RealClimate logo


Unforced variations: Sep 2019

Filed under: — group @ 1 September 2019

This month’s open thread for climate science topics. A new two-part community assessment of tropical storms and climate change is online at BAMS: Knutson et al. (2019a ; 2019b). And for those interested in Arctic Sea Ice, there is always the NSIDC.

References

  1. T. Knutson, S.J. Camargo, J.C.L. Chan, K. Emanuel, C. Ho, J. Kossin, M. Mohapatra, M. Satoh, M. Sugi, K. Walsh, and L. Wu, "Tropical Cyclones and Climate Change Assessment: Part I: Detection and Attribution", Bulletin of the American Meteorological Society, vol. 100, pp. 1987-2007, 2019. http://dx.doi.org/10.1175/BAMS-D-18-0189.1
  2. T. Knutson, S.J. Camargo, J.C.L. Chan, K. Emanuel, C. Ho, J. Kossin, M. Mohapatra, M. Satoh, M. Sugi, K. Walsh, and L. Wu, "Tropical Cyclones and Climate Change Assessment: Part II: Projected Response to Anthropogenic Warming", Bulletin of the American Meteorological Society, vol. 101, pp. E303-E322, 2020. http://dx.doi.org/10.1175/BAMS-D-18-0194.1

278 Responses to “Unforced variations: Sep 2019”

  1. 201
    Chuck says:

    Hey guys, don’t be hard on Weaktor. He’s quite a prolific writer on multiple topics, not just the existential threat of Climate Change. This is probably his best seller:

    https://i.imgur.com/ddqefwg.jpg

  2. 202
    Dan DaSilva says:

    You are correct.

    Do believe that all of Mann’s calculations and notes on the hockey stick were provided to the court? He had more than 8 years to do so.

  3. 203
    Victor says:

    AB: How about posting three single-sentence excerpts that capture your book’s essence?

    Happy to oblige:

    “What makes this book different is the fact that I no longer really care whether or not you believe me. As I see things, it’s already too late to argue one way or another on this topic. It’s not that “the science is settled” – I feel sure it isn’t – it’s that the issue is settled. Climate change is no longer a scientific matter, but a social construct. The debate is over and it’s been won by those most adept at influencing public opinion.”

    You can learn a lot more free of charge by accessing the “Look Inside” feature at the Amazon site.

  4. 204
    Ray Ladbury says:

    AB: How about posting three single-sentence excerpts that capture your book’s essence?

    Ooh, sounds fun. Let’s open that up to the commentariat.

    My first entry: Veni, vidi, et non intellegetis

  5. 205
    Mal Adapted says:

    nigelj:

    https://public.wmo.int/en/media/press-release/global-climate-2015-2019-climate-change-accelerates:

    “Global Climate in 2015-2019: Climate change accelerates.”

    Thanks, pretty interesting. From the Executive summary:

    Compared to the previous five-year assessment period 2011–2015, the current five-year period 2015–2019 has seen a continued increase in carbon dioxide (CO2) emissions and an accelerated increase in the atmospheric concentration of major greenhouse gases (GHGs), with growth rates nearly 20% higher. The increase in the oceanic CO2 concentration has increased the ocean’s acidity.

    The five-year period 2015–20191 is likely to be the warmest of any equivalent period on record globally, with a 1.1 °C global temperature increase since the pre-industrial period and a 0.2 °C increase compared to the previous five-year period.

    In a quinquennial report, it’s not surprising the focus is on 5-year periods. The WMO specifies a 30-year interval for establishing climate normals, however, so presumably the broad claim in the title is from simple observation, rather than a rigorous statistical finding? There’s discussion lately (e.g. Mann et al. 2017; Runge et al. 2016) that conventional statistical methods are inadequate to track rapid climate change. I’m also dimly aware of progress in attribution. I’ll leave it to the specialists. Until there’s expert consensus, I’m content not to know the ‘true’ second derivative of the GMST curve. The first, at 0.2°C/decade since 1990, is plenty scary thank you.

  6. 206
    MA Rodger says:

    The WHO Global Clmate Report 2015-19 is being well quoted in the press but, despite being published, it is itself quite difficult to unearth – but not impossible – here it is.

    The assertion that 2015-19 ‘is set’ to be the warmest 5-year period rather ignores just how cold the globe must be over the next few months for that accolade not to become true. As the WHO report says, 2015, 2016, 2017 & 2018 are the warmest on record and 2019 likely to slot in as the second warmest on record. So for 2015-19, the five warmest years on record averaging +0.83ºC (this the simple average of GISS, NOAA, HadCRUT & BEST), now to drop below +0.63ºC (this the same average for 2010-14, the second warmest 5-year period on record) would require these global averages to run below -2.82ºC for the remaining months of 2019. Note that the lowest such anomaly on record for the final three months of the year was -0.57ºC in 1910. There is no dodging it – these last five years are ‘scortchyisimo!!!’

    And just to provoke the skyrockety folk, the grand headline of “Increases in CO2 concentrations continue to accelerate” found on some WHO webpages (eg here) is not borne out by the underlying documents. Also the bullet-point “CO​2 emissions from fossil fuel use continue to grow by over 1% annually and 2% in 2018 reaching a new high” refers to a ‘high’ in emissions/year and not to gowth-rates reaching a new high. The underlying document from the GCP says:-

    “After a three-year hiatus with stable global emissions from 2014 to 2016 (Jackson et al. 2016, Le Quéré et al. 2018, IEA 2018), CO2 emissions grew by 1.4% in 2017 and 2.1% in 2018 to 37 Gt (billion tonnes), and are expected to continue to grow in 2019 (updated from Le Quéré et al. 2018). Additional increases through 2019 and 2020 remain uncertain but appear likely because of persistent growth in oil and natural gas use and growth projected for the global economy. Coal use has slowed markedly in the last few years, potentially peaking, but its future trajectory remains uncertain.”

