Reposted from Dr. Roy Spencer’s blog
July 2nd, 2019 by Roy W. Spencer, Ph. D.
News reporting of the recent heat wave in France and other European countries was accompanied with the usual blame on humans for causing the event. For example, here’s the CBS News headline: Record-breaking heat is scorching France. Experts say climate change is to blame.
While it is possible that the human component of recent warming might have made the heat wave slightly worse, there are three facts the media routinely ignore when reporting on such “record hot” events. If these facts were to be mentioned, few people with the ability to think for themselves would conclude that our greenhouse gas emissions had much of an impact.
1. Record High Temperatures Occur Even Without Global Warming
The time period covered by reliable thermometer records is relatively short, even in Europe. Due to the chaotic nature of weather, record high and record low temperatures can be expected to occur from time to time, even with no long-term warming trend.
The question is, are the number of record high temperatures increasing over time? At least in the U.S., the answer is ‘no’, as the number of days over 100 and 105 deg. F have not increased (see Fig. 5 here). One would need to study the data for Europe to see if the number of record highs is increasing over time.
Then, even if they are increasing, one needs to determine the cause. Most of the warming since the Little Ice Age (up to about 1900) occurred before greenhouse gases could be blamed. We have no temperature measurements during the Medieval Warm Period of 1,000 years ago. How hot were some of the summer days back then? No one knows. Weather changes, which leads me to my next point.
2. Summer Heat Waves are Weather-Related, and Unusual Cold is Usually Nearby
The recent excessive heat in Europe wasn’t caused by summer air sitting there and cooking in a bath of increased human-emitted carbon dioxide. It was caused by a Saharan Air Layer (SAL) flowing in from that gigantic desert to the south.
This happens from time to time. Here’s what the temperature departures from normal looked like at ~ 5,000 ft. altitude:
Fig. 1. GFS model depiction of the 850 hPa level (about 5,000 ft. altitude) temperature departures from normal at midday 29 June 2019, showing a hot Saharan air mass that had flowed north over western Europe, as a cold arctic air mass flowed south over eastern Europe. (Graphic courtesy of WeatherBell.com)
The SAL event flowed north from the Sahara Desert to cover western Europe while a cold air mass flowed south over eastern Europe. As evidence of just how large natural weather variations can be, the full range of temperature departures from normal just over this small section of the world spanned 25 deg. C (45 deg. F).
Meanwhile, the global average temperature anomaly for June (from NOAA’s Climate Forecast System, CFSv2 model) at the surface was only +0.3 deg. C (0.5 deg. F), and even for one day (July 1, 2019, from WeatherBell.com) remains at +0.3 deg. C.
Do you see the disparity between those two numbers?: weather-related temperature variations of 45 deg. F versus a climate-related global average “warmth” of only 0.5 deg. F.
Here’s what the situation looked like at the surface:
Fig. 2. As in Fig. 1, but for surface air temperature.
The range in surface air temperature departures from normal was was 32 deg. C (about 58 deg. F), again swamping (by a factor of 100) the global “climate” warmth of only 0.5 deg. F.
Thus, when we talk of new temperature records, we should be looking at normal weather variations first.
3. Most Thermometer Measurements Have Been Spuriously Warmed by the Urban Heat Island Effect
I am thoroughly convinced that the global thermometer record has exaggerated warming trends due to the Urban Heat Island (UHI) effect. When natural vegetation is replaced with buildings, pavement, and we add spurious heat sources like air conditioning units, cars, and ice cream trucks, the microclimate around thermometer sites changes.
Many of us experience this on a daily basis as we commute from more rural surroundings to our jobs in more urban settings.
For example, Miami International Airport recently set a new high temperature record of 98 deg. F for the month of May. The thermometer in question is at the west end of the south runway at the airport, at the center of the Miami-Ft. Lauderdale metroplex. Only 120 years ago, virtually no one lived in Miami; in 1896 it had a population of 300.
