From Stanford News Service:
MEDIA ADVISORY. Stanford at AGU Fall Meeting.
Global warming’s influence on extreme weather
Understanding the cause-and-effect relationship between global warming and record-breaking weather requires asking precisely the right questions.
Extreme climate and weather events such as record high temperatures, intense downpours and severe storm surges are becoming more common in many parts of the world. But because high-quality weather records go back only about 100 years, most scientists have been reluctant to say if global warming affected particular extreme events.
On Wednesday, Dec. 17, at the American Geophysical Union’s Fall Meeting in San Francisco, Noah Diffenbaugh, an associate professor of environmental Earth system science at the Stanford School of Earth Sciences, will discuss approaches to this challenge in a talk titled “Quantifying the Influence of Observed Global Warming on the Probability of Unprecedented Extreme Climate Events.” He will focus on weather events that – at the time they occur – are more extreme than any other event in the historical record.
Diffenbaugh emphasizes that asking precisely the right question is critical for finding the correct answer.
“The media are often focused on whether global warming caused a particular event,” said Diffenbaugh, who is a senior fellow at the Stanford Woods Institute for the Environment. “The more useful question for real-world decisions is: ‘Is the probability of a particular event statistically different now compared with a climate without human influence?'”
Diffenbaugh said the research requires three elements: a long record of climate observations; a large collection of climate model experiments that accurately simulate the observed variations in climate; and advanced statistical techniques to analyze both the observations and the climate models.
One research challenge involves having just a few decades or a century of high-quality weather data with which to make sense of events that might occur once every 1,000 or 10,000 years in a theoretical climate without human influence.
But decision makers need to appreciate the influence of global warming on extreme climate and weather events.
“If we look over the last decade in the United States, there have been more than 70 events that have each caused at least $1 billion in damage, and a number of those have been considerably more costly,” said Diffenbaugh. “Understanding whether the probability of those high-impact events has changed can help us to plan for future extreme events, and to value the costs and benefits of avoiding future global warming.”
Diffenbaugh’s talk takes place Dec. 17 at 2:44 p.m. PT in Room 3005 of Moscone West, Moscone Convention Center.
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But saying that the question should be ” ‘Is the probability of a particular event statistically different now compared with a climate without human influence?’” misses the point. It should be ” ‘Is the probability of a particular event statistically different now compared with a climate without human influence and with all other known recent natural trends removed?’” The if that shows signs of a trend then science should set out to eliminate any other natural trends before concluding that human influence is a trigger. It is not many years ago since those who argued for a solar trigger and suggested that vulcanism was improperly assessed were dismissed. Not so now…
And the “precisely right question” is never, “Might all this just be natural?”.
“…Understanding the cause-and-effect relationship between global warming and record-breaking weather requires asking precisely the right questions….”
More importantly, “understanding” this putotive [!] relationship requires NOT asking any of dozens of embarrassing questions, such as:
Q: What physical mechanism would reasonably permit an increase in CO₂ of 0.01% to result in an increase in weather phenomena at both ends of the spectrum?
A: None known to humankind.
Q: How can a flat-lined temperature trend extending 18 years result in any record-breaking weather at all, beyond normal statistical variation?
A: It can easily do this in scientists’ imagination if you simply pay them enough money.
“Diffenbaugh said the research requires three elements: a long record of climate observations; a large collection of climate model experiments that accurately simulate the observed variations in climate; and advanced statistical techniques to analyze both the observations and the climate models.”
So, I make that a nice round zero out of three.
Nul points.
Diffenbaugh said the research requires three elements [the second being:] a large collection of climate model experiments that accurately simulate the observed variations in climate.
Assuming “accurate simulation”, would not one model suffice?
The “requirement” for a “large collection” exposes the fraud (as been eloquently discussed on WUWT previously; rgbatduke comes to mind.)
”
Excellent question. If the answer is of the same quality, there is nothing remonstrate about.
