Gradual Trends and Extreme Events
Professor Krugman: “I’ve spent a lot of the last several days reading about climate change, extreme weather events, food prices, and so on. And one thing that became clear to me is that there’s widespread misunderstanding of the relationship between the gradual trend of rising temperatures and the extreme weather events that have become so much more common. What I’m about to say may seem obvious, because it is obvious, at least if you approach it the right way; but I still think it needs saying.”
“The point is that the usual casual denier arguments — it’s cold outside; you can’t prove that climate change did it — miss the point. What you’re looking for is a pattern. And that pattern is obvious.”
from Ryan Maue: January 2011 Global Tropical Cyclone Update
During the last 12-months on planet Earth, 68 tropical cyclones occurred. This is near the record low of 66, which was set last month. Now for over 4-years, global tropical cyclone energy and frequency has plummeted to the lowest levels observed in our historical record.
This is all the evidence that Krugman needs to convince himself of the perils of climate change. Expect to see this (tired) argument parroted throughout the mainstream (liberal) media during the next few days, and when the next storm or weather event pops up. It is almost word for word from the Trenberth AMS talk in Seattle last month.
The Climate Science Rapid Response Team at work…
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“…Second, no individual weather event can properly be said to have been “caused” by global warming. Heat waves happened 30 years ago; there’s no way to prove that any individual heat wave now might not have happened even if we hadn’t emitted all that CO2.
But the pattern should have changed: we should be getting lots of record highs, and not as many record lows — which is exactly what we do see. And we should be seeing 100-year heat waves and similar events much more often than history would have suggested likely; again, that’s what we actually do see…”
Maybe someone needs to re-define the “100-year event” they’re tossing around. If the Weather Service Records only go back 180 years or so, exactly how many “100 year events” should we have seen?
BTW, from Wikipedia:
“…The extreme value analysis only considers the most extreme event observed in a given year. So, between the large spring runoff and a heavy summer rain storm, whichever resulted in more runoff would be considered the extreme event, while the smaller event would be ignored in the analysis (even though both may have been capable of causing terrible flooding in their own right)…”
So, according to this idea, there can only be ONE 100-year event per year – worldwide. But to pad their numbers, they may consider each storm – by city, county, state, country, region – to be 100 year events.
“…There are a number of assumptions which are made to complete the analysis which determines the 100-year flood.
First, the extreme events observed in each year, must be independent from year-to-year. In other words the maximum river flow rate from 1984, can not be found to be significantly correlated with the observed flow rate in 1985. 1985 can not be correlated with 1986, and so forth.
The second assumption is that the observed extreme events must come from the same probability distribution function.
The third assumption is that the probability distribution relates to the largest storm (rainfall or river flow rate measurement) that occurs in any one year.
The fourth assumption is that the probability distribution function is stationary, meaning that the mean (average), standard deviation and max/min values are not increasing or decreasing over time. This concept is referred to as stationarity…”
So if the temps are changing, then one cannot assume that the historical data are, or can be, considered valid as input into the extreme event analysis.
Yasser Arafat, Al Gore and Paul Krugman. The nobelista has given us so much insight!
Global warming causes dyslexia.
I’m not sure it’s true, but I’m throwing it out there to be the first to make that claim.
Bold of Krugman to link the riots to AGW when even the most alarmist scientists don’t dare make such a claim. Bold and stupid.
As a caveat to the above, if you take a normal distribution and shift the mean/mode in one direction, you can increase the area under the extremes. So if you take a normal distribution with mean 0 and sd of 0.5, you get 2.3% of the curve above 1 or below -1 (4.6% “extreme events”). If you now shift the mean to 0.1, you get 3.6% of the curve above 1 and 1.4% below -1 (5% “extreme events”). If now you shift the mean/mode to 1, you get 50% of the curve exceeding 1, so 50% “extreme events”.
This all assumes a normal distribution, and that the mode/mean is exactly between the two definitions of “extreme events” to begin with.
One more thing: Global warming causes riots against oppressive regime = Global warming causes liberation?
As a friend of liberty and democarcy, I welcome AGW for liberating the people on planet earth. May Exxon Mobile win the next Nobel Peace Prize.
[ryanm: best thread comment winner: uplifting]
I think Krugman’s analysis is beautiful. It applies everything we know to be wrong about financial economics (efficient market hypothesis is wrong, fat tails are real and the normal distribution curve shown here doesn’t apply) – and applies it wrongly on many levels to climate science (predictions for extreme weather assoc with 3-4 deg rise, not now, objective evidence of temp rise lacking, objective evidence of rise in extreme weather events lacking)
In this case, many wrongs do not make a right
The fact that more weather events, among other things, are reported by the media is a function of a more global media coverage surely?