The UHI effect is so strong and pervasive that it is now included in the GFS weather forecast model, and in the case of Miami’s recent hot spell, we see the metroplex at midnight was nearly 10 deg. F warmer than the rural surroundings:
Fig. 3. GFS surface temperature analysis for around midnight, 28 May 2019.
When a thermometer site has that kind of spurious warming at night, it’s going to produce spuriously warm temperatures during the day (and vice versa).
The most thorough analysis of the UHI effect on U.S. temperature was by Anthony Watts and co-authors, who analyzed the siting of hundreds of thermometers around the U.S. and showed that if only the best (most rural) sited thermometers are used, U.S. warming trends are roughly cut in half. Curiously, they found that the official NOAA-adjusted temperature data (which uses both urban and rural data) has even more warming than if no UHI adjustments were made, leading many of us to conclude that the NOAA UHI adjustment procedure has made the rural data look like urban, rather than the other way around as it should be.
How does this impact the recent record high temperatures in France? There is no question that temperatures were unusually hot, I’m only addressing the reasons why high temperature records are set. I’ve already established that (1) record high temperatures will occur without global warming; (2) weather variations are the primary cause (in this case, an intrusion of Saharan air), and now (3) many thermometer sites have experienced spurious warming.
On this third point, this MeteoFrance page lists the temperature records from the event, and one location (Mont Aigoua) caught my eye because it is a high altitude observatory with little development, on a peak that would be well-ventilated. The previous high temperature record there from 1923 was beat by only 0.5 deg. C.
Some of the other records listed on that page are also from the early 20th Century, which naturally begs the question of how it could have been so hot back then with no anthropogenic greenhouse effect and little urban development.
The bottom line is that record high temperatures occur naturally, with or without climate change, and our ability to identify them has been compromised by spurious warming in most thermometer data which has yet to be properly removed.
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So, European heat waves are just the Sirocco on steroids?
From the head post
“The question is, are the number of record high temperatures increasing over time? At least in the U.S., the answer is ‘no’, as the number of days over 100 and 105 deg. F have not increased (…). One would need to study the data for Europe to see if the number of record highs is increasing over time.”
Yes, for the U.S., the answer is ‘no’:
http://www.drroyspencer.com/wp-content/uploads/US-extreme-high-temperatures-1895-2017.jpg
But for the Globe, the answer is (of course according to a layman’s home work), clearly ‘yes’.
1. As John Christy generated his record high stat out of the USHCN record, I first switched to the GHCN daily record with around 18000 US stations in the grand total over the period, and around 36000 worldwide, and generated a similar stat for CONUS:
https://drive.google.com/file/d/1qGV5LfKw_lFKNdZMlq15ZHz6sA1CA294/view
I chosed 35 / 40 °C instead of 100 / 105 F: nobody uses Fahrenheit ouside of the USA and some of its backyards. But it seems that the stuff, though based on a considerably greater data set, nevertheless fits to John Christy’s work quite well.
2. Extending the stat worldwide then gave this:
https://drive.google.com/file/d/1TFdltVVFSyDLPM4ftZUCEl33GmjJnasT/view
The station data was distributed over a grid of 2.5 ° cell size, in order to have 200 US grid cells competing with 2000 cells worldwide, instead of having in the yearly average about 8000 US stations competing with about 8000 worldwide, what lets the Globe look like CONUS’ backyard 🙂
Who has some doubt concerning accuracy and precision is kindly invited to to the same job. We can then compare the results.
Maybe I redo the stat work again, this time restricted to Europe or even to France, when I have some idle time.
Rgds
J.-P. D.
#1 way to know a statement is false: It is preceded by the phrase “experts say”.
Roy Spencer already gave the right answer but I will reformulate the pretentious vocabulary in simple, really common sense words.
Attribution theory deals with the question how to modify a hypothesis about a process when new data about the same process are available . Common sense, right ?
