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Rapid attribution of PNW heatwave

Summary: It was almost impossible for the temperatures seen recently in the Pacific North West heatwave to have occurred without global warming. And only improbable with it.

It’s been clear for at least a decade that global warming has been in general increasing the intensity of heat waves, with clear trends in observed maximum temperatures that match what climate models have been predicting. For the specific situation in the Pacific NorthWest at the end of June, we now have the first attribution analysis from the World Weather Attribution group – a consortium of climate experts from around the world working on extreme event attribution. Their preprint (Philip et al.) is available here.

Trends in Tmax globally

In the paper, they show that this event was truly exceptional in the temperature statistics in the region and specifically in Vancouver, Seattle and Portland, but that the geopotential height anomaly (one measure of the ‘heat dome’ or the ridging) was not that far off from the underlying trends. Using various methods to construct the return time for this event, they show that even in today’s climate this was a one in 400 yrs or longer event. Using only data from before 2021, an anomaly this large is estimated to never occur!

What happened?

Everyone is agreed that the specific synoptic situation is unusual. A large ‘omega’ pattern (so-called because of the resemblance to the Greek letter \Omega) set up by a Rossby wave breaking event, intersecting with the topography and the warm temperatures to the south-west that were advected to the PNW. But the question is whether the temperature extremes are being made substantially more likely by underlying climate changes.

First, look the maximum annual daily temperature in the region (according to the ERA5 reanalysis for the historical data and the actual weather forecast analyses since June 1st). There is a real trend of about 4ºC over the last 70 years – roughly 3 to 4 times the trend in the global mean temperature. Nonetheless, the magnitude of the regional anomaly is more than 5ºC above the previous record. That is, literally, phenomenal.

ERA5 regional temperature anomaly
Figure 4 from Philip et al., (preprint).

The temperature anomaly at the local station level is similarly huge at SeaTac airport, Portland International Airport and New Westminster (nr. Vancouver). Note that while the cities might be affected by urban heat island effects that would exacerbate the temperature signal, that would not affect the regional analysis above, nor the situation in village of Lytton, BC which set a massive new all-time Canada-wide temperature record on Tuesday June 29th and promptly burnt down a day later.

However, the situation is a little different if you look at the geopotential height anomalies – these are affected by the synoptic situation as well as the integrated temperature anomalies. In that case, while still record-breaking, the anomaly is not totally beyond expectations. Indeed, the trend in z500 values is similar to the situation in Western Europe last year.

Geopotential maxima trends

Together these analyses suggest a synoptic situation that is rare, but not inconceivable, but with temperature anomalies that are off the charts.


The way that attribution for extreme events works (as discussed previously on RealClimate here and here etc.) is that you look at the situation with and without the anthropogenic global warming signal and calculate the ratio of probabilities. If an event is say, twice as common with the GW, then one can give a fractional attribution of 50% to anthropogenic forcing and the return time is half what it used to be. If it is five times more likely, the attribution is 80% = 100*(5-1)/5 and the return time is a fifth of what it used to be. In this case, we are seeing probability ratios of 150 to 1000s, suggesting that these, improbable, temperatures can be almost entirely attributed to global warming. Without the anthropogenic signal, temperatures this extreme wouldn’t have happened in thousands to tens of thousands of years.

Figure 8 in Philip et al: The GEV fit to the regional anomaly and the probability of regional temperature extremes with and without anthropogenic warming.

Rainfall and soil moisture deficits as a precursor?

In many previous extreme heat events, such as the 2003 European heatwave, rainfall deficits and dry soils the prior spring were shown to have made an important contribution to the temperature extremes, and so it’s worth looking at the same phenomena here. The IMERG data which are mostly based on satellite rainfall amounts do show a moderate deficit in the area over the last four months, but not so much of an effect that it could explain the anomaly on it’s own. The magnitude of this effect will be examined further in the months to come.

Preceding precipitation anomaly

All models are wrong?

This kind of attribution is of course only as good as the models being used. In such a rapid attribution study, that means that the authors depend on an existing database – in this case, from CMIP5 and CMIP6 – and while they screen the models for fidelity in matching this genre of event, it’s possible that there are systematic issues with this class of model for a specific aspect of the situation. For instance, Mann et al., (2018) find that the CMIP5 models have a poor representation of a quasi-resonant (QR) phenomena in jet stream waves that are associated with the ‘omega’ pattern blocking event seen here. [Update: the specific claim in the paper relates to oscillations with wavenumber 6-8, while this event was more of a wavenumber 4 phenomena – see comment #9 below]. The expected trends in QR suggest an increase of about 30% in such events today over the situation in the pre-industrial. If models don’t capture this behaviour, it will make the event seem more unlikely than it really is. This might be resolved in higher resolution modeling specific to this event, but doesn’t really affect the broader conclusions.

Maybe it was just really, really, really unlikely?

Some people still reject these lines of argument, typical of this is Cliff Mass in this recent blog post. For them, the trends in max temperatures are (literally) ignored, and the fact that this phenomenon is being seen around the world is just a series of increasing unlikely combinations of factors that for some inexplicable reason keep happening. But this is really just a case of synoptic myopia – paying too much close attention to the series of specific events that lead to the specific situation, and not seeing the wood for the (burning) trees.

p.s. (8 July): In 2012 we published the highly relevant post Extremely hot, starting like this:

One claim frequently heard regarding extreme heat waves goes something like this: ”Since this heat wave broke the previous record by 5 °C, global warming can’t have much to do with it since that has been only 1 °C over the 20th century”. Here we explain why we find this logic doubly flawed.

Pretty much exactly what happened! And it ends thus:

So in summary: even in the most simple, linear case of a shift in the normal distribution, the probability for “outlandish” heat records increases greatly due to global warming. But the more outlandish a record is, the more would we suspect that non-linear feedbacks are at play – which could increase their likelihood even more.


  1. M.E. Mann, S. Rahmstorf, K. Kornhuber, B.A. Steinman, S.K. Miller, S. Petri, and D. Coumou, "Projected changes in persistent extreme summer weather events: The role of quasi-resonant amplification", Science Advances, vol. 4, pp. eaat3272, 2018.

200 Responses to “Rapid attribution of PNW heatwave”

  1. 101
    Killian says:

    85 Michael Corn

    While Cliff does not call himself a climate change denier, he is clearly a climate change minimizer.

    This is a distinction without a difference, like saying guns don’t kill, people do.


    We’re trying to save EArth, et al., eh? Bore Hole, please:

    67 Piotr

    55 nigelj

    84 Swallow

  2. 102
    Carbomontanus says:

    @ Dr.R. Climate:


    :/Blow boys blow
    to Californai oh
    There`s plenty of gold
    so I am told
    on the banks of Sacramento/:

    We have that tune also here.

    “as I was walking down the street
    :/to my oh da/:
    A pitty girl I came to see
    to my oh da oh da day
    oh boys
    Blow boyus blow..”