    Ignoring the bad news that emissions have grown higher than those “hiatus [years] with stable global emissions” and that they may yet grow more before we see the peak, may I be so bold to suggest that if the underlying atmospheric growth of CO2 was 2.2ppm/yr, a 1.4% increase in emissions followed by a 2.1% increase would boost emissions by 3.5% and presumably boost the underlying atmospheric concentrations increase by a similar amount, ie from 2.2ppm/yr to 2.3ppm/yr.

  7. 207
    Mr. Know It All says:

    184 – nigelj
    “…Instead do what other climate websites do like skepticalscience.com. They insist sceptics back their wild claims with references to the peer reviewed literature, and if they repeatedly fail to do this the comments get crossed out or deleted…”

    Maybe, but a lot of skepticism is not based on peer-reviewed studies, are not “wild claims”, but are based on the historical record, common knowledge, and on CC studies. A couple of irrefutable examples: it is common knowledge that there were unusually warm and cool periods in recorded history (and in pre-history)long before we changed the CO2 concentration, also it is common knowledge that Dorian’s clone occurred in 1935, and it is common knowledge that we don’t have enough data on hurricane frequency, sea temps, global air temps, or hurricane intensity prior to the 1900s; therefore making statements about “trends” being due to CO2 is problematic.

    Victor – to increase book sales I’d provide links to it in comments on CC articles at: AmericanThinker dot com, breitbart dot com, townhall dot com, the federalist dot com, zerohedge dot com, and many others. I would also NOT reveal my real identity or location to reduce risk of retaliation. ;)

  8. 208
    Mr. Know It All says:

    153 – nigelj
    “My understanding from general reading is this is likely to effect Hurricanes in some way, because they get their energy and precipitation from warm oceans and we are warming the oceans. If you disagree you would need to explain why. It seems like its a point that is very hard to disagree with.”

    Maybe, but it sounds like you are saying that a specific hurricane has more energy than others because of global warming. Unless we have calculated the energy in hurricanes of the past and come up with a plot comparing it to sea temps, or something, we cannot say that one hurricane had more “energy” than another one. They vary in volume, wind speed, pressure, humidity, etc.

    ” ….I think it would be just a matter of time before clear evidence emerges that Atlantic hurricanes are becoming more intense. ”

    That may happen, but it is not clear at this point – hurricane frequency, path, wind speeds, pressures, are all over the map – they’re kind of random – like tornados, hail storms, snow storms, hot and cold spells, and all other weather phenomenon. That’s a skeptic point for all of climate – kind of hard to argue with it. Last year here in the PNW USA we roasted, this year we were cool yet CO2 was higher. Random.

  9. 209
    nigelj says:

    I suggest a new monthly thread called “Deliberate Ignorance: (Date) for most of the denialists stuff. It would un-clutter the UV and FR threads. Nobody likes being humiliated, so it might make the denialists improve. This is a simple workable plan.

  10. 210

    JCH, #189–

    If an atmosphere like earth’s existed as it currently is, but miraculously no back radiation reached the surface of its planet, would there be a greenhouse effect?

    I think the problem with such a question is that the parameters of “miraculously” are undefined, and thus call all inferences and extrapolations into question, too. For example, while Callendar (1938) conceptualized back-radiation as essential to the GHE, others (going back at least to Nils Ekholm’s paper (OTOMH, 1905 or 6?) conceptualized the essential mechanism of the GHE as being the raising of the effective radiating altitude, and therefore decreasing radiative efficacy. Both effects appear to me to be inherently related–consequences of the decreased mean path length in certain IR frequencies.

    So, does “miraculously” encompass altering the first, but not the second? If so, there would still be a GHE. But what do we learn from that?

  11. 211

    Nigel said:

    “Why is this website giving Victor a platform to spread his climate denialism and assorted nonsense? Talk about shooting yourselves in your own foot:)”

    Unfortunately, it’s impossible to review the book on Amazon unless one first buys it. But who wants to do that? I know what’s in it based on what Victor writes here, but the majority of the people that may purchase it won’t have a clue.

  12. 212
    Alastair B. McDonald says:

    Al Bunby @200,

    You can see an introduction to Victor’s (aka Bill Blake) by clicking on “Look Inside” at the Amazon page Victor supplied: here.

  13. 213
    Alastair B. McDonald says:

    @189 JCH asks:

    “If an atmosphere like earth’s existed as it currently is, but miraculously no back radiation reached the surface of its planet, would there be a greenhouse effect?”

    The answer is yes! The greenhouse effect works by the long-wave radiation being absorbed by the H2O and CO2 molecules which heat the air. The short-wave radiation from the Sun only heats the surface of the Earth, not the air. Back radiation only produces a small positive feedback; it is not the driver of the greenhouse effect.

    See my translation of H-B de Saussure’s work to which Fourier refers. See Travels in the Alps, Chapter 35.

    Note that the greenhouse effect should really be called the hotbox effect as it was Sausure’s helio-thermometer that Fourier describes. See Saussure’s letter to the Journal de Paris

  14. 214
    Al Bundy says:

    nigelj: I don’t see why the moderators would have to read most incoming comments

    AB: uh, WOULD is not equal to MUST. You read most incoming comments even though nobody is saying you must, eh? Or are you saying that pressing a button or two (with exceptions) for each comment you read would be a hardship? Naw, the only thing a good system asks is for you to do what you already do but more efficiently and with way better results.

