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Unforced Variations: Sep 2017

Filed under: — group @ 1 September 2017

This month’s open thread…. and let’s stay on climate topics this month. It’s not like there isn’t anything climate-y to talk about (sea ice minimums, extreme events, climate model tunings, past ‘hyperthermals’… etc.). Anything too far off-topic will get binned. Thanks!

321 Responses to “Unforced Variations: Sep 2017”

  1. 1
    Adam Lea says:

    I wondered when someone would try to attribute hurricane Harvey to climate change.

    Until an attribution study has been performed I am skeptical that Harvey and the unfolding disaster has much, if anything, to do with climnate change. The primary cause of this disaster is a tropical cyclone making landfall then stalling close enough to a warm ocean that firstly, it takes much longer to wind down, secondly, continues to dump torrential rain for days, and thirdly, it happened in a major metropolitan area. I can appreciate that in a warmer climate the water vapour content of a saturated atmosphere will be higher, and so will the precipitable water content. My last reading up of this suggested projections of about 15% increase in tropical rainfall over the coming century (I need to double check this). Even if you knock 15% off Harvey’s rainfall, you are talking about the difference between something like 40 inches and 35 inches of rainfall. It is still going to be a huge flood event. There have been many very high rainfall events on the magnitude of Harvey globally going back as far as the 18th century.

    I think that pulling out the climate change card every time a major weather disaster occurs does moree harm than good. People will end up just saying “year, whatever” and switch off, then ignore you when something happens that can be attributed to climate change with significant probability.

  2. 2
    Thomas says:

    Very large release of mostly volcanic carbon during the Palaeocene–Eocene Thermal Maximum by Marcus Gutjahr et al
    http://www.nature.com/nature/journal/v548/n7669/full/nature23646.html?foxtrotcallback=true (paid access req)
    or
    https://www.theguardian.com/science/2017/aug/30/volcanic-eruptions-triggered-global-warming-56m-years-ago-study-reveals

    ‘Seems’ to confirm/support Peter Ward et al about this issue.

  3. 3
  4. 4
    Martin says:

    Apologies for being off-topic, but what is happening to your site in terms of Google searches for real climate? – it appears that a lot of either sceptic or non-climate related sites are getting in first.

  5. 5
    Michael Roddy says:

    After Katrina, many homes in the Ninth Ward had to be dismantled and hauled away after the water receded. The reason was two by four construction: lumber is weaker and tends to bow when wet for long periods, and wet plywood or OSB release toxic chemicals as well as losing shear strength. Structural steel rusts after extended periods underwater, but G60 galvanized steel studs to not, and have been calculated to last for 600 years.

    Some years ago I was part of a team with steel industry support that tried to wean America away from building houses that fail under stress. There is also an emissions factor: based on IPCC reports, lumber is at least 4 times more CO2 intensive than steel in a similar application.

    Texas had a budding steel framing industry in those days, but price spikes killed it. Steel framing currently adds about 2% to home construction costs, while we once approached parity. Houston could rebuild with steel and save enormous amounts of money when the next flood hits. NAHB is unlikely to help here. Let’s see if this solution is even raised.

  6. 6
    MA Rodger says:

    The back of August has turned a rather placid Atlantic Hurricane Season into a quite terriflying one. Up to the start of the month the predictions had been slowly strengthening with the predicted numbers of storms for the season (as see here) rising to 8 hurricanes, 3 of them major hurricanes, and an ACE of 135 for the season.
    August then delivered 4 hurricanes with 2 of them major, while ACE has risen to 29 (a comparison with previous years here (usually 2 clicks to ‘download your attachment’) and that ACE figure much lower than you would expect from such activity because Franklin, Gert & Harvey formed into hurricanes so late in their lives and Irma has only just begun by the end of the month. So they didn’t contribute much ACE during August.
    Conversely, August having spawned Irma. This now-Cat3 hurricane is forecast to reach Cat4 well out in the Atlantic approaches and is on a course to either plough through the full length of the Carabbean or up the US Atlantic coastline, perhaps providing the full predicted ‘7 major hurricane days’ all on its own and that even before it hits its first island victim.
    Back in 2005 with the record year for North Atlantic Hurricanes grabbing headline after headline, there was much panic that we were seeing the first signs of a new tropical-cyclone-packed world that was to be unleashed by AGW. Mind, the science was less exercised by it all and remains so. To quote the UN IPCC AR5 TS.5.8.4:-

    “Projections for the 21st century indicate that it is likely that the global frequency of tropical cyclones will either decrease or remain essentially unchanged, concurrent with a likely increase in both global mean tropical cyclone maximum wind speed and rain rates (Figure TS.26)*. The influence of future climate change on tropical cyclones is likely to vary by region, but there is low confidence in region-specific projections. The frequency of the most intense storms will more likely than not increase in some basins. More extreme precipitation near the centers of tropical cyclones making landfall is projected in North and Central America, East Africa, West, East, South and Southeast Asia as well as in Australia and many Pacific islands (medium confidence).”