    Even in Hamburg. De Hamborger Viermaster, that was quite shabby.

    As dat Schepp so wörn ok de Kaptein
    :/To my oh da…/:
    De Lüd vor dat Ship wörn ok bloss schanghait
    to my oh da oh da day
    oh boys
    Blow boys blow..

    Schanghait means that you are asked on board for a cheap schnapps,

    and wake up again on high sea as cheap crew.

    But they knew methods. The Boss happened to be Norwegian, supposed to lead the songs also for the work on board. So he sang:

    Og vil de no seile
    ek seg dat ja nur
    :/to my oh da/:

    Da løper tri akter og fir i retur…

    (That was the munity).

    Well Hr schmidt, this is in order to suggest that Stefan Rahmstorf should be asked now to comment on the rain and flood cathastrophy in Rheinland Pfalz, Westfalen, and the Rijn- Maas- and Waal- delta. Where it looks severe.

    Normal perscipitation maximum here in the western european monsune is end of July and beginning of August, but very variable. I have seen a handwidth high in a jug under open sky in one day near Bremen. But what happens now is obviously a bit more. Köln reports 5 inches a day for longer times and over wider areas.

    We call it Mari Vassause and Jacob våthatt, that is noted at 20 & 24 july.

    If you check up the 4 seasons of Vivaldi, you will recognize that the end of summer is characterizede by thunderstorms. The same is normal center of hurricane season in the west indies.

    Aristoteles was right on this allready 2400 years ago, stating that “what goes up must aloso come down”.

    That was before the invention of the space rockets.

    But Aristoteles principle does still rule for possible moisture in the atmosphere and at higher temperatures, which explains it all.

    I once experienced late summer rain and riverflow in north Italia. Dry riverbeds with only a creek in the middle were all crowded with camping waggons on cheapest ground. In just a few hours that grew up to large mighty rivers, where the narrow exit gates through the obviously traditional and meaningful river walls everywhere in the villages were all clogged with waggons and tourists inside.

    When will people learn?

    Having come well over in Bavaria, we drove aside and slept in the car. There were not just kits and dogs, there were long frogs falling down on our tin- roof all the night.

    Vivaldi had a point there.

    Also take a look at the lower Bramaputra river downstream from the Assam province, with Mari Vassause against the Himalaya in the late summer season, which may be the most dramatic monsune rain season on earth.

  3. 103
    Richard Brenne says:

    While Cliff Mass has a great understanding of PNW weather, he appears to have an ideology that includes almost literally worshipping natural variability with very little understanding of the baseline shift of climate change.

    If climate change is changing the behavior of the jet stream as Jennifer Francis and others belief (regardless of whether it’s her mechanism of Arctic warming reducing the temperature differential with lower latitudes that historically drove a more vigorous west to east jet stream with a lower amplitude of waves or another), then that could’ve increased the likelihood of the Omega-shaped heat dome that was centered in southern British Columbia for so many days that caused the late June PNW heat wave.

    Mass says that climate change only increased that heat wave and all others by the two degrees F of global average temperature increase. And he says so with absolute certainty – a language actual publishing scientists in the field (or any other field) don’t use.

    And so he’s amassed an army of climate change deniers or delayers or whatever who are convinced he’s right, and that the vast majority of publishing atmospheric scientists who specialize in attribution are wrong.

    If you read their comments on his blog, their breathless adoration of him – evidently the only scientists they’ve ever had that much contact with – comes very close to the definition of a cult.

    Given what climate change is doing and will do to current and all future generations, they’re part of the larger, most dangerous cult ever.

  4. 104

    Richard said:

    ” the Omega-shaped heat dome”

    It was actually 4 sinusoidal cycles that perfectly encircled the earth — essentially a wavenumber=4 standing wave (4 Omegas in a row). Standing waves such as this are commonplace in many physical phenomena and they occur because that is a minimum energy state subject to the boundary conditions. The question should be asked if this specific state could be locked in again sometime in the future.

  5. 105
    Matthew R Marler says:

    There have been a number of extreme events so far in 2021. Here is a short list:

    Have there been more? Can you do the same kind of analysis on these (and others) as described in the rapid attribution paper? Can that combination of modeling and statistical analysis be used to forecast the extreme events likely to occur in the remainder of 2021, including their geographic distribution?

    For 2022, instead of waiting for an extreme event to occur and then doing the rapid attribution analysis for it alone, could you select at random at the start of the year some 20 or so regions of equal size and perform the rapid attribution analysis on them all at year-end?

    And for every year after, sampling places randomly with replacement as the models are improved?

    The authors write as though the models are reliable enough for the results of the analyses to be believed, but I think a more systematic approach as I outlined would be more informative. Right now I am doubtful that such analyses are sound enough to be relied upon, but I am hopeful of seeing actual accurate predictions (without post hoc excuse mongering) in my lifetime (I am 74.)

    Thanks to the site managers. I saw the rapid attribution paper elsewhere first, but I am thankful that it was linked here. It repays close study, and is, I think I hinted, a good method to repeat in the future.

  6. 106
    John Monro says:

    Hi Folks, thanks for this posting and the comments. I have no expertise in climate science or any “pure” science except as a retired GP and my scientific training for that occupation, and my continued interest in science and the environment for many years. During my 47 years of active practice I would have prescribed many tens of thousands of pharmaceuticals. I depended on randomised double blind trials to assess the effectiveness and safety of my prescriptions. As I understand it, any drug that reaches a confidence interval of worth around 95% or 2SD can be considered effective, especially if repeated trials and or higher statistical confidence confirm this. Many millions of dollars and huge effort is expanded on this quest for 1 in 20 effective treatments, and billions, trillions, of dollars are made by drug companies for their shareholders on the basis of this 95% confidence. So when I look at temperature records around the globe, my first thought is to try and ascertain what the likelihood of such a record would be in a static/stable climate. So take the heatwaves in Europe – two incredible waves in 2003 and 2019. Now each of these, by my rough calculations, must have been about 4 standard deviations above the norm, but I’m not sure exactly what this represents in terms of percentage likelihood. But even if we took 3SD that’s a 99.7% or 1 in 330 chance. In regard to temperature statistics, a 1 in 330 year event. But Europe had two such outlying events within 16 years, so that chance, would, roughly, be 1 in 100,000. At any rate, an entirely improbable/impossible event in a static/stable climate, and can be ascribed to a heating climate with a huge degree of confidence on these statistics alone. But in 2019 I heard a lady meteorologist and climate scientist in Europe say on TV that in any “one” event like this, it’s always difficult to ascribe to climate change, apparently ignoring the history of just 16 years prior of an even more destructive heat wave in her same continent. But on the basis that we can all accept being medicated with drugs that reach only a 1 in 20 confidence interval, how can anyone rationally refute a 1 in 100,000 likelihood of a positive correlation – to actually deny or fail to accept this heatwave was not due to global warming has a 99,000 to 1 chance of being wrong. Surely the time is long past when we should have to keep reading or hearing, as we do ad infinitum in the papers, on the internet, on TV “according to scientists ascribing such events to global warming is difficult”. What we are seeing is exactly what global warming looks like and was predicted many years ago – scientists should stop adding ridiculously inapt and actually dangerously misleading caveats to their commentary in the face of this certainty, as did my European lady meteorologist. (Though I will admit that the media may well have a part to play here; I suspect this caveat is repeated as a matter of routine in every report of the latest climate catastrophe and may well not be a contemporaneous quote from a meteorologist or climate scientist on that particular event). Thank for your time. John Monro, NZ