For, according to pure logic, relationship between probabilities of the same weather event in a particular region under human influence and without it can be one of the following three kinds:
1. probability of its occurrence is significantly higher under human influence
2. there is no statistically significant difference
3. probability of its occurrence is significantly lower under human influence
An objective scientific study, as opposed to wacky press releases, would provide an exhaustive list of weather events by region tagged with (1;2;3), irrespective of their effect on human affairs. Along with all the evidence, of course, which would make the exercise replicable.
Analysing this list for possible effects on habitability, economics, etc. is an entirely different job, requiring different expertise in a number of completely different fields, therefore one would expect an Associate Professor of Environmental Earth System Science refrain from such comments, simply because it is not a task he is supposed to be better at than anyone else.
Furthermore, if the list is large enough, one would expect the vast majority of items fall into category (2) and the rest to be divided evenly between (1) and (3). Any other result would be quite surprising, requiring an in-depth explanation.
Dr. Diffenbaugh’s statement is logically correct but as a practical matter, completely useless as we do not have two Earths, one with and one without people.
Apparently that is not how Science works any longer.
Agree that he is out of his field, but apparently that doesn’t matter any more either.
Wonder what a probability distribution could look like in computer models of climate? Taking your hypotheses (do they have those at Stanford any longer?), “one would expect the vast majority of items fall into category (2)” and ultimately accept the null that this work is no different than most of the others = quackery.
Thanks for your logic. . . however the plus thing works here.
The main influence Man has had in the “CA” part of “CAGW” is what Man has built in a weather events path.
For Man to build nothing or eliminate himself is not an option. (Even though some would propose that for us lesser mortals.)
Berényi Péter writes “…” Yeah but why do all that when you can instead cherry pick some events and compare them to model output?
Diffenbaugh asks “Understanding the cause-and-effect relationship between global warming and record-breaking weather requires asking precisely the right questions.”
Cant argue with that. One “right question” might be to wonder what climatic conditions would cause less extreme weather. It seems to me that a cooling earth isn’t going to cause less extreme conditions and so I believe their main assumption is that the earth is currently (or at least say 50 years ago) in its minimum extreme weather configuration.
These people never stop amazing me.
Sounds suspiciously like lawyers. Just the right kind of questions. If you ask the wrong questions, you lose, or worse, get ad-hom’d to bits. I call bullsh*t.
They (AGU) have gone whole hog into the CAGW realm. Is there any cautionary /skeptic/realistic presentations at all? Somebody saying ‘whoa, there other points of view’?
Seems there are pitfalls in not presenting a balanced view.
Extreme weather events are caused by the Sun. “Global” warming was caused by the Sun’s Modern Maximum. The Pause was (is) caused by the Sun’s slowdown since the Modern Maximum ended in 2002. The global cooling that is still naiscent was caused by the Sun as it started it’s decline after 2002. 2014 warm records were caused by the Sun during the recent SC24 activity peak.
The Maunder and Dalton minimums and their cold legacies were caused by a weak Sun. Post-peak SC24 cooling is imminent, to be caused by a weak Sun.
The SUN causes warming, cooling, and extreme weather events, not CO2.
Photons, protons, and electrons cause weather and climate to change, not CO2.
The clash of cold polar air with recently solar warmed heat-laden evaporated water vapor off the tropics driven by higher solar flux periods in addition to solar wind – Earth’s global electric circuit electrodynamic processes are the cause of extreme weather events.
The AGU is barking up the wrong tree.
The SUN drives the weather and climate, not CO2!
But if it’s the sun and Dr. Malinkovitch in the climate driver’s seat, then how can a societal cost of carbon (SCC) be calculated, taxes levied, and wealth transferred??……oooopps.
Milankovitch cycles work on very long time scales, well beyond the historical timeframe. Solar variability is what caused the recent “calamity”, and is what this world needs to understand more than anything right now.