    Zebra @165 says “John, in your comment to me, you are not responding to what I said #148. Do you agree or disagree with my conclusion that Dorian… not ‘something like Dorian’, but that specific event with all its measurable characteristics, on that specific date… would have essentially zero probability of occurring on Earth B?”

    nigelj: In a climate warming situation it is probable that most hurricanes will change in some way,

    AB: You miss the point. IF your dad had never met your mother how would your life change? Dorian would NOT have happened without climate change. Not even a reduced Dorian. There would be NO Dorian, just like there would be NO you if your parents had never met. Thus, attribution is stupid other than as a meta analysis. “This sort of storm would happen once in 100 years without climate change. This sort of storm has occurred three times in five years with climate change. We have no clue when that one in 100 year storm would happen sans climate change but the odds that a one in 100 year storm would occur precisely when Dorian occurred with climate change is laughably remote”.

    Nigelj: I have this sneaking suspicion that nobody is going to want this time consuming job, but feel free to volunteer for moderation duties. Will you do that?

    AB: Sure. It’s not like it will take ANY time because….

    nigelj: Already happens. In a sense we are all moderators.

    AB: Duh. Yet you think that having seven folks do the same thing ever so inefficiently is less work than one person doing it when it is their turn and with far superior tools?

    nigel: Why is this website giving Victor a platform to…

    AB: Because the scientists have day jobs and don’t spend time on the comments for fun. “Jobs” should be done by those who are already spending the time trying to do the function for fun. Enabling a person at play to perform a service is ever so much better, cheaper, and more fulfilling than having someone who’d rather be somewhere else do a job. Another Duh.
    _________

    zebra,

    Aw, consider the source. “Magic” is a supreme compliment. After all, my books are “Quantum Magic part 1” and, unfinished, “Quantum Magic part 2”.
    ____

    killian: Refocus, eh?

    AB: Yep. Which is what my proposal aims to do. Thoughts?

  15. 215
    Al Bundy says:

    Nigel,

    Think about it. IF the scientists were only presented with puzzles that were above our pay grade do you think that “inline responses” would increase in number and depth?

    This whole “scientists pretending to be preschool teachers” model prevents them from doing what all of us desperately wish they would do.

    Do you want them to herd and corral us or talk to us?

  16. 216
    Al Bundy says:

    zebra,

    Here’s the second half of Quantum Magic part 2’s back cover, which is titled “For the English Teacher”:

    He approached her and asked her advice, saying that he was a writer looking for a contest to enter. The problem was that his writing didn’t fit any current genre. He’d made up his own, which he called “weaving”. It’s a type of interactive nonfiction where one must write the most fantastical story using/explaining facts that can be easily and solidly verified, but of apparently supernatural origin: there can be no physical fiction or forcing.

    She read two of Harmless and Intriguing’s chapters. (As of 040117, the rest were still being woven.)
    .

    For a writer, it’s high praise when an English teacher tries to melt through a counter five feet away. Did my Work instill “the terror of what couldn’t possibly be”? Was she afraid of an old one-legged man? Maybe she was in a hurry to get back to collating.

    Her suggestion? Science fiction. I agree. It’s time for you to finally read some SF you can’t put down.

    Doc

    PS to the English teacher: Have you applied your skills as a teacher to the ancient texts by analyzing the characters for motivation? Why would anyone join the losing side on purpose? Well, what if your reality is a story to me, and I’m trying to win the shortest shelf’s writing contest?

    “Faith is ever so fun as long as it stays fiction.”
    ______________

    And no. Unlike Vic’s masterpiece my books ain’t for sale.

  17. 217
    Thomas says:

    The World Meteorological Organization has gone all “Skyrockety” on us.

    some examples include:
    The data, compiled by the World Meteorological Organization (WMO), says climate change is accelerating, with sea levels rising, carbon dioxide levels increasing and ice sheets melting faster than ever before.

    The report “highlights the urgent need for the development of concrete actions that halt global warming and the worst effects of climate change,” said its authors, the Science Advisory Group to the summit.

    It highlighted that global temperatures have risen by 1.1 degrees Celsius since 1850, and have gone up 0.2C between 2011 and 2015.

    And rather than falling, carbon dioxide grew 2 per cent in 2018, reaching a record high of 37 billion tonnes and locking in further warming.

    According to the report, carbon emissions between 2015 and 2019 had grown by 20 per cent compared with the previous five years.

    Sea levels have been rising by an average of 5 millimetres a year in the past five years, compared to 3.2mm a year on average since 1993, with much of the rise attributed to melting glaciers and ice sheets.

    The report flagged that Arctic summer sea ice has declined at a rate of 12 per cent per decade over the past 40 years, with the four lowest values between 2015 and 2019.

    The amount of ice lost from the Antarctic ice sheet increased by a factor of six each year between 1979 and 2017, while glacier loss for 2015-19 is also the highest for any five-year period on record.

    “Sea-level rise has accelerated and we are concerned [about] an abrupt decline in the Antarctic and Greenland ice sheets, which will exacerbate future rise,” said WMO secretary-general Petteri Taalas.

    The current levels of ambition would need to be tripled to meet the 2C goal and increased five-fold to meet the 1.5C goal — which is technically still possible.

