RealClimate logo


Unforced variations: May 2020

Filed under: — group @ 1 May 2020

This month’s climate science open thread.

188 Responses to “Unforced variations: May 2020”

  1. 101

    #90, AB–

    AB: Bull. The IPCC analysis is the literature as warped and degraded as much as possible by fossil fueled governments.

    And back atcha. Your comment applies to the SPM, which is documented to have been so warped and degraded on multiple occasions. But “fossil fueled governments” have no say in author appointments, writing, or editing of the main or technical reports. It’s kind of amazing, actually, how well their fingers have been kept out of the cookie jar.

  2. 102

    #98, mike–

    I’m fine with your restatement about science and surprise; it makes more explicit but doesn’t alter what I intended by “sort of the goal.”

    You say “I would appreciate it if anyone can point at science papers or studies from anytime after 2000 that did identify and predict the kind of lethal heat waves that are covered in the Guardian article.”

    I had actually responded to the desire before it was uttered, back when I first tried to comment on the matter, by providing a bit of a literature review. Sadly, my browser became unstable while and I was writing it and had to be restarted. The post was lost. But the bottom line was as I indicated it in the briefer comment that did appear, the one about ‘gradual progress’ on the matter.

    Basically, I walked through ten years of scholarship on the issue, discovering that the initial theoretical suggestion was responded to with quite a number of investigations. What those investigations essentially did was to demonstrate that the prospect of 35C(WB) and the consequent mortality was very real, and in fact to be expected on a BAU trajectory. The initial estimates were, as we know, toward the end of the century, but over the decade that people were looking at the problem, that date tended to creep a little nearer and to become problematic in a wider selection of locations. (Initial investigation spotlighted the Persian Gulf.)

    Then we got the bombshell that we had already seen what I’ve been calling ‘flickers.’

    Was it unexpected? Sure. Were there previous studies taking a comparable approach? Not that I saw. That’s presumably why they found those ‘flickers’ first–they were the first to look in the right ‘place.’ There was a ‘near miss’ in 2015, with this article, which plots a heat index of 54C in Karachi:

    https://journals.ametsoc.org/doi/pdf/10.1175/BAMS-D-16-0145.1

    Would it have been nice to know this sooner? Of course. But if you can suggest how scientists can possibly always know in advance what the most fruitful and efficient lines of research are going to be, I’m sure they’d be all ears.

    By the way, I found that paper by checking the bibiliography from Raymond et al (the ‘flickers’ paper). The direct link for that paper is here, for anyone who wants to investigate the chain of scholarship and see ‘who knew what and when.’

    https://advances.sciencemag.org/content/6/19/eaaw1838

  3. 103
    mike says:

    Lethal Heat study from Science Advances: https://advances.sciencemag.org/content/6/19/eaaw1838

    “Abstract

    Humans’ ability to efficiently shed heat has enabled us to range over every continent, but a wet-bulb temperature (TW) of 35°C marks our upper physiological limit, and much lower values have serious health and productivity impacts. Climate models project the first 35°C TW occurrences by the mid-21st century. However, a comprehensive evaluation of weather station data shows that some coastal subtropical locations have already reported a TW of 35°C and that extreme humid heat overall has more than doubled in frequency since 1979. Recent exceedances of 35°C in global maximum sea surface temperature provide further support for the validity of these dangerously high TW values. We find the most extreme humid heat is highly localized in both space and time and is correspondingly substantially underestimated in reanalysis products. Our findings thus underscore the serious challenge posed by humid heat that is more intense than previously reported and increasingly severe.”

    ScienceAdvances is accepting eLetters regarding this study, so please… feel free to argue with the authors there about whether the lethal heat is “more intense and increasingly severe than previously reported” or whether the “Climate models project the first 35°C TW occurrences by the mid-21st century” when compared to the lethal heat being reported now is earlier than expected. Jump to it, friends! Don’t waste your time arguing with me, go right to the experts who are ringing the bell and creating news that a rag like the Guardian covers to sell papers.

    Cheers,

    Mike

  4. 104
    Snape says:

    Playing contrarian……..

    23 states set their all-time high temperature in the 1930’s, compared to only 4 states where the record was set this century:

    https://en.wikipedia.org/wiki/U.S._state_and_territory_temperature_extremes

  5. 105
    Snape says:

    Of the 13 Canadian provinces/territories, 7 set their all-time high temperature in the 1930’s, compared to only 1 where the record was set this century.

    https://en.wikipedia.org/wiki/List_of_extreme_temperatures_in_Canada

  6. 106
    Astringent says:

    Snape in 104 and 105 has commented on when North American temperature records were set – I am looking forward to their repetition of the exercise for other continents (spoiler alert; it won’t go the way they want).

    A Wikipedia ‘back of envelope’ suggests that in 67 countries/territories out of 131 that are listed, record highs were set since 2010! – so that’s new records in half the reporting countries in the last 11 years. In fact, looked at by continent, North America is the anomaly, with only a 3rd of countries reporting record highs in the last 11 years. So did Snape choose North America for their posts because they don’t do geography, or because they don’t do science?

  7. 107
    CCHolley says:

    RE. Snape @104

    Playing contrarian……..

    23 states set their all-time high temperature in the 1930’s, compared to only 4 states where the record was set this century

    Good job…typical contrarian cherrypick.

    Looking at countries worldwide out of 103 countries with extreme high temperatures recorded only four (3.8%) were in the 1930s. 59 of these 103 countries (57%) have recorded their all-time high temperatures in this century and 80 (78%) since 1970.

    https://en.wikipedia.org/wiki/List_of_countries_and_territories_by_extreme_temperatures

    The extreme record temperatures in North America in the 1930s were anomalies due to highly unusual weather conditions.

    Factors Contributing to Record-Breaking Heat Waves over the Great Plains during the 1930s Dust Bowl
    https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-16-0436.1

    In addition worldwide, record daily high temperatures are far out pacing record lows.

    https://www.climatecentral.org/gallery/graphics/record-highs-vs-record-lows

  8. 108
    MA Rodger says:

    You point to data showing more record high daily temperatures in the 1930s than this century. If you are “playing ontrarian”, perhaps we should tap the ball back into your side of the court for you.

    Firstly, the data for record-low-temperatures is also provided and also shows (although more weakly) a similar result, the decade with the largest number of record lows being again the 1930s with just a small number this century.
    Secondly, the data you link-to shows the dates for record high daily temperatiures for the various US states and also US territories. Do note that the simplistic analysis you use is representative only of the contiguous US states (& perhaps also Canadian provinces as @104).

    Record temperature data of US states & territories
    Records per decade

    … … . Record High … & Low … … Record High .Low
    … … (all US states & territories) … (Non-contiguous US)
    1880 … … … 0 … … … 1
    1890 … … … 0 … … … 5
    1900 … … … 0 … … … 5 … … … … … 0 … 1
    1910 … … … 6 … … … 3 … … … … … 1 … 2
    1920 … … … 2 … … … 0 … … … … … 0 … 1
    1930 … … … 24 .. … … 9
    1940 … … … 1 … … … 4 … … … … … 1
    1950 … … … 4 … … … 3 … … … … … 1 … 2
    1960 … … … 1 … … … 5
    1970 … … … 3 … … … 4 … … … … … 1
    1980 … … … 4 … … … 8 … … … … … 0 … 1
    1990 … … … 7 … … … 5 … … … … … 2
    2000 … … … 1 … … … 2
    2010 … … … 3 … … … 2 … … … … … 1

    The contiguous US evidently had both the most high records and the most low records all in the same decade. So what are we to conclude? US weather is crazier than Trump? Or perhaps your data analysis is a little bit too simplistic & needs upping a gear. Perhaps Meehl et al (2016) ‘US daily temperature records past, present, and future’ can do a proper job.

