Tag Archives: Heat wave

The fact check of the (hard to find) claim that the heat wave of 1976 was hotter than 2022

Belgium had some hot days between July 17 and July 20. As expected, the media was full of it. I noticed that around the same time some news media companies made a comparison with the summer of 1976, putting forward that it was hotter now than in the summer of 1976 and, although the number of hot days were much lower, that this doesn’t mean that its severity is being exaggerated by them.

The Flemish public broadcasting company (VRT) did a similar thing and made it into a fact check format. Here is the title of the fact check (translated from Dutch):

CHECK – No, the hot summer of 1976 was not hotter and doesn’t show that climate change doesn’t exist

I naively expected that the fact checker actually found some examples of claims that the summer of 1976 was hotter than 2022 and that this observation somehow would call climate change into question. The fact check linked to four examples that seemingly illustrate such claims, but following those links that isn’t the case…

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The air quality in Flanders is getting worse … while getting better

The VRT news item from last post not only listed how we already feel the effects of “global warming” in Flanders, but also four ways in which “climate change” will affect Flanders in the future. One of those is:

  • The air quality is getting worse. Higher temperatures lead to more ozone in the air, and also particulate matter will peak.

That statement really surprised me. When I compare to when I was a kid, air quality has improved, nay, vastly improved. Back then, there were no filters in car exhausts, factories spewed their exhaust gases directly in the air, there still was heavy industry back then, houses were heated by coal or oil,… I don’t know the age of the one who wrote this, but from my personal experience I am not really agreeing.

The two components that apparently made the difference are ozone and particulate matter. Ozone was quite a lot in the media a decade ago when we heard a lot about ozone pollution. Ozone increases under certain circumstances like heatwaves, low wind speed and wind from East, South or South-East direction, absence of precipitation or substances that break it down,,… But during the last years I didn’t hear much about it anymore. Particulate matter is different in that regard. The last years it is often in the media and described as a problem. However, in the MIRA report I couldn’t find a trend or a graph from ozone or particulate matter. So I became rather curious about how big that increase actually is, given that global warming is already here, ya know.

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Heat waves: extreme temperatures or just higher summer temperatures?

In previous post I ended rather abruptly by saying that one of the problems with the vagueness of the definition of a heat wave, is that they are difficult to compare. What I meant by that is that those of the public, who don’t catch the nuances of those different definitions, think that is being talked about exactly the same thing, while they are in fact distinctly different.

For example, when the weather (wo)men in our region talk about a heat wave, they mean a period of five consecutive days with temperatures over 25 °C of which three days with temperatures over 30 °C at Uccle (Belgium) or De Bilt (the Netherlands). We have no real problem with that because in our country we are used to 20 °C, 25 °C temperatures or even higher. But we don’t cope well with 30+ °C temperatures, especially when they last more than a couple days. These are rare occurrences in our region and we are not used to them.

Bottom line: when our weather services declare a heat wave, it is hot and we need to take measures to cope with such (rare) heat. That is the significance of the definition: it captures the extremes of a region. Extremes that could have an impact those who are weak like small children, old people or those who are ill. In our current societal structure and in our climate, we just aren’t accustomed to these temperatures.

Now enter that new definition of a heat wave: the average temperature of three consecutive days. There is no regional threshold anymore, because the investigators wanted to compare between the different countries with different local definitions. Now we see an upwards going graph:

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Heat wave definitions: if one doesn’t suit us, we will take another one

Last week we had a heat wave in Belgium. But just a day before it officially became a heat wave, it was already connected to Global Warming. The alarmist on duty is Jill Peeters, a Flemish weather woman: Jill Peeters warns: a heat wave like this one will occur once every 3 years (Dutch). In it a graph that shows heat waves in De Bilt (The Netherlands) are on the rise:

heatwave climate central

That’s odd. I have been looking for some time at the heat wave data of Belgium and the Netherlands, but as far as I could see there was no reason for alarm, on the contrary. This was nothing like I have seen in the heat wave data of the De Bilt weather station. Where did they get this result?

In a tweet she linked to Climate Central that described the analysis. They tried to find out how likely heatwaves became using “observational weather and climate data, weather forecasts and climate models”. Color me unimpressed.

Apparently they also were in quite a hurry, beside observations, they used forecasts and they presented their result in the beginning of the period in which heat waves occur and apparently couldn’t wait for a couple days… This made me guess there is an hidden agenda here. It is definitely not scientific.