    (*Spookily, Fig TS 26 is not provided within the IPCC All Graphics page.) Yet don’t imagine such scientific opinion is going to be standing in the way of a good headline.
    And the science, while it seemingly underplays the likes of all those 2005 Hurricanes, and may do so again in 2017, this is because there is so much more to AGW that we should be terrified of creating with our past-&-future GHG emissions. In the grand play of AGW, the odd devastating hurricane is neither here nor there.

  7. 7

    AL 1: Until an attribution study has been performed I am skeptical that Harvey and the unfolding disaster has much, if anything, to do with climnate change.

    BPL: Katrina, Mitch, Sandy, Harvey, all 100-500 years storms, all in the past twelve years. Minus an attribution study, I take we can take a pretty damn good guess.

  8. 8

    @Adam Lea,

    Houston happened because of human effects, as has been noted by many observers, primarily because of a complete absence of city planning, and because of the perverse moral hazard which flood policy in the United States creates.

    This is true whether or not climate change was a significant contributor to the event.

    Unless things are done differently, the same will happen again the next storm which, for whatever reason, clobbers Houston happens.

  9. 9
    Scott Strough says:

    Harvey was a weather event. Global warming is a climate change event.

    Climate is the average weather over long periods of time. ie 30+ years or more.

    Hurricanes usually last just days or weeks at most.

    Please don’t confuse weather, no matter how bad, with climate. They are not the same.

    The link between the two is that global warming has been gradually warming the seas and oceans for over 30+ years. Warm tropical waters are what feed hurricanes. So warmer waters mean more surface evaporation of the water which means when weather conditions are right for hurricanes, they contain more rain than they would otherwise.

    In this case they just happened to let loose all that rain on Houston.

    No way for anyone to say Global warming did or didn’t cause that hurricane, but warmer seas mean the hurricanes are stronger and wetter than they would have been over cooler seas.
    https://search.proquest.com/openview/166827dd8bc8b0aaa580b69a44988e64/1?cbl=40569&pq-origsite=gscholar

    Hurricane Harvey was NOT, I repeat NOT a climate change event… Hurricane Harvey was a weather event. Climate change events take 30+ years or more to even begin to happen. You guys start jumping on that bandwagon and it will surely backfire on you.

  10. 10

    In 1, Adam Lea says (with implicit acknowledgment by Hank Roberts in 3), “I wondered when someone would try to attribute hurricane Harvey to climate change.”

    (Mr. Roberts cited a USA Today editorial, but could cite much else, including op-eds from scientists, like https://www.nytimes.com/2017/08/28/opinion/hurricane-harvey-global-warming.html and https://www.theguardian.com/commentisfree/2017/aug/28/climate-change-hurricane-harvey-more-deadly — Michael Mann’s “It’s a fact: climate change made Hurricane Harvey more deadly.”)

    I’m hoping in particular to learn how experts see today’s Wall Street Journal editorial and accompanying Roger Pielke Jr. op-ed:

    https://www.wsj.com/articles/texas-thou-hast-sinned-1504221194
    https://www.wsj.com/articles/the-hurricane-lull-couldnt-last-1504220969

    The editorial contains this, for instance: “No less than the United Nations Intergovernmental Panel on Climate Change says it lacks evidence to show that global warming is making storms and flooding worse. But climate scolds still blame Harvey on climate change because, well, this is what the climate models say *should* happen as the climate warms.”

    Pielke says, for instance, “Without data to support their wilder claims, climate partisans have now resorted to shouting that every extreme weather event was somehow ‘made worse’ by the emission of greenhouse gases.” Leaving aside “partisans” and “shouting,” it seems to me that Mann’s unambiguous adamancy notwithstanding, most climate scientists are saying only that those emissions’ effects raise the odds of extreme weather being “made worse.”

    Anyway, I hope to see these Harvey matters discussed by experts. Thanks.

  11. 11

    RE: Thomas (#2) – This study definitely does NOT support Peter Ward’s ideas about volcanoes, quite the opposite actually. I’ve had extensive conversations over email with Peter about his ideas, and he continues to claim that CO2 cannot cause significant warming and thus the greenhouse effect is not a factor in the climate system. I’ve tried to convince him otherwise to no avail. The study you cited is about connecting volcanoes to the PETM as a source of CO2, so it has no bearing on his ideas.

  12. 12
    nigelj says:

    Adam Lea @1

    You are sceptical about attributing Hurricane Harvey to climate change, and make a claim that atmospheric moisture content would only increase rainfall by about 15%. You mention how warm oceans have caused the hurricane to stall.

    Well nobody is actually claiming Hurricane Harvey was caused by climate change. Micheal Mann has said it was made significantly worse as below.

    https://www.theguardian.com/commentisfree/2017/aug/28/climate-change-hurricane-harvey-more-deadly

    And as has been pointed out there have been a lot of 1:100 year hurricanes within a decade or so, which suggests the frequency of intense types of hurricanes is increasing.

    And it’s not just a question of atmospheric moisture and rain. As you mention a warm ocean has caused the hurricane to stall, and climate change is causing very significantly warmer oceans, so perhaps hurricanes that stall more often and / or longer?

    The point is it’s not one thing with hurricanes, its an accumulation of climate change effects that add up to something significant.