You are right Joel, solar activity can’t be taxed and we can’t be made to feel responsible or guilty for it, so the subject of solar variability and its effects are ignored by the controllers who seek to imprison us in their faulty groupthink, ooooopps, I mean CO2 “science”.
“But decision makers need to appreciate the influence of global warming on extreme climate and weather events.
“If we look over the last decade in the United States, there have been more than 70 events that have each caused at least $1 billion in damage, and a number of those have been considerably more costly,” said Diffenbaugh. “Understanding whether the probability of those high-impact events has changed can help us to plan for future extreme events, and to value the costs and benefits of avoiding future global warming.””
More misleading statements from a group with self serving interests, cognitive bias and lack of scientific, authentic empirical data and evidence to support their contention.
From the American Society of Civil Engineers, Natural Hazards Review:
Reconciliation of Trends in Global and Regional Economic Losses from Weather Events: 1980-2008
http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29NH.1527-6996.0000141
“In recent years, claims have been made in venues including the authoritative reports of the Intergovernmental Panel on Climate Change (IPCC) and in testimony before the U.S. Congress that economic losses from weather events have been increasing beyond that which can be explained by societal change, based on loss data from the reinsurance industry and aggregated since 1980 at the global level. Such claims imply a contradiction with a large set of peer-reviewed studies focused on regional losses, typically over a much longer time period, which concludes that loss trends are explained entirely by societal change”
“To address this implied mismatch, this study disaggregates global losses from a widely utilized reinsurance data set into regional components and compares this disaggregation directly to the findings from the literature at the regional scale, most of which reach back much further in time. The study finds that global losses increased at a rate of $3.1 billion/year (2008 USD) from 1980?2008 and losses from North American, Asian, European, and Australian storms and floods account for 97% of the increase. In particular, North American storms, of which U.S. hurricane losses compose the bulk, account for 57% of global economic losses. Longer-term loss trends in these regions can be explained entirely by socioeconomic factors in each region such as increasing wealth, population growth, and increasing development in vulnerable areas. The remaining 3% of the global increase 1980 to 2008 is the result of losses for which regionally based studies have not yet been completed. On climate timescales, societal change is sufficient to explain the increasing costs of disasters at the global level and claims to the contrary are not supported by aggregate loss data from the reinsurance industry”
That’s just not fair – you are using DATA.
“http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29NH.1527-6996.0000141”
Succinctly discredits the claim.
If we had some wilder weather, we could blame it on global warming, if we had some global warming…
CO2 is a magic gas.
This is OT but may be of some interest.
Some time last week I downloaded the NOAA’s global land temperatures from
http://www.ncdc.noaa.gov/cag/time-series/global
then again today.
Comparing two, out of 135 records 77 have been altered, granted it is only second decimal point, a minor difference, largest being 0.03C for 1913, but even so, I wonder if this is happening on a weekly basis or what?
Here you can see both records
Is there no note to explain these changes?
Else they may be a cumulative shift instead of one-off or random.
Minor changes that are one-off and balance out isn’t really a problem, except for traceability of data.
But systematic, iterated adjustments… That would be curious.
I shall occasionally look at the data file and log the values.
Thanks V. Good spot and good luck in the monitoring.
This may be bad practise of little import or it may be acceptable practice of great import or somewhere in between.
But if we don’t know what the cumulative effect is we can’t say.
And I also thank you, vukcevic. I found the information interesting and useful. 1912 was -.95/6 the coldest year My 7 year old is interested in all thing about the Titanic. I will be showing him this.
michael
No note. And don’t ask them for their correspondence from the White House. That hard drive has failed.
I see the changes you mentioned. There may be a legit reason but many more downward adjustments were made in the past and upward for recent temps.
I would not have responded to anybody else pointing out the same thing but have tremendous respect for your gifted abilities to observe, graph, analyze and interpret empirical data.
Thanks, your comment is appreciated.
