Thursday, June 16, 2011

More extreme weather?

Whenever I talk to colleagues or friends, they take it for granted that we already see the effects of climate change, manifesting itself in more extreme and unexpected weather. John Vidal has a piece in the Guardian which sums up many instances of such changes. There are not many scientific studies among his sources but this should not count against him, if we are going to take public percpetion seriously. So what do you make of this? Is the weather getting weirder? Should we worry?


Anonymous said...
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Harry Dale Huffman said...

The short answer is a fatherly "No". For example, you show a tornado as illustration; the recent tornados in the USA are evidently being recalled. But they were not unexpected, or rare. "Tornado alley" is a well-known description across the country, expressing their common occurrence (in varying numbers and intensities) every year (records are routinely kept), just as earthquakes are well-known and common in California. Around 1990, I climbed onto the roof to watch 4 tornados at once around Denver Colorado, 25 miles away from my location (you can see a long way in Colorado, and a mile high in elevation). If anyone is worried about the weather getting out of control, worldwide and over the long-term, don't. Extreme weather events have always taken some of those who experience them by surprise, but afterwards they remember the time before (when the storm hit the next town, or the next district, or the next state where their kinfolk live), and the time before that, and they know they are like highway accidents -- they will always happen, but they are events spawned by immediate conditions, not long-term climate (which has not changed in my 63 years, and shows no sign of having changed substantially since long before America was discovered, or globally since the beginning of known history). Human memory is basically unbroken and confident on this: The old folks will tell you about the big storms of their own past, but they are quick to tell you their fathers and mothers told them of equally powerful natural disasters, and in the times of their ancestors, as far back as anyone cares to take it. And the mass of men -- of all life on the planet -- amounts to only a thin slime, just a few millimeters thick, if spread evenly over the surface of the globe. The point is, mankind is insignificant and ineffective, in a world that is naturally varying, to an extent that may be impressive or frightening to man, but is in the long-term (from season to season, or year to year, or solar cycle to solar cycle) merely repetitious after all.

Anonymous said...

@ R. Grundmann

Das Gefühl vieler Menschen über eine bereits eingesetzte Veränderung wird in diesem kurzen Film, basierend auf einem Artikel von McKibben, dem Gründer von, eindrucksvoll dargestellt:

Inwieweit dieses Gefühl wissenschaftlich untermauert werden kann, ist noch zum größten Teil unklar. Belegt ist allerdings, dass die Atmosphäre schon mehr Wasserdampf enthält (4%, Referenzzeitraum leider vergessen).

Ihr Bild ist etwas unglücklich ausgewählt. Mit dem Beispiel eines Tornados haben Sie ein Extremereignis ausgewählt, bei dem es keinen direkten Zusammenhang zwischen globaler Erwärmung und Zunahme gibt, weder gemessen noch theoretisch.


Zajko said...

Use of the blanket category "extreme weather" in this instance borders on meaninglessness, and contributes to false impressions. To throw tornadoes (especially tornadoes), hurricanes, droughts and rain together under the umbrella of "global weirding" might help make sense of these events, but is misleading. Maybe the weather is getting "weirder" - it's hard to say unless there is good data for specific phenomena. Where such data exists, it does not always point in the same direction.

Freddy Schenk said...


für die Hansestadt Hamburg

gültig von: Donnerstag, 16.06.2011 17:00 Uhr bis: Donnerstag, 16.06.2011 18:30 Uhr

Es besteht die Gefahr von Gewittern mit Starkregen 25 Liter
pro Quadratmeter und Stunde sowie orkanartigen Böen 110 km/h
Stärke 11), und Hagel.

Eigentlich ein normales Sommergewitter, oder? Wenn man aber dann die Warnstufe "ROT" sieht und UNWETTER-Warnung liest, bekommt man eben schnell den Eindruck es handele sich um Extremwetter - was es aber nicht ist. Da inzwischen lieber zu viel als zu wenig gewarnt wird, mag subjektiv der Eindruck entstehen, dass es früher weniger Warnung = Extreme gab.

Der psychologische Effekt ist ggf. nicht zu vernachlässigen. Aber auch eine Abstumpfung erscheint nach einiger Zeit denkbar.