  9. 109
    CCHolley says:

    More on Snape @104

    The use of the high temperatures of the 1930s in North America to cast doubt on AGW is quite lame. I guess to the ignorant it can be construed to show that perhaps the world isn’t really warming. Of course, this is silly. In fact, the more sophisticated deniers readily admit that the planet is warming because to claim otherwise would make them appear foolish, the evidence for warming is unequivocal.

    Some of the evidence for a warming planet beyond the global surface temperature sets which, in fact, by themselves, clearly indicate it is warming:

    Sea levels are rising which can only be attributed to expansion due to added heat along with more water from run off of melting land ice.

    Ocean heat content has steadily risen as per increased measured sea surface temperatures and in more modern times by the wide coverage of the ARGO float system measuring at multiple depths.

    The vast majority of glaciers are rapidly losing ice mass.

    Arctic sea ice is declining.

    Snow cover is declining.

    Growing seasons around the world are getting longer.

    Species are migrating towards the poles and to higher elevations.

    Humidity has increased, warm air holds more moisture so the atmosphere must be warming.

    One in a thousand year weather events are happening every few years. Weather is becoming more extreme…extreme precipitation events and severe droughts. This can only be the result of increased temperatures.

    Measurements of CO2 shows levels in the atmosphere have increased and physics says this will slow heat loss from the surface.

    Nights are warming faster than days and winters faster than summers (hmmm, how do you think that effects the number of overall record highest temperatures?) which indicates warming is due to the slowing of heat loss from the surface rather than increases in energy into the system.

    Yup, it is warming just as shown by the surface temperature record and it is us causing it.

  10. 110
    Snape says:

    @MA Rodger #108

    I was hoping to start a conversation about the underwhelming trends in extreme heat. You wrote,

    “Do note that the simplistic analysis you use is representative only of the contiguous US states (& perhaps also Canadian provinces as @104).”

    The Wikipedia article does include Alaska, which helps make my point – Alaska is by far the fastest warming US state, and yet its all-time high temperature was set over 100 years ago. Canada is among the fastest warming nations, and yet its all-time
    high was set 83 years ago. Not a single province or territory has set an all time high in the past 15 years.

    ******

    Looking at trends, much of the US Midwest and Southeast actually show a decrease in extreme heat. Atlanta is a good example:

    Atlanta Tmax,
    June-August, 1930-2019: – 0.4 F/decade

    https://www.ncdc.noaa.gov/cag/city/time-series/USW00013874/tmax/3/8/1895-2020?base_prd=true&begbaseyear=1901&endbaseyear=2000&trend=true&trend_base=10&begtrendyear=1895&endtrendyear=2020

    *********

    What interests me is the “why”. In this case, precipitation gives a clue:

    Atlanta precipitation,
    June – August, 1930 – 2019: + 0.24”/year

    https://www.ncdc.noaa.gov/cag/city/time-series/USW00013874/pcp/3/8/1895-2020?base_prd=true&begbaseyear=1901&endbaseyear=2000&trend=true&trend_base=10&begtrendyear=1895&endtrendyear=2020

    The Midwest has also been trending towards wetter summers.

    Des Moines, Iowa, June-August, 1946 – 2019

    Tmax: – 0.3 F/decade
    Precipitation: + 0.53”/decade

    https://www.ncdc.noaa.gov/cag/city/time-series/USW00014933/tmax/3/8/1895-2020?base_prd=true&begbaseyear=1901&endbaseyear=2000&trend=true&trend_base=10&begtrendyear=1895&endtrendyear=2020

  11. 111
    Snape says:

    @Astringent, CCHolley

    Sorry….. please see my response to MA Rodger. I was trying to start a conversation about extreme heat, not disprove global warming. Yeah, North America was a cherry-picked location, but not necessarily unique WRT trends:

    “Heatwaves in a relatively small area of India are becoming more frequent and more intense, but this is not true for most of the country.”

    https://www.worldweatherattribution.org/india-heat-wave-2016/

  12. 112
    Al Bundy says:

    Kevin McKinney: But “fossil fueled governments” have no say in author appointments, writing, or editing of the main or technical reports. It’s kind of amazing, actually, how well their fingers have been kept out of the cookie jar.

    AB: Perhaps it’s that they only snuck enough fingers in to snitch the tastiest cookies? As you know, nobody who matters reads the oatmeal raisin bleck sections you describe. Only the yummy Chocolate Chip Executive Summaries and such things actually matter, and only to the degree to which they can’t be spun (and with Spin Doctor being the most granted PhD, things keep rotating faster and faster).

    I read (on Quora) a piece written by a denialist who claimed to be a, um, durn, I don’t know the phrase (Executive Reviewer?) but someone who analyses and comments on the work. He was torpedoed by another guy who remarked that the only requirement for that Highly-Respectable-Sounding Title was to submit an offer to be such a respectable sort.

    “We’re all stupid” or “we’re all smart” depends on the standards and the analysis. We’re so stupid that we’re playing in a way that will result in dang near the worst possible physical results but too damn smart to refrain from focusing on Cookie-Jar invasions and protections.

    “Winning” is both addictive and toxic since it generally ignores everything except one or another barely relevant metric. Is Second Place “pretty-much-equal-to-and-woulda-won-if-things-rolled-slightly-different” or “First Loser”?

    Kevin McKinney (on deadly heat): Then we got the bombshell that we had already seen what I’ve been calling ‘flickers.’ Was it unexpected? Sure.

    AB: Naw. Fatal heat was obviously on the horizon and obviously the “near 2100” crowd were just ignoring the data. Those flickers weren’t outliers. They were what simple extrapolations showed to be inevitable near-term certainties (NOTE: This is an unsubstantiated claim. If you disagree, feel free to post a correction). Near-fatal-heat has been intermittently in the news forever. Remember Europe 2003? I’ve been wondering for at least a decade when the first city was going to get a blackout at the wrong moment and toast close to a six-figure number of people in a week. I’ll take a stab with 2025, the same year I’m dartboarding a Blue Arctic Ocean. But hey, random is as random kills. It might be 2030.

    Unfortunately, brains take lots of energy and produce copious amounts of waste heat. So GOPpers and other dimwitted dinosaurs will probably survive my hypothetical 2025 fatal heat wave.