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If you want to enjoy the warm weather at its best, go where the heatwave is!

Last week I got to hear that there was a heatwave in Belgium. That was odd, because I didn’t hear something of that kind in the news, nor on the meteo-website. I didn’t had much time to look into it at that time, so forgot about it for a couple days. Today I had some time on my hand and found myself looking for that announcement. It seemed to be on the VTM news of July 15, 2014.

In that news bulletin Jill Peeters (weather woman) declared a heatwave … for De Kempen. “De Kempen” is an area in the North East of Belgium. This is how it seemed to be announced (translated from Dutch):

“We officially define a heatwave when it is warmer than 25 degrees for five days in a row, from which three days are warmer than 30 degrees,” said Jill. “The coming days this will be the case in De Kempen. Tropical air is already entering our country.”

First, I can agree with her definition, except for one point. Officially a heatwave in Belgium is indeed defined as a period of at least 5 consecutive days in which the maximum temperature exceeds 25 °C (77 °F), provided that on at least 3 days in this period the maximum temperature exceeds 30 °C, but as measured … in Uccle … not somewhere in De Kempen.

Why is this so important? The definition of a heatwave is calibrated for a climatological location. Our definition of a heatwave would not make much sense for example in Spain (summer would be one continuous heatwave) or in Helsinki (there would hardly be heatwaves).

Belgium has a maritime climate, but De Kempen is a bit different. There is a sandy soil, which is drier than the regions at the coast or in the middle of Belgium (where Uccle is situated). This means that it warms up quicker there. The difference is mostly 1 °C or bit more, but can in some exceptional cases exceed 10 °C. The warmest temperature ever was measured in that region. The heatwaves of De Kempen and Uccle are not exactly comparable.

Secondly, the day the announcement was done, there wasn’t a heatwave yet, according to the definition. It only would become a confirmed heatwave in the “coming days” if the forecast was correct.

My first idea was that she wanted to declare a heatwave as soon as possible. She is known to be quite alarmist, although that doesn’t show much in her weather talks.

But I was very surprised to read this statement on the same page (translated from Dutch):

Those who wants to enjoy the warm weather at its best in the coming days, will have to go to De Kempen. Says Jill Peeters.

That was not what I expected. What happened to “Global Warming will give more extreme heatwaves” we all heard in the media only just a couple years ago? Was this the separation between her role as weather woman (bringing a weather event that people seem to be fond of) and that of alarmist (hyping the story to scare people into action)? I have to admit that the reactions of the public on heatwaves changed quite a bit. From “Ay ay ay, global warming is happening” to “Yippeekyay! Let’s enjoy this nice weather”. Or is the heatwave scare already replaced by something else?

Time will learn if some climatologist stands up and make some doom and gloom projections on heatwaves. Forecast is that next week temperatures will go up again. Probably, to be continued.

Weather is not climate, unless we say so

Plants in my garden suffering from four, euh, two months of "drought"...

Plants in my garden suffering from four months of “drought”…

Since about six months the Belgian newspaper Het Laatste Nieuws (The Latest News), seemed to be slowing climate alarmism. I first noticed this when reading their reporting on Haiyan. The reporting on it was surprisingly balanced. But yesterday they apparently couldn’t resist. They wrote an article about our warm winter and warm spring that we are experiencing now, interviewing their (alarmist) weatherwoman (from their paper edition, translated from Dutch):

[…] The weather has lost its bearings. According to official KMI terminology, it is ‘abnormally’ warm now for already five months. And except for February there was also much less rainfall than normal since December. […]
“It is no longer news that the earth is warming”, said Jill Peeters, our weatherwoman. “But when you see these numbers, then it is only becoming clearer. The average temperatures used by KMI, are over the past thirty years. If you were to compare with the start of the measurements, then the differences would be even more extreme”. […]

What happened to global warming? Belgium is roughly a whopping 0.006% of the earth. I have to admit that there are more countries than Belgium with this weather, but she forgot to mention for example the United States, where they had their coldest winter. If our warm winter is some kind of evidence that the earth is warming, why is the current cold winter in the United States or our “winter that never ended” just from last year, not evidence that the theory is not coping well? She has no problem with that (translated from Dutch):

The earth is warming up, but within that upward trend there will always be variability.

Here you have it. When it is a warm winter, apparently it is more evidence of global warming. When it is a cold winter, it is just natural variability… In that sense global warming can never be falsifiable and is always true. No matter what the observations are.