@ReinerGrundmann said...

Harry, Andreas

I chose the picture because it is the picture which accompanies the article in the Guardian. But I am sure that any other picture (dry soil, flooding, etc) would have been equally apt or misleading.


I take your point about insufficient data, but such an argument frames the issue as a scientific problem (which it is, of course, too). The insufficient data argument does not (and cannot) address the question if the public perception is of a certain kind (namely that we already witness climate change), and what might follow from it.

Zajko said...

These articles are typically a mix of scientific claims/expert quotes and climate common sense. I think you're correct in that many people have now adopted such common sense as a way of making sense of the weather. For others such claims feed skepticism. What are the consequences? On the one hand climate change is made real for many people, but it is a type of climate change largely defined and brought into focus by highly-visible and often spectacular events. While it has been argued that this can distract from the real sources of disaster risk (social vulnerability), I think it is also possible that this may lead people to take disaster preparedness more seriously, since a key part of such claims is that we will experience a whole lot more of [enter weather disaster here] in the future. This doesn't stop me from being troubled by the fact that the quickest way to climate awareness seems to be on the back of what is often the weakest of scientific evidence (or the existence of evidence to the contrary).
Interesting quote from Gavin Schmidt at dot earth (May 4):

"...the close emotional connection between weather and climate means that climate scientists are *always* being asked what connection there is between extreme weather and climate. This will also often be the only exposure the TV news gives any climate scientists at all. This is not going to change."

Maybe the fundamental media logic won't change, but the way journalists and experts build these stories just might. There has been some good reporting on this issue already, along with the bad. However, this extreme weather business seems to be the one aspect of the climate issue that has some momentum at the moment, and I expect stories promoting a fairly straightforward link be the new normal.

Anonymous said...

Germany's nuclear shutdown by 2022 wasn't caused by scientific studies on risks, rather by people's emotions.

So the extreme weather events in 2010 and 2011 could be a turning point in the perception of climate change. And who knows, maybe it will help to push the stumbling climate policy.

Is it important to know, if the disasters in 2010/11 were influenced by global warming or happened by accident?

I think another issue is more important:
People can see and experience nowadays, what climate change is supposed to be in future times.


Freddy Schenk said...

Extremes are by definition rare, so long homogeneous observations are needed being mostly not available. Many extremes are local to regional. So you might have more frequent or intense extremes in one region and less in another. If you want to explain a singular extreme event or ongoing changes in the weather statistics at a given region you need to analyse and understand the related regional synoptic situations. Then estimate if sth. “unusual” is going on (again long time scales needed). If so, can you attribute it to “unusual” behaviour of the large-scale circulation? If so, can you attribute it to external forcing (e.g. CO2) or internal variations (e.g. ENSO). Might e.g. ENSO already be influenced by changes in external forcing? And finally who is who in Katmandu based on relatively short observations? Voting for climate change as explanation of extremes is consequently based on weak statistical evidence and complicated or unknown physical reasoning.

A good example is the second paragraph in the article above:

Welcome to the climate rollercoaster, or what is being coined the "new normal" of weather. What was, until quite recently, predictable, temperate, mild and equable British weather, guaranteed to be warmish and wettish, ensuring green lawns in August, now sees the seasons reversed and temperature and rainfall records broken almost every year […]

Two simple explanations are available here on first glance: These extremes coincide with “unusual” low westerly flow (incl. a record breaking negative NAO phase) and atmospheric blocking allowing direct meridional advection of heat/cold from subtropical/arctic regions. If you want to attribute the observed extremes to climate change you need to attribute also the circulation anomalies to climate change or at least show that there might be an increased likelihood for such anomalies incl. a physical hint why this should be the case.

According to my (limited) knowledge there is no clear evidence for such a conclusion neither from observations nor from numerical simulations (models don’t agree in this point).