    And your link: Once the air (dry-bulb) temperature (T) rises above this threshold, metabolic heat can only be shed via sweat-based latent cooling,

    AB: Error! Drinking cold water sheds heat through both urine and non-evaporated sweat. Drink 0C, sweat 37C, get cooled without any evaporation at all. But most of the rest was good and dang obvious to anybody fifteen years ago who chose to ponder the subject. You can’t have ocean surface temps above 35C without the occasional mass death. Scientists are way way way too subservient to the Scientific Method. The Scientific Method is based on the premise that there is absolutely no requirement for speed, that to wait 1,000 years for an answer to be “properly” come to is preferable even when total destruction of society could come in 50. Churchill didn’t use the scientific method to fight them on the beaches, in the fields, and in towns. He used sense instead.
    ______

    MaRodger on Snape: Or perhaps your data analysis is a little bit too simplistic & needs upping a gear.

    AB: Didn’t read your link but I agree. The 1930s US did not have significant irrigation and did have abysmal farming practices. Every litre of water pumped from the Ogallala represents a decline in temperature. So if ya want to compare the 1930s USA to the 2020s USA ya gots to back out all that irrigational cooling (2020s) and crappy farming practices heating (1930s).

    Snape, I suggest you start thinking to learn and advance your knowledge instead of to anchor your mind more firmly to the sea floor cuz as sea level rises you’re gonna drown. Seriously, are you NOT smart enough to actually compare the two periods apples to apples? I doubt that. I suspect that you’re one of Tamino’s Proud To Be Stupid Corps, someone who doesn’t care a whit about truth but only about “winning an argument”.

  13. 113
    Al Bundy says:

    Snape,

    You’ve been given enough irrefutable information to come to the conclusion that your initial hypotheses was 100% wrong. Therefore, we’ve entered the Critical Phase of the discussion: are you moral and ethical? If so, you will post accordingly. If not, you will GOPper up.

    Note that “I was wrong” is the absolute #1 way to get folks to put you on a pillar of undeniable merit. Seriously, have you EVER responded to someone admitting error with anything but a gush of amazement about how grand said previously erroneous person is?

  14. 114
    Barry Nicholson says:

    So, is the MAGICC model correct in estimating that, if all CO2 production was stopped, the impact by 2100 would be a reduction of 0.2degC? Is that really what climate scientists are working towards? If not, what is the estimated effect from the ‘best’ climate models?

    [Response: The contrast should be with what happens if we continue to emit. Then you are talking about +2, +3ºC or higher levels of warming. – gavin]

  15. 115
    CCHolley says:

    RE. Snape @110 & 111

    I was hoping to start a conversation about the underwhelming trends in extreme heat.

    Okay, although it seems a bit hard to recognize that desire from the original statement.

    I don’t think that any lack of significant trend in extreme heat is any kind of a surprise really.

    Consider that nights are warming faster than days. Simply put, the increases in temperature caused by the addition of greenhouse gases to the atmosphere is not uniform throughout the daily temperature profile. The effect from slowing down radiation heat loss from the surface is more sensitive at night. The reasons for this are interesting and worthy of its own discussion, but Im not going to go into this here because that is not the conversation requested.

    Anyway, accept that nights are warming faster than days, that’s a fact.

    It should be obvious that maximum temperatures occur during daytime and minimum temperatures occur at night. Of course this isn’t always true due to movement of air masses (fronts), but it is true in general and most certainly any record breaking temperature will have been recorded during daytime while any record breaking low temperature will have occurred at night.

    Because of this, with warming caused by an increase in greenhouse gases how would one expect that to influence maximum versus minimum temperatures? Obviously this would have a greater effect on increasing the minimums at night than increasing the maximums during the day, hence, you are much more likely to see record low temperatures decrease over time at a greater rate than you see an increase in record high temperatures. And this is exactly what the record shows. In other words, since more of the warming is actually occurring at night, you are less likely to see a huge increase in extreme high temperatures events as you are a decrease in extremely low temperatures.

    Having said that, I don’t believe that what is currently being experienced in the way of temperature extremes is outside that predicted by the models. As I said at the beginning, the current trends are not unexpected. The paper linked below is a study on how extremes will change in a warming world from the perspective of how it will effect poor countries. The paper states that with the exception of higher latitudes, signals of these changes have not yet risen to the level where they can be readily detected over that of natural variability.

    Sebastian Bathiany, et al, Climate Models Predict Increasing Temperature Variability in Poor Countries, Science Advances, 02 May 2018: Vol. 4, no. 5, DOI: 10.1126/sciadv.aar5809
    https://advances.sciencemag.org/content/4/5/eaar5809

  16. 116

    #113, Al–

    …nobody who matters reads the oatmeal raisin bleck sections you describe. Only the yummy Chocolate Chip Executive Summaries and such things actually matter…

    That hasn’t been my experience; lots of ‘oatmeal raisin’ stuff has recieved considerable attention, even in popular reporting. And remember that 1) even in the SPM, the substantive content isn’t changed, just the language describing it; and 2) even that is done by intense debate among the Parties, which means that the influence of the contrarian nations–historically, often the Saudis, for reasons needing no explanation–is restrained by nations more concerned about the problem.

    I read (on Quora) a piece written by a denialist who claimed to be a, um, durn, I don’t know the phrase (Executive Reviewer?) but someone who analyses and comments on the work. He was torpedoed by another guy who remarked that the only requirement for that Highly-Respectable-Sounding Title was to submit an offer to be such a respectable sort.

    Yes, there’s an almost completely open public comment phase, and there’s been no shortage of denialati who have participated. (That was the basis for the amusing claim of the lamentable/risible Lord Monckton to a share of the 2007 Nobel.) But they don’t get to determine, they get to question and suggest. The chapter authors will respond, but they aren’t obligated to change anything unless the point is actually a valid one. And the comments and responses are public record–there’s a link somewhere on the IPCC pages.

    …we’re playing in a way that will result in dang near the worst possible physical results…

    Technically, no, in the sense that the worst emissions trajectories have been closed down by mitigation that’s already occurred. But then again, sensitivity is to atmospheric concentration, not primarily how fast you get there, so we could still screw ourselves quite thoroughly, and the current trajectory is bad enough that it won’t be easy to avoid.

    My guess: results that range from bad to worse, but not worse to worst.

    Fatal heat was obviously on the horizon and obviously the “near 2100” crowd were just ignoring the data. Those flickers weren’t outliers. They were what simple extrapolations showed to be inevitable near-term certainties (NOTE: This is an unsubstantiated claim. If you disagree, feel free to post a correction).

    Apples and oranges! We weren’t talking about ‘fatal heat,’ which, far from being “on the horizon” has already been responsible for hundreds of thousands of deaths this century. (More rigorous estimates run into at least millions, actually.) We were talking about 35C (wet bulb) specifically.

    Essentially, what the researchers in what you call the “the “near 2100” crowd” did was an extrapolative process. Far from “ignoring the data,” they used it. See the papers already cited.

  17. 117

    On Canadian extreme heat, Weather Canada doesn’t seem to make the official records easy to find, but from what I did see from unofficial sources seems to agree that the provincial/territorial records don’t tend toward recent years as much as one would expect.

    However, there are only 10 provinces and 3 territories, many of which are really, really big (especially in the north-south direction), spanning several climatic zones. And observation stations are, unsurprisingly, *very* heavily concentrated where the people are, which is mostly within a couple of hundred miles of the US border. That’s not where the warming is at its most rapid. Together these could bias the record, because the odds of an extreme outlier occurring are much higher where it’s warmest to start with and warming the slowest. (As an example, even for Nunavut–Canada’s eastern Arctic territory–the record is from sub-Arctic Kugluktuk, ~67N, not Alert, ~82N.)