    Yes crying wolf can be a problem, but Michael Mann seems to be saying what is scientifically plausible, and it just has to be said. We need information,

  13. 13
    Radge Havers says:

    @1

    “…People will end up just saying…”
    Which people?

    In any case, this from ScienceBlogs:
    New Research on Assessing Climate Change Impact on Extreme Weather
    Posted by Greg Laden on August 31, 2017

    “As I’ve pointed out elsewhere, I’m not particularly fond of the standard detection & attribution approach for an event like Hurricane Harvey for a number of reasons. First of all, the question isn’t whether or not climate change made Harvey happen, but how it modified the impacts of Harvey. For one thing, climate change-related Sea Level Rise was an important factor here, increasing the storm surge by at least half a foot.” Mann recalls the approach taken by climate scientist Kevin Trenberth, who “talks about how warmer sea surface temperatures mean more moisture in the atmosphere (about 7% per degree C) and more rainfall. That’s basic physics and thermodynamics we can be quite certain of.”
    Michael Mann
    http://scienceblogs.com/gregladen/2017/08/31/new-research-on-assessing-climate-change-impact-on-extreme-weather/

  14. 14
    Mr. Know It All says:

    1 Adam
    Agree, these storms are not new to the gulf coast. Back in 1979, a hurricane dumped 42+ inches of rain on Houston in 24 hours! That’s almost as much as the rainfall from Harvey that occurred over a few days.

    8 Jan
    Agreed, all the concrete down there makes it worse today, as well as the fact that the land has been sinking due to depletion of the aquifers. The land has subsided between about 1 foot and 15 feet depending on where you are. Not sure how the levees affected the flooding this time, but they did mention failing dams on the news. I wonder if some of the roads hold back water that wants to flow toward the gulf?

    4:37pm pacific 9/1/2017

  15. 15
    Thomas says:

    Misc.

    @4 Martin et al, RC on top here
    https://www.bing.com/search?q=real+climate&src=IE-SearchBox&FORM=IENTTR&conversationid=&pc=EUPP_

    If you’re using “google” whether logged in with a google account or not, it is serving up your searches individually …. based on your use, cookies and bookmarks and other advanced “ID monitoring activity” being fed to marketing companies.

    However, adopting the name realclimatescience was no accident, it was an intentional act, has been massaged accordingly by teh powers that be (lots of $$$) because what they ahve done is internet marketing and SEO:101 …. plus all the high ranking links later directed to it pushes it up instantly on the page rankings .. and about 90% of all search feeds now come out of THE GOOGLE MONSTER (not Cookie) .. that and traffic vs traffic to RC makes a difference. People have paid hard money to get RCS up and above RC results … it’s intentional and it’s globally coordinated among those in the know. and no I don’t buy into “conspiracy theories” but am fine with conspiracy facts and evidenced based Logic based on expertise and true knowledge.

    Want better search results? Never login with a user name. Use a “Private/anon” Window for searching; use a VPN connection; never use GOOGLE SEARCH unless it is via a third party such as https://www.startpage.com

    There is nothing RC or Gavin can do about this unless one of you want to donate them about $20K to fix it over a year. No? Didn’t think so.

    In fact never use Android or anything Google based…. saying that I still do … it’s like “air” and hard to avoid being corralled in that direction. That’s an issue as important as AGW/CC, but off topic. :-((

    Think Globally – Act Locally?
    CBS buys Australian TV10 Network blocking the expected purchase by Murdoch’s NewsCorp and his son Lachlan the current CEO of TV10 – (and other right winger funders) eg Mining Magnate (heiress) Gina Reinhardt, me ‘mate’ Jack Cowan, & other mining Corps, RW activists who tried to take control of Fairfax Media (newspapers mainly) the last few years but failed to get above 10%. Reinhardt is of course one of the funders who brought denialist propaganda artist Chris Monckton out to Australia on multiple occasions … meanwhile the RW government here was just about to change the Laws to help out Murdoch NewsCorp, Sky, Fox and son Lachlan yet again by changing ownership diversity laws that would have let them (and fellow travelers) scoop up TV10 for a dead set bargain basement price … it’s in receivership and fwiw Lachlan Murdoch run a business or make a profit if his life depended on it, let along a national TV broadcasters, but I digress.
    https://www.theguardian.com/politics/2017/sep/01/ed-miliband-evidence-against-murdoch-bid-for-sky-is-growing

    For anyone interested in non-consensus science/evidence based professorial perspective addressing ‘voodoo economics’
    https://www.youtube.com/results?search_query=steve+keen+on+austrians+voodoo+economics
    As Hayek wrote, economic theories can never be verified or falsified by reference to facts. Understanding where Professor Yanis Varoufakis et al are coming from is also insightful and mind expanding.

    Meanwhile, who mentioned Harvey? :-)
    https://www.democracynow.org/2017/8/30/ex_nasa_scientist_james_hansen_there

    Jeez, people hadn’t even stopped dying before M.E. Mann was doing the rounds and writing editorials on the subject. I sent one such example in last UV … here we go again. :-/

  16. 16
    Russell says:

    Viscount Monckton, has been in Moscow telling Russia’s Academicians to pay no attention to the 100 degree temperatures in Red Square.

    https://vvattsupwiththat.blogspot.com/2017/09/and-now-comrades-few-words-from.html

  17. 17
    Thomas says:

    @10 Steven T. Corneliussen recommends reading that bastion of ‘integrity’ the WSJ and asks for expert advice. The WSJ is so untrustworthy I wouldn’t use it to start a fire under my BBQ.

