Vulnerability and resilience

I’m starting to better understand why some reasonable people are often concerned about the way in which the impact of extreme weather events are sometimes framed. It’s quite well explained in this recent paper by Myanna Lahsen and Jesse Ribot called the [p]olitics of attributing extreme events and disasters to climate change.

As I understand it, the basic issue is that the impact of an extreme weather event on a community typically depends quite strongly on how vulnerable or, conversely, how resilient the community happens to be. If a particular community has invested in becoming more resilient, they may be far less severely impacted than another community who have either chosen not to make such investments, or have not been in a position to do so.

So, even if one can demonstrate that climate change has influenced the severity of an extreme weather event, one should be cautious of claiming that it has had a significant influence on the resulting damages to the communities that are affected. Various socio-economic factors will almost certainly play a very large role, and framing it as being due to climate change can end up over-looking these important socio-political factors. It can also allow local policy makers to absolve themselves of responsibility.

However, as the paper above does acknowledge, how we frame these kind of things always involves some kind of judgement. The climate is clearly changing, this is mostly due to human emissions of greenhouse gases into the atmosphere, and it will almost certainly influence extreme weather events. It also won’t stop until we get emissions to ~zero.

It may well be that socio-economic influences are often the dominant factor in determining how vulnerable a community is to extreme weather events. However, this may not remain true if we continue to emit greenhouse gases into the atmosphere. It could be that communities that are currently resilient may struggle to maintain this, and there may be no level of investment that will make some vulnerable communities sufficiently resilient.

However, I completely agree that we have to be careful of how we frame the impact of extreme weather events, and should try to be aware of how our own biases may influence how we choose to do so. We should also distinguish between the influence of climate change on the extreme event itself, and the subsequent impact of the extreme event on local communities. Socio-economic factors may well play a much larger role in the latter than climate change.

However, we also mustn’t – in my opinion – lose sight of the fact that climate change is happening, that it will almost certainly increase the frequency and intensity of many extreme weather events, and that these changes will continue until human emissions of greenhouse gases get to zero. This doesn’t mean that it isn’t also important to invest in making communities more resilient, but maintaining this resilience will be increasingly challenging if we don’t also act to stop climate change.

Links:

Politics of attributing extreme events and disasters to climate change — paper by Myanna Lahsen and Jesse Ribot

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145 Responses to Vulnerability and resilience

  1. Anyone who has been involved in the climate debate will probably be aware that there are a number of people who have spent many years claiming that natural disasters have not been impacted by climate change. There’s been a lot of push-back against this, because the way they choose to frame it then gets interpreted as suggesting that climate change isn’t influencing extreme weather events.

    Partly because of this, I think it’s taken me quite some time to understand the nuance of the situation and that there are good reasons for being careful of the framing of the impact of climate change on natural disasters. I think it’s good that more nuanced voices are becoming more prominent.

  2. Jim Eager says:

    Anders, it seems to me that it is most often the “red team” opening go-to to set up the strawman argument that “warmists” blame the extreme event on climate change, and then proceed to knock it down, when in reality it is the “warmist” contention that climate change has made the event stronger or worse, or more frequent, while saying nothing at all about it being the cause of the event.
    The “red team” having framed the debate at the outset have already gotten their message out.

  3. Well actually, the argument(s) most frequently made against the Xtreme Weather meme are:
    1. Extreme weather events are uncommon, hence are not readily amenable to statistical analysis with regards to either strength or frequency
    2. The Intergovernmental Panel on Climate Change has resolutely maintained that the impacts of human contributions to climate change, including extreme weather events, are not likely to be felt until 2040 at the earliest and for most impacts decades later
    3. Much of the media’s association of extreme weather events to climate change are without basis. See current headlines about tornadoes in Kentucky as an example. Closer examination of past extreme weather events (floods in Pakistan, droughts in Texas, changes in monsoon behavior, etc.,) have resulted in scientific papers asserting that climate change was not involved

    Some skeptics make ridiculous arguments with regards to extreme weather events. So do some adherents to the consensus point of view. It seems reasonable to look at current extreme weather events as potential previews of coming attractions to a theatre near you.