    So, I think if one wants a less-scanty picture of extreme heat in Canada, it would be necessary to construct a more comprehensive survey of *local* records which would better capture the geographic spectrum. Otherwise, you miss records like this one:

    https://www.cbc.ca/news/canada/north/heat-wave-alert-nunavut-1.5212801

    A stunning record from last July:

    Alert, NU: 21C

    Records have been falling — not by fractions, but by large margins.

    “That’s what we’re seeing more often,” Phillips said. “It’s not just half a degree or a 10th of a millimetre. It’s like hitting a ball out of the ballpark. It is so different than what the previous record was.”

    The story doesn’t say what the previous record was, but the normal high for Alert in July is just 7C. (Kugluktuk’s, by contrast, is ~10C warmer.)

  18. 118
    Piotr says:

    Snape: “I was trying to start a conversation about extreme heat, not disprove global warming”

    What for? This website is about GLOBAL CLIMATE, so the local weather events are relevant here ONLY if they shed light on … global climate.

    Others pointed out that 1930s weather anomalies in the US associated with the Dust Bowl do not translate onto global climate and that the temp. records outside of North America contradict this narrative (Astringent: “67 countries/territories out of 131 that are listed, record highs were set since 2010”)

    To which you didn’t have the balls, I mean cherries, to own up to your actions and instead claim that you … didn’t intend any implication to the global climate. ;-)

    And then in the next sentence – you bring in … India, which would make sense ONLY if you wanted to argue that the regional temperature extremes had implications to the global climate.
    How to eat the cake and still have it, eh?

    P.S. Picking two cherries instead of one, does not prove that you do not cherry-pick.

    As for your disclaimer: “Playing contrarian……” – if it cherry-picks like a duck, and quack like a Donald (Duck?), e.g.:
    “In the East, it could be the COLDEST New Year’s Eve on record. Perhaps we could use a little bit of that good old Global Warming” – a Very Stable Genius
    then … it doesn’t really matter that it claims that it only “plays” a duck.

  19. 119
    MA Rodger says:

    Snape @110,
    I would suggest that if you were “hoping to start a conversation about the underwhelming trends in extreme heat,” it would not be helpful kicking-off such a conversation by telling us you were “Playing contrarian.”
    You make little attempt to explain further what you wish of this “conversation.” Perhaps you wish to chew over why extreme heat shows “underwhelming trends.”

    Comment has already been made that AGW is less ‘warming-up’ and more ‘not-cooling-down’ so that daily max temperatures and summer temperatures are less ‘trendy’ than daily mins and winter tempertures.
    Further there is a lot of noise in daily max temperatures such that to create a new max record temperature through the hottest part of the year becomes particularly random in nature and little to do with any changing climate, this especially so when a record is set by any one of a number of met stations within a geographical area.

    Thus consider the whole of Canada. The record daily max was seemingly set on 5th July 1937 +0.6ºC above any other recorded daily max at two locations – Midale which has data 1923-1991 and Yellow Grass with available data 1911-2017. Yet the relationship of this record heat to climate is tenuous.
    At Midale the record was set during the 7th warmest month on record (absolute average of max-min) and in the calender year ranked 41st out of the 67 years of data. The trend 1924-90 is more wobble that upward.
    At Yellow Grass the record was set during the 6th warmest month (absolute average of max-min) on record and in the calender year ranked 81st warmest out of the 105 years of data. The trend with the data running for a couple of decades more with AGW that does Midale does show a trend: +0.13ºC/decade over the full 105 years and twice that 1975-2016. Yet the July monthly temperatures wobble along with zero trend, the highest wobble of average consecutive Julys being back in the 1930, this more because of a lack of cool Julys rather than they being individually warm.

    Is that “underwhelming” enough for you?
    And do note that a country the size of Canada is not charcterised by a single rate of warming to allow such assertions as “Canada is among the fastest warming nations”. Saskatchewan, where these records were set is certainly not warming fast from a 1930s base-line. Indeed, is it so far warming at all?

  20. 120
    Snape says:

    @Al Bundy #113

    “You’ve been given enough irrefutable information to come to the conclusion that your initial hypotheses was 100% wrong.”

    My initial comment was an observation, not an hypothesis:

    “Playing contrarian……..
    23 states set their all-time high temperature in the 1930’s, compared to only 4 states where the record was set this century.”

    ********
    I stated an hypothesis earlier on this thread, but didn’t get any replies:
    “49
    Snape says:
    10 May 2020 at 10:45 AM
    OT, but last summer I got into a heated argument (pun intended) with the regulars at ATTP regarding the effective radiating level (ERL). They argued that only at that general altitude – the layer of atmosphere centered around 5.5 Km – will an increase in greenhouse gases result in global warming.

    I disagreed, believing that the increase in GHG’s nearer the surface also plays a critical role.”

    *********
    If you can convince me I’m wrong, I will readily admit it.

  21. 121
    Killian says:

    Re #114 Barry Nicholson said So, is the MAGICC model correct in estimating that, if all CO2 production was stopped, the impact by 2100 would be a reduction of 0.2degC? Is that really what climate scientists are working towards? If not, what is the estimated effect from the ‘best’ climate models?

    [Response: The contrast should be with what happens if we continue to emit. Then you are talking about +2, +3ºC or higher levels of warming. – gavin]

    And this is why mitigation is the correct pathway. Not only are emissions not going to suddenly stop outside of a massive mitigation regime, they will keep growing for decades so that -0.2 is a fairy tale no matter what under anything but a massive shift to regenerative systems.

    Further, the models are not predictions and do not define what will happen, but actually are best case scenarios… even on the high end. 8.5? That’s the best case scenario for the high end. Please witness the recent findings on Wet Bulb temps.

  22. 122
    gilles delaygue says:

    Dear all, i would like to get your comments on an estimate of CO2 emissions drop related to the Covid pandemic. The draft is posted on Arxiv (https://arxiv.org/abs/2004.13614 , revised 4th of May). Authors are a bunch of Chinese people, with few people from Paris (Ph. Ciais and O. Boucher), and H-J Schellnhuber, so without doubt a serious work. They used real time data of transportation, energy and industry activities from tens of countries to estime CO2 emissions, per country and globally. The methodology is somehow different from the estimate of the Global Carbon Projet, which has been just published (see also post #23; Le Quéré et al. Nature Clim. Change https://doi.org/10.1038/s41558-020-0797-x).

    The study compares the 2019 and 2020 emissions over their first 3 months (the work is ongoing, not sure where to find an update; one is at the bottom of this blog: https://www.lemonde.fr/blog/huet/2020/05/11/covid-19-combien-de-co2-evite/).

    1. For China (Fig 1), emissions variations are just amazing: 2019 and 2020 emissions were just parallel through Januaries, with a huge drop probably related to the ‘Chinese New Year Migration’ (Chunyun), and they only differed during Februaries (explaining almost half of the global difference). In fact, the seasonal drop in emissions in 2019 (a ‘normal year’) is just huge (~twice higher) compared to the 2020 drop due to the lockdown. Could someone confirm that this drop is due to the ‘Chinese New Year Migration’, and happens each year?