  7. 107
    MA Rodger says:

    Willard @94,
    You respond to the statement “There is a reason he [Cliff Mass] has been fired from two different Seattle area public radio commentary jobs” made by Michael Corn @85 with details of Cliff Mass’s recent dismissal from the KNKX radio service, adding “Not sure what happened the first time.”

    I see from this Seattle Times story that “the first time” was Mass’s dismissal from KUOW radio back in 2011. (Seattle Times also cover the recent second dismissal.)

  8. 108
    John Monro says:

    Apropos my earlier post, berating the “you can’t attribute any one climate event to global warming” or other similar caveats, here’s a classic example from today’s CNN on the internet. There’s an excellent and totally disturbing video from the CNN correspondent. But at the end of the page we are require to read this “While it’s too early for scientists to say how big a role climate change has played in causing this particular flooding, extreme rain events like the ones seen in western Europe this week are becoming more common and more severe”. This after demonstrating the flood line at hotel by the river reached the third floor and was hugely higher than any prior flood (recall these little towns and villages have been there for hundreds of years)

  9. 109
    J Doug Swallow says:

    #93 where MA Rodger says basically what one could predict him to say, little that deals with the subject of the conversation but mostly ad hominem attacks on me, who he calls a troll because I do not agree with him regarding this hoax of anthropogenic climate change. I have looked at MA Rodger’s list of graphs that he proudly displays at his site. The one, that is labeled; ‘Monthly Global Temperature Anomalies Over The Past 10 Years’ where both the surface and satellite readings show a distinct downward trend in the Earth’s temperature. Could it be that even MA Rodger, on occasion, can be honest about the Earth’s temperature? I didn’t see this graph on his list of graphs for obvious reasons; but it does show what the a for mentioned graph shows what the Earth’s temperature is doing, falling.
    Latest Global Average Tropospheric Temperatures

    This site that records the Earth’s temperatures puts forth this information.
    The Earth’s Temperature
    Currently: 57.01°F/13.89°C
    Deviation: -0.19°F/-0.11°C
    Stations processed last hour: 46493
    Last station processed: Hong Kong, Hong Kong
    Update time: 2021-07-19 03:02:29 UTC

    [Response: you realise that these two sources are completely inconsistent? The numbers are weird – I think they are doing (inadvertently) is some kind of cumulative mean which is why their ‘anomalies’ are trending to zero – but AFAIK no-one has replicated what they are doing and the anonymous producers of the site have never really described their algorithm or shared code. You ok with that? – gavin]

  10. 110
    Susan Anderson says:


    You’re just amplifying the crazy; it doesn’t matter if you are right or wrong, it is removing value, not adding it. Just stop.

    It is my impression that the people who “own” RealClimate are too busy to deal with this garbage: Gavin Schmidt, Mike Mann, Stefan Rahmstorf, et al. It’s theirs. Making the comment section a battlefield is a terrible waste of time and energy that is better sent elsewhere.

    If you want to hold forth, please start your own blog. Don’t take ownership of other people’s stuff.

  11. 111
    J Doug Swallow says:

    #91 nigelj says: “This JDS guy doesn’t seem to realise heatwaves and droughts are different things. For his benefit heatwaves are unusually hot periods while droughts are unusually dry periods”. I am grateful to nigelj for taking the time to point that out to me, without explaining, that most generally droughts, as was the case in the 1930’s in America, occur when the temperatures are very high. nigelj offers up this bit of wisdom; “JDS breathlessly quotes the 1930s dustbowl as if this somehow suggests more recent droughts and heatwaves are nothing to worry about or are not influenced by global warming”.

    nigelj seeks to get me up to speed on this subject of heat waves and droughts with these two links. How climate change is worsening drought April 30, 2021
    How heat waves form, and how climate change makes them worse
    Heat domes, heat islands, mega-droughts, and climate change: the anatomy of worsening heat waves.
    Jun 30, 2021, 11:16am EDT

    nigelj will need to do some explaining about what part his ‘global warming’ plays in these flooding events now occurring in various parts of the planet.

    Cars washed away after severe flash floods hit Flagstaff, Arizona
    July 16, 2021 at 11:50 UTC (2 days ago)

    Catastrophic floods claim lives of more than 150 people, leave more than 1 000 missing, Europe
    July 17, 2021 at 15:49 UTC (1 day ago)

    I have been to New Zealand on three different occasions and I did not witness this happening when I was there.
    Marlborough hit by its largest-ever recorded flood, New Zealand
    July 18, 2021 at 09:43 UTC (17 hours ago)
    New Zealand’s Marlborough, the country’s largest wine-growing region, was hit by its worst flood on record on July 17, 2021.

    “Where all think alike, no one thinks very much.” Walter Lippman

    “The growth of knowledge depends entirely on disagreement” — Karl Popper

  12. 112
    nigelj says:

    An eye opener: “The number of lives that clean energy could save, by U.S. state”

    “A recent study found that air pollution from fossil fuels kills 8 million people per year, worldwide. In the U.S. alone, a 2019 study estimated that fossil fuel use causes over 50,000 deaths and $445 billion in economic damage annually. (See also: Burning fossil fuels heats the climate. It also harms public health)”

    “The economic and health burdens of air pollution are borne by individuals, families, and society, not by energy companies. The damage is socially and racially unjust, levying the heaviest toll on those least responsible for causing the problem. The fossil fuel industry’s ability to freely pollute and cause widespread degradation to public health is an example of a generous subsidy, because society bears the costs for oil, gas, and coal’s business model.”

    IMHO this is another great reason to change our energy system in addition to the climate issue which is such a threat to our well being both individually and collectively. My observation is 30 years of considerable climate scaremongering in the media (and I’ve done my fair share of this) have clearly NOT motivated sufficient climate change mitigation efforts. While there is some evidence emissions might have peaked they most certainly havent fallen globally. But if we ALSO communicate the wider benefits of clean zero carbon energy, this might be enough to tip things more in favour of that energy.

