Tag Archives: Extreme Weather

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.

How not to compare thunderstorm days


This is part of my story – you might see the category: My Story first if you haven’t already (begin at the bottom of the page and work yourself up).

Since my beliefs in Global Warming had crumbled I got the desire to be able to check out some things myself and not to rely on the opinion of others. But what could I do as an interested layman to achieve this goal? The first thing I intended to do was to take a closer look at the messages that appeared in the media, but not to take them on face value as I did before. My impression until then was that the mainstream media tells a very one sided story climate-wise and it could be interesting to discover the neglected data…

This is about the first story I checked. It made an impression back then. We write August 23, 2011. A big thunderstorm crossed Belgium. I experienced it when I was at work. It was surreal: at about 10 AM it gradually got darker and darker, until it was pitch black. It seemed like it was night time. Then came the wind, rain and thunder. Afterwards we learned that it was so dark because the thundercloud was about 16 kilometer high and not much sunlight could come through. A couple days before (August 18) we also had a heavy local thunderstorm which killed 5 music lovers at Pukkelpop festival when a tent collapsed and 140 others needed medical attention.

As expected, the next day I found articles in newspapers that made the connection of these storms with Global Warming. One such story was in the newspaper Het Laatste Nieuws of August 24, 2011. The title over two full pages was: “87,000 lightings and more rain than previous storm” and subtitle (over almost one page) “Warming of the earth increases storms” (translated from Dutch):

Coincidence? Yes and no
Two very severe thunderstorms in less than a week time: could this still be a coincidence? “Yes and no” according to Luc Debontridder. It is a coincidence that these thunderstorms are so severe. But it is certain that there are more thunderstorms than in the past. We reexamined the numbers and noticed that the number of detected thunderstorms in the previous decades did increase: from on average 88 days per year in the 1980s to 94 days now. Be careful: literary every thunder-activity on Belgian area is in this number. A thunderstorm that makes havoc in for example Vlaams-Brabant, but didn’t effect Limburg, will be counted as 1 thunderstorm day. But the increase of 88 to 94 thunderstorm days is irrefutable and according to Debontridder blamed on global warming.
The prominent Belgian climate expert Jean-Pascal van Ypersele confirms this. “When the climate warms by greenhouse gases and the temperature rises, there will be more evaporation from the oceans and seas, that is the way it is. Therefor clouds will be filled with more water vapor and those clouds will turn quicker into thurderstorm clouds. I see those weather extremes increase in the next 30 to 40 years anyway, says van Ypersele.

At first glance this seemed rather balanced: according to both of them, the severity of both thunderstorms was a coincidence, but not the frequency. There doesn’t seem to be strange looking statements. But yet some things caught my attention.

[…] We reexamined the numbers […]
What do they mean by this exactly? Did they simply looked at the numbers again when the last two thunderstorms came over? Or did they reexamined/adjusted/normalized/reconstructed the historical/current data? Whatever, after this “reexamining” they noticed an increase of 6 thunderstorm days per year in comparison with the 1980s.
[…] literary every thunder-activity on Belgian area is in this number […]
It seems the author left a back-door open. It tells us that these numbers alone will not say much. A local storm will have exactly the same weight as a heavy storm over the entire country. There are 6 storm days more per year on average. This could well be small local storms. With such a way of counting this doesn’t necessarily mean a significant change.
[…] from on average 88 days per year in the 1980s to 94 days now […]
The way this is stated reminded me of a statement I read some time ago. Can’t find the reference a the moment, but here is the gist: the mean temperature of the previous decade was compared with the mean temperature of the current decade and the conclusion was that the current average was higher. But when one looked at the current trend it went down. The fact the mean was higher was because the beginning of the period was much warmer and this pulled the mean upwards. So with this in mind this statement caught my attention. It also made me wonder if there was a specific reason why they skipped the 1990s altogether and took the 1980s to compare with?

I went searching what was known about thunderstorms in Belgium. I didn’t find much (what didn’t come as a surprise at all), but found that the climate experts of the KNMI(Royal Meteorologic Institute of the Netherlands) were not so sure about this connection (translated from Dutch):

[…] To what extend climate change effects thunderstorms and lightning is difficult to determine. The data series with observations of the number of thunderstorm days are of variable quality and don’t say anything about the frequency of lightning. […]

That is an interesting statement. “Variable quality”. Probably it means no consistent measurements over time? This made me wonder if this was the same for our country? After some searching, it seems KMI (Royal Metereologic Institute of Belgium) used manual systems (which only partly detected lighting activity) and those were replaced in August 1992 by SAFIR (Système d’Alerte Foudre par Interférométrie Radioélectrique) which can detect lightnings with a high resolution. SAFIR was later extended to BELLS (BElgian Lightning Location System) with an even higher resolution.

For those who don’t yet get it: 1992 is just after their base period of the 1980s. Let me rephrase that: KMI replaced in 1992 a low resolution system with a high resolution system. So in the 1980s they used a system that didn’t detect all thunderstorms. In the 2000s they used a automatic system that detects much more thunderstorms, if not all. How did they manage to compare those two correctly? Maybe they had to adjust the previous measurement data to be able to compare those two? Is that what they meant by “reexamining” the numbers?

It is true that if you count the observed number of thunderstorm days you will find more in this decade compared to the 1980s, there is no doubt about that. But they “forgot” to mention that there are better detection methods now than back then in the 1980s.