    2. The beginning of 2020 was much warmer than in 2019. If i correctly understand the study, only the electricity production has been corrected for this temperature difference (with a rough linear sensitivity). However heating also uses fuel. Any idea whether this limitation could explain part of the 2020 difference?

    Thanks for your comments.
    Take care. -gilles

  23. 123
    Chuck says:

    Snape says:
    18 May 2020 at 4:21 PM

    “I was hoping to start a conversation about the underwhelming trends in extreme heat.”

    Bullshit.

    You’re trolling with cherry picked data to see if you can stir up fake controversy over the FACT that we’re in a period of unprecedented warming due to human activity and CO2 emissions.

  24. 124
    Chuck says:

    109
    CCHolley says:
    18 May 2020 at 9:52 AM

    Another Excellent Troll Takedown!

    Thank you.

  25. 125
    MA Rodger says:

    Snape @120,
    At the time I did note your enquiry within your comment @49 but felt the thought experiment you set out poorly framed. It was the mention of water vapour that was the step too far for me.
    To belatedly reply (and ignoring water vapour & other feedbacks), the mechanism which results in AGW from increased CO2 is the change in the altitude from which IR in the 15 micron waveband can escape the atmosphere into space. If this altitude changes (as it will with increasing concentrations of CO2) and the new altitude is effectively cooler than before the change, the planet will warm. The concentrations of CO2 below that altitude simplistically do not matter.

    Mind, I see no connection between this thought experiment and recorded temperature extremes.

  26. 126
    zebra says:

    #120 Snape,

    Snape, I did not assume that your suggesting the lack of heat extremes was an attempt to question ACC. However, it has been well answered by the reference supplied by CC Holley #115:

    “The paper states that with the exception of higher latitudes, signals of these changes have not yet risen to the level where they can be readily detected over that of natural variability.”

    (Which also should answer those who are breathlessly telling us about heat extremes.)

    But with respect to your earlier comment:

    “the increase in GHG’s nearer the surface also plays a critical role.”

    That’s really way too vague to be “an hypothesis”, and I for one am not willing to try and decipher what in the world you are talking about. If you want a response, you have to be clearer about what you are saying.

  27. 127
    Snape says:

    @group

    By “underwhelming”, I only meant in comparison to the other trends.
    If you could introduce an Earth-like atmosphere to the moon, the mean temperature would increase but the maximums would fall like a rock. Seems like this is happening to a lesser extent on Earth (as a result of increasing water vapor). The overall trend is summertime highs is positive, but much weaker than daily minimums or the annual means:

    CONUS, 1950 -2019
    June-August Tmax: +0.16F/decade
    Dec.- Feb. Tmin: +0.43F/decade
    Annual Tmean: +0.31F/decade

    https://www.ncdc.noaa.gov/cag/national/time-series/110/tmax/3/8/1950-2020?base_prd=true&begbaseyear=1901&endbaseyear=2000&trend=true&trend_base=10&begtrendyear=1950&endtrendyear=2020

    (I don’t have the global trends but I’m guessing they’re in the same ballpark.)

    *******
    I brought up the Dust Bowl as an example of the above, where water/water vapor was greatly reduced and the Midwest became a little more moon-like.

    Sad to see these metrics so egregiously misrepresented in the familiar “bell curve” projections, where the whole temperature profile – extreme heat, cold and everything in between – is shown to warm at exactly the same rate:

    https://www.yaleclimateconnections.org/pics/0619_2017SummerHeat_BellCurve.gif

    https://www.skepticalscience.com/Review-Rough-Winds-Extreme-Weather-Climate-Change-James-Powell.html

    ……. hopefully just an oversight??

    *********
    I agree that wet-bulb temperatures will be a big problem going forward. Las Vegas, for example, is seeing more extreme heat…..

    https://www.ncdc.noaa.gov/cag/city/time-series/USW00023169/tmax/3/8/1950-2020?base_prd=true&begbaseyear=1901&endbaseyear=2000&trend=true&trend_base=10&begtrendyear=1950&endtrendyear=2020

    …… AND is getting more humid (yeah, this contradicts my moon narrative):

    https://ccimgs.s3.amazonaws.com/2016DewPoint/2016DewPoint_lasvegas_en_title_lg.jpg

    *******

    As for the claim that Canada is one of the fastest warming countries? Probably a mistake. Turns out the rate is not much higher than the global land-area mean:

    https://www.usnews.com/news/best-countries/articles/2019-04-05/global-warming-is-twice-as-fast-in-canada-as-rest-of-the-world-report-says?context=amp

  28. 128
    CCHolley says:

    RE. Snape @120

    OT, but last summer I got into a heated argument (pun intended) with the regulars at ATTP regarding the effective radiating level (ERL). They argued that only at that general altitude – the layer of atmosphere centered around 5.5 Km – will an increase in greenhouse gases result in global warming.

    I disagreed, believing that the increase in GHG’s nearer the surface also plays a critical role.”

    Don’t remember the particular discussion.

    All CO2 in the troposphere plays a role in the surface temperature. That’s because CO2 is a well mixed gas so in order to change its density higher in the atmosphere its proportion must be raised throughout. However, most, if not all, of the infrared radiation emitted from the surface in the CO2 bands is absorbed in the first 10s of meters or so of the atmosphere. The addition of more CO2 into the atmosphere does not appreciably change that fact. The heat from the surface travels up the atmosphere through the reradiating of heat by the greenhouse gases along with convection and heat of evaporation. How that heat actually moves up is mostly moot to the final radiation of heat to space.

    The Stefan-Boltzmann law tells us that a body the size of the earth must radiate at 255 degrees Kelvin in order to maintain energy equilibrium with the incoming solar radiation. Without greenhouse gases the average temperature of the surface would be that 255 degrees. But it isn’t. That’s because the greenhouse gases prevent that radiation from escaping freely. The layer in the atmosphere where the density of those gases is such that the radiation finally can escape unimpeded is effectively where the temperature is that 255 degrees for equilibrium. That is your ERL. In order for that 255 degree temperature to be obtained at that layer, the surface must be hotter, hence the surface increases in temperature. If you add more CO2, the density of the CO2 where the radiation can freely escape moves up and in order for that level to then reach 255 degrees and maintain equilibrium, the surface must obviously warm further. That’s he physics which is irrefutable.

    The level of CO2 near the surface is just as critical as the levels higher in the atmosphere only because without one you wouldn’t have the other. However, once the levels are saturated and all the radiation is absorbed, it is only the levels higher up that actually determine surface temperatures.

    Anyway, not really interested in Snape’s alternative laws of physics. Claiming that a declaration of the record highs in N.A. were in the 1930s was just an attempt to create discussion on “underwhelming trends in extreme heat” makes me believe that any further discussion on any topic would likely be futile. Communication in both the ability to express oneself clearly and to grasp points made by others does not appear to be a strength.