    A new clean zero carbon energy grid in 20 – 30 years is “system change”. It’s changing the power generation system that is fundamental to the wider economy. Is this incremental or revolutionary, fast or slow, centrist or extreme? Who knows and nobody will agree anyway. Such labels are ultimately pointless, and these words have emotive and political overtones that can be unhelpful. I believe the Paris accord plan is still workable, appropriate and achievable and thats what counts. Its still a monumental goal even on a war footing basis.

  13. 113
    Martin Smith says:

    Does ‘natural variability’ mean the event has natural causes but either we don’t know what the causes are or we can’t attribute the event to those causes, or does it mean there are no causes, it’s just the noisy nature of the system and the event is within the noise?

  14. 114
    John Pollack says:

    Zebra @95 “When we look at the typical two-dimensional representation, the entity “jet stream” is obviously longer when it is wavy. So how do you guys define the cross-section along the path (which determines the volume), and how does the density vary (if it does) between more meridional v zonal states?”

    I will include a lot of caveats in attempting to answer your question, because I’m not sure that you’re even getting the 2D picture, and you need 3D. From my viewpoint, the jet stream is not an entity, but a formation or temporary structure that air moves through. It’s a recognizable pattern, but not a sharply defined one. So, you get to define your own cross section. A lot of forecast model displays colorize different wind speeds, starting with an (arbitrary) minimum, but a display for TV would probably be simplified to a single line, so you get no idea of intensity or areal coverage.

    It is not obvious that the jet streams are longer when the pattern is wavy, because a wavy pattern in general reflects a weaker pole-to-tropics temperature gradient, and weaker winds. Weaker winds may no longer qualify as being part of a jet stream, depending on what you choose for a low speed cutoff when defining a jet stream. So, instead of a strong jet stream on a shorter path, you get a weaker, more discontinuous one that may wash out for great distances. The same goes for the cross section of the jet.

    Density is easier. At constant pressure, it varies as 1/K, where K is the absolute temperature (in degrees K). However, it also varies directly with P, the air pressure. The fastest winds are vertically located near the tropopause, because this is the level of the atmosphere where the temperature and density gradients are the strongest. So, to the extent that a more meridional “wavy” pattern reflects the pole-to-tropics temperature gradient, it also means that the polar region is warmer. This raises the tropopause. So, the density will be lower both because the air at a given level is warmer, and because the strongest winds have moved to a higher level with lower atmospheric pressure.

    I never answered your energy question earlier, because I asked for definitions. The VERY BROAD SIMPLIFICATION is that a wavy pattern would contain less energy because the density is lower, and the winds are also weaker. Energy varies directly with the density, and the square of the wind speed. However, this is just a broad overall average. Energy can be concentrated in the “kinks” of the waves, which sometimes evolve into eddies. It can also be enhanced when the circulation aloft strengthens a low pressure cyclone near the surface, and concentrates precipitation. The condensation of precipitation releases more energy into the circulation.
    Of course, there are many different regional configurations that are compatible with the same overall temperature gradient, and some places will be seeing more energetic patterns at the same time others have less.

  15. 115
    tamino says:

    I would like to address statements that “scientists failed to predict” the recent disasters (heat wave in the northwest USA, flooding in Europe).

    We’ve been predicting this for decades.

    We aren’t close to being able to predict when and where such disasters will hit in the future, but we have predicted, and continue to predict, that such events will get more frequent and more intense. That’s the prediction we’ve made for decades, and it’s the prediction which has come true.

    So: instead of news stories about how “scientists failed to predict” what happened, I suggest some news stories about how society and governments failed to heed the warnings they already got.

  16. 116
    MA Rodger says:

    The website linked-to by the troll J Doug Swallow @109 (so yet another off-topic posting by the troll) is the work of folk I would not simply call “anonymous.” There is another page from them that has been floating about the interweb since Jan 2018 which explains that their authorship is a secret for fear of being picked-on. (The language doesn’t sound like a native English speaker so presumably they are worried about being “targeted professionally” rather than being “professionally targeted.”)

    “Temperature.Global meteorologists have over 20 years experience collecting and analyzing surface weather observations. Temperature.Global meteorologists hold undergraduate degrees in meteorology and graduate degrees in Climate Studies. Their identity will not be revealed in fear of being professionally targeted as climate skeptics.”

    So they are pukka meteorologists/climatologists!! Of course they are! What was it Abe Lincoln said? “You can be anything you want to be … if you hold to that desire with singleness of purpose.” And when you are as stupid as these Temperature.Global folk, “singleness of purpose” is probably all they are capable of holding in mind.

    Interestingly, although these pukkaologists are incapable of showing the temperature record from which they derive their “the 30 year mean” and the individual monthly anomalies they do provide are entirely crazy**, the 2015-to-date temperature series they present actually has more of a warming trend in it that GISS LOTI does over the same period.

    (**The first two years 2015 & 2016 show numbers that are not that far off the GISS LOTI anomaly base although with some seriously big monthly deviations between the two years. The following years seem to have cancelled most of the seasons somehow.)

  17. 117
    nigelj says:

    Apologies for my comment @112. Posted it on the wrong page.

  18. 118
    nigelj says:

    JDS @11 says “I have have been to New Zealand on three different occasions and I did not witness this happening when I was there: Marlborough hit by its largest-ever recorded flood, New Zealand July 18, 2021 at 09:43 UTC (17 hours ago)”

    I LIVE in New Zealand. This flood certainly happened and its a huge event. Its been all over our news with plenty of video footage. JDS asks is it affected by climate change? Nobody has analysed this in detail yet to my knowledge, but climate change increases atmospheric water content so you would logically expect rainfall events to generally be more intense.

  19. 119
    John Pollack says:

    John Monro @106,108 I agree in general that much of the news media, and some scientists, are much too reluctant in attributing what ought to be very rare meteorological events to climate change – if they are truly becoming more frequent, and are consistent with predictions.

    I don’t think that your statistical interpretation works properly, and I will attempt a medical analogue.

    You noted the importance of the 95% significance test in clinical medicine, “especially if repeated trials and or higher statistical confidence confirm this.” It’s an important qualification, because if I’m not sure what my drug will do best, and I test it on 20 different conditions, there is a good chance that I will get at least one to pass the 95% significance test, just by chance. Repeat trials will eliminate these false positive results.

    We don’t get to do that very often with meteorological attribution.

    The situation is closer to testing a new pharmaceutical for side effects.
    If you test enough people, you can expect to see rare conditions occur, and possibly clusters. Are these the result of the drug, or random chance? Statistical tests may be revealing, but you will need a lot of treatments before you can reliably attribute a rare side effect to the drug. You can’t just take one case, no matter how rare, and say “this case is a 5SD anomaly, so it must be the drug.”