On the second glance, many additional maybe more sophisticated explanations might be possible like e.g. that the observed circulation anomalies (patterns) are part of natural variability but lead to modified local/regional impacts due to changes within the transported air masses etc. E.g. Hartmut Grassl in many talks refers to Clausius-Clapeyron when talking about global warming as a very simplified thermodynamic argument what might happen if…

From the past historical climate since 1500 AD we know a lot of such extremes observed in recent years i.e. for England and Central Europe (maybe not the >6 K heat wave in 2010 in E-Europe, see also Hot summer of 2010). Since around 1500 AD, I found in my master thesis most extreme events (unusual severe weather conditions on daily to monthly scale) for the Baltic Sea region clearly linked to strong anomalies of NAO albeit additional factors contributed. It was partly shocking how extreme it can get just from more or less natural variability. I think this is a lesson not learned in the public discussion or media… natural variability can already be quite extreme… as extremes are rare, not many have experienced it... But maybe ask your grand parents…

@ReinerGrundmann said...


you may be right but ordinary people don't care about ENSOs, NAO or Clausius. See my previous comment which asks the question: what if people perceive more extreme weather events and see them as manifestation of climate change?

Freddy Schenk said...

what if people perceive more extreme weather events and ...

You mean just hypothetical? Or
is there any broad statistical evidence that people (and how many) indeed perceive more extreme events? In the media it looks like - but do ordinary people too? Or maybe only if being asked by a scientist or journalist?

If you read the comments below such articles, not many share the oppinion of such journalists and many "ordinary" people are much more educated about the topic than the journalist seems to be.

However, it could be that those who agree are fine and don't proceed to the comments. And others just don't care completely.

For me it is still totally unclear what people really perceive or think and what we suppose they might do. But I even don't know why most scientist don't refer recent extremes to historical extremes or don't attribute it to circulation anomalies. Laziness? They don't know? Or don't like natural variations? It's inconvenient truth when spreading arlamistic messages?

"...natural variability can already be quite extreme..." is maybe not fitting to climate alarmist's mainstream both, for scientists and journalists?

So what ordinary people should perceive and attribute?

Werner Krauss said...

The Guardian article is a sermon from inside the temples of nature (to paraphrase Hoelderlin). Even the scientists stand in awe - they are also only witnesses. In this article, everything is connected - what we do, the climate and the places where we live, as well as all places in this world.

It is an enchanted world, not a dead (scientific) one. The main message is not climate change; the main message is that we live in a dis-enchanted world. That's the sin. That's why science is of no use here anymore except to give testimony that the end is near.

Just watch the video Andreas already has recommended above - it perfectly adds the emotion to the text:

It's a beautiful world, and it's a fragile world. No doubt, you can see it in this video. Can't you?

In the center of the article, there is the example of Texas, where there is a drought and bush-fires are currently stronger than ever. (about the symbolic meaning of the burning bush, read here: All the biblical plagues haunt Texas these days, also in the town of Lubbock, as we learn from the Guardian article. Lubbock? I know Lubbock quite well:

In their famous hit "Lubbock or leave it", the local pop group Dixie Chicks give an ambivalent (but nonetheless correct) portrait of Lubbock:

"Dust bowl, Bible belt / Got more churches than trees / Raise me, praise me, couldn't save me / Couldn't keep me on my knees /
oh, boy, rave on down loop 289 /
That'll be the day you see me back /
In this fool's paradise"

In the Guardian article, we read this about Lubbock, Texas:

"I don't know how much more we can take," says John Butcher, a peanut and cotton farmer near Lubbock, Texas. "It's dry like we have never seen it before. I don't remember anything like this. We may lose everything."

Is it already worse than the dust bowl which brought so much misery and inspired so many gospel-folksongs? Such as the one by Hank Williams "I won't get out of this world alive". The Dixie Chicks remind us at the end of their song, that each time you try to get out of Lubbock by plane, you are reminded of the face of Buddy Holly - the famous rock'n roller and son of Lubbock, who died in an airplane crash... Lubbock is identical with the world in times of climate change - there is no way out alive, unless you ...change your life.

Thus, the Guardian article is not really about climate change in the scientific sense of the term. It's a sermon, a gospel, and it's a prayer. You cannot argue with prayers. But, of course, you can acknowledge this kind of perception and its ethics and make them a base for climate policies, as for example Wardekker, Petersen and van der Sluijs (2009, Global Environmental Change 19, 512-521) suggest:

"Religious framings of climate change resonate with the electorates of both progressive and conservative politicians and could serve as bridging devices for bipartisan climate-policy initiatives".