  29. 129
    Al Bundy says:

    Snape: My initial comment was an observation

    AB: Yes, cherry picks are observations. And you did caveat with “playing contrarian”, which could mean that you were setting up a volleyball so others could spike it as they saw fit. I do that. (Kevin is grand at spiking volleyballs). So, were you “playing” or “being”?

    Snape: If you can convince me I’m wrong, I will readily admit it.

    AB: Wow. All I gots ta do is convince someone on the internet!

    Hmm. So far you’ve just ignored my point, that the USA’s temps spiked in the 1930s because of poor farming practices, so I’m not optimistic…

    Drought feeds on itself since plants humidify, baked dirt resists water infiltration, etc. And when plants die and stop recycling water the whole system craters, as in the Dustbowl.

    “there were record breaking heat waves as a result of the dry ground, which allows for more sunlight to be absorbed”
    https://sites.psu.edu/yangpassion/2016/10/03/the-dust-bowl/

    Great Plains farmers developed their practices during a rather wet period. Unfortunately such practices fail spectacularly during drought, especially since there were no drought-tolerant hybrids (the first was accidentally developed in the Dustbowl when one plot kept producing ).

    So that largely explains 1930s heat. A bad drought was made catastrophic by farming practices. The Amazon is on the cusp of doing something similar.

    Currently the USA uses incredible amounts of irrigation, often via center-pivots that turn the landscape into a Go board of huge green dots that can be seen from space. All that water puts an amazing brake on heat and drought (until it runs low).

    I’ve dug into this a few times. One analysis that impressed me tried to back out irrigation (and other stuff?) and then compare the eras apples to apples. It concluded that current USA weather sans irrigation is worse than the Dustbowl. Sorry, no quote or link; twas a couple years ago.

    So, do you readily admit that the USA’s 1930s record highs were largely an artificial artifact arising from drought-intolerant farming practices? That those 1930s records would drop like flies if we still farmed like it was 1934?

  30. 130
    nigelj says:

    New research relating to the heatwave issue: “Present-day greenhouse gases could cause more frequent and longer Dust Bowl heatwaves”

    https://www.nature.com/articles/s41558-020-0771-7

  31. 131
    nigelj says:

    New open access research of interest: “Temporary reduction in daily global CO2 emissions during the COVID-19 forced confinement”

    https://www.nature.com/articles/s41558-020-0797-x

  32. 132

    Snape said:
    ” I was trying to start a conversation about extreme heat, not disprove global warming. “

    Skeptic trolls have so poisoned the well of climate discussion that the immediate response to earnest questions is to assume the worst.

  33. 133
    Al Bundy says:

    Killian,

    I goofed. What a doofus, eh? Gavin made more than one comment. IIRC he DID give you a shout out earlier this month.

    Sorry about that.

  34. 134
    Ray Ladbury says:

    Snape,
    Unfortunately, the particular observation you chose to start your conversation was an Extreme Value problem. Extreme value statistics are inherently poorly understood for the precise reason that they are rare. However, it makes little sense to discuss extreme-value statistics unless you are comparing them to other extreme-value statistics, e.g. what was the previous maximum in the data series, how long ago did it occur, how much of a delta was there.

    One thing about extreme value stats is that often the time between one maximum and the value that supersedes it, is that the time interval tends to increase. The new value is less probable, and so it will take longer for fluctuations to conspire to generate it.

    The other thing about extrema is that often they are short-lived phenomena and so have little practical effect. I would urge you to take a look at a text on extreme value stats if you want to understand the problem better.

  35. 135
    Piotr says:

    Snape: “If you could introduce an Earth-like atmosphere to the moon, the mean temperature would increase but the maximums would fall like a rock. Seems like this is happening to a lesser extent on Earth (as a result of increasing water vapor).”

    P: No, for the global climate (subject of this website) it’s primarily the thermal inertia of the water in the oceans that makes Earth not having the temp. maxima like the Moon. The main change in the effect of oceans over the time scale of climate change (subject of this website) is that it got warmer. So the GLOBAL
    trend:
    global warmer ocean -> shorter distance for a weather fluctuation to reach the new maximum -> globally there should be more maxima and fewer minima
    Hence, as explained to you be Astringent: “67 countries/territories out of 131 that are listed, record highs were set since 2010”.

    LOCALLY it may be obscured by the regional weather patterns: meandering of the Jet Stream, phase of decadal oscillations, local human irrigation etc. – like in your cherry-pick of the hot temps in the US during the Dust Bowl conditions.

    Hence climate change deniers will cherry-pick the local weather extrema to question the reality of the global climate change. And like you – will often use
    American wether for that – e.g.:
    “In the beautiful Midwest, windchill temperatures are reaching minus 60 degrees, the coldest ever recorded. In coming days, expected to get even colder. People can’t last outside even for minutes. What the hell is going on with Global Warming? Please come back fast, we need you!”
    Donald J. Trump, Jan. 2019

    in Jan. 2019 _globally_ there were only 2 all-time low temp records (both of them in the US) and 35 all-time high records, even though the number of weather stations in the Southern hemisphere is much smaller than that in the Northern hemisphere.
    https://www.newscientist.com/article/2192369-so-far-2019-has-set-35-records-for-heat-and-2-for-cold/
    Hence the colder than usual weather in North America in 2019 no more disproves global warming than your temperature records during Dust Bowl in the US.

    But all this is just a rephrasing of arguments already given to you in the previous posts, which you pretty much ignored. So much for the assurances: “If you can convince me I’m wrong, I will readily admit it.” ;-)

  36. 136
    Mal Adapted says:

    Snape’s sea-lion starts the conversation by ignoring the simplest definition of “climate”: “statistical weather”. We know that climate is changing because weather statistics are changing. Various extreme heat statistics can be computed, although whether they’re over- or underwhelming depends entirely on the beholder. What’s intersubjectively verifiable is that by a lopsided margin, salient ones show trends consistent with theoretical expectations from anthropogenically increasing atmospheric CO2. IOW, they’re a win for the standard model of physics.

    If Snape is genuinely skeptical, he’ll acknowledge the WMO’s latest five-year report: The Global Climate in 2015–2019. The press release for it added a subtitle: “Climate Change Accelerates”. I, for one, am merely whelmed by the report. For more than a century, science has predicted the consequences of transferring fossil carbon to the climatically-active pool by the petatonne. Knowing the radiative properties of CO2 in the atmosphere, we’d be astonished if global climate wasn’t changing. Behold, it is!

    Snape:

    If you can convince me I’m wrong, I will readily admit it.

    If you’re not yet convinced that your alleged conversation-starter was a red herring (gotta love metaphor), you never will be.

  37. 137
    Snape says:

    @MA Rodger #125, Zebra #126 and CCHolley @128

    MA wrote,
    “The concentrations of CO2 below that altitude simplistically do not matter.”

    CC wrote,
    “The level of CO2 near the surface is just as critical as the levels higher in the atmosphere only because without one you wouldn’t have the other. However, once the levels are saturated and all the radiation is absorbed, it is only the levels higher up that actually determine surface temperatures.”

