less-intense-globally/
I always love seeing the grid for the IPCC confidence levels. High agreement is ALWAYS high confidence – no matter the evidence.
SCIENCE! At least, as defined by the Church of AGW.
I’m not advocating for or against but the presentation raises some questions that I can’t answer. The graph, and the trend calculated for it, cover 120+years, presented in a very small space. Whether or not they are significant in any way to humans or other life, how many of those “tiny ripples” or significant changes in their frequency, might disappear in that CEEMD Smooth and Linear Trend, to say nothing of the Monthly Data?
Is the data really fit for purpose? I suppose that might depend on what the purpose is.
I really like the RED LINE OF DEATH…graph and concept. If we can get the suburban wine moms and impressionable teenage activist clamoring to be saved from the RED LINE OF DEATH… Most of the worlds problems would be solved.