    Meanwhile back to anecdotal ‘weather’ data, Australia just had the warmest August since records began in 1900. Averaging 2C above mean avg. with many regions experiencing extended periods of +5-8C highs above mean High Temps. It’s “winter” here, somewhere, but few can locate it in any ‘historical sense’.

    However, my ouija board is predicting a very strong El Nino through 2018-> (smile)

    OT Geolpoliticts lecture re Google earth, nsa, silicon valley, cia, cfr, msm, wash.post, corporations, ‘deep state’, et al (just skip the flaky unproven theoretical stuff via this ‘geoengineeringwatch’ site and focus on what the ex-cia dude actually says — and do question his bona fides and available confirmatory evidence/reports about what he says) https://youtu.be/XHbrOg092GA?t=9m42sNow enter Donald Trump https://youtu.be/XHbrOg092GA?t=36m43s

    also, fwiw, really good interview of Robert Fisk: life as a war correspondent a great human being imho, and what ‘Journalists’ used to do more often than they do today. http://www.abc.net.au/radio/programs/conversations/conversations-robert-fisk/8840776 Worth sitting back and listening to the whole thing from go to woe. (a special ref to share with Americans especially)

  18. 18
    Mal Adapted says:

    Scott Strough:

    Hurricane Harvey was NOT, I repeat NOT a climate change event… Hurricane Harvey was a weather event.

    Every local weather event is embedded in a regional and and global climate. Hurricane Harvey was a weather event embedded in a warming global climate, which as you point out has resulted in warmer SSTs in the Gulf and more precipitable water in the air over SE Texas. Hurricanes are driven by evaporation from warm surface waters and latent heat of condensation. Hurricane Harvey was therefore as much a climate change event as any individual weather event can be.

  19. 19
    Thomas says:

    @11, “is about connecting volcanoes to the PETM as a source of CO2”

    Um, isn’t that what Peter said himself back when … ?

    and “and he continues to claim that CO2 cannot cause significant warming and thus the greenhouse effect is not a factor in the climate system”

    are we talking about the same peter ward? https://www.ess.washington.edu/people/profile.php?pid=ward–peter

  20. 20
    Thomas says:

    “Climate change events take 30+ years or more to even begin to happen.”

    So there’s no evidence that Hurricane Harvey is a ‘climate change event’ happening now which had it’s seminal origins in the state of the climate during 1980-1990 and since?

    Sometimes words are not enough. :-/

  21. 21
    John Kelly says:

    First post. Not a scientist, so feel free to skip to the next, although it hardly seems to disqualify me. Extreme event attribution seems a nonsensical political exercise, in that it is not measurable. Weather events happen in their then-current climate system state, and we’re rapidly and continually changing that state. Of course weather events will change as the state changes, but it seems impossible to prove how and how much due to the complexity of the system. To me, the most interesting aspects of the recent storms were not their strength, but their unusual behavior, with Sandy’s odd track and Harvey’s slow-motion meandering. These aspects seem to me to be better signals of the changes brought on by a changing system. They suggest to me we’re going to see more and more weird stuff, in unusual places. Of course, I can’t measure that.

    Special thanks to Professors Curry and Christy for starting my education. You see, I read a Washington Post article about climate experts’ opinions on record temperatures, and their comments were roughly (paraphrasing) that the high temps weren’t confirmed by satellite measurements. I didn’t understand. That started a search that first landed me on the AIP site and then sent me here. The AIP site stunned me, as I realized climate science was based on a deep foundation of discoveries, theories and revisions as new evidence developed.

    It seems exceedingly clear to me now that we are adding massive amounts of energy to the climate system, and the nature and timing of the eventual manifestations are shrouded in mystery due to the system’s complexity. We can see ice melting, and measure the first inning (the first batter, really) of a big, long rise in sea levels, but so much of the rest, like the effect of warmer oceans and an ice-free Arctic on ocean and atmospheric currents, we’ll just have to see when it gets here. Like Harvey spinning in place like a top. It’s like waiting to open presents on Christmas morning, but Christmas is in Hades.

  22. 22
    Thomas says:

    One classic anecdote:

    Adrian van Rensburg, whose house flooded west of Barker reservoir, stood next to a pile of cleaning supplies in the parking lot of an animal clinic. He was picking up some bleach.

    “I’ve been here for five years and I’ve experienced a 100-year, a 500-year and a thousand-year flood,” he said. “Something is not working out here.”
    https://www.theguardian.com/us-news/2017/sep/01/hurricane-harvey-death-toll-rises-houston-residents-return

  23. 23
    Mr. Know It All says:

    12 – nigel

    After Katrina, predictions were made about how we’d experience much more frequent and more powerful hurricanes in the US. For 12 years there were few if any hurricanes. This lack of hurricanes was a significant data point for those in the US who are skeptical about AGW.

  24. 24

    Th 15: As Hayek wrote, economic theories can never be verified or falsified by reference to facts.