    *********

    The above is my main point of contention. Simply put, if the upwelling IR flux emitted by the ERL is ~ 240 w/m^2 (should be noted that this value is arrived at by ignoring the atmosphere window), then the downwelling flux is also about 240 w/m^2.
    Notice, however, that the downwelling longwave flux to the surface is about 340 w/m^2:

    https://www.nasa.gov/sites/default/files/thumbnails/image/ceres-poster-011-v2.jpg

    From this, we can infer that most of the missing 100 w/m^2 flux to the surface is coming from GHG’s located BENEATH the ERL (clouds are responsible for about 30 w/m^2). Hence my initial comment, “the increase in GHG’s nearer the surface also plays a critical role.”

  38. 138
    Snape says:

    I need to clarify my last comment – should be obvious that most of the 340 w/m^2 absorbed by the surface was actually emitted from an average altitude much lower than the ERL…. maybe lower than 1000 meters.

    My argument was a hypothetical look at what would happen if this was NOT the case, if GHG concentrations beneath the ERL “did not matter” to surface temperature. As mentioned, the total downwelling flux to the surface would be roughly 100 w/m^2 less than what is observed.

  39. 139
    Snape says:

    @CCHolley #28

    “ However, most, if not all, of the infrared radiation emitted from the surface in the CO2 bands is absorbed in the first 10s of meters or so of the atmosphere. The addition of more CO2 into the atmosphere does not appreciably change that fact.”

    If you raise the near-surface CO2 concentration, then the infrared radiation emitted from the surface will be absorbed at a lower altitude. Given a constant lapse rate, the resulting backradiation will therefore come from a hotter layer of atmosphere (lower equals hotter) and will be more intense.

  40. 140
    CCHolley says:

    RE. Snape @127

    By “underwhelming”, I only meant in comparison to the other trends.

    In other words, “underwhelming” is only in the eyes of the beholder.

    If you could introduce an Earth-like atmosphere to the moon, the mean temperature would increase but the maximums would fall like a rock. Seems like this is happening to a lesser extent on Earth (as a result of increasing water vapor). The overall trend is summertime highs is positive, but much weaker than daily minimums or the annual means.

    Humidity and clouds slow warming during the day yet also slow cooling at night. Nights are warming faster than days. As usual, not sure what the point is here.

    Sad to see these metrics so egregiously misrepresented in the familiar “bell curve” projections, where the whole temperature profile – extreme heat, cold and everything in between – is shown to warm at exactly the same rate.

    Not egregious at all, they make a point. The bell curves are generally correct as those differences would not be perceivable to most. If there is really much of an inaccuracy it would largely be that the distribution becomes broader as temperatures warm. Anyway, Snape somehow seems to misconstrue record highest temperature ever by country as a representation of overall temperature extremes.

    This NY Times article based on Hansen’s work shows how summers are getting hotter–gives the actual bell curve shifts over time:

    It’s Not Your Imagination. Summers Are Getting Hotter.
    https://www.nytimes.com/interactive/2017/07/28/climate/more-frequent-extreme-summer-heat.html

    As for the claim that Canada is one of the fastest warming countries? Probably a mistake. Turns out the rate is not much higher than the global land-area mean:

    With a link to an article that discusses Canada warming twice as fast as the globe?

    Canada Warming Twice as Fast as the World, Report Warns

  41. 141
    CCHolley says:

    RE. Snape @139

    If you raise the near-surface CO2 concentration, then the infrared radiation emitted from the surface will be absorbed at a lower altitude. Given a constant lapse rate, the resulting backradiation will therefore come from a hotter layer of atmosphere (lower equals hotter) and will be more intense.

    Nonsense.

    The ERL must be at 255 degrees Kelvin for there to be an equal amount of radiated energy out as there is in from the sun. As the ERL raises in height due to more CO2, the lapse rate assures that the surface will warm until that higher ERL warms to 255 degrees and equilibrium is obtained. (BTW, the lapse rate is mostly due to convection and the radiative processes play little or no role.) Of course, with equal proportion of CO2 throughout the troposphere, each layer below the ERL will absorb and emit more as they will have also warmed proportionately and it is the net of the resulting downwelling radiation that warms the surface enough for the lapse rate to raise the temperature of the ERL to 255 degrees.

    However, if in fact the the distribution of CO2 was not proportionate, yet saturated, and you were able to only add CO2 at and above the current ERL, then the resulting warming would still be the same as the warming caused by an equal ERL with the uniform proportion of CO2 in the atmosphere. This is because the lapse rate would require the surface to warm the same amount until that new layer where the density of CO2 was such that the radiation could escape unimpeded, the new ERL, warmed to 255 degrees K. That surface warming driving that increase still must come from an increase in the net downwelling radiation–it cannot come from anywhere else. The only difference between the uniform distribution case would be in how much each particular layer contributes to the net downwelling radiation, i.e. more can reach the surface from the warmed next higher layer because the density below has not increased.

    Once there is enough CO2 in the atmosphere to absorb all surface radiation, it is only the additional CO2 at and above the ERL that drives additional warming.

  42. 142
    MA Rodger says:

    Snape @137 & 138,
    Your contention set out within your ‘thought experiment’ presented @49 that the CO2 back-radiation at the surface has some impact on the OLR up at the ‘escape’ altitude is unfounded. Your ‘thought experiment’ you described thus:-

    “Consider this hypothetical: what if water vapor and CO2 concentrations at the layer, surface to 2 Km, had remained at pre-industrial levels? Would the warming trend we see today be unchanged?”

    As we here have attempted to describe to you, the intensity of IR emitted by CO2 is defined by the temperature of the CO2 from which it radiates. (This is true for back-radiation at the surface as well as OLR escaping to space.)
    As it is much warmer near the surface than it is at the ‘escape’ altitude, this surface CO2 back-radiation will be greater than that OLR up at the ‘escape’ altitude (as you describe @137).

    If the CO2 concentrations had increased but only above 2km altitude, the CO2 back-radiation at the surface will increase as the global temperature responds to the lost escaping OLR. With near-surface CO2 remaining at 280ppm, it would mean no ~50% increase to the 415ppm we actually see. Because the CO2 is ~50% less ‘dense’, the IR emissions are ~50% less dense but the path-length of the surface back-radiation would also be ~50% longer than with 415ppm. Thus the surface is being warmed to the same amount with-or-without the sub-2km CO2 increase.

    I ignore here the H2O effects but essentially they are also temperature dependent. By adding the condition that sub-2km H2O is also fixed at pre-industrial, you will be negating some of the major AGW feedbacks resulting from H2O as the 2km altitude is yet still high enough to find H2O impacts on escaping OLR. (A quick play on MODTRAN suggests about 30% of the H2O GHG effect is sub-2km in a no-cloud atmosphere.)

  43. 143

    A couple of comments on the foregoing.

    piotr said:

    …for the global climate (subject of this website) it’s primarily the thermal inertia of the water in the oceans that makes Earth not having the temp. maxima like the Moon.

    OK, perhaps, but even stipulating that, without that GHG-rich atmosphere–and in simulations, water vapor isn’t enough; you need the CO2 as well–the oceans would freeze solid, and you’d be back to Lunar surface temperature swings, more or less.

    Also, on the ERL vs. surface question, it strikes me as a sterile distinction at best: surface conditions and TOA conditions can’t be delinked, even in simulations. So advocating that the greenhouse is “really” due to this or that aspect seems to me to be highly analogous to arguing which end of a pushrod is “really” doing the work.