The Bayes theorem which gives the conditionnal probabilities is the statistical tool to quantify how to adapt causal hypothesis to data (but NOT the other way round !) . Again common sense.
So the first sentence should have been “If we use Bayes theorem , should we change our opinion about climate change causes after we got new data about the weather in France end of june 2019 ?” . Clear enough.
But now comes the catch that R.Spencer already caught.
This method works ONLY if you know the prior probability distribution ! In this case you must know what the weather in France would be if there was no perturbation (e.g if the CO2 was not what it is).
If you don’t know that, Bayes doesn’t give you anything.
Yet obviously this is precisely what you do NOT know.
So if you want to say some random non sense anyway (like odds 4:1 etc) you simply must postulate some non “perturbed” probability distribution which you pull out of your hat or out of some computer model.
And this boils down to simply assume that global warming is caused by man and the computer models give an accurate answer on the question what would be if ….
So finally it is a tautology because if you postulate that the weather in France is given by the global warming and that the global warming is caused by man then without surprise you find that indeed the global warming dictates the weather and that it is caused by man 🙂
Tom Vonk, nice to see you again.
I live in rural Limousin, apart from Limoges it’s very rural. One day During the heatwave Limoges was forecast to be the hottest place in France 41’C.
I have a simple gauge for hot spells, the road tar melting last week saw very little evidence around where I am. We also had a trip Saumur on the day it was also one of the warmest places, again not much tar melting. Using that yardstick the last heatwave was hotter and/or longer
Back in the 80’s we called this a Sirocco wind event: a Lp above the UK and HP at the east, which “sucks the hot air from the sahara in. Happens usually in the winter where you suddenly have 14-17 degrees C in january.
CO2 blankets the earth in 410 ppm CO2. There is no way for CO2 to cause localized warming. There is also no way for CO2 to trap outgoing heat and cause warming or a record high. Record highs require new energy be put into the system. Trapping outgoing radiation won’t cause warming, it slows cooling. Visible radiation warms the earth, not outgoing LWIR. Clear skies will warm the earth, not CO2.
Extreme Climate and Droughts are Nothing New; Collapse of the Akkadian Empire Circa 2,200 B.C.
https://co2islife.wordpress.com/2019/06/30/extreme-climate-and-droughts-are-nothing-new-collapse-of-the-akkadian-empire-circa-2200-b-c/
Why Today’s and Past Heat Waves Have Nothing to do with CO2
https://co2islife.wordpress.com/2019/06/30/why-todays-and-past-heat-waves-have-nothing-to-do-with-co2/
The other issue is scale. Most of the temperature records show an anomaly up to 1 degree (base date varies) The new record was 45.9 and the previous was 44.1 (1.8 degree difference). Most data sets show current global temperatures lower than the 2016 peak.
The hottest recorded day for the last 200 years. How have temperatures been recorded 200 years ago? By having someone loom at the mercury. Who has seen an old mercury thermometer? Any confidence that we were able to detect a difference of a tenth degree celsius? I remember when I was a kid, we could sometimes not make out to one degree what temperature it really was. Most stuff from before WW2 is mush, anything from before WW1 is guesswork at best. But we constantly see those lines with extremely intricate and precise temperature developments over hundreds, sometimes thousands of years. It should be stated that they are all guesswork and could be off by entire degrees Celsius. But that’s not what we are told. If it supports the Global Warming script, it’s elevated to be a fact, if it does not, it’s adjusted until it fits.
Even if they could determine down to a tenth, they only recorded to a degree. Using best judgement as to whether they should round up or down.