    BPL: He said that about his own theory, not theories in general. And while Hayek may be popular reading among Libertarians, most economists that I know do not take him seriously. “Austrian economics” is pseudoscience simply because it can’t be tested. Please don’t equate economics in general with the nutty Austrian school.

  25. 25
    Adam Lea says:

    12: “You mention how warm oceans have caused the hurricane to stall.”

    I didn’t make such a statement. I said the cause of the disaster was the hurricane stalling inland close to the warm ocean, thusa dumping a huge amount of rain, not that the warm ocean caused the hurricane to stall.

    For the person mentioning recent 100-150 year events, here is a list of wettest tropical cyclones globally:

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

    It is evident from this list that a bulk of these do occur in the period of greatest warming since about 1970, although there are still plenty that go back before that. The bias toward recent decades could be either because there genuinely is a climate influence on extreme rainfall events, or that population increase means more people are exposed to extreme weather events, so they affect more people and property, and thus get reported more frequently. If a storm drops 40 inches of rain over an unpopulated island, does it get recognised?

  26. 26
    MA Rodger says:

    Walter Hannah @11,
    I was left scratching my head over who “Peter Ward et al” could be referring to @2. The paper that kicked off the comment Gutjahr et al (2017) gives no clues and as you point out, the paper certainly does not “‘Seems’ to confirm/support (Peter Langdon Ward) about this issue.” This should come as no surprise as you also have demonstrated that PL Ward’s theory is “unconvincing”.
    I did wonder if there was some aspect of the work of Peter Douglas Ward that fitted the bill. I’m not familiar with this alternative Peter Ward as his work is wholly squirreled away in books and YouTube videos but his ‘Under A Green Sky’ had been recently brought to my mind by the theorising about last week’s toxic haze over Beachy Head.
    Of course, there could be other Peter Wards, and perhaps even ones not called Peter Ward at all who’s work is confirmed/supported by the Gutjahr et al (2017) finding that:-

    “Our pH reconstruction, in conjunction with the observed δ13C decline, suggests that the dominant carbon source during PETM onset had a comparatively heavy carbon isotope ratio, strongly implicating volcanism in triggering and driving the event. Our inferred mean δ13C source of −11‰ to −17‰ is consistent with the isotopically relatively heavy source (about −15‰; Payne et al 2010) inferred for the warming event at the end of the Permian period—suggesting mechanistic similarities between this and the PETM. The implied important role for organic-carbon deposition in the recovery after peak warming represents another diagnostic feature of OAEs (and of the end-Permian event). Arguably, the PETM will be of greatest value in further quantifying and understanding the precise role of feedbacks—those that amplify the initial CO2 release and those that aid recovery from global warming — thereby helping researchers to reduce the uncertainties surrounding the response of the global carbon cycle and climate system to perturbation “

    However, those particularly worried by an imminent multi-Shakhova methane event will probably require more convincing.

  27. 27
    jgnfld says:

    @Harvey nonattributors…

    It is not an actual counterargument to say consequence X happened once in, say, 1964, therefore there is no reason to worry.

    The actual counterargument is to show that the probabilities of consequence X are unchanged in a changing climate environment. That is, for example, that the probability of a 500 year rain event is unchanged with more moisture in the air.

    None of the denier comments here have shown that in the slightest degree.

  28. 28
    JCH says:

    When it comes to damages in Harris and surrounding Texas counties, Tropical Storm Claudette was a drop in the bucket versus 21st-century examples: TS Allison; Hurricane Ike; Tax-Day Flood; and Hurricane Harvey.

  29. 29
  30. 30
    CCHolley says:

    Scott Strough @#9

    Hurricane Harvey was NOT, I repeat NOT a climate change event… Hurricane Harvey was a weather event. Climate change events take 30+ years or more to even begin to happen. You guys start jumping on that bandwagon and it will surely backfire on you.

    When did climate change actually begin, what exactly will these *climate change events* be and how will we know that they’ve actually arrived?

  31. 31
    TPP85 says:

    “Until an attribution study has been performed I am skeptical that Harvey and the unfolding disaster has much, if anything, to do with climnate change.”

    Climate change excites statistics and this is (too) complicated to investigate how does it work for individual events, but it does work for the sum of events.
    The case of Harvey is not really important. The case of Harvey+Sandy+Katrina and repeated tenths of billions of losses within 20 years is more important. Statistics prove that Harvey+Sandy+Katrina is a sum consistent with climate change.
    The result is statistically clear and should convince any insurance companies, development planners, traders, “think tanks”… etc.

  32. 32

    “Climate change events take 30+ years or more to even begin to happen…”

    And Harvey occurred roughly 45 years after the anthropogenic signal, as defined post hoc by statistical analysis, began to emerge in the surface air temp record…

    Just sayin’.

  33. 33
    Scott Strough says:

    CCHolley @30,
    1) “When did climate change actually begin”?
    According to the Ruddiman Hypothesis when mankind developed agriculture about 13,000 to 10,000 years ago and really kicked off beginning when the founder crops like wheat and rice were developed.

    http://www.realclimate.org/index.php/archives/2016/03/the-early-anthropocene-hypothesis-an-update/

    I personally would put it even farther back and include the climatic disruption caused by the mega-fauna extinctions. But that is even more controversial.