“..there may be a legit reason.” Such as ? Enlighten me.
vukcevic, the new data gives a steeper trend line, exactly the effect I have heard them accused of previously. As you say, these changes don’t amount to anything significant, but obviously many small changes over time, all of them biased steeper, would add up… That is really interesting. I couldn’t imagine them actually doing something so easily detected without valid reason behind it. Surely some skeptic out there has locally saved data from way back, which would be interesting to compare to the current data.
If we are going to stick with the effect of “observed” rather than modeled global warming, the effect should be effectively zero.
I’m getting pretty confused by this new type of global warming that doesn’t involve heat or temperature in any way…
It’s post-modern warming. It doesn’t need any of that ‘sciency’ stuff. If you ‘feel’ that it’s warmer, then it is warmer.
The Global Warming has been temporarily hiding with catastrophic sea level rise in the deep ocean while anthropogenic CO2 has been engaging in this almost two decade long stop work action (aka ‘STRIKE’) in protest against capitalism and non-believers.
The emphasis on asking the correct question that will lead to the ‘correct answer’ says it all. That is a statement akin to someone pushing a religious position not a scientific one.
OT: now that I am a confirmed AGW skeptic- are other blogs anyone is aware of (besides the wacko conspiracy places) which host real “sceptic” scientists questioning other “mainstream” consensus science? I truly believe that much of what is currently accepted in many fields of science today is not being questioned sufficiently. thanks, and keep up the anti-AGW work. I refer people here constantly.
wattsupwiththat.com is the best, but search for “Skeptical Views” on the home page. It is off to right hand side. From there, you can scroll up and down for other sites of different types.
http://www.climatedepot.com/ will direct you to articles (some good).
Scientific sites:
http://www.drroyspencer.com/
http://climateaudit.org/
Lukewarmists sites
http://judithcurry.com/
http://rogerpielkejr.blogspot.com/
‘Is the probability of a particular event statistically different now compared with a climate without human influence?’
Convoluted much?…
OT Has anyone heard any more about the Lima IPCC, or have they disappeared into the Andean Triangle? Maybe they decided to stay on a few more days and head down to the beach, get a few rays.
They are just saying it’s all a WAG
“If we look over the last decade in the United States, there have been more than 70 events …. blah blah blah”
Last decade, eh ? Shouldn’t he be linking these events to cooling then, not warming ?
Doesn’t William M. Briggs (aka Staff Sergeant Briggs) claim one should look at the data and “advanced statistical techniques” likely won’t help if there is nothing to see?
Just got ‘Error 404’ when I went looking for his classic posts, so sorry, no link.
Noah Diffenbaugh should read the history lessons of ‘tonyb’ and the collections of Paul Homewood and Steven Goddard regarding past weather events. Other things (Jimbo’s lists) could be added.
wmbriggs.com
That’s Cmdr. Briggs to you!
Well he’s got the theory of asking the right question, however like much in climate science the implementation is poor.
What the quote should say, is,
Keeping things simple, is a high ideal like asking the right questions. However “keeping it simple” should not be confused with “keeping it simple and stupid”.
“If you torture the data enough, nature will always confess” — Ronald Coase
When Michael Mann and the Team were in their heyday they were throwing down wardrobes and shelves stacked with all sorts of stuff in the path of the reality cops chasing them through the offices of CAGW Central. Now the latest crop of scientific fringe fraudsters are reduced to throwing down doilies and paper napkins as they keep on running. The cops take a break to catch their breath cos its really hard to run and laugh at the same time and The Teamsters still shout “Deniers” “Deniers” like it is meant to hurt!
Forget Hockey Schtick hokey science, this is Slapstick Science.
and to value the costs and benefits of avoiding future global warming….
It’s all about charging people more money……..
If they were really honest they would have said ‘evaluate’ in place of ‘value’.
That’s because it looks ridiculous to claim that global warming could have contributed to the lower occurrence of hurricanes and cyclones recorded during the HIATUS.
Wonder how many scientists weren’t reluctant to say “probably not”?