I agree that the temperatures rose in the last thirty years and even more in the last 160 years. But this doesn’t necessarily means that humans were the primary cause or that it is catastrophic in nature. It could as well be a recovery from the Little Ice Age. Looking at the longer term datasets cycles of about 60 years become visible. So her definition of 30 years for climate is only a measly half of one cycle, more specifically the upwards part of it. When one takes the satellite dataset (that should be the most accurate globally) temperatures didn’t rise much from the end of the 1970s on and it didn’t rise at all for a decade and a half now. Although we pumped an unprecedented amount of CO2 in the atmosphere during that period.

That would let the temperature rise dangerously.

By 2100.

Or so.

There seemingly wasn’t enough hyperbole until that point in the article. This is how she concludes (translated from Dutch):

The weatherwoman hopes that the weather makes a jump again. “And I’m talking mostly about the drought. If the coming months bring so little rain, then we really will really suffer a long heat wave. We should not hope for that. Nature is in full bloom, but therefor she needs plenty of water, and there is too little of that now.

While it had rained less than normal in most of those months it is not that it didn’t rain. She said that “except for February there was much less rain than normal since December”. This gives the (false) impression that it was much too dry in this period (except for one month). This is her own data:

Month Average (mm) Precipitation (mm)
December 2013 81 77.1
January 2014 76.1 70.1
February 2014 63.1 66.2
March 2014 70 18
April 2014 51.3 20.1

December 2013 and January 2014 were slightly below average, February 2014 was above average and only the two last months rainfall were well below average (before that, November 2013 was extremely wet, almost doubling the average for that month).

A couple months with below average rainfall is nothing special in Belgium. It happened before, it certainly will happen again. That is what averages are. Sometimes less, sometimes more. By the way, most projections for Belgium are about more precipitation in the future and we are told to worry about that. Now we should start worrying about droughts in the future too? Unless climate is changing within the time span of a couple months, the chance that this “drought” will last for long is very small. Even before her article went to press, a rain zone crossed our country and even more rain is forecasted for next week. So much for the drought.

I remember vividly the times that global warmers were saying that “weather is not climate” when they got stuck for an explanation. Now they even have to resort to the variability of weather to make their case…

Climate begins at the 1950s


When someone would ask “Are heatwaves increasing?”, what would you answer? Probably something like “That’s common knowledge, we all know that!”. Sure, but why? “We hear it everywhere”.

I heard it many times before and had no doubt it was true. At first glance it seems straight forward and logical. When temperatures go up (global warming, you know), the frequency of extreme temperatures go up. It has been told that the frequency of heatwaves is unprecedented and even ramping up in the last years.

I hear around me that we now live in a more extreme world. In stead of just believing this story line, I wanted to see for myself. I came to realize that this data exist. We call extremes in temperatures “heatwaves” and “coldwaves”. Okay, heatwaves increase, but the problem started when I asked myself: “How much?”. The answer was not exactly what I expected it to be…

First things first: looking for the dataset. The Belgian dataset seemed to be very hard to find and was really confusing. I found bits and pieces of it and nothing seem to match. I found that their definition of “heatwave” changed over time. That could well be the reason for these bits and pieces. The Belgian temperature dataset was not freely available either, so reconstructing it would not be possible. This wasn’t going to be easy.

But our neighbors in the North kept their records as well and, more important, they share their data with the world. It was very easy to find the list of heatwaves in De Bilt from 1900. It is not exactly what I searching for, but the situation from the Netherlands should be relatively similar. De Bilt is only a couple 100 km from Brussels. With the same definition, there will be probably somewhat more heatwaves recorded in Brussels (it is more to the South), but considering that in the average in the GISS dataset are made with stations until 1,200 km from each other, this should not be a problem.

This is what the Dutch call a heatwave (it is the current Belgian definition also):

A heatwave is a succession of minimum five summer days (maximum temperature of 25.0 °C or higher) from which minimum three tropical days (maximum temperature of 30.0 °C or higher).

I thought the heatwave data would represent extremes well. It is the threshold above which temperatures are recorded, so only the extremes are visible. The more data comes above this threshold, the more extreme the temperatures.

So I fired up Calc and loaded the KNMI data in a spreadsheet. Then I plotted it as a graph. The result was surprising. I expected, well, a steadily increase. Maybe not as steep as people suppose it is, but yet increasing. But that is not really what I saw.