    “This reads like a credit card statement after a five-year-long spending binge,” said Dave Reay, chair in carbon management at the University of Edinburgh.

    “Our global carbon credit is maxed out,” he added.

    “If emissions don’t start falling there will be hell to pay.”

    The report also found that heatwaves were the deadliest weather hazard in the 2015-19 period, affecting all continents and setting new national temperature records.

    The summer of 2019, which included the hottest ever month on record in July, saw unprecedented wildfires in the Arctic.

    In June, these were responsible for emitting 50 megatons of carbon dioxide.

    from https://www.abc.net.au/news/2019-09-23/climate-change-accelerating-warn-scientists/11537240

    Gee, using all those emotionally charged words like “concerned” and “hell to pay” and “deadliest” needs to stop, while saying things like “50 megatons” is being hysterical and manipualtive.

    Don’t you think MAR?

    Others?

  18. 218
    Thomas says:

    181 Victor … do I need to spell it out where you can put your book Victor?

    I see RC moderators still have learned next to nothing all these years.

  19. 219
    Al Bundy says:

    zebra,

    You got my neurons firing. This bit needed sanding. Now it’s:

    It’s a type of interactive nonfiction where one must write the most fantastical story using/explaining facts that can be easily and solidly verified, but are of apparently supernatural origin when informed by the story.

    There can be no physical fiction. There can be no forcing. Weaving’s not magic tricks but the stacking of improbabilities for the sake of the story.

  20. 220
    Killian says:

    Re #194 nigelj said Mike, regarding your question on whether climate change is accelerating. I just came across this, which has just been released by the WMO:

    https://public.wmo.int/en/media/press-release/global-climate-2015-2019-climate-change-accelerates

    “Global Climate in 2015-2019: Climate change accelerates.”

    Shush! No skyrocketry allowed!! (Because god forbid any sane risk analysis be done.)

    More seriously – though that is one of the most serious errors humanity is making, using absolutely isht risk analysis – that is essentially the same source as the post I made. Scary stuff therein.

  21. 221

    KIA 207: it is common knowledge that there were unusually warm and cool periods in recorded history (and in pre-history)long before we changed the CO2 concentration

    BPL: You need an introductory course in statistics, Killed In Action. And one in logic. The straw man that climate scientists are saying CO2 alone can affect temperature is one example of your love of fallacies.

  22. 222

    ABB 213: The short-wave radiation from the Sun only heats the surface of the Earth, not the air.

    BPL: No, there is plenty of absortion of sunlight by the atmosphere, though mostly by clouds.

    ABB: Back radiation only produces a small positive feedback; it is not the driver of the greenhouse effect.

    BPL: Yes it is. Stop spreading nonsense.

  23. 223
    zebra says:

    Al Bundy,

    “magic”

    The thing is, it’s really difficult to write words (or read words) about it if that’s how you directly experience the world already. It’s not a better or worse interaction, but what I’m stuck with.

    My background, apart from physics/engineering/design, is in visual arts; I do images… takes a while since I build them out of wood and stuff… and then (maybe) find a clever title, in the hope that it’s enough of a hint to trigger some relatively congruent understanding.

    Right now I’m in crisis mode because I have to dip back into the factoid world; I’m on a deadline to get some photos taken to submit for a show… using a digital camera (new for me) and suddenly having to deal with a seriously crashed hard drive. It’s great that all the info is a click away, but as we all know, there’s way too much of it to sort through efficiently.

    Anyway, I am truly appreciative of your efforts to translate what should be obvious to people who have been reading about the climate/Dorian all this time.

    And I note, going back to the idea of establishing basic “warrants” that form a starting point for actual discussion and learning about science, that neither KIA nor John Pollack are going to do that… their rhetorical positions require ignoring the characteristics of chaotic systems in favor of “God did it”. We’ll see about other people. ;-)

  24. 224
    William B Jackson says:

    209 That sounds like just the place for Wicktor and Know It All’s posts… deliberate use of unsubstantiated nonsense even after others have pointed out the errors. I am no scientist…a common excuse used by many before posting denialist twaddle…but I recognize that actual scientific consensus is to be preferred!

  25. 225
    MA Rodger says:

    Finally HadCRUT has posted for August with an anomaly of +0.742ºC, a bit up on July’s anomaly of +0.706ºC. It is the 3rd warmest August on the HadCRUT record (2nd on GISTEMP & BEST, =2nd on NOAA), putting it behind August 2016 (+0.79ºC) and 2014 (+0.74ºC) and ahead of August 2017 (+0.71ºC), 2014 (+0.68ºC), 1998 (+0.61ºC) and 2018 & 2009 (+0.59ºC). August 2019 was 31st in the HadCRUT all-month record (35th in GISTEMP, 31st in BEST, =29th in NOAA).
    A ranking of the HadCRUT year-to-date data puts 2019 in third place which looks its likely position for the full calendar year although 2nd or 4th is not impossible. (In both GISTEMP & BEST, 2nd place is looking the very likely outcome, in NOAA 2nd, 3rd or 4th all very possible.)