  4. Joshua says:

    Anders –

    I thought that paper was very interesting and definitely worth some thought from a lefty perspective. I cam across it at RPJr’s substack by way of Judith’s Twitter:

    Of course, RPJr. managed to pretty much butcher the paper in his standard way. I left him a comment which he’ll ignore, no doubt:

    https://rogerpielkejr.substack.com/p/the-politics-of-our-climate-attribution/comment/3983663

  5. Tom,
    You claim that the media’s association of climate change to extreme weather is without basis, but I actually think they’ve got better. Often they do add suitable caveats. Of course, the media gets lots of things wrong, but it seems to me that they’ve more careful about how they frame extreme weather events.

  6. Joshua,
    RPJ managing to misrepresent, or not fully represent, what the paper actually says is not really a surprise.

  7. Joshua,
    What’s fascinating (in a way) is that the same people who seem completely comfortable with the misinformation promoted by certain sites, get quite worked up by the way in which the impact of extreme weather events are framed. I do have some sympathy with the latter, and there are some very reasonable people who are highlighting that care should be taken. It is hard, though, to take those whose actions make it seem that they regard this as a much bigger issue than the misinformation spread by contrarian think tanks, and blogs.

  8. Clive Best says:

    The following was not attributed to Climate Change. For sure it would be now !

    “Thirty four years ago on October 15, 1987 BBC weatherman Michael Fish told viewers: “Earlier on today, a woman rang the BBC and said she heard a hurricane was on the way. Well, if you’re watching, don’t worry, there isn’t.”

    That night Britain was hit by the most catastrophic storm since 1703. Gusts of wind of 94 mph were observed in London between 3am and 4am. A maximum gust of 115 miles per hour was recorded at Shoreham, West Sussex. Across the country it is estimated that 15 million trees were uprooted or blown down including six of the seven Oaks in Sevenoaks. Knole Park reportedly lost more than 70 per cent of its trees.

  9. gwws says:

    Aren’t you a bit optimistic when you write:

    ‘and that these changes will continue until human emissions of greenhouse gases get to zero. ‘

    There is a considerable lag. A time lag between the forcing and settling down to a steady state. My guess is that we will be seeing an increase in anomalies in the weather at least ten years into the era of zero emission.

  10. gwws,
    Roughly speaking, we expect global warming to stop when human emissions get to zero. This is largely because the natural sinks (oceans mainly) are expected to continue taking up some of what we’ve emitted so that this compensates for what would be a lag in warming if concentrations were to remain constant.

    There’s a good Carbon Brief article that explains this. I’ve also written some posts about this.

  11. Clive,

    The following was not attributed to Climate Change. For sure it would be now !

    If it happened today, there’s a decent change that it would have been influenced by climate change.

  12. Clive Best says:

    I think it is “black magic” to attribute one individual weather event to climate change. The best you can do is to compare the frequency of such extreme weather events on decadal time scales. As I understand it the attribution method attempts to assign a probability for a particular extreme weather event to occur based on climate models (1 in 100 years). The only events that makes sense for would be heat waves or summer temperature records.

  13. Clive,
    You’re illustrating the issue with this discussion. Few, if any, are attributing an individual event to climate change. There is, however, evidence that climate change is influencing many of these events. For example, intense precipitation, sea level rise enhancing storm surge, the intensity of some tropical cyclones, the intensity of some heatwaves, the frequency/intensity of some wildfires.

    If you think they every association between climate change and extreme events is claiming something like “climate change *caused* this event” then maybe you need to read more carefully.

  14. Chubbs says:

    Regarding tornadoes, this recent paper using CMIP6 projects a 5-20% increase in severe convective weather proxies per degree C of warming.

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021EF002277

  15. Chubbs says:

    Minnesota has never had a December tornado. May happen today.

    Embedded gusts of 80-100 mph and a nocturnal strong tornado or two are also
    possible, particularly across western to northern Iowa and southeast
    Minnesota.

    https://www.spc.noaa.gov/products/outlook/day1otlk.html

  16. Joshua says:

    Clive –

    > I think it is “black magic” to attribute one individual weather event to climate change.

    When did you stop practicing black magic on your wife?

  17. Joshua says:

    Anders –

    > . I do have some sympathy with the latter, and there are some very reasonable people who are highlighting that care should be taken.

    I thought that paper was a very good example.

    > It is hard, though, to take those whose actions make it seem that they regard this as a much bigger issue than the misinformation spread by contrarian think tanks, and blogs

    Yah. That’s the problem – to not let our old friends Tom, Clive, and RPJr., and the like, to become a distraction.