    But those changes were slower than the current changes due to fossil fuel use.

    2) “what exactly will these *climate change events* be”?
    A good example of a climate change event would be the desertification of the Sahara starting around 8,000-10,000 years ago.

    http://www.popsci.com/sahara-desert-drought-humans

    We are not looking at any one weather event but rather a wider change on average lasting far longer. They will include both floods and droughts and thawing of the arctic regions, ocean currents changing as ice melts etc… No single weather event but averages over 30 years or more.

    3)”how will we know that they’ve actually arrived?”
    They are here already. We know because of careful data collection and skillful climate models.

  34. 34
    JCH says:

    Bold mine:

    ACTION WAS TAKEN

    On April 23,1937, after local leaders submitted a petition with dramatic photographs of past flood devastation, the 45th Texas Legislature unanimously passed the bill which created the Harris County Flood Control District.

    NATURE ALWAYS PREVAILS

    Since the District’s creation, and despite a history of successful flood damage reduction projects and progress throughout Harris County, close to 30 damaging floods have occurred in the area, resulting in hundreds of millions of dollars in damages in just under 70 years. However, after the 1940’s, the Harris County area did not suffer what would be considered a widespread, regional flood, that is, until June 2001.

    ALLISON: A NAME WE’LL NEVER FORGET

    Tropical Storm Allison suddenly formed 80 miles off the coast of Galveston, Texas, on Tuesday, June 5, 2001, no one expected that, five days later, it would go on record as one of the most devastating rain events in the history of the United States. Neither historical data nor weather forecasts could adequately predict this extraordinary storm that, before leaving the area, would dump as much as 80 percent of the area’s average annual rainfall over much of Harris County, simultaneously affecting more than 2 million people. When the rains finally eased, Allison had left Harris County, Texas, with 22 fatalities, 95,000 damaged automobiles and trucks, 73,000 damaged residences, 30,000 stranded residents in shelters, and over $5 billion in property damage in its wake. Leaving 31 counties with declared disasters in Texas, Allison went on to spread disaster declarations to Louisiana (25 parishes), Florida (nine counties), Mississippi (5 counties) and Pennsylvania (2 counties). Allison was the costliest tropical storm in the history of the United States.

  35. 35
    Hank Roberts says:

    https://www.usatoday.com/story/news/politics/2017/09/02/trump-nominates-oklahoma-congressman-next-nasa-administrator/628263001/

    Bridenstine’s nomination, announced days before Vice President Pence is expected to convene his first National Space Council meeting, is already generating pushback.

    Sen. Bill Nelson, D-Fl., the top Democrat on the Commerce, Science and Technology Committee that will handle Bridenstine’s confirmation, said appointing a member of Congress to run NASA could hurt the agency’s reputation as a non-political institution.

    “The head of NASA ought to be a space professional, not a politician,” he said in a statement released by his office Saturday morning.

    Democrats like Nelson also are likely to bring up Bridenstine’s dismissal of climate change and its link to human activity during a floor speech in 2013.

    “Global temperatures stopped rising 10 years ago,” Bridenstine said, refuting the overwhelming conclusion of the scientific community. “Global temperature changes, when they exist, correlate with sun output and ocean cycles.”

    Sad.

  36. 36
    Mr. Know It All says:

    27 jgnfld

    The Texas gulf coast before around 1800 might have had a CAT 5 hurricane every year, but with little population, we may not know about it. Same for many other parts of the world.

    Warmer air/water should result in higher rainfall, as it does today in many parts of the world. That is not in debate. What is questioned by skeptics is what is causing the warmer air/water. Weather history is part of the reason they are skeptics. Like for example, look at all these CAT 5 Atlantic Hurricanes that occurred when CO2 levels were much lower than today:

    https://en.wikipedia.org/wiki/List_of_Category_5_Atlantic_hurricanes

    It’s not proof of anything, but is a good argument for more study before enacting legislation that would disrupt current economic systems. There’s lots of other evidence of warm periods in the past of course, and these are also part of the basis for legitimate skepticism. Sure, climate scientists say the problem is CO2 – they may be right, probably are – but to badmouth and sneer at skeptics, calling them science deniers, just causes them to dig their heels in deeper. They have a legitimate argument – just because it is not based on the physics of CO2 does not make it illegitimate. (I’m not saying 27 jgnfld is badmouthing anyone, I’m just talking believers in general. Believers do it regularly and have politicized and polarized the debate by repeatedly insulting skeptics.)