Heatwaves De Bilt 1900 until 2013

Heatwaves De Bilt 1900 until 2013

It looks more like a cyclical event in which temperatures didn’t get above the threshold before 1911 and also between 1951 and 1975 (smack in the middle of the period of the rise and fall of the ice age scare).

Also, our well feared heatwaves in the 1990s and 2000s seem to be very bleak against the 1940s. I knew that the 1930s-1940s were warmer globally, but I didn’t expect to see it that clearly in the data closer to home.

The heatwave data consists of summer days (maximum temperature ≥ 25.0) and tropical days (≥ 30.0 °C or higher). The ratio between the two are about the same. One would expect with “global warming” that the tropical days increase against the summer days. It isn’t.

But, but, why do those people say that there are more heatwaves than before? Do they use other data? No, just look at just a very small selection of quotes about more heatwaves than before.

One from Belgium (translated from Dutch):

[…] Between 1981 and 2010, 10 percent of the world’s surface had to deal with extreme heat waves. That is 50 to 100 times more than the 0.1 to 0.2 percent during the period from 1951 to 1980. […]

One from The Netherlands (translated from Dutch):

[…] There were more heat waves in the last thirty years than in the fifties, sixties and seventies of the last century. […]

Not only in our little country, but also from the States:

[…] A new study examining six decades of global temperature data concludes that a sharp increase in the frequency of extremely hot summers can only be the result of human-caused global warming. […]

See a pattern emerging? They all talk about the last 60 years, the period from the 1950s, etcetera. They seem to forget there was life before 1950. If you take this period, where does that takes us in the graph? Let’s look at what they compare with:

Heatwaves De Bilt 1951 until 2013

Heatwaves De Bilt 1951 until 2013

This makes some things clear. The different time frame gives the (false) impression that:

  • this warming is unprecedented (it isn’t, there was a period with similar or even more heatwaves in the past, but when one only looks from the 1950s this could not be seen)
  • the intensity increased in the late 1990s till the half of 2000s (it did, but this happened before).
  • there were no heatwaves at the beginning of this period and then from the 1970s heatwaves start popping up (that’s true, but there was a period with a similar, even hotter temperatures, before the 1950s)
  • heatwaves are ever increasing since the 1970s (if you don’t look at the period before 1950 it is, otherwise it isn’t)
  • in 2006 the intensity increased from 1 to 2, the speed is increasing! (it was increasing, certainly when one saw this in 2006-2007, but there were identical or even bigger increases in the past).

This seems not to be much different than many things in climate communication: there is a core of truth in it, but it lacks balance. Although it is an excellent opportunity for those who want to dig into it (I learned a thing or two about climate/weather by figuring things out after being surprised by some claims), for the public this is misleading. If one only look at the data from the 1950s on, there is a reason for alarm. But that scare has more to do with a lack of perspective.

Some like it hot


Two posts ago I ended with the rhetorical question: “How long would it take before someone uses this thunderstorm to connect it with extreme weather/global warming/climate disruption?”. In the mainstream media that I normally follow there was none that seemed to try this. Not a peep. I was surprised. Just a couple years ago the media brought two full pages after two storms (see previous post).

Now we had a cold winter, followed by a cold spring, then a heatwave, after this half a dozen thunderstorms (from which two large ones) and finally the hottest day of the century with temperatures over 35 °C. One would expect cries that this is evidence of global warming, climate change or at least climate disruption. Where I usually look I found nothing. Rien du tout. Nada. Zip. Noppes.

At first I found this hard to explain. Well, time to throw in some wild theory: fear sells, but one can not sell fear of something that people are enjoying.

This is how I think it works. After a warm, dry and sunny spring, the summer of 2011 was extremely wet and dark (low number of sunshine days). People didn’t liked it much. They were fed up by that kind of summers. Then came two big thunderstorms and climatologists jostled each other to declare this the new normal. If this doesn’t get the message across: people didn’t like that summer, they didn’t like the thunderstorms and feared for the future if this was the climate that we will get.

Fast forward to today. This year we endured a cold winter and a cold spring. People were longing for the sun, for “better” weather. When it started to warm people were relieved, they enjoyed this weather. Even when there was a “heatwave”. The word that initially had a bad taste, now seemed to be a good thing. Fear tactics would not work here. If you would ask, many people would sign for such summers.