    Responsibility for that, if it happens, doesn’t really rest with them. They are who they are. It’s all so easily predictable. They reflexively strive to be the focus, to create defensiveness rheifj their aggression. It’s a human trait – one that we all share.

    The responsibility lies with us. We don’t have to be distracted.

    Here’s my add-on. It’s a matter of letting go of the allure of the reflexive, addictive, dopamine-driven goal of engaging with, and somehow defeating them.

  18. Joshua,

    The responsibility lies with us. We don’t have to be distracted.

    Indeed, and I’m trying harder to bear this in mind.

  19. Joshua says:

    Anders –

    It’s hard, I acknowledge.

    Again, I thought that article was very interesting. Thanks for highlighting it.
    And I shall go back to RPJr.’s substack to thank him for highlighting that article also.

    I look forward to seeing of there’s more discussion of the article itself.

    I’ve passed it on to some people who are engaged in organizing work related to climate change. I’m curious to see how they’ll react.

  20. JE says: “Anders, it seems to me that it is most often the “red team” opening go-to to set up the strawman argument that “warmists” blame the extreme event on climate change, and then proceed to knock it down…”
    An accurate and nuanced statement is in big trouble competing with deliberate hyperbole, overstatement and misstatement that has a goal of obscuring truth, facts and appropriate societal response. Maybe a pithy response can become a meme to help the public understand how deliberate hyperbole, overstatement and misstatement are used for cynical gain? In that regard, I would suggest something like the following: Read carefully and think better, please. or Your motivated reasoning is overwhelming your fundamental reasoning skills. Ooops, time for a mirror check! works when a person tries to insult someone over a practice they engage in on a regular basis.

    Human beings understand ridicule. If someone engages in cynical arguments and pushes ridiculous claim, maybe a little ridicule is the appropriate response.

    I am impressed with how so much of this group and ATTP in particular is consistently respectful with folks who appear to engage in cynical arguments and push ridiculous positions, but when scientists are studying how to engage AI to counteract misinformation and false statements, I think maybe we need to engage a little more wetware/natural intelligence in that struggle as well.

    As JE notes, the “red team” have framed the debate and the red team’s rhetorical success is now producing unfortunate real world impacts.

    I think we should be considering reframing the debate quickly by cutting people down to size if we want an accurate understanding of global warming to gain more traction in the world.

  21. dikranmarsupial says:

    “As I understand it the attribution method attempts to assign a probability for a particular extreme weather event to occur based on climate models (1 in 100 years). The only events that makes sense for would be heat waves or summer temperature records.”

    err, no. Uncertainty quantification and extreme value statistics provide means to make a variety of inferences about extreme or rare events, not just records. I’ve found them pretty useful for modelling excedances of statutory thresholds on air pollution and in statistical downscaling of heavy precipitation.

  22. dikranmarsupial says:

    “1. Extreme weather events are uncommon, hence are not readily amenable to statistical analysis with regards to either strength or frequency”

    This is incorrect. There is a branch of statistics called “extreme value theory” that is designed for exactly that sort of problem.

  23. dikranmarsupial says:

    I am skeptical of RPJr’s view on this as his own work demonstrates a lack of understanding of null hypothesis statistical tests, namely a lack of statistical significance is not good evidence of “not happening”. Of course I have pointed this out to him and he refused to engage in a discussion of that point.

  24. Clive Best says:

    “Uncertainty quantification” = sigma or standard deviation
    “extreme value statistics” = probability of x-A where A is the normal mean

  25. Willard says:

    > the media gets lots of things wrong

    You bet they do:

    In an email to supporters, Climate Depot’s headline claimed a “Meteorologist calls Biden’s tornado climate link ‘utter bullsh*t,’” quoting and linking to Chris Martz, who is in fact not only not a meteorologist, but not even a college graduate, having just completed his first semester at Millersville University. […]

    Marc Morano’s email also cites an old post by climate satellite mistake-maker Roy Spencer, followed by a reference to Roger Pielke Jr, who is making good use of his cramped office by tweeting quotes from the IPCC as though the consensus view of tornado trends has a bearing on this specific event’s conditions. (Generous of Jr. to stop publicly airing his weird daddy issues long enough to give his opinion on tornadogenesis!)

    https://www.dailykos.com/stories/2021/12/14/2069194/-We-re-Wobbling-Tornado-Takes-from-Murdoch-Media-Anti-Vaxxers-Climate-Conspiracists-and-Aliens

    Who would have thunk that MarcM still had a red telephone line to Junior’s batcave?