I would also opine that the global media has a predilection for reporting weather events because they are visually dramatic and have a big human interest content. I don’t even want to consider that there may be underlying sinister reasons for the media to carry these stories.
Today it is virtually impossible for a severe weather event to go unnoticed by the news aware people anywhere. In the past TV coverage was limited and the news was often local or at best regional whilst today the news is global. Here I get CNN, BBC, SKY, AJ, RTE, CCN over and above my local stations. All of these channels carry similar or identical coverage of floods, hurricanes, blizzards and so on from almost everywhere.
Because of this one gets the impression that the world is in continual meteorological turmoil and because I don’t recall this being the case when I was younger and when this country had little global news coming in it seems much worse now.
Having said all of that my own local weather seems no more or less extreme than ever it did. We get a few major downpours each year during our rainy season, every few years we get a cyclone coming in from the East, some winters are colder than others with the occasional frost but our last reported snow here was in 1948 and there are signs of glacier activity in some parts. I am a civil engineer and I have been involved with the design and construction of dams and related infrastructure here in Zimbabwe for 40 years and none of the design parameters for runoff have had to be bumped up to accommodate more extreme conditions let alone more frequent flooding.
The media has a great power over our perception of things but one has to be critical, skeptical even, to make sure we aren’t be led by letting other people think on our behalf.
The point is heightened awareness thanks to better global weather news gathering doesn’t mean there has been an “uptick” in extreme weather events. You can see that by simply, as was done with the QLD flooding, going back through the records nothing unprecedented is going on.
If “extremes” are increasing, how come that winds are weakening?
http://www.msnbc.msn.com/id/31205508/ns/us_news-environment/
If “extremes” are direct result of absolute local temperature, how come our summers are not full of extremes compared to winters, since summers are on average warmer by 20°C than winters?
If “extremes” are direct result of absolute global temperature, how come NH summer are not full of extremes compared to winter, since the global temperature during the NH summers is by 4 °C warmer than during NH winters?
If December global average was lower than monthly global averages in 1940-45, how come there are “more extremes” now?
Funny I look at the graph and see the career’s of the Team.
Its interesting first there was “CO2 global warming” with milder winters forecast and less rain (droughts) so on. Well that did not work.
Lets try climate change – yes but that inferred much the same yet we were seeing freezing temperatures.
Well lets try saying “ Scientists have been saying for decades……………..” sounds good except they haven’t.
Lets also say that warming means cooling or freezing as well (Al Gore).
That’s not working so now its “extreme events” Pathetic !!
Any weather event is now “CO2 global warming” wet, cold, drought, fires, heat wave, floods, cyclones. Grasshopper beliefs based on climate astrology. A pile of horse dung the same shape as the “probability” curve. What heap of poo.
Shevva says:
February 9, 2011 at 1:25 am
Funny I look at the graph and see the career’s of the Team.
_______________________________________
Yes. Such a shame. It used to be a hockey stick!
Mike says:
February 8, 2011 at 8:57 pm
“Most people do not have the training to follow the science in any depth. For them the issue is figuring out who to trust. I am not saying they should blindly trust authority. They should be skeptical and ask questions. But that is not what is going on on this blog or others like it.”
What you say would appear to true of at least one semi frequent commenter here.
Remember that we are talking about a temperature rise over the last 100 years of 0.35%…. OMG we’re all going to die…. how did I reach that figure…. using science and the great work of William Thompson, First Lord Kelvin…. Kelvin… remember Kelvin…. average temperature of planet Earth… 15 C = 288K.
Temperature rise 1C = 1K…. therefore % increase = 1K/288K = 0.35%….
P.S. TSI varies by about 3W/m2….. therefore %change in TSI is 3/1300 = 0.23%. Clearly the Sun has no role in AGW (sarc)
Mike says: “If your mechanic says you need a new transmission and you don’t know much about cars you might get a couple more expert opinions, and if they agree you get the new transmission.”
You are opening yourself up to getting ripped off. I have seen the TV exposures of rip-off mechanics, where a TV crew with an expert mechanic take a car with one simple problem to a large number of garages to see if the garage only fixes the problem, or invents loads of new ones to fix, thus increasing their own revenue. In these exposures, most garages ripped people off.
The trick with car maintenance (for the non-mechanically minded) is asking around everyone else you know to discover which mechanic can be trusted. Even posting details of whatever problem you are having with your car onto car forums and getting independent advice.
For example, my car recently developed a problem with the anti-lock brakes. At low speed the brakes would judder as if the ABS was activated, and at speeds above 30MPH the ABS system would shut down.
According to the main dealers for my type of car, I needed a new drive-shaft costing about 350 pounds to replace. According to several other garages, they said the same thing.