    …….. Jan-Aug Ave … Annual Ave ..Annual ranking
    2016 .. +0.88ºC … … … +0.80ºC … … … 1st
    2017 .. +0.73ºC … … … +0.68ºC … … … 3rd
    2019 .. +0.73ºC
    2015 .. +0.71ºC … … … +0.76ºC … … … 2nd
    1998 .. +0.61ºC … … … +0.54ºC … … … 8th
    2010 .. +0.61ºC … … … +0.56ºC … … … 6th
    2018 .. +0.58ºC … … … +0.60ºC … … … 4th
    2014 .. +0.57ºC … … … +0.58ºC … … … 5th
    2002 .. +0.55ºC … … … +0.50ºC … … … 13th
    2005 .. +0.53ºC … … … +0.55ºC … … … 7th
    2007 .. +0.53ºC … … … +0.49ºC … … … 14th

    The last decade’s monthly anomalies for HadCRUT, NOAA, GISS, BEST as well as RSS & UAH TLT are graphed out here (usually 2 clicks to ‘download your attachment’).

  26. 226
    Al Bundy says:

    Mal Adapted: The WMO specifies a 30-year interval for establishing climate normals,

    AB: It’s amazing that rules of thumb continue to be given life long after the truism they rely on has been shattered. As if 30-years is a short enough time to measure a climate normal. Like photographing a walker in the dark with a long exposure shot. One big smudge.

    5 years seems about right to me, with the data cleaned up by subtracting ENSO, the sun, volcanoes, et al.

  27. 227
    Al Bundy says:

    To clarify, “A Duh thing” is something that is both obvious and generally invisible until it is pointed out.

  28. 228
    nigelj says:

    Victor @203 says “What makes this book different is the fact that I no longer really care whether or not you believe me. As I see things, it’s already too late to argue one way or another on this topic. It’s not that “the science is settled” – I feel sure it isn’t – it’s that the issue is settled. Climate change is no longer a scientific matter, but a social construct. The debate is over and it’s been won by those most adept at influencing public opinion.”

    I hear where he is coming from, but as usual Victor hasn’t thought about it clearly enough and possibly isn’t aware of the pertinent facts. The science is settled for all practical purposes, because numerous formal studies show a 90 – 97% consensus among climate scientists. ( refer to the scientific consensus on climate change on wikipedia for a list and references) . Governments would be unwise to ignore such a strong consensus, and takes sides with a few sceptics with dubious funding sources.

    The climate change issue is not strictly speaking a social construct. The definition of social construct from Mirriam Webster “An idea that has been created and accepted by the people in a society” . Examples of social constructs include Gender, Femininity/Masculinity, Illness, Marriage and family. Climate science is a scientific discovery, as opposed to something social and created by society. Mitigation flows from this and social “institutions” might buy into this but that doesn’t make it a social construct. You might better argue that “environmentalism” is a social construct, possibly.

    In any event, even if one defines the climate issue as a “social construct”, this does not ipso facto make it a bad thing. Marriage and family are not generally considered bad things. Social constructs are really multi faceted ideas with many dimensions.

    The climate debate is not over, because there’s still some denial about the science and mitigation. The debate hasn’t been won by those most influential at influencing public opinion. With respect, the scientists trying to convince people of the problem are mostly not great with persuasive rhetoric, or at least they are not skilled like politicians or PR people. Frankly I prefer the scientists directness and candour. The denialists are sadly better at influencing opinion, because they tell a pack of lies, but this only works in the short term, and their hollowness is increasingly being exposed. A good analogy might be certain politicians in very recent history.

  29. 229
    nigelj says:

    Mr. Know It All @207

    “Maybe, but a lot of skepticism is not based on peer-reviewed studies, are not “wild claims”, but are based on the historical record, common knowledge, and on CC studies…”

    Yes fair enough, and the rule about backing claims with references to peer reviewed literature doesn’t have to be rigidly enforced. Properly sourced empirical data is fine. The intent of the rule is to send a signal to prevent people posting long repetitive lists of wild, unproven allegations which are nothing more than propaganda. Nobody is obliged to provide a platform for that.

    ” it is common knowledge that we don’t have enough data on hurricane frequency, sea temps, global air temps, or hurricane intensity prior to the 1900s; therefore making statements about “trends” being due to CO2 is problematic.”

    We have good paleo evidence on temperature trends prior to 1900. It’s not perfect but its accurate enough to be very useful and to show a clear trend very long term, but the validity of AGW is not dependent on this anyway. We don’t need data on hurricane intensity prior to 1900 in the pre agw warming period. All we need is data on the trend since 1900.

    ——————–

    Mr. Know It All @208

    “My understanding from general reading is this is likely to effect Hurricanes in some way, because they get their energy and precipitation from warm oceans and we are warming the oceans. If you disagree you would need to explain why. It seems like its a point that is very hard to disagree with.”

    “Maybe, but it sounds like you are saying that a specific hurricane has more energy than others because of global warming. Unless we have calculated the energy in hurricanes of the past and come up with a plot comparing it to sea temps, or something, we cannot say that one hurricane had more “energy” than another one. They vary in volume, wind speed, pressure, humidity, etc.”

    We don’t have to measure increased heat energy content as such, and you couldn’t anyway. We can measure the effects of this on hurricane dynamics or intensity, such as wind speed, precipitation and core pressure. Climate change is expected to increase wind speed and precipitation and deepen pressure. There is empirical evidence that pacific hurricane trends have changed in this way, but data is currently not good enough to be sure about Atlantic hurricane trends, however its hard to see any reason why they wouldn’t be effected. It would be a very bad bet to assume they would not be affected.

    Also there is Zebras point that a warmed climate increases heat energy and this by definition is going to effect all weather systems. Again you would need to say why you disagree, and it seems a hard one to disagree with. But of course its a case of determining whether the effects are significant, and their particulars.

  30. 230
    nigelj says:

    Al Bundy @214

    AB: You miss the point…

    Nigelj: I did not miss the point. I said at 185 “More energy in the system must affect ALL weather events, but it doesn’t tell us how or whether its significant….”