  44. 144
    John Pollack says:

    Ray @134 Your comments about extreme value statistics are appropriate.
    Concerning the “bell curve” discussion, individual daily extreme probabilities will not generally follow the bell curve. However, monthly or seasonal averages will come a lot closer, due to the Central Limit Theorem.
    In the particular case of the northern Plains states of the U.S., the 1930s really were very extreme, with a rather large “delta.” They produced a lot of standout heat records at sites with 125 to 150 years of record keeping. For example, Aberdeen SD – with 126 years of records – a daily maximum of 110F (43C) or greater was recorded only once before the 1930s, 18 times during the 1930s (in five different years) and 2 times since, the most recent in 1966. The hottest, 46C (114-115F) occurred 4 times in the 1930s, in two different years. The hottest previous was 111F (44C) and afterward 112F (44C). Many daily and station records for hot minimum temperatures were also set in the 1930s, throughout the region.
    I do not think that the regional extremes reached during the 1930s are sufficiently appreciated. The meteorology during the period was unusual, but megadroughts also occurred in the region prior to European settlement and agriculture. In the context of AGW, expect the next occurrence to be even more extreme. Thanks CCHolley @107 for a good reference.

  45. 145

    #140, CC Holley–

    Yes, I stumbled over that link as well, because Snape doesn’t make explicit what he implies. So it appears that he’s quoting something that says the opposite of his comment.

    But note that “the rest of the globe” is mostly ocean. So what he means is that the rate of warming for Canada as a whole is about the same as that of the rest of the *land area* of the globe.

    Which is more or less right.

    Of course, there’s another issue here, which is that the Canadian far north *is* warming much more rapidly than the non-marine norm, just as the rest of the Arctic is. People forget that Canada extends from roughly 80N (Alert) all the way down to 41.7 N (Middle Island). That’s 4,500 km, more or less.

  46. 146
    Piotr says:

    Snape (137):”The above is my main point of contention. Simply put, if the upwelling IR flux emitted by the ERL is ~ 240 w/m^2, then the downwelling flux is also about 240 w/m^2. Notice, however, that the downwelling longwave flux to the surface is about 340 w/m^2. From this, we can infer that most of the missing 100 w/m^2 flux to the surface is coming from GHG’s located BENEATH the ERL (clouds are responsible for about 30 w/m^2). Hence my initial comment, “the increase in GHG’s nearer the surface also plays a critical role.”

    Well, that’s … not the only inference we can draw. Other, and I would argue, a much better documented one, is that despite dropping scientifically-sounding words (e.g.”ERL”) – you don’t know (pardon my scientific jargon) shit. To falsify your claim alll you need to know is that:
    a) the air temperature drops with altitude (see the snow on top of mountains)
    b) IR emissions are lower in lower temps (see the Stefan–Boltzmann law from high-school)
    Hence: warm air near Earth surface – high emissions in (340W/m2), cold air at ERL – low emissions out (200 W/m2). See – no need to invoke your nonexisting dramatic spike in GHGs near the Earth’s surface:
    “I disagreed, believing that the increase in GHG’s nearer the surface also plays a critical role.”)?

    Given that – are you going to go back to your opponents from ATTP and eat the crow? “If you can convince me I’m wrong, I will readily admit it”, right?

  47. 147
    Snape says:

    @Al Bundy #129

    “And you did caveat with “playing contrarian”, which could mean that you were setting up a volleyball so others could spike it as they saw fit. I do that. (Kevin is grand at spiking volleyballs). So, were you “playing” or “being”?”

    I was “playing contrarian” by bringing up one of their favorite talking points – the dust bowl. It interests me for a different reason, as an example of how a lack of moisture affects temperature.

    “There were were record breaking heat waves as a result of the dry ground, which allows for more sunlight to be absorbed”
    https://sites.psu.edu/yangpassion/2016/10/03/the-dust-bowl/“

    More sunlight to be absorbed? That’s a complicated claim. Albedo varies with the type of crop or vegetation. The albedo of soil varies according to soil type and whether the soil is wet or dry – dry ground having greater albedo than wet.

    ********

    “I’ve dug into this a few times. One analysis that impressed me tried to back out irrigation (and other stuff?) and then compare the eras apples to apples. It concluded that current USA weather sans irrigation is worse than the Dustbowl. Sorry, no quote or link; twas a couple years ago.”

    I think this is the study you were thinking of, courtesy of nigelj #130

    https://www.nature.com/articles/s41558-020-0771-7

    ********

    So, do you readily admit that the USA’s 1930s record highs were largely an artificial artifact arising from drought-intolerant farming practices? That those 1930s records would drop like flies if we still farmed like it was 1934?”

    Absolutely. Irrigation has played a big role in keeping down summertime highs. From a really interesting study,

    “Our results indicate that the impact of irrigation on climate extremes is much more pronounced than its influence on the mean climate. This is highly relevant for understanding the past and possible future climatic effects of irrigation, particularly since most research to date has focused only on the influence on the mean climate. The strong response also suggests that irrigation may have masked warming trends for temperature extremes in some regions of the world. The next step for research thus consists of verifying whether irrigation-induced cooling has been offsetting CO2-induced warming.”

    https://phys.org/news/2017-04-cooling-effect-agricultural-irrigation.html

  48. 148
    Snape says:

    @Ray Ladbury #134

    “One thing about extreme value stats is that often the time between one maximum and the value that supersedes it, is that the time interval tends to increase.”

    Understood. Thanks for pointing this out.

  49. 149
    Snape says:

    @Piotr #135

    No, for the global climate (subject of this website) it’s primarily the thermal inertia of the water in the oceans that makes Earth not having the temp. maxima like the Moon.”

    You could be right, but consider this claim (which I can’t verify),

    “Besides creating the above-mentioned weather events, convection serves another purpose — it removes excess heat from the earth’s surface. Without it, it has been calculated that the average surface air temperature on earth would be somewhere around 125° F rather than the current liveable 59° F.”

    https://www.thoughtco.com/what-is-convection-4041318

  50. 150
    MA Rodger says:

    CCHolley @140,
    The rather-unfortunately chosen citation by Snape @127 with the title ‘Canada Warming Twice as Fast as World, Report Warns’ to support Canada’s temperture record being “not much higher than the global land-area mean” originates in Chapter4 of CCCR2019 which tells us:-

    “The annual average temperature in Canada increased by 1.7°C (likely range 1.1°C–2.3°C) between 1948 and 2016, roughly twice the increase observed for the Earth as a whole (0.8°C for 1948–2016 according to the global mean surface temperature dataset produced by the Met Office Hadley Centre and the Climatic Research Unit at the University of East Anglia, UK, HadCRUT4.)”

    The HadCRUT4 increase 1948-2016 is +0.84°C but HadCRUT isn’t usually seen as having good global coverage. GISS gives the value as +1.13°C globally but even this is a bit of an apples-&-oranges comparison as land temperature is increasing faster than land+ocean. The GISS value for global land 1948-2016 is +1.40°C. So the CCCR2019 report of +1.7°C is indeed “not much higher than the global land-area mean”