People were relieved when the storm came and began cooling down a bit after the warm weather. Plus, these storms were mostly when people were not really outside. The first one (small) one was at night, when not many were aware of it. The second (large) one was on a Saturday morning when people tend to sleep a bit longer. The storm was intense, but done in a jiffy and the rest of the day it was somewhat cooler, but really nice weather. The third (also large) thunderstorm was Sunday late in the evening. Also here, people enjoyed the cooling effect of it. Scare tactics wouldn’t work here.

I can imagine that when those hot days continues, people eventually get fed of it and then stories linking those to global warming could seep in again.

Then I looked a bit closer and in the end I found after all some stories mentioning global warming/greenhouse gases and this warmer weather. But it was not what I expected. Some things got my attention (links go to sites in Dutch).

I didn’t find any mention of global warming on the hottest days in the heatwave. I did find a lot of prevention methods for the sun: drink a lot, don’t stay in the sun for a long time, take care of the elderly and the young,… That’s fair. Although the sun is nice, it can kill the weak, we saw that in the heatwave of 2003 in France.

There seemed to be a disconnect between reporting of meteorologists and climatologists.

I don’t know if this was a coincidence, but the reporting in the press of The Netherlands was realistic, even skeptic and in the Belgium press more alarmist. The only one direct attribution of global warming with the heatwave that I could find was deliciously vague (see previous link): “Our last heatwave was three year ago. And because of global warming we will have more of them in the next years, say the climatologists”.

Another story of global warming report it elsewhere (in Alaska, Greenland, Siberia), not here at home.

And the public. Well, most of them seemed to enjoy it. Heck, a radio station even threw a “heatwave”-party! Who knows, maybe people were dreaming of the day when global warming would give us a Mediterranean style climate, that we were told just a couple years ago.

Thoughts on storms, teacups and mindsets


Until a couple weeks ago the summer of 2013 sucked big time. But then we got sunny weather at last. People were longing for a long time for this kind of weather and breathed a sigh of relief when it finally came. The coastal cities, that complained because hotel reservations were very low, now had full house. At work we heard on the radio that this weather was “extremely well”.

Then came the news that we might have a heatwave (5 days of minimum 25 °C and 3 days of minimum 30 °C). I was expecting the worse, for example people taking this heatwave directly after a bad winter and bad spring and a bad start of summer as proof of global warming (or climate change or climate disruption or whatever). To my surprise this was only minimal. Most of the reactions were extremely positive, more like “Hey, we will have a heatwave! How nice!”. I didn’t expect that. In the end we officially got our heatwave on Thursday. Most people seemed to enjoyed it, even longing for more.

After such a period of warm weather, the chance of having a thunderstorm is really high. We got one this morning. First it was cloudy, humid and rather warm. Then the first drops began to fall and from the South-West side it began to get much darker. There were impressive waving clouds and white upwelling clouds. Then lighting started and rain was pouring. After ten minutes the worst part was over. After that still lots of rain. After an hour or so the rain stopped and the sun started to shine again. We had a nice day afterwards.

Thunderstorm July 27, 2013. Image: buienradar.be

Thunderstorm July 27, 2013. Image: buienradar.be

I don’t want to minimize it. It was a hefty thunderstorm with heavy wind and loads of rain in a very short time frame. So there is a high chance it will create problems somewhere, somehow. But in my lifetime I have been through several thunderstorms before and I was not particularly alarmed by it. But I can imagine that some people would take this thunderstorm as an additional proof that climate change is real and is happening right now. You know. We tend to seek patterns around us. It is all about the mindset. If I would hear day-in-day-out that our climate is changing and we get more extreme weather because of CO2, then this storm could well fit the pattern and it comes natural to add it to the list of proofs of climate change. That is what the mindset is about. Been there, done that.

For example, when Katrina hit New Orleans in 2005, I was still a believer. Before the event I had seen a documentary about New Orleans. In that documentary a scientist explained that hurricanes hit New Orleans on a regularly basis in the past and that they were already overdue for a big one. Yet when later was said that Katrina was an example of global warming in action … I just believed it. Not bothered by this knowledge I believed the statement, because it fitted my beliefs perfectly and therefor ignoring the inconvenient piece of information. If I would still been a believer, I guess I would see this storm as proof of extreme weather. Not because of the data, but because it fitted my beliefs.

It seems inevitable. How long would it take before someone uses this thunderstorm to connect it with extreme weather/global warming/climate disruption? In four, three, two, one…