  37. 37
    Adam Lea says:

    31: The repeated tens of billions of losses in the last 20 years isn’t necessarily due to a significant increase in weather related disasters. Increases in wealth, inflation, increases in population along vulnerable coastlines also contribute to increased damage. How do you tease out all those other factors to obtain any climate change signal? You mention Katrina and Sandy. The damage inflicted by Katrina was not to do with the intensity, but the height of the storm surge, which was mostly due to its very large breadth. It also happened to hit near possibly the most vulnerable city along the Gulf coast. Even then, the levees almost held the water back, if they had been built a bit stronger or maintained a bit better they may not have failed, and the damage would have been lower. With Sandy, that was very bads luck, a transitioning hurricane being diverted by a high pressure block right into one of the biggest cities in America with a big storm surge, again, due to the size, not the intensity. If Sandy had hit a hundred miles further north or south, would it have done the same damage? Somehow I doubt it. I don’t think the statistics prove anything about climate change and hurricane impacts, if anything, they show little evidence, if the normalised hurricane losses back to 1900 are to be believed (although I am skeptical of these figures, as they imply improvements in construction standards and building codes have made no significant difference since 1900).

    http://www.nhc.noaa.gov/pdf/NormalizedHurricane2008.pdf

    I wouldn’t be surprised if there was a small enhancement of climate change to hurricane damage, due to sea level rise and increasing water vapour content of the atmosphere. I just think that the effect is small compared to the non-climate change related human factors, such as the desire to live along vulnerable tropical coastlines, and possibly the poor response to the vulnerability of flooding (like in the UK, housing being built on flood plains).

  38. 38

    Leaving aside (mostly) Thomas’s (17) tone, his misreporting of what I actually recommended in 10, and his ancient news about the Wall Street Journal’s trustworthiness, I simply repeat the request I made in 10. I note in addition, though: it’s understandable–after all these years of justified consternation about the WSJ’s climate-science obtuseness and worse–that scientists and the science-minded continue to find dreary the thought of engaging the WSJ in any way. Nevertheless I also assert that because it’s still one of the most widely circulated national newspapers and because it still reaches influential people including many who are willing to listen, the WSJ matters for science and the planet no matter how Thomas lights his barbecue.

  39. 39

    Everytime I see that the name of this thread is “Unforced Variations”, I question whether I should discuss the topic of external forcing ;)

    There is an interesting argument concerning the Hawkmoth Effect taking place in the journals.

    The Hawkmoth Effect supplements the Butterfly Effect when the initial conditions have no real effect on a behavior, such as occurs with ocean tides. Ocean tides are of course forced based on the lunar-sun-earth cycles, which have no initial conditions.

    Extend this to something such as ENSO and I perhaps we should consider that there is no Butterfly Effect and the ENSO behavior is all based on boundary conditions, analogous to tides. The only thing that matters then is the model structure and the details of the forcing.

  40. 40
    Polly says:

    If Katrina was the first event that woke up people, Harvey will be the one that jolts the rest into action … or at least I hope it does.

  41. 41
    nigelj says:

    Mr. Know It All @23

    “After Katrina, predictions were made about how we’d experience much more frequent and more powerful hurricanes in the US. For 12 years there were few if any hurricanes. This lack of hurricanes was a significant data point for those in the US who are skeptical about AGW.”

    You must be joking surely? There have been a dozen Hurricanes after Katrina as below:

    https://www.usatoday.com/story/weather/2017/08/24/all-hurricanes-hit-u-s-since-2005/598113001/

    And which climate scientist exactly claimed there would be more numerous hurricanes after Katrina, with a link to their claims please.

    And I never said there were increasing numbers of hurricanes recently. I merely noted that those that have occurred recently have had unusual intensity. Its becoming clear climate change is not causing more hurricanes, but is generally making them more intense and this trend is likely to continue.

  42. 42
    nigelj says:

    Adam Lea @25,

    Yes fair enough. I was paraphrasing your long comment, and over paraphrased. However its interesting that the reason the hurricane stalled has been put down to partly to changing atmospheric circulation itself due to climate change:

    https://www.theguardian.com/commentisfree/2017/aug/28/climate-change-hurricane-harvey-more-deadly

    I don’t think the increased rainfall would just be due to more reporting of incidents. Rainfall has been specifically measured with rain gauge’s for decades now. I think your issue would have more relevance to things like property damage from wind, where its harder to track things objectively and other factors influence the issue.

  43. 43
    Thomas says:

    @MA Rodger

    https://www.brainyquote.com/quotes/quotes/e/eleanorroo385439.html

    https://www.york.ac.uk/depts/maths/histstat/lies.htm

    Do let me know when you have the data which empirically shows in a plus 1.2-1.5C world that the historical dynamics of ENSO are not effected in duration and extent. Yes, I do have a well functioning memory.

    In the meantime Rodger, when you have something intelligent to say which is worth sharing with the world or RC please do so.

  44. 44
    Thomas says:

    24 Barton Paul Levenson says: “Please don’t equate economics in general with the nutty Austrian school.”

    Have you been briefed on the psychological term ‘anally retentive’ BPL? Look it up.

    Now BPL, you are telling the wrong person what not to do. I suggest you telephone your members of Congress and those that lead the Democratic Party and the Clintons and Rupert Murdoch and the WSJ et al (well if you truly care about that group of US leading lights and their ideologies and the economic theories they promote.) For someone asserting to be knowledgeable about ‘economics’ to feel authoritative enough to tell others what the ‘facts’ are and what to think/do, you appear to missing the bleeding obvious elephant in the room.