Thus, it's not about who is wrong or right - science or public perception, skeptics or alarmists. It's about where they can meet in order to start effective climate policies.

I think both could accept the final words of the Guardian article:

"The WMO concludes, tentatively, that global weather will now return to something approaching normal. The trouble is, no one is too sure what normal is any more."

@ReinerGrundmann said...


I don't think the question is what the public should think but what they actually think. We know something about this (more research is needed!). The BBC survey from Feb 2010 found that 75% think climate change is happening. According to a Gallup poll, only 49% of US citizens hold this view. Hans's small survey on a cruise ship had 91% in this category.

It would be good to ask respondents why they think that climate change is already happening. My guess is that many would quote the 'weird' weather.


"it's not about who is wrong or right - science or public perception, skeptics or alarmists. It's about where they can meet in order to start effective climate policies"

I agree with this. But bear in mind that some skeptics will always insist that climate policies are not warranted before the scientific proof of anthropogenic causes is in. And the alarmists respond that there is enough evidence (and consensus), if not proof. This has led to the unproductive situation where we a gridlocked over the science.

Maybe a new approach, taking into account what citizens think and perceive is in order. In no other policy field do we wait for scientific debates to be settled before we act.

Werner Krauss said...

Reiner, I agree with your caveat concerning skeptics / alarmists; indeed, once framed in this constellation, it all too easily leads to a gridlock. But besides this, different perceptions (religious / scientific for example; apocalyptic / moderate; different education levels etc) are not necessarily a problem on the way to start action concerning new ways of energy use, emission control, etc...there are also many examples when those who hate everything "Green" are eager to participate in energy activities on a community level etc. I think this is indeed a lesson to learn for climate science: climate is always about people, too.
Furthermore, science is not a neutral language; it is framing information, as do other ways of climate knowledge (burning bushes, for example). In the end, it is undecidable whether recent extreme weather events are a sign of climate change or not. Important is a common concern about weather and climate.
Once different views and perceptions are acknowledged, people start to listen to the expert in new ways; once they don't have to defend their view vis à vis the expert, the road is paved to real communication.

Mathis Hampel said...

you raise some interesting points. For example when you mention climate policies I am wondering on which authoritative basis they rest.
In your opinion why do we grant science authority on extreme weather. What are the foundations of this authority if - as Arendt argues - authority is between persuasion and force. This would mean that I do not have to persuade anyone that extreme weather is due to AGW since 'anyone' simply accepts it (as the majority seems to do) due to science' alleged authority. Arendt also notes that authority rooted in ancestors, tradition or religion belongs to the past. What about science then?


Anonymous said...

As far as I remember, two of the most famous german climate scientists (Rahmstorf and Latif) explained how and when they noticed that climate change was a very serious threat for mankind.

This happened shortly after the famous german "Elbeflut". I thought that these thoughts were very unscientific.

"A Shifting Band of Rain

By mapping equatorial rainfall since A.D. 800, scientists have figured out how tropical weather may change through 2100
By Julian P. Sachs and Conor L. Myhrvold | March 7, 2011" (Scientific American)

What they also figured out: This rain belt shifted (dramatically?) to the south during the little iceage and shifted back afterwards until it holds today the same position than during the medieval warmperiopd.

Where we have historical weather data, they show us that nothing ist still extreme today. It might become extreme until 2100, but today we have reached the same level than 900 years ago. Would a next little iceage really be less dramatic?

Hey, the tropical rain belt would drift dramatically to the south. Yes we know now that it did.

So what do we really know and can we really expect a static climate?

Any kind of "Bauchgefühl" has nothing to do with science. So why ist climate science poisened by this "Bauchgefühl".

Yes my English is very bad, sorry. ;-)


Anonymous said...

The "new normal" goes on:

China evacuates 500,000 as flooding breaks worst drought in 50 years


Werner Krauss said...

@Mathis #15

We shouldn't reduce climate policy to AGW only. Just an idea: isn't climate policy also based on the authority of weather and climate? AGW or not, we have to adapt to climate effects, to weather events - extreme or not. The same is true for mitigation: of course, we need sustainable energy policies and have to substitute coal and oil in the long run - those resources are not endless, and they are politically and environmentally problematic to say the least. We always had climate policies, consciously or not.