    An exact copy of Dorian would not have happened in a different climate, if that’s what you are getting at. I think climate change must effect all hurricanes somehow (but would like to know what the experts think), and generally make them mostly more intense, but the more important point is whether AGW has “significantly” effected specific weather events. Attribution studies try to ascertain exactly whether climate change had a SIGNIFICANT effect on a specific event and how, and whether a particularly intense event would have happened without climate change . I can’t see whats wrong with the studies, because it seems a natural question to ask, but for me personally the trend of hurricanes as a whole is more important.

    Nigelj: I have this sneaking suspicion that nobody is going to want this time consuming job, but feel free to volunteer for moderation duties. Will you do that?

    AB: Sure. It’s not like it will take ANY time because….

    Nigelj: Yes it wont take much time, I rushed my comment. I wish we had that edit button you mentioned. But my implied point is you are loading the website moderators down with a lot of ideas , that cumulatively create a lot of extra work, yet you seem unwilling to take on the role yourself. So credibility problem…

    nigelj: Already happens. In a sense we are all moderators.

    AB: Duh. Yet you think that having seven folks do the same thing ever so inefficiently is less work than one person doing it when it is their turn and with far superior tools?

    NigelJ: Please stop putting words in my mouth. Plus its up to realcimate to decide such things and get the best moderators they can and as many as needed, surely? Whats that got to do with Me? I’m not about to tell these people how to cook eggs.

    Like I already said, I think the moderators are currently doing a good job and nasty abusive comments have reduced. The crank hole is a good repository for completely silly things. Are you proposing a solution looking for a problem? :)

    nigel: Why is this website giving Victor a platform to…

    AB: Because the scientists have day jobs and don’t spend time on the comments for fun. “Jobs” should be done by those who are already spending the time trying to do the function for fun. Enabling a person at play to perform a service is ever so much better, cheaper, and more fulfilling than having someone who’d rather be somewhere else do a job. Another Duh.

    nigelj: My comment was obviously in reference to his BOOK. Ie, why is this website allowing him to promote his book? Doesn’t seem a great idea.

    I agree they cant always sift through every detail he says and the rest of your comments, but like I said if you are keen on the idea of farming out moderation duties, you should volunteer for moderation duties, and not simply tell people what they should do.

    ———————–

    Al Bundy @215

    “Think about it. IF the scientists were only presented with puzzles that were above our pay grade do you think that “inline responses” would increase in number and depth? This whole “scientists pretending to be preschool teachers” model prevents them from doing what all of us desperately wish they would do.Do you want them to herd and corral us or talk to us?”

    I’m not really sure what you are saying. Perhaps you should clarify it. It depends on the target audience. This website is a public forum not a private discussion. Presumably as such realclimate are trying to communicate with both ordinary lay people and experts, so it’s a bit of a balancing act. There is some preschool teaching and herding and some more advanced discussion and one on one discussion. Looks fine to me, and I can’t see how else they can do it. Of course, it would be great to have plenty of what you appear to be suggesting.

  31. 231
    nigelj says:

    Al Bundy @215, in hindsight I have deciphered your comment. You appear to be saying if the scientists spent less time on moderation duties, they would have more time to interact with people. Well true enough and nice idea, but if we do moderation we may have less time to then interact on the website.

    I suspect the mods wont love farming the job out. They probably want to maintain control over moderation, and maintain consistency, and a lot of crazy stuff gets culled out that we never see. However the delays publishing comments are a bit frustrating sometimes. Most websites are much faster.

  32. 232
    TPaine says:

    Some of my denier friends use the accumulated cyclone energy to show hurricane activity is not increasing and hurricanes are not getting stronger. When I look on Wikipedia at that index it shows a table that has the accumulated cyclone energy ‘classification’ to be a lot worse this century. Can someone explain this apparent contradiction?

  33. 233
    Lee Hustead says:

    I am a retired engineer (Communications). It is in the learned elements of my bones (Including Chief Engineer experience-management) to be skeptical and at the same time a devotee of “peer reviewed progressive truth in all things”.

    Seems to me you experts in climate science are well convinced (convinced me) that present use of fossil fuels represents a definite threat to continuance of human life, perhaps even life period. Having perused the literature on the 5 (possibly 6) previous extinctions, the shortest of which was about 20,000 years at its 1 sigma duration – this is at the least thought provoking if not frightful. How much of 20,000 years will it take to verify your predictions?

    If we inoculate humans should we not inoculate the world – – shut down all fossil fuel sites? By force if necessary. One present US Presidential candidate has asserted he will declare the environmental threat to constitute a “national emergency”. Scientists and Engineers tend to reluctantly and reticently enter political debate. Have we reached the point where that is appropriate, maybe essential? Perhaps one or more of you should volunteer your expert services to every major political candidate.

  34. 234
    Chuck says:

    Killed-In-Action Says: Victor – to increase book sales I’d provide links to it in comments on CC articles at: AmericanThinker dot com, breitbart dot com, townhall dot com, the federalist dot com, zerohedge dot com, and many others. I would also NOT reveal my real identity or location to reduce risk.

    > That’s a GREAT idea! Advertise on Reich Wing websites. Those people don’t read anyway. You may need a Coloring Book edition so those who can’t read two-syllable words will have something to do. They can color Greenland green and use their white crayon for Iceland!

  35. 235
    mike says:

    from the WMO report:
    “Climate change causes and impacts are increasing rather than slowing down,” said WMO Secretary-General Petteri Taalas, who is co-chair of the Science Advisory Group of the UN Climate Summit.