    To take it another step: since we aren’t operating in complete ignorance about what the effects of climate change are, you would have an idea of what effects to look for. Let’s say that you had a new drug that gave people strong relief from arthritis, but large clinical trials also revealed a robust average increase in blood pressure by 1-2mm. Taken over the entire population, you would not be surprised to see a statistically significant increase in strokes and kidney failures suffered by people using the new drug, adjusted appropriately for age, weight, etc. The increased risk might be small for otherwise healthy people who are gaining a lot of quality of life, but the case for people already at high risk for blood-pressure related morbidity is not so clear cut.

    Now, let’s say that further research revealed that the blood pressure rise for people using the new medication tended to increase over time, and a medical mechanism behind the increase was discovered. However, by then, the medication was in widespread use, and very popular. The incidence of strokes goes up, and statistically unusual clusters of stroke patients become more frequent. Do you attribute each individual cluster to the new medication? Some doctors and public health officials might. Others would be more cautious, wanting to know how old the people in the cluster were, how heavy, how much of the medication had they used, etc?

    I think that this is about where we are at with climate change. We are seeing more unusual clustering of events that are expected to increase under climate change, and more extremes. However, we also know that there will be confounding factors with each event. Event attribution isn’t always obvious, even though the big picture is very clear.

  20. 120
    William Jackson says:

    To the surprise of no one JDS appears to be a troll. SAD but true! Please ignore him.

  21. 121

    In all signal processing, noise is signal you don’t want.
    In the unique world of climate modelling, any non-AGW variation is called natural variability, or noise

  22. 122
    Martin Smith says:

    Then that is an explanatory problem, because there really are two signals. AGW is one signal, and the other signal is the one for “Of course climate is changing, climate is always changing.” Natural GW, NGW. We only ever see a graph with one signal + noise, and it is called AGW, but the deniers can always say, “No, it’s just natural climate change.” They’re wrong, but they don’t care about being right; they just want to create doubt.

    Tony Heller is infamous for always plotting raw data and adjusted data on the same graph and claiming the difference is proof of manipulation and fraud. It is deceitful, but for readers who can’t point to and name a country on a world map showing only the silhouettes of continents (see a recent episode of Jimmy Kimmel), it must be very effective.

    So instead of just showing the graph of the global average temperature anomaly and calling it AGW, the graph should also always show the data for NGW as well. Then it is clear what AGW is compared to NGW.

  23. 123
    MA Rodger says:

    Martin Smith @113,
    I have to rebut the comment of Keith Woollard @121 when he says “In the unique world of climate modelling, any non-AGW variation is called natural variability, or noise.” This is flat wrong.

    “Natural variability” is simply changes in the climate system that are not caused by human-kind. There are two types of “natural variability.” The first is that attributable to events external to the climate system, things like orbital change, solar variations and also volcanic eruptions. These are called ‘Forced Variations’, as is AGW. (We ignore here the obvious daily & annual cycles that are also ‘forced’.)

    It is likely that it is the other sort of “natural variability” you are interested; the “Unforced Variations”. (You will note the title of the open sciencey monthly comment threads at Real|Climate is “Unforced Variations”. Our hosts’ little joke.)
    The causes of these “Unforced Variations” can often be attributed to particular climatic behaviours, the most prominent by far being ENSO, the El Niño–Southern Oscillation, which amongst other things waggles average global temperatures up and down by up-to a couple of tenths of a degree celsius (this enough to allow the denialists of this world to start screaming about “pauses” in AGW).
    There is quite a bit of effort trying to identify other ‘oscillations’ etc to explain the ‘noisy’ nature of climate. As some of these are potentially longer in length than our climate records, effort is also made to create longer records from proxy data. It was such work hoping to identify the size of our wobbly climate through past centuries that led to the Hockey Stick graph. And such work ranges from the sublime to the seriously ridiculous, the latter often seen in the work of ‘curve-fitting’ denialists trying to find some argument that shows the recent four decades of warming was not AGW but some crazy climate oscillation.

    And much wobble & scatter within the climate data remains unattributed and thus will be seen as ‘noise’ but being measurement from physical system it will always have a ’cause’, just not one that has been yet attributed.

  24. 124
    Jim Eager says:

    Gavin, JDS is perfectly OK with anything that supports his assertion of the “hoax of anthropogenic climate change,” no matter how inconsistent or how anonymous. The proper place for any comment posted by JDS is the Bore Hole.

  25. 125
    S.B. Ripman says:

    Tamino #115: saw a recent article in the NY Times about how the average summer high temperatures on the East Coast have increased to the extent that average current summer highs in Washington DC are now equivalent to what average summer Atlanta highs were 20-25 years ago (and Atlanta’s average highs are now like Miami’s). If memory serves, this northward migration of temperatures is EXACTLY what was predicted by climate scientists 20-25 years ago.

  26. 126
    jgnfld says:

    @113 Re. Natural variability

    Mathematically it is the variance left over after all the predictable variance has been partitioned out of the data.

    As an example, given the sequence x = 1,2,4,3,6,7,9,10 can be partitioned into 2 components:

    1. A line defined by the parameters y= 1.1.3214x-.5714 which give a close and quite statistically significant “prediction”.

    2. The differences between the predicted value and the observed value. In many settings it is simply called “error variance”.

    The problem for nonstats people is they define error rather differently with a far different connotation. It is NOT a “mistake” of any kind whatsoever, it is simply the variation left over once the part which is predictable is partitioned out. As Keith notes in 121, in signal processing this is labeled “noise” rather than “error” which is certainly a better way to look at it in this context.

  27. 127
    Piotr says:

    jgnfld(126): “As Keith notes in 121, in signal processing this is labeled “noise” rather than “error” which is certainly a better way to look at it in this context“.

    Nice move, jg, this subversion of a denier’s post against him ;-)
    All our poor Keith wanted was to discredit climate science in his 121. But you came with your big warmist boots, ignored his intentions, and used his setup piece (the line on signal processing) to … help Martin to appreciate that climate science is not as mistake-prone as the lay understanding of the word “error” would suggest.
    Well played! ;-)

  28. 128
    Piotr says:

    Keith Woollard (121): “In all signal processing, noise is signal you don’t want. In the unique world of climate modelling, any non-AGW variation is called natural variability, or noise.

    You meant: “in the unique^* world of climate change ATTRIBUTION”, right? ;-)

    ^* I don’t know about you calling it “unique”. If you wanted to quantify the side effects of a COVID vaccine – how ELSE would you go about it – IGNORE the probability of various symptoms without the vaccine?