The only difference to former climate policies is: we are more aware than ever that we have to design our environment carefully and not in neglect of things natural - atmosphere included.
AGW is "just" an additional problem for climate policies, not it's only legitimization. (and in effect, it adds urgency, but not a total change in climate policies which deal with adaptation and mitigation anyway).

Anonymous said...

Ein wunderbarer Artikel des Guardians! Endlich ist der menschengemachte Klimawandel bewiesen ohne so komplizierte Zahlen und Statistiken, die ich sowieso nicht verstehe. Die anekdotische Aufzählung von ein paar Ereignissen reicht mir völlig. Auch die Aussagen vom "peanut farmer near Lubbock" sind ein glasklarer Beweis. Auch die Zunahme der versicherten Schäden hat sicher nichts mit der Zunahme an Versicherungsverträgen zu tun, sondern nur mit der Zunahme an Extrmwettern. Diese Grösse ist auch viel genauer als z.B. eine Angabe der Temperaturvarianz. Oder die Zunahme an "pitched roofs" in Nepal ist viel genauer als jede Regenstatistik. Der wichtigste Satz am Schluss: "no one is too sure what normal is any more"! Somit ist ALLES was in Zukunft passiert abnormal und beweist den menschengemachten Klimawandel!

Werner Krauss said...

This is the real climate rollercoaster: next day, in the very same Guardian, we read that we are entering into a phase similar to the Maunder minimum, maybe a new ice-age is coming:

Hej, that's real climate rollercoaster - yesterday the world was getting warmer; tomorrow it will get colder, and I, well, I don't know what I shall wear today...

Anonymous said...

Werner Krauss, that's quite the misinterpretation of that Guardian article. Of all the experts cited, none think an ice age is a-coming.


Mathis Hampel said...


I agree. When you write "isn't climate policy also based on the authority of weather and climate?" I wonder who the legitimate spokesperson of weather and climate is (and why). In your comments you often play with people's "irrational" responses to climate change. If policies should rest on science this rationality seems to be in stark contrast to people's 'irrationality'. This suggests mitigation policies a la "Hartwell".

But what about adaptation. In what authority can we ground climate adaptation policies? Doesnt it make sense to speak of weather risk since we can only learn from past weather (using climate models as heuristic). Who can authoritatively speak of past weather and why? Again, it seems that people's 'irrational' memories do not necessarily agree with science' rationality. How to think about adaptation policies then?


Werner Krauss said...

@barn #21
You are absolutely right. I already anticipated comments from AGW skeptics; see discussions here

and here

Anonymous said...

Extremwetter 1974 und ihre Ursachen. Muss man gelesen haben:

Mathis Hampel said...

Adaptation is different from mitigation, mitigation supposedly concerns all of us (some more some less) while adaptation arguably concerns only the vulnerable sectors/people. First we need to know who the vulnerable are and according to whose standards they are vulnerable. Then we need policies that are grounded in authority. Science can speak authoritatively about past weather, though it is less clear why/and who “science” is and how it became authoritative. Also it has no global authority...

Freddy Schenk said...


delayed response on #13:

It would be good to ask respondents why they think that climate change is already happening. My guess is that many would quote the 'weird' weather.

That was also my point: WHY do they think climate is changing?

For most people it will be related to weather anomalies. But the interesting questions is if they relate it to anomalies THEY have experienced or just those extremes having watched in the media all the time (sort of "globalised experience of extremes").

Maybe a poll should go in this directions:

Why do you think climate change is happening?

1) collect first open answers

suggest now different reasons:

2) personally experienced changes
a) more extreme weather
b) seasonal shifts
c) changes in vegetation

3) not personally experienced changes (TV, other media etc.)
a) more extreme weather
b) seasonal shifts
c) changes in vegetation
d) changes of atmospheric state variables reported by science etc.
e) changes in aquatic state variables

Of course these questions should be more precise and adjusted to ordinary people's level. I just wanted to suggest to which direction it might go...

The same poll should also be made for scientists for comparison.

@ReinerGrundmann said...


it would be a good idea to include a question about the reasons for their belief in future surveys (also in Hans von Storch's as discussed on the other thread).