According to “independent” experts online, who had NOTHING financial to gain from their advice, they said that there is an ABS sensor ring on the drive-shaft that is probably cracked, giving a false reading, leading to the ABS system shutting down. If that ring is replaced, then the problem would be fixed and it would be a lot less expense.
I took my car to a local independent garage who I have trusted for many years, told them the symptoms of the problem, and without me even telling them that I know about the ABS ring on the drive-shaft, that is exactly what they said it would be and they replaced just that ring, for seventy two pounds. My car is now fixed.
That garage is honest and only interested in the truthful remedy for real and known problems.
Your advice would have cost me much much more than is necessary.
The same is true with “climate experts”. They are making a load of money from their fearmongering, so I am automatically suspicious. When their doom-laden prophecies are NOT coming true, and the rate of warming this century has NOT kept pace with what is necessary to create the 4 – 6 degrees warming by 2100, then I am no longer going to take the word of such “scientists” When I discover that such scientists have ignored the scientific method, acted in unprofessional ways in relation to bullying journals and editors, hidden data, deleted data and cherry-picked convenient data whilst ignoring other relevant data, then I do not trust such scientists at all.
They are the equivalent to cowboy mechanics. But then you would rather I trusted them and got ripped off!
Mike Haseler
I saw that show….. I’ll never forget it…. LMAO…..your analogy is gold!!!!!
Except…. if animals were trying to tax us, steal our cars and send us back to the dark ages we wouldn’t be laughing…. AGW Nuts….funny…. maybe….. dangerous…. definitely….
P.S. Watching Nazi Storm Troopers goose-stepping down the street is pretty funny too….. see what I mean
@- pwl
I was delighted to see one of my favourite quotes appear –
“The meaning of the world is the separation of wish and fact.” – KURT GÖDEL
I find thta when people first read it they don’t grasp its implications, to be honest after a decade of having this among my top ten aphorisms I am STILL finding new depths to its meaning.
The Korzybski quote on maps and territories is also apposite for computer modelling.
Maps are oftern useful – to the extent they share a structural similarity to the reality, but missleading to the extent they omit or distort what they portray.
Krugman’s graph is simplistic as others have pointed out, and it is based on the underlying premise that warmer temperatures result in more extreme weather in the form of droughts, floods and storms.
There is a way to test this assumption from real-world evidence, at least on a small temporal scale and at slightly less than global extent.
The El Nino/La Nina cycles might show more extreme weather during the warmer El Nino phase if warming does increase the probability of extreme events.
If the graph of storms in the article above shows any correlation with the ENSO cycle, and that is also present in drought and flood records it would be prima facia evidence that warmer temperatures are linked with more extreme weather.
Perhaps Professor Krugman could publish the data from which his probability density distributions are constructed?
Oh, and the code used to do the calculations…
…and what is the physical science basis of the vertical ‘Threshold’ line?
Billy Liar says:
February 8, 2011 at 6:13 pm
It’s odd that the record global high temperature was set on Sept 13th 1922, the record Australian high temperature on Jan 16th 1889, US high temperature on July 10th 1913, Europe high temperature on Aug 4th 1881.
The highest temperature in Antarctica was recorded at Vanda Station on Jan 5th 1974 but no-one was there before 1967.
Shouldn’t we be expecting at least one of these to be broken by relentless global warming?
———————-
Amazing how if you cherry pick the continents you can find no warming.
Here’s the Uk’s record temps for you:
England: 38.5C 101.3F in Brogdale, near Faversham, Kent on 10 August 2003
Wales: 35.2C 95.4F in Hawarden Bridge, Flintshire on 2 August 1990
Scotland: 32.9C 91.2F in Greycrook, Scottish Borders on 9 August 2003
You must now agree that based on this data the last two decades have been the warmest on record and this proves that global warming is happening. /sarc
Simon Hopkinson says:
February 8, 2011 at 5:54 pm
Yeah, I watched it when broadcast and immediately thought ‘what about the reduction in extreme events at the other end of the graph?’ See – they have drawn it as a ‘shift’ to the right – but to do that, requires there be no or many less extreme events at the other end. Logically, in practise, surely the curve will simply be spread out a ‘little’ more and squashed or flattenend at its peak?
And of course, this all assumes that we know what the normal distribution is! or what the maximum ‘normal’ extreme events are – which we don’t – at least not in a timescale of 150 years of records!
Its like saying our earth is an average size planet – (well it is to us I s’pose) – but until we started to see other sizes of objects, planets and stars, that may have been a reasonable assumption (but an assumption nonetheless) – except that nowadays we KNOW that we are but a tiny speck compared to other objects.
this is a good video of that point.
@Ken Hall “In these exposures, most garages ripped people off.”