    “Sea level rise has accelerated and we are concerned that an abrupt decline in the Antarctic and Greenland ice sheets, which will exacerbate future rise. As we have seen this year with tragic effect in the Bahamas and Mozambique, sea level rise and intense tropical storms led to humanitarian and economic catastrophes,” he said.

    “The challenges are immense. Besides mitigation of climate change, there is a growing need to adapt. According to the recent Global Adaptation Commission report the most powerful way to adapt is to invest in early warning services, and pay special attention to impact-based forecasts,” he said.

    “It is highly important that we reduce greenhouse gas emissions, notably from energy production, industry and transport. This is critical if we are to mitigate climate change and meet the targets set out in the Paris Agreement,” he said.

    “To stop a global temperature increase of more than 2 degrees Celsius above pre-industrial levels, the level of ambition needs to be tripled. And to limit the increase to 1.5 degrees, it needs to be multiplied by five,” he said.”

    https://public.wmo.int/en/media/press-release/global-climate-2015-2019-climate-change-accelerates

    Some will quibble. It was ever thus.

    Mike

  36. 236
    Ken D says:

    This paper concerning the incorporation of a spherical atmosphere into climate models appears to a this layman to be very significant. I was wondering if a member of the RC group could offer a brief comment on what it might mean for model projections as this was not clear to me from the discussion in the paper. https://doi.org/10.1073/pnas.1908198116

  37. 237
    Bob Loblaw says:

    A further comment on JCH’s question in #189: If an atmosphere like earth’s existed as it currently is, but miraculously no back radiation reached the surface of its planet, would there be a greenhouse effect?

    Let’s do a thought experiment on what sort of miracle it would take to accomplish this. I can think of three ways:

    1) There is no atmosphere, so nothing to to emit radiation. Probably not what JCH has in mind, as JCH explicitly says “..an atmosphere like earth’s…”

    2) The atmosphere is at a temperature of 0K, so no radiation emission. To do this, the atmosphere would have to be completely transparent to all radiation (zero absorption), and also be completely thermally isolated from the earth (no thermal or latent heat transfer from the surface to the atmosphere).

    3) Our understanding of physics is completely wrong, and solids, liquids, and gases do not emit radiation after all.

    Any other ideas? None of those three options seem worth thinking about to me….

  38. 238
    Al Bundy says:

    Thomas: I see RC moderators still have learned next to nothing all these years.

    AB: Priorities. The planet is on fire and monitoring a preschool scrum isn’t the highest best use for their level of scientific expertise. I’m sure the comments are a PITA to them. They chose to let them run free instead of closing them down. I doubt many folks here REALLY want their ask: “Please do LESS work on climate science and do MORE to police my playground.”

    The kids gotta do it themselves. Unlike many/most, these particular grownups have important stuff to do.

  39. 239
    Al Bundy says:

    killian: , using absolutely isht risk analysis

    AB: Exactly. When the Prime Risk Window is “the next quarter” it doesn’t take a climate scientist to figure out that climate risk is just an annoying irrelevancy that refuses to go away already.

  40. 240
    Mblanc says:

    5mm/year then, hmm. I remember it was described as being low 3’s for many years, up until very recently. I had barely registered it was up to 4mm-ish, tbh. I understand that 5 years is a very short period to derive an average, but I can’t imagine many on here think that SLR will fall back to previous values.

    Anyone bright enough to say how this lines up with Hansen’s doubling time concerns? How about a rough guess of when we will hit 1cm/year? I’ll take an untutored stab at 2045. I understand SLR will be non-linear, but it is a decent way of estimating how much of a threat our coastal infrastructure faces.

    Since I have read about the new, higher numbers coming out of the latest round of models I’ve been hoping there will be a real push to get the public to understand that the predictions have worsened, and this week appears to be it (hat’s off to young Greta, obvs).

    It is certainly being pushed hard in the UK media (actual scientists saying don’t by sea-front properties!), but I have seen virtually no references to 5mm/year (with one or two honourable written exceptions), just lots of references to 2100. Try keeping an eye out for the 5mm/year figure yourself, it isn’t easy to find in most of the media response.

    I think telling people about a very vague number which will occur when virtually all of us reading/watching are dead is a very strange way of trying to get a response.

    5mm/year, 1cm every 2 years and 5cm/decade are all more relevant to my life now, especially when we consider SLR will continue to accelerate for decades to come, even if we throw every last bit of energy we have into decarbonistaion.

    PS first post in a good few years, it’s funny to see how the tolerance of dubious posters is still pretty loose. It does diminish the usefulness of the site to me (I hardly look at the comments any more, and visit very intermittently), no matter how worthy the motivations of our esteemed hosts are.

    Regards to all the sincere contributors.

  41. 241
  42. 242
  43. 243
    Mal Adapted says:

    More modestly meliorative news in the NY Times: Kathryn Murdoch Steps Out of the Family Shadow to Fight Climate Change.

    You know her last name, and her father-in-law, Rupert, the conservative media mogul. Now, she hopes to remove partisan obstacles to climate progress that her family’s empire helped build.

    That might help 8^}!

  44. 244
    FrancisMcN says:

    MA Rodger @ 188

    Many thanks indeed for the links to the Manley paper and the later ones by Parker which give me the sort of background I was looking for to understand the context of how CET should be understood.

    As you point out, it is the distribution of annual data points that makes the point best, even if only for a relatively limited area.