    And if you wish to make a comment about one of my comments it is basic respect and incredibly useful to be able to connect the dots and see the whole of what has been said and referenced before attacking the keyboard with your ‘insightful’ feedback. iow if you are not going to read what’s already been written about a specific ‘topic’ in context and check the basics of refs provided over time then maybe it’s best to remain silent and thought to be a X, rather than opening one’s mouth only to remove all doubt. (smile)

    Today seems to be a classic quotes day for me. Happy Father’s Day for all the Dad’s out there.

  45. 45
    Hank Roberts says:

    https://www.nytimes.com/2017/09/02/opinion/climate-hurricanes-flooding-harvey.html

    What Climate Scientists Want You to See in the Floodwaters

    By KATHARINE MACH and MIYUKI HINOSEPT. 2, 2017

  46. 46
  47. 47
    Thomas says:

    584 alan2102, useful intelligent contribution shared @ http://www.realclimate.org/index.php/archives/2017/08/unforced-variations-august-2017/comment-page-12/#comment-682514

    repost: “The Global Restructuring of Science as a Marketplace of Ideas” https://www.youtube.com/watch?v=2J13SDqmaNw (can lead a horse to water, but ….)

    30 CCHolley, those are the ‘right’ questions to be rhetorically answered by Scott imho.

    26 MA Rodger, used a lot of words to say nothing and clarify even less than nothing.

    23 Mr. Know It All, it would help if you got an education on AGW/CC and got your facts right. However, no one can help you with your IQ and Gullibility Quotient Mr KIA.

    21 John Kelly says: “These aspects seem to me to be better signals of the changes brought on by a changing system. They suggest to me we’re going to see more and more weird stuff, in unusual places. Of course, I can’t measure that.” That’s called rational logic based on evidence John. One doesn’t need to be an active AGW/CC scientist to posses those qualities and use them effectively. You may not ahve the data or skills to measure the dynamics you stated, but your obvious intelligence and willingness ‘to do the personal work’ required in order to understand the essentials of AGW/CC and separate that out from BS is indeed measurable. :-)

    18 Mal Adapted says to Scott: “Hurricane Harvey was therefore as much a climate change event as any individual weather event can be.”
    Bingo! Nailed it! As per ref provided by me in recent months about Cognitive Scientist George Lakoff’s analysis of “systemic causation” in relation to AGW/CC communications and why that is such a difficult concept for large portions of society to grasp psychologically. Not only the ‘public’ is affected either. ‘Scientist’ MA Rodger may one day become motivated to dig deeper into ENSO dynamics and what drives them at their core and realize they cannot and do not ever operate in a vacuum. Thus things ‘change’ while keeping in mind that ‘beliefs’ very seldom do, until death.

    Have a great day.

  48. 48
    Thomas says:

    Be inspired and be guided by youth on how best to communicate clearly and effectively.
    https://www.democracynow.org/2017/8/31/james_hansen_hails_landmark_youth_climate

  49. 49
    mike says:

    August 20 – 26, 2017 404.48 ppm
    August 20 – 26, 2016 401.97 ppm

    running at that ugly number – about 2.5 ppm over last year.

    It’s a buyer’s market in the south texas flood plains right now for those of you who think global warming has nothing to do with Harvey’s impact. Please cash out all your investments and buy everything you can that got a little bit wet. Talk is cheap, put your money in play. How much sea level rise could actually happen? Warmed gulf waters don’t necessarily mean more flooding, do they?

    As for me, no, not going to buy low lying coastal properties. Wouldn’t be prudent.

    Warm regards

    Mike

  50. 50
    Thomas says:

    It has been an interesting/unusual summer in the Arctic this year. One potential take-away message I am lightly ‘concluding’ is that SIE as a measure is somewhat disconnecting from the PIOMASS measure, where SIE is being reported at higher levels relative to total Mass historically.

    Various providers of data analysis are also improving and offering new kinds of data sets of both short term predictions and animations of what’s going on. Too varied and complex to report on here, and not easy for the avg joe public to get one’s head around either, but good to see such cutting edge developments unfolding still.

    a couple of snippets with a recommendation and hat tip to Neven’s forum for anyone wishing to dig deeper as the 2017 minimum looms ahead. see http://forum.arctic-sea-ice.net

    Tropical air on train-tracks to the Arctic.sept2nd
    http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=1834.0;attach=51571;image

    So yes it can get there but the path is more circuitous. Below is GFS Sept. 6th forecast for Precipitable Water and 500hpa winds – note hurricane Irma in lower left. We can see the moisture mostly from Harvey spanning across northern Atlantic.
    http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=1834.0;attach=51612;image

    Below is the same ESRL sea ice motion as above re-animated using different Panoply features and options. This is a vast improvement over Hycom’s forecast motion both in scientific accuracy and graphical communication of it. http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=1834.0;attach=51533;image

    several areas still look vulnerable in the few weeks remaining (before surface refreeze starts to dominate satellite imagery), including the remaining Beaufort tongue, the Laptev bite, and the area NE of Svalbard. Stay tuned… Aug16-Aug25
    http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=1834.0;attach=51146;image

    whole Arctic n(n-1)(n-2) 13-30 Aug 17.gif
    http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=1834.0;attach=51528;image

    Temps to Sept 2nd http://ocean.dmi.dk/arctic/plots/meanTarchive/meanT_2017.png

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