The fact that the weather fluctuates on its own without any human input, does not negate the fact that in the last 300 years human activity has destroyed, polluted, or poisoned (your choice) a large part of the ecosystem. No person in their right mind could possibly think that human actions have no effect on climate. Industrial production, deforesting (by half) the planet, heating (and cooling) massive buildings, (the heat produced by these processes all leaks out later, or you would only have to heat/cool them once), human produced radiation (electrical/electronics, atomic processes), dumping trillions of tons of toxic chemicals into the water, air and land, not to mention that each organism itself produces some amount of heat from simply living all affect the entire system. If we do not take action to limit our excessive consumption of resources, and production of harmful products we might as well just line up and all jump over the cliff now.
Patching the hole in the boat is not the solution, we need to rethink our entire approach as to what a good life is. If the definition of a good life destroys the chances of the next generation having any decent chance of a life, the your definition of a good life is merely a delusion.
If we do not take action to limit our excessive consumption of resources, and production of harmful products we might as well just line up and all jump over the cliff now.
Actually the problem of this person is that it lives in another Univers or another time.
In our Universe and in our time what we observe is :
– the life expectation has never been so high in history
– we have no famines, no Black Deaths and the medical science cures diseases that have been killing millions only 100 years ago. We go on the Moon and we might colonize Mars and Jupiter satellites in a few centuries too.
– the living standards have never been so high in history. In most countries everybody has electricity, water, hospitals and mobility. We work much less than 100 years ago.
– the quality of air and water is much better than what it was 100 years ago.
– the Earth’s population keeps increasing. Well this one may be ambiguous : on one hand it shows that the environment (including climate) is more and more favorable but on the other hand it asks a question if there is/should be some limit for the number of people on the Earth.
You weren’t paying attention, I said 300 years ago, the only reason medical science had to keep up with most of the current solutions is the fact that we did so much damage to the planet to start with. There was a plague outbreak last year in Madagascar; there is currently outbreaks of Ebola and Congo Fever in Congo; over 200,000 had cholera last year in India alone; there is are currently almost 2 billion under nourished or starving people on the planet, about 1 billion people have no access to clean drinking water. Saying there are no plagues or famines makes you look very uninformed. You want sources check out the WHO website, or here https://outbreaks.globalincidentmap.com/. The oceans are so full of man made garbage that some of the marine life is dying off. Science reported recently that this generation will be the 1st in a long time to have shorter lifespans than there parents. If attitudes and actions do not change this will not be the last generation to see reduced lifespans. Some things science or medicine cannot fix, although for others both of these are quite useful. Until people start taking some responsibility for their own actions and poor thinking, the problems will be getting worse. And this is nothing new, like Jack said “You want truth? You can’t handle the truth.” Until people learn from their mistakes they are going to repeat them.
Chris,
No need for apologies, big words often camouflage ponci schemes as in
“investing in Elon Musk interventions”:
https://www.google.com/search?client=ms-android-huawei&ei=GiUeXeW5EKmqrgS6ipmwDg&q=investing+in+Elon+musk+interventions&oq=investing+in+Elon+musk+interventions&gs_l=mobile-gws-wiz-serp.
Chris,
No need for apologies, big words often camouflage ponci schemes as in
“investing in Elon Musk interventions”:
https://www.google.com/search?client=ms-android-huawei&ei=GiUeXeW5EKmqrgS6ipmwDg&q=investing+in+Elon+musk+interventions&oq=investing+in+Elon+musk+interventions&gs_l=mobile-gws-wiz-serp.
Sure you’re a management consultant, Chris.
You’ll never consult alone.
Since using bad high readings as some kind of proof of human culpability is FRAUD I would like to point out that the random highs caused by UHI and the intentionally/unintentionally compromised station positions as well as any idiocy of blowing heat across them is CRIMINAL in nature, not “spurious”.
Apply the correct verbage, reporting a temperature from a station that doesn’t meet the standards is a criminal act akin to yelling “fire” in a theater.
Cut no tape, call it as it is. France has committed fraud through neglect of its social services.
Hang on … What? I live in London, which according to this graph matched temperatures in France of almost 45 degrees. Only, it didn’t. It was a balmy 23 for the week.