  45. 245
    Mal Adapted says:

    Al Bundy:

    It’s amazing that rules of thumb continue to be given life long after the truism they rely on has been shattered. As if 30-years is a short enough time to measure a climate normal. Like photographing a walker in the dark with a long exposure shot. One big smudge.

    5 years seems about right to me, with the data cleaned up by subtracting ENSO, the sun, volcanoes, et al.

    Heh. Nicely put. 5 years seems about right to me too, but I’m wary of mere seeming, and insufficiently expert to be confident in my Mark I eyeball. I’m trying to escape the DK effect here 8^}.
    Meh. My interest in statistically justifying claims for accelerated warming is mostly because I required the same of ‘pause’ claimants, who failed to furnish it. As with the post-2000, short-term slowing of the observed GMST trend relative to model ensemble projections (e.g. Medhaug et al. 2017), that doesn’t mean hypothesizing about causes and consequences of apparent acceleration is unwarranted (h/t Gavin Schmidt). Also see previous ‘hiatus’ posts on this blog, especially Hiatus or Bye-atus? (groan) by Lewandowsky, Risbey and Oreskes.

  46. 246
    MA Rodger says:

    TPaine @233,
    Arguing the toss over tropical cyclone strength is as easy as it was for the temperature record but without the ground being so well trampled. If your “denier friends use the accumulated cyclone energy to show hurricane activity is not increasing and hurricanes are not getting stronger,” knowing what data they are using to “show” this lack of trend would be helpful.

    The table you are examining is presumably the table of Atlantic Hurricane Seasons 1851-2019 on the Wikithing ACE page. This is probably not the best format for judging the annual ACE values for N Atlantic hurricanes. The same data is graphed out here (usually 2 clicks to ‘download your attachment’). This does show recent years as being collectively the most active since the 1850s but it also shows a lot of variability as well as longer term wobbles spanning half a century. These are enough to prevent any simple assertion that N Atlantic hurricanes seasons are getting more energetic, especially when the earlier part of the record is dismissed with calls that the data cannot be complete back in the days of sailing ships, let alone before satellites.
    Beyond the N Atlantic, there is a lot less data from these earlier decades and so globally such records are only taken back to the beginning of the satellite era, thus over a period shorter than those N Atlantic wobbles. This 45-years of global data doesn’t show much of a trend.
    Yet more detailed analysis does seem to show that hurricanes are getting more energetic, but not obviously enough to convince those who don’t want to see.
    Thus in the N Atlantic, Cat5 hurricanes, for instance, are far more common than in previous decades with the last 4 years 2016-19 all featuring Cat5 storms as did the years 2003-05. Yet prior to 2000 Cat5 hurricanes were rare beasts with Cat5 storms appearing in just consecutive years – 1932-33, 1979-80 & 1987-88.

  47. 247
    JCH says:

    Rob – the explanation I am thinking about is usually expressed like this: with additional emissions of CO2 into the atmosphere, the effective radiation level goes up, and consequently the surface warms. It’s an explanation that, so to speak, stays far above the weeds.

    Which allows people to claim back radiation to the surface does nothing. Which I think is pretty miraculous – it doing nothing at all.

  48. 248
    William B Jackson says:

    227 Thanks for the fine explanation for the melting glaciers the abnormally warm conditions in Alaska and other regions that are now warmer than was historically true… Oh wait your post deny these truths…SAD!

  49. 249
    William B Jackson says:

    Dear Moderator…241 is a link to an adult site…We may have young people here!

  50. 250
    Victor says:

    #242 mblanc: “5mm/year, 1cm every 2 years and 5cm/decade are all more relevant to my life now, especially when we consider SLR will continue to accelerate for decades to come, even if we throw every last bit of energy we have into decarbonistaion.”

    V: “Global mean sea level rise estimated from satellite altimetry provides a strong constraint on climate variability and change and is expected to accelerate as the rates of both ocean warming and cryospheric mass loss increase over time. In stark contrast to this expectation however, current altimeter products show the rate of sea level rise to have decreased from the first to second decades of the altimeter era.” From “Is the detection of accelerated sea level rise imminent?” J. T. Fasullo, R. S. Nerem & B. Hamlington, 2016 ( https://www.nature.com/articles/srep31245 )

    NASA: “New Study Finds Sea Level Rise Accelerating,” 2018. (https://www.nasa.gov/feature/goddard/2018/new-study-finds-sea-level-rise-accelerating )

    V: And who is the “lead author” behind the “new study”? Steve Nerem, the same R. S. Nerem quoted above, the one whose data indicated a DECREASE in the rate of sea level rise. Interesting. And how did this magical transformation come about?

    “Nerem and his team used climate models to account for the volcanic effects and other datasets to determine the El Niño/La Niña effects, ultimately uncovering the underlying rate and acceleration of sea level rise over the last quarter century.”

    From my book:
    “Seek and ye shall find. A result in line with expectations would have been uncritically accepted, with no need to look for some additional factor that might complicate, and possibly negate, the desired conclusion. But since the result was contrary to expectations, it then became necessary to cast about for some additional factor that might have masked the expected acceleration.”

    “. . . [F]or each accepted explanation of a phenomenon, there is always an infinite number of possible and more complex alternatives, because one can always burden failing explanations with ad hoc hypotheses to prevent them from being falsified . . . This endless supply of elaborate competing explanations, called saving hypotheses, cannot be ruled out—but by using Occam’s Razor.” (Occam’s Razor – Wikipedia — https://en.wikipedia.org/wiki/Occam%27s_razor)