  26. dikranmarsupial says:

    ““Uncertainty quantification” = sigma or standard deviation”

    had you bothered to look at the papers, or google it, you would know there is a lot more to it than that.

    ” “extreme value statistics” = probability of x-A where A is the normal mean”

    Hubris. Again, there is a *lot* more to it than that. The book by Stuart Coles is a good place to start.

  27. dikranmarsupial says:

    I do say as a joke that a statistican is someone who knows what to assume is Gaussian, but it *is* a joke. Partly because knowing what can be reasonably assumed to be Gaussian actually takes some expertise (i.e. to go beyond “cook-book” statistics), but also because statisticians know that not everything is Gaussian, the mean is not the only quantity of interest, etc. etc. etc.

  28. dikranmarsupial says:

    Is part of the problem here that past damages are being used as a proxy for the past severity (in meteorological terms) of the storm, but that is the only data we really have for a lot of the historical record, so we can’t consider physical severity separate from damages (and hence separate off the vulnerability/resiliance factor).

  29. Joshua says:

    dikran –

    A question. When certain unnamed folks reference “normalized” damages as a way to measure trends in weather severity, do they control for growth in the overall value of existing built environment?

  30. dikranmarsupial says:

    I think I may have asked that unnamed person on Twitter when I reviewed their book (but I had so many questions that may be one I didn’t ask ;o)?

    I was mainly wondering if the framing was sort of imposed on the analysis because of the limitations of the data?

  31. Joshua,
    As I understand it, that is what they control for and is one reason why they claim there is little evidence for a climate change signal. You can explain it all as being due to more exposed wealth. Something that I think that is not included is the amount invested in better infrastructure, or early warning systems. Hence, even if you can explain it all as being a consequence of changes in exposed wealth, it’s still not clear that this captures all of the associated costs.

  32. Willard says:

    Speaking of media, if you look at this list:

    https://climaterealism.com/?s=roger+pielke+jr

    you’ll notice the last item, which ends thus:

    Improved infrastructure including better mitigation policies, planning, construction materials, and building codes may account for the fact normalized losses have not increased despite an increase in population and an associated increase in the number of homes, businesses, and infrastructure on or near the coasts of the United States.

    That’s some fine caveats!

    Here are few articles that cite J18:

    https://scholar.google.com/scholar?as_ylo=2021&hl=fr&as_sdt=2005&sciodt=0,5&cites=11703412933213729310&scipsc=

    Some, but not me, might argue that Junior’s reliance on his own work is a bit overoptimistic. I’d rather underline the following assertion:

    Disclosure statement

    No potential conflict of interest was reported by the author(s).

    https://doi.org/10.1080/17477891.2020.1800440

    Auditors ought to ask whether Junior has any conflict of interest in reviewing papers which many are his own, and by which he becomes a Climateball megaphone for inactivists!

  33. Joshua says:

    Anders –

    > . Something that I think that is not included is the amount invested in better infrastructure, or early warning systems.

    I do recall a discussion where the claim was made that aspects like improved building standards were controlled for – which I would imagine would go towards controlling for increased protective infrastructure.

    Also, IIRC, there was an argument that early warning systems can only have a limited impact (e.g., you can’t move a house because you got an early warning, although you can leave the area).

    But my actual question is whether there’s really control for the % of built environment that sustains damage. It seems to me a complicated issue. There’s more built environment so you’d have to discount the $ in damage in that sense. But at some point there needs to be a ratio introduced as well. X % of land used to have built environment. Now theres X + % of land that has built environment. So the same amount of extreme weather could cause more damage now, so you’d have to discount the $ in damage as a result. However, what if a higher % of built environment is being damaged? How would that be measured? How would that be controlled for the increase in built environment?

    Not sure if that makes any sense.