  29. 129

    Martin@121, I will try an explain a little better as MAR wants to play semantic games. Have a look at this graph:-
    The red and blue lines are two common measures of the global temperature anomaly. On the assumption that humans are causing all the current measurable long term trend in temperatures, then the black line represents the AGW component at about 0.0023 degrees C per year (Happy with that so far MAR?)
    Obviously there are significant departures away from this black line and that is what you are asking about Martin. Is that correct?
    The first thing to look at is the error bars which of course there are none, but to get an idea of what they should be, look at the green line. This is the normalised difference between the two datasets. They are both trying to measure the same thing using (effectively) the same data but due to different methodologies they come up with slightly different answers. Some is pseudo-random but there is clearly systemic errors as well. From this green line, the error bars of the datasets need to be at least 0.2 degrees wide. If I were to incorporate more datasets, then that size could rise. Or if we were to measure the temperature more regularly than once every 70,000km2 then these errors would reduce. This is not natural variability, just measurement issues and are of the order of a couple of tenths of a degree – curiously the same size as MAR claims as the ENSO contribution.

    So with proper error bars, the remaining excursions from that linear trend could be called “natural variability”. A large chunk of these more obvious events will be when the ocean currents decide to drag down a lot more heat than normal. These variations are up to about half a degree over a period of a few months. MAR calls these “unforced” but in reality all changes to the surface temperature are forced, you just need to define your boundaries correctly

  30. 130

    You have missed my 121 point Piotr@127, I was not suggesting noise was error, they are completely different things and that was my point. I was genuinely trying to help Martin understand. To understand AGW you must understand and remove natural signals (noise)

    jgnfld’s problem is that they are conflating error and noise. Are the excursions from the linear trend a mistake or are they that the linear trend of integer measurements is not representative of the real world. I don’t know. Is the linear trend an appropriate predictor of future values? Clearly not to any sort of precision

    Not being able to predict future values to the desired precision means your (linear in this case) model is wrong and/or your data is not sufficiently correct (precise and accurate)

  31. 131
    Jim Eager says:

    “In the unique world of climate modelling, any non-AGW variation is called natural variability, or noise”

    Maybe that’s because what is being studied is what is causing climate to change, so you want to separate what changes are due to natural causes, which we can’t do much about, from what changes are caused by humans, which we can do something about.

    Tell you what, why don’t you leave it up to those who are actually studying it, since you don’t even know what is being studied or why.

  32. 132
    jgnfld says:

    Re. 122/127

    Yeah. To use an analogy familiar to any digital photographer, RAW files (i.e., the direct sensor output values) almost always are less clear to the eye than (slightly) sharpened files.

    But of course the last thing any denier wants is heightened clarity.

  33. 133
    zebra says:

    John Pollack #114 (and others),

    Thanks for the input, John. As you may have figured out, my interest is in improving the communication on these issues, which includes getting established definitions and clarifying fundamental concepts like cause and effect.

    So when you say the jet stream is not an entity, and that some sections of the line typically used to illustrate it graphically in publication may be moving too slowly to qualify as “jet”, this seems to contradict the typical framing about it.

    I think most lay people have this concept of the JS as an ‘independent’ factor which guides the weather patterns; JS “slows down” because of reduced meridional T gradient, “it” gets wavy, and that’s why we see these slow moving or stalled conditions.

    But from what you and the others have said, the boundary where we draw that line for the maps may occur at some location as a result of local conditions in three dimensions. (?)

    So to get to my underlying question, yet another zebra thought experiment:

    If the energy in the climate system had been increased to the current level by CO2 without Arctic amplification, how might the pattern of weather be different, or similar?

  34. 134
    Ric Merritt says:

    @Keith Woolard

    So, obviously, your point of view and opinions differ substantially from most all scientists publishing professionally about climate science.

    1) What past predictions have you or those with similar opinions made that have proved more successful than those of mainstream climate science?

    2) What current predictions do you have for the future that vary significantly from those of mainstream climate science?

    To interest me, such predictions need to be falsifiable and based on measurements. Also, they need to be about something major, not obscure details. For example, global surfact temps.

  35. 135
    Ric Merritt says:

    And, apologies for missing the double L in “Keith Woollard” in my previous post.

  36. 136
    Piotr says:

    Zebra (96):”Piotr, you like to parse the comments of others but maybe you should read your own words more critically before you post them

    Coming from the person whose main (only?) contribution to this group is … parsing the comments of others and lecturing them on their lack of proper definitions – this means… so much! (?)

    Zebra:“ “The departure starts from a higher mean” ???? But you claim you are not confusing the metric with the physics?

    Huh? The global warming can be questioned by the absence of a rising trend in the metric describing it (global avg. temp.), AND/OR by the absence of plausible physical mechanism. Since this denialist claim used the former, I proved it wrong EVEN WITHIN IT’S OWN (metric–based) argument. So much for your patronizing” It’s The Physics Stupid” and “confusing the metric with the physics“.

    Zebra(96): “So you did all that calculation about how minor the effect of the extreme was on the mean, and you then said “it is not true the other way around”… but now you want to pretend that you weren’t implying again that the shifting of the mean somehow affected the extreme????

    Huh??? WHY would I “pretend NOT to imply, when my argument IS TO IMPLY that the shifting of the distribution, which includes shifting of the mean, WOULD increase the probability of more extreme heat? (IPCC 2007 figure).
    In other words – “Not true the other way around” does NOT mean I sneakingly ABANDONED using metrics half way through my post, but merely points to the different IMPLICATIONS in the two discussed cases: local extremes having negligible influence on the global trend vs. the global trend having NON-negligible influence on the local extremes.

    But don’t let it stop you from pontificating on the virtues of “ careful reading“, particularly when on your careful reading you have based your accusations of intellectual dishonesty ( “but now you want to pretend that you weren’t implying”).

    Zebra: many here[…] engage in weird analogies and supernatural mind-control explanations, much like the Denialists” “ You are, indeed, allowing the Denialists to “own” you, because you adopt their framing when you try to refute their points.

    ;-) Not surprisingly, I see it slightly differently:

    – I have used a scientific framing (statistical description of results of “the Physics”) that WAS used by the Denialists, and successfully shown the absurd of their points WITHIN the very frame they have used

    – Zebra joined in with his: “ It’s The Physics Stupid”, lectured me on the difference between “ cause and ”effect ” (all boldfaces- Zebra’s), accused me of intellectual dishonesty ( “but now you want to pretend that you weren’t implying ”) and portrayed my proving Denialists wrong EVEN within their own argument as …. allowing the Denialists to “own” me and lectured the “many [non-Deniers] here” on adopting the Denialist framing: “ many here […] engage in weird analogies and supernatural mind-control explanations, much like the Denialists

    And to top it – our Zebra … illustrated what he meant, in the spirit of “do what I tell you not what I do”: having failed to refute my arguments within my framing, our Zebra adopted the framing of … supernatural attribution of the global warming by the (evangelical) Denialist: that humans can’t change climate only God can [1]:

    -Zebra: You can’t “shift the distribution [2], because you are not God

    [1]Sen. James Inhofe [R]: “The arrogance of people to think that we, human beings, would be able to change what He [God] is doing in the climate is to me outrageous.
    [2] usurping God’s prerogative for shifting distributions: IPCC 2007

  37. 137
    Piotr says:

    Keith Woollard (130) You have missed my 121 point Piotr@127, I was not suggesting noise was error

    You have missed my 127 point Keith Woollard@130.
    It was a tongue-in-cheek comment on your (121) manipulation aimed to discredit climate modelling, by insinuating that it DOES NOT follow the standards of “all signal processing” – but instead uses “noise” to dismiss the politically-inconvenient “non-AGW variation”, I quote:

    In all signal processing, noise is signal you don’t want. In the unique world of climate modelling, any non-AGW variation is called natural variability, or noise.” Keith Woollard (121)

    So the linchpin of this particular manipulation was in applying it to “ climate-modelling” in general, instead to one specific use of of climate modelling, the one studying human impact on the climate, in which case removing the “non-AGW variation” signal is not only acceptable, but the ONLY WAY to get the answer to this question. And as such – far from being “unique” (see my 128).