Thank you for making this point very clear. It is a matter of common sense that neither a majority nor a minority is any guide to whether a group of advisers are right. Quantity is not quality. We even have simple catch-phrases for this common sense notion. We want “the top man” not the “mediocre average”.
The fact that AGW advocates so often rely on this “majority opinion” fallacy is indicative of just how WEAK their case is, if they can’t think of anything better than to just cite a fallacious argument.
Plus it spreads brain rot. In another topic I already start hearing people talk about the “vast weight of overwhelming consensus” as if that was a valid argument. It is frankly making everyone dumb.
Economists who live in Egypt have commented on the migration of millions of young people to urban areas, leading to labor shortages and decreasing the production of food staples, which led to the rise in food prices in Egypt. They live there and have been studying the specific situation for more than a few months.
Also: can Kruger provide the figures for the trend in food production worldwide to prove that “climate change” is leading to a decrease in total food produced?
Nik
Mike, what is it that you see on WUWT that most of us regulars don’t? I find your posts to be mostly appeals to often dubious or even fraudulent authority, and that you regularly imply that few of us can think or reason without the aid or instructions from that authority. Your use of the ‘precautionary principle’ is specious too, and excellent arguments against it abound.
I don’t have a science degree, but by examining Krugman’s arguments I am convinced that Krugman is talking nonsense, nonsense which ignores actual measurement, records of those measurements and trends derived from the records. His record as an advisor to Enron does not recommend him to me, either.
Or have I missed something that is obvious to you but not to me?
This makes no sense… why should a change in temperature imply a change in the probability of an “extreme event”, globally speaking? His whole argument implicitly assumes that there is some sort of optimum temperature for minimizing the probability of these extreme events (since they can occur at colder temperatures as well the temperature scale must be a deviation from this optimum, so the curves should not be Gaussian but Poissonian or Binomial or something). As the Earth warms then some locations must move *towards* the optimium as well as other locations moving away from it… so why the heck does he imagine that his argument stands up? I’d expect such basic conceptual errors from a journalist or other person untrained in distributions or calculus. But this guy is supposed to have a Nobel prize in a vaguely quantitative discipline (which I assume means he spent more than a few days reading up on!)!
Krugman…. It never ceases to amaze me.. how the demonstration of belief , argued vehemently, can be so completely devoid of the requisite facts..
Like saying the my electric Bill should not go up in the summer, because I never change my thermostat.(FLorida air conditioning performance and rates of radiant conductive heat gain as my point)
SO I will say It.. He is a strange Angry Bearded little man.. and I heard he smells like feta cheese and old couch(I heard it so it must be true.)
That very argument showing the bell-shaped graph of temperatures was used by the BBC in their TV program about disappearing belief in science (already reported and slated on this site)
That moving the whole of the temperature curve up slightly increases the probablitity of extreme weather considerably is a total leap of faith. Where is the evidence that temperature distribution world-wide is an exact bell curve, let alone that it might stay the same shape if the earth as a whole warmed up ? Bonkers argument. Totally unsubstantiated and virtually unprovable.
Like Simon Hopkinson, I saw this diagram on Ben Miller’s Horizon programme. It smelt wrong to me then and it still smells wrong.
I decided to follow my nose (and Ryan’s link above) to Klugman’s original article and ended up surrounded by more holes than you’d find in a Swiss cheese.
I understand the principle of the bell curve and I am quite happy to accept Professor Klugman’s suggestion that as the temperature increases so the distribution curve will shift right. I am also prepared to accept the concept of a “threshold” beyond which there will be events that can be described as “extreme”.
But this is where the Professor and I part company because I am not prepared, as he would like, to “define an extreme event as a case in which the temperature exceeds some threshold.”
That is not a scientific request, statement, or hypothesis. The Professor has missed out several rather important stages in the argument. While he tries to convince me that there is a “relationship between the gradual trend of rising temperatures and … extreme weather events” he does not attempt to make any case — convincing or otherwise — for what these events might be. He is, I assume though he doesn’t say so, trying to leave me with the impression that the 2003 European and the 2010 Russian heatwaves, and the 2010 and 2011 floods in Pakistan and Australia together with assorted other “events” that “have become so much more common” are due to global warming.
But nowhere does he make any attempt to support this statement nor the link; they are merely assertions, and the only source he quotes for an increase in the number of temperature events beyond his threshold is a cherry-picked chart from climateprogress.org giving a ratio of record highs vs record lows in the US since 1950.
Pity that 1930s and 1940s aren’t included; it might tell a different story.
So all I end up with is a chart that tells me that in a warming world I will see more warmer days and that more of these will be warmer than some arbitrary “threshold” and …. that’s it!
Sorry, Professor. Try again.