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…

Chilling lesson from the past


When hearing about the “global warming creates cold weather”-ad hoc explanation for our cold winter/spring, it all seemed familiar to me. I definitely heard that before. In the 1970s this was also how the coming Ice Age was explained. For example, this is how Science News brought it in 1975:

The principal weather change likely to accompany the cooling trend is increased variability-alternating extremes of temperature and precipitation in any given area-which would almost certainly lower average crop yields. The cause of this increased variability can best be seen by examining upper atmosphere wind patterns that accompany cooler climate. During warm periods a “zonal circulation” predominates, in which the prevailing westerly winds of the temperate zones are swept over long distances by a few powerful high and low pressure centers. The result is a more evenly distributed pattern of weather, varying relatively little from month to month or season to season. During cooler climatic periods, however, the high-altitude winds are broken up into irregular cells by weaker and more plentiful pressure centers, causing formation of a “meridional circulation” pattern. These small, weak cells may stagnate over vast areas for many months, bringing unseasonably cold weather on one side and unseasonably warm weather on the other. Droughts and floods become more frequent and may alternate season to season, as they did last year in India. Thus, while the hemisphere as a whole is cooler, individual areas may alternately break temperature and precipitation records at both extremes.

Indeed, very familiar when comparing what is proposed now as the reason for the current cold weather. Just somewhat different word preference. Read “Jet stream” for “upper atmosphere wind patterns”, “positive phase” for “warm periods”, “negative phase” for “cooler periods”, “Blocking” for “Stagnate”.

What were/are the effects:

  • Increased variability: check.
  • Alternating extremes of temperature and precipitation. Broken up into irregular cells. Check.
  • May stagnate over vast areas for many months, Check.
  • Unseasonably cold weather on one side and unseasonably warm weather on the other, Check.
  • Droughts and floods become more frequent. Check.

These effects are not unusual for a negative phase of the Arctic Oscillation. The Arctic Oscillation was predominantly positive for the 1980s and 1990s, which had an influence on the winters in the Northern Hemisphere. One time or another it was bound to go negative again. So how can one differentiate clearly between the two when the explanation has the same effect as the natural variation? Not to mention the scientists were surprised and had to again rebuild their theory to match the new observations.

The name of the phenomenon “Arctic Oscillation” is not used because at that time the phenomenon didn’t have a name yet. It was given by Wallace and Thompson at the end of the 1990s, who seem to consider it a natural process. In the current explanations of the warm cold, the name is not stated either, probably for other reasons.

This is how they showed it graphically in 1975:

Source: Science News: Climate Change – Chilling possibilities

Compare it with current graphics:

Source: http://www.ees.rochester.edu/fehnlab/ees215/

So the same process seemed to be used to explain two opposites. In the 1970s to explain it was colder and we might go towards a new ice age. Now to explain global warming is still here and hey, it is getting colder because of “global” warming.

Flashback in La Douce France


More than a week ago I was on vacation in the South of France. The weather was rather cold and rainy, not really how I experienced it before in this time of the year. Other places in France seemed to have other weather than where I stayed. The East had a heath wave, The South-West had floods. To me it was just weather. It changes all the time. Some weather events don’t make a trend.

I was there with a friend who believes the alarmist statements. For her the case was really clear. We, humans, messed up the planet and now we get erratic weather patterns as a result. Normally I keep away of such topics with my alarmist friends. In the past I sparely reacted on this. I remember one time where the question was raised if there were more storms than before. I then pointed out that the data said otherwise, the number of storms diminished over the last decades. My friends were genuinely surprised to hear what the data really said. They were told it went UP.

This time the topic was raised that this weather was so unusual that humans clearly had a hand in this. I said that weather is chaotic and that it naturally slowly changes over several decades. This time again she seemed really surprised to hear this.

“But don’t you believe in global warming then?” she asked a bit hesitant. She knows I am green at heart and obviously didn’t see this coming. I said that there was an increase in temperatures since measurements started, but it was probably only in the order of tenths of a degree, not degrees. It also could be part of a natural cycle. She was really surprised to hear that. She thought it was in the order of ten degrees…

I suggested that those weather patterns change naturally over many decades in cycles and we could now be over the peak and maybe even going slowly downwards. In this case this cold and rainy weather isn’t necessarily due to human influences, but following a cycle. She said that nobody told her that before. Then she posed the million euro question: “Why do we think this weather is worse than before?”. Which she answered straight away: “Is it because we now have more information available to us about these events?”. I agreed with that. I also think this is one of the reasons why we view this weather as unusually bad.

When I was a kid we had a radio, a television and my parents had a subscription to one newspaper. In that time we were considered very well informed because of this. On that television there were only two channels we could view. There were some other channels, but they gave a rather snowy view which made viewing really difficult. From those two there was one Dutch and one French channel, so basically we only viewed one of them. If there was a storm or other extreme event, it had to be a really big one, otherwise we would not have noticed it. Today my television has 40+ crisp channels, on workdays I have the possibility to read two different newspapers and the internet is a huge information source. Nowadays when there is a storm or an other unusual weather pattern, however small, there is an avalanche of data from different sources.

Here I was in a remote village in the South of France and although we had no internet access whatsoever, no newspaper, no television and no radio, we learned that there was different weather in different places in France. In my youth, we probably wouldn’t even have noticed these events. We are hugely more informed than just a couple decades before. It is easy to confuse that increase in quantity of reporting with an increase in severity.

It is not because we heard less about extreme events in the past that they didn’t exist back then. It is not because there is more reporting on events that there are more of it now. Just as there weren’t less planets before because ancient astronomers only found few planets and the Hubble telescope loads more. Those planets were already there, the Hubble telescope only made them visible.

This took me back in time. I came a long way. Just four years ago I had exactly the same preconceptions as she has. It is so easy to forget where I once came from. It also made some things clear. I realized more than ever that most of the people, even if interested in the topic, only get very one-sided information. They are not being told about climate cycles, about insecurity about the data, the halt in temperature increase and so on. I am not surprised most people buy into the scare. Repeat something long enough and we tend to believe it.

Can we really be well informed about our climate if we only hear about one (alarmist) side of it?