  38. 138
    jgnfld says:

    Slightly off topic, but not really…

    An Alabama physician says: “I’m admitting young healthy people to the hospital with very serious COVID infections. One of the last things they do before they’re intubated is beg me for the vaccine. I hold their hand and tell them that I’m sorry, but it’s too late. A few days later when I call time of death, I hug their family members and I tell them the best way to honor their loved one is to go get vaccinated and encourage everyone they know to do the same. They cry. And they tell me they didn’t know. They thought it was a hoax. They thought it was political. They thought because they had a certain blood type or a certain skin color they wouldn’t get as sick. They thought it was ‘just the flu’. But they were wrong. And they wish they could go back. But they can’t. So they thank me and they go get the vaccine. And I go back to my office, write their death note, and say a small prayer that this loss will save more lives.”


    We’ll be seeing more and more of this in climate areas as time goes on.

  39. 139
    John Pollack says:

    Zebra @133 One of the problems for communicating meteorology in general is that it requires identifying patterns in the behavior of fluids. Once you find one and name it, you make it a “thing” or “entity.” It may then be adopted as if it has an independent existence, rather than being an incompletely discrete pattern within a continuum. People like to have a simple descriptive terminology, whether accurate or not. Weathercasters are constrained to use it heavily, since they have little time to get the picture across to the public. So, popular terms like “jet stream” and “El Nino” can get overused or distorted.

    If you want to delve a bit deeper, I encourage you to check out the ECMWF analysis and forecasts:

    “Wind and geopotential height at various pressure levels” is a good chart set to start with. 00 hrs. is the analysis. Take a look at the Arctic, where the temperature gradient is at its weakest. For a set of slices into 3-D, look at 200 hPa, 250, and 300. Strong wind areas are colored. Note that as you step down in the atmosphere from the 200 to the 300 level, the winds in the subtropics get weaker, while the polar jet (what there is of it) tends to strengthen. Also note that the strong wind areas are discontinuous and vary in maximum strength. Next try the Antarctic, where the temperature gradient is stronger. The jet areas are both stronger and more continuous.

    Now, to your question. “If the energy in the climate system had been increased to the current level by CO2 without Arctic amplification, how might the pattern of weather be different, or similar?” I have difficulty with questions of this type, which posit abandoning reality in some respects, while keeping it in others. I don’t see a way to increase the energy of the climate system without also, in reality, inducing Arctic amplification. The closest I can come is to speculate what might happen if the oceans were instantly warmed, from equator to pole, by some constant amount. I would expect that the overall configuration of upper atmospheric circulation and jet streams wouldn’t change greatly. However, the cool season contrast between the continents and oceans would increase. This might increase blocking or slow the progression of atmospheric long waves, because the sources of surface heating from the oceans would be stronger.
    Also, the amount of energy available to storms over the ocean and continental margins would be greater. Both the baroclinic energy due to temperature gradients, and the heat energy released into storms due to condensation/freezing would be increased. This would result in more “bomb” storms. This type of energy tends to be injected upscale into the planetary circulation. This would apply to both cool season storms, and tropical storms that eventually become extratropical. These storms can help break a block and allow larger atmospheric waves to progress.

    So, more “stuck” weather, bigger storms, and greater concentration of precipitation, and probably to an even greater extent than if Arctic amplification is included.

  40. 140
    Carbomontanus says:

    @138 jgnfld

    It is not so off topic.

    I have recognized or identified pandemics as it was explained to us by the Veterinary institute on National TV during the H5N1 avian flue,… and the AGW situation for both having the same root and cause, namely too high wear on the biosphere (wherefore fossile fuel had to be used and poultry & swinery heavily industrialized).

    Denialism and obvious political trolling is also very similar in both cases, and obviously carried out by the same persons and learnt and trained interests- backgrounds.

    In a way, I feel quite well prepared and experienced having had to defend a henyard under H5N1 quarantaine.

    What I find worst of all is that they commit civil war, “Class warfare” against my very learnings and culture, that will become quite necessary in foreseeable future in order for humanity to tackle AGW and its consequenses.

    As it also quite obviously has come to be in order to tackle and to defend myself and my interests and family against the Covid 19.

    To my opinion, This aspect is also the most accute & short term problem and threat.

    That can also be dealt with.

  41. 141
    jgnfld says:

    Re. KW and “jgnfld’s problem is that they are conflating error and noise.”

    Wow! Whudda thunk that stats/research professionals are unaware that some noise/error/random-variation-of-any-sort is necessarily correlated with other causal variables!!! I mean the probability density of an exactly zero correlation is 0.0 by definition, after all! Therefore there must be some plus or minus overlap that totally destroys the value of the research (not)!

    And whudda thunk that they haven’t developed numerous, well worn techniques starting with the t distribution way back when in the 19th Century and extending for scores and hundreds of other techniques to deal with that issue as well as many other issues??? All of which are fully described in many sources.

    Of course, then there’s the additional issue that since the Earth is in a Milankovitch cooling period (to the best of my knowledge), even zero rise in temps would mean that human-caused warming is likely occurring even if the temp record remained flat once it is modeled in (which is rarely done as it is small compared to the human effect).

    A “problem”? Yes. Are there good solutions? Absolutely.

  42. 142
    John says:

    “It’s been clear for at least a decade that global warming has been in general increasing the intensity of heat waves, with clear trends in observed maximum temperatures that match what climate models have been predicting.”

    Match? Baloney.

    “Using various methods to construct the return time for this event, they show that even in today’s climate this was a one in 400 yrs or longer event. Using only data from before 2021, an anomaly this large is estimated to never occur! ”

    If they “matched”, this would have been predicted. It would also have been expected. And it will happen again, either this year, or next year. So much for the “400 yrs or longer event” claim (more baloney).

    The models are inaccurate. Obviously. They fit the false predictions of climate scientists, but not the reality being measured on the ground.