However, I am less convinced that you can neatly separate personal experience from mediated experience just by posing a question to this effect. If you wanted to find out you would need a whole set of different additional questions, taking into account their media consumption, and who or what they use (and trust) as news source (media, friends, specific people/experts, etc).

Freddy Schenk said...

I am less convinced that you can neatly separate personal experience from mediated experience just by posing a question to this effect.

You're right. But it might be quite important to adress personal vs. mediated experiences here.

fmassen said...

@ anonymous:
I repeatably read the last months that the atmosphere is getting more "humid", holding more water(vapour) than previously (anonymous says +4%).
The excellent website of Prof. Ole Humlum shows that total water column, as well as columns at different altitudes have not increased (either constant or possibly small diminishing trend). As thse graphs come from actual observational data, not models,I tend to believe the former.

Werner Krauss said...

@Mathis #22
Maybe the differentiation "rational" versus "irrational" is not fair. The Guardian article is not "irrational". You and I, we easily understand it. That's the interesting part. We should accept multiple voices, narratives, discourses, instead of discrediting them as "irrational".
On the other hand, we shouldn't overburden science. We should leave science with all their uncertainties, possibilities and open questions instead of restricting them to their political role as legitimization of power. They are much more useful when we let them play.
Good policies are based on the choir of the many voices of a polyphonic orchestra. We should accept different voices and acknowledge their own rationalities. This leads to much more consensual and sustainable policies.

Just one thought: Do people really have opinions just like they have cars or houses?
Or do we just want them to have opinions in order to create a "public" that can be governed and educated? (I just stumbled about the repeatedly "they" in your comments.)

wflamme said...

With temperatures becoming more evenly distributed due to GW (poles/tropics, day/night) I would probably expect a slight decrease in the frequency of stormy conditions. OTOH we might expect an overall increase in hurricanes, thunderstorms and related intense precipitation. However monitoring Schumann wave intensity (as a proxy for global thunderstorm activity) to my knowledge didn't confirm any significant changes. If there's an ongoing change, it appears to be slow.

So I'm not very concerned because I expect the pace of change in human affairs to remain doinant in this respect.

Freddy Schenk said...

Do people really have opinions just like they have cars or houses?

I don't have a car ;-)

(I just stumbled about the repeatedly "they" in your comments.)

"They" was referred to "ordinary people" - what ever that means - who might answer a survey. I think there might be a tendency that we want people to have an opionion on climate change, don't we? However, others might not answer the poll?

Werner Krauss said...

@Freddy #33

"I think there might be a tendency that we want people to have an opionion on climate change, don't we?"

Hm. What?

Stan said...

The perception that there may be extreme weather happening now should be accorded the same respect and consideration accorded other similar perceptions, e.g. Chicken Little's perception that the sky was falling.

jgdes said...

In more enlightened times meteorologists were more worried about the jet stream behaviour that was causing many of these extremes. Is there something happening to the jet stream and if so, is it more related to solar phenomena where we at least have some theory to guide us. By contrast there is zero theory that links carbon dioxide to weather extremes. And the Trenberth 4% extra water vapour explanation is utterly risible.

@ReinerGrundmann said...

your comment misses the point of the post. Of course you can go on patronizing and belittling the public but what if they are right and the sky is falling?
And if they are not right we have to live with the consequences of this perception, if we like it or not. This is self-evident (call it truth) in democracies, and known in Sociology as the Thomas theorem.

Stan said...


You apparently missed the point of my comment. Unsubstantiated perceptions shouldn't be accorded any merit by policymakers (govt officials). A lot of people might be convinced that George Bush or Barack Obama were engaged in a plot to destroy America, but without any substantiation they should be ignored. Even if the consequences of the destruction of America might be regarded by some as a significant problem.

Obviously, if the belief became widespread enough, it could have political repercussions in a democracy -- but that's just a truism of politics.

Chicken Little's perception was wrong, even after it was accepted by Turkey Lurkey and the rest of the gang.

@ReinerGrundmann said...

"A lot of people might be convinced that George Bush or Barack Obama were engaged in a plot to destroy America, but without any substantiation they should be ignored"

Who would be able to ignore them? If they are the majority they would chase Bush (or Obama) out of government.