  43. 143
    J Doug Swallow says:

    #105 Matthew R Marler says: “There have been a number of extreme events so far in 2021. Here is a short list:”
    It is obvious that no one on this site where, “Summary: It was almost impossible for the temperatures seen recently in the Pacific North West heatwave to have occurred without global warming. And only improbable with it”; really wanted to try to deal with what Matthew R Marler posted in an interesting list of a number of extreme events so far in 2021. It appears that being able to call someone that has different views on this subject of anthropogenic climate change a troll is more important than dealing with the facts about recent climatic events that are far from being “almost impossible for the temperatures seen recently in the Pacific North West heatwave to have occurred without global warming. And only improbable with it”.

  44. 144

    RM said :

    “To interest me, such predictions need to be falsifiable and based on measurements”

    Relying on predictions alone is much too limiting. Consider that for ENSO, to determine that a model is correct based only on predictions will take at least 10 years or perhaps 20 years to validate. That’s due to ENSO having a natural cycle of anywhere from 3 to 7 years, and several correct predictions in a row would need to be made to consider it useful.

    Or if there are past predictions that were made and are in the pipeline waiting to be verified, who is maintaining these? Is there a climate predictions committee that saves the results and judges how they pan out? Why can’t someone put as much effort into that kind of repository as they do for Olympic sports records?

    So granted that will never be done, what scientists need to do more of is intensive cross-validation of past data against models of natural climate variability. Yes of course the issues of over-fitting can arise, but no one is even keeping track of the leading models in terms of a Pareto optimum, where one considers accuracy and least-complexity measures. That can all be done if there is interest.

    Just like there are historical temperature anomaly models such as GISTemp, HadCRUT, etc there should be available archives for models of ENSO predictions and cross-validation so that the public can easily see how they pan out.

  45. 145
    William Jackson says:

    #142 Any citation to support your BALONEY? I don’t expect any.

  46. 146
    MA Rodger says:

    John @142,
    You write “The models are inaccurate. Obviously. They fit the false predictions of climate scientists, but not the reality being measured on the ground.”
    Could you give an actual example of this ‘obvious’ inaccuracy of climate models? It shouldn’t be difficult for you if it is so ‘obvious’.

    J Doug Swallow @143,
    Do you actually consider the absence of any comments so far replying to Matthew R Marler @105 as having some relevance to your troll-like status within this site? Or do you think pointing it out would give your comment less the appearance of a piece of trolling trying to cause trouble?

  47. 147
    Dan says:

    re: 142. Wow, what a clueless post that was. All around. You have no clue about statistics or climatology. A 1 in 400 year event refers to the intensity of an event. It can happen any year. Read up on probability for starters. With climate change it now means that the odds of a 400 year event occurring have increased. A basic textbook on climatology would have taught you that. Instead, you spew your ignorance and baloney for all to see.

    And the models have predicted just that: That such events are more likely to appear.

    Of course now we know you will run and hide under a rock, unable to admit to being so completely and utter wrong. Cowards always do. Or change the subject. Busted!

  48. 148
    John Monro says:

    John Pollack @119

    Hello. Thanks for taking the time to read my inexpert (informed amateur) post. You make some interesting points about the analogy I was trying to convey and you explore that quite a bit further in regard to how a side effect might be examined and statistically determined and how it more closely relates to what is happening in regards to our warming climate. As you summarise “event attribution isn’t always obvious even though the big picture is clear” Yes, that’s exactly what I was trying to counter.

    It’s like trying to put “certainty” into perspective. That the sun will rise every morning is as certain as anything can be, but getting into an aeroplane and arriving safely at one’s destination is almost, but not quite ,as certain. Crossing the street to meet your friend for a coffee is the sort of accepted certainty that we take for granted, but again, it’s rather less certain again. Taking a medication approved on the basis of a 95% confidence is even less so. So all the time we take actions or accept statements on the basis of a continuum of truthfulness or certainty. We couldn’t live or make sense of anything without accepting this principle. I was merely trying to put in place a comparison with what’s happening with the climate with this continuum. And on that basis, what’s happening to the climate is more akin to the sun rising in the morning than even the medicines I prescribe – and it is not useful, as you’ve agreed, thank you, that we – ie climate scientists, meteorologists, anyone in a position of authority that has to deal with this matter, or indeed the general public – to insist on some sort of perfection or absolutism in regard to climate change, the science and the actuality in the face of the infinitesimal likelihood or nigh impossibility that we’re wrong.

    So to return to your continued analogy, and the likelihood of strokes in a population from a side-effect of the drug iI prescribed. I don’t think that parallel completely holds. Because a record temperature isn’t just an event on the background of a general level of such events, but is an outlier. A stroke, on its own, is not an outlier. It would be as if those peoples’ stroke actually became more severe or unusual in some way that bore the imprint of the drug’s side effect. What we’re seeing with the climate change is these outliers bearing the imprint of global warming. They are lasting longer, becoming more frequent (that’s like your drug side effect) and most importantly, the events themselves are massively unlikely more severe – several SDs above the previous normal.

    To pursue a different analogy on this basis . The hundred metre sprint record presently is 9.58, Usain Bolt, Berlin 2009. It was 10.06 in 1964 (Bob Hayes, Tokyo) No record has improved the previous record by more than 0.14 second since Ben Johnson in 1988. If a sprinter was tomorrow suddenly run 100 metres in 8.81 seconds then this is a total outlier and would seem to be physiologically impossible. We would have to assume some sort of assistance, either in the track, the shoes, or with artificial aids or drugs. I would contend that the sort of records we are now experiencing in regard to our climate are such outliers and are impossible to conceive without the assistance of global warming – and which furthermore are totally to be expected, and not come as a massive surprise like my analagous sprinter, from predicted scientific theory, knowledge and measurement for the last forty years or more. Thanks for you time, JKM

  49. 149
    Dan says:

    Addendum to my post: The idea that somehow you think you know more than literally every major climate science professional organization in the world and peer-reviewed climate scientists is the absolute height of scientific ignorance and arrogance. Ludicrous. How’s your peer-reviewed paper on the topic coming to disprove thousands of actual climate scientists? Yeah, crickets chirping. Clue for you: Peer-review is part of the scientific method. You ought to have learned it in grade school. And the scientific method is precisely the way climate change research has been done. It is the way science has been conducted for centuries. The 17th to be specific.

    Your failure to understand science and statistics does not make it less factual. Facts>>Your opinion. Every single day.

  50. 150
    Killian says:

    115 tamino says:
    19 Jul 2021 at 12:22 PM

    I would like to address statements that “scientists failed to predict” the recent disasters (heat wave in the northwest USA, flooding in Europe).

    We’ve been predicting this for decades.

    Let’s be honest here: It been predicted for decades that these things would be happening decades later than they have.

    I, on the other hand, did predict these things would happen much sooner than the science was saying.

    Still, nobody is curious how I did that… And, no, it wasn’t “alarmism” or the “broken clock,” it was logic and analysis.

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