  34. Willard says:

    One recent open access paper:

    (1) Background: Hurricane events are expected to increase as a consequence of climate change, increasing their intensity and severity. Destructive hurricane activities pose the greatest threat to coastal communities along the U.S. Gulf of Mexico and Atlantic Coasts in the conterminous United States. This study investigated the historical extent of hurricane-related damage, identifying the most at-risk areas of hurricanes using geospatial big data. As a supplement to analysis, this study further examined the overall population trend within the hurricane at-risk zones. (2) Methods: The Sea, Lake, and Overland Surges from Hurricanes (SLOSH) model and the HURRECON model were used to estimate the geographical extent of the storm surge inundation and wind damage of historical hurricanes from 1950 to 2018. The modeled results from every hurricane were then aggregated to a single unified spatial surface to examine the generalized hurricane patterns across the affected coastal counties. Based on this singular spatial boundary coupled with demographic datasets, zonal analysis was applied to explore the historical population at risk. (3) Results: A total of 777 counties were found to comprise the “hurricane-prone coastal counties” that have experienced at least one instance of hurricane damage over the study period. The overall demographic trends within the hurricane-prone coastal counties revealed that the coastal populations are growing at a faster pace than the national average, and this growth puts more people at greater risk of hurricane hazards. (4) Conclusions: This study is the first comprehensive investigation of hurricane vulnerability encompassing the Atlantic and Gulf Coasts stretching from Texas to Maine over a long span of time. The findings from this study can serve as a basis for understanding the exposure of at-risk populations to hurricane-related damage within the coastal counties at a national scale

    https://doi.org/10.3390/ijgi10110781

    Any chance that Marc Morano and the Heartland Institute will promote that study? I doubt it. Here’s what I expect: more appeals to Junior with titles such as “the science says” and “the leading expert on hurricane damage says” with caveats such as “but Junior believes in AGW.” Since contrarians have no bench to speak of, can they do things differently than to promote Junior?

    Contrarianism is the fastest track to the public spotlight.

    “But the media” indeed.

  35. Joshua,
    Aslak Grinsted actually has a paper that looks at damage in terms of equivalent area of total destruction, and they claim to find a climate change signal.

    https://www.pnas.org/content/116/48/23942.short

    One of my main issues (which I think Andrew Dessler highlights too) is that we don’t really know what the null hypothesis is. Given the various changes that have taken place over the last ~100 years, what would we expect the damages to be in the absence of climate change. What seems to happen is that the damages are normalised in some way and a graph is plotted showing that the normalised damages haven’t increased. It’s not clear to me that this immediately indicates that climate change has played no role, because you don’t know what the signal should be in its absence.

  36. Joshua says:

    Anders –

    Thanks. Yes, that’s what I was circling around. Good to know I’m not just wacky. Seems to me like equivalent area destroyed mixed with costs normalized by growth in total built structure value would make some sense.

    > One of my main issues (which I think Andrew Dessler highlights too) is that we don’t really know what the null hypothesis is.

    Yes. I tend to think of it as assumed counterfactual scenarios. One might even say stealth assumptions about countefactual scenarios. 🤔

    But maybe a poorly specified null hypothesis is a better way to describe it.

  37. Brandon Gates says:

    The best media treatment I picked up in my news scan of the recent tornado outbreak comes by way of USA Today, ‘We can expect more’: Did climate change play a role in the deadly weekend tornadoes?

    This was the only one of several articles I saw that named an expert instead of politicians to back the claim that climate change is (or may be) in part responsible for the timing and severity of this event:

    The latest science also indicates that the combination of these factors is increasing over time, particularly in the winter months in the south-central and southeastern states, Mann said. “The latest science also indicates a trend toward more intense, destructive tornadoes,” he said. “The tornado that hit Mayfield, Kentucky, was at the upper end of the scale, with radar-measured winds that neared 300 mph.”

    This raised my eyebrows since my recollection from AR5 was no trend found in frequency/intensity of tornadic events, and low confidence that same is to be expected. Annoyingly no citations to any papers representing what is this latest science. Perhaps someone in our sewing circle on speaking terms with Dr. Mann could ask him to specify.

    ***

    Chubbs: nice paper, thanks.

  38. mrkenfabian says:

    When does GHG driven global warming become the null hypothesis?

  39. Brandon Gates says:

    Willard,

    > Since contrarians have no bench to speak of, can they do things differently than to promote Junior?

    I wouldn’t bet on it; Dr. Roy, vintage 2018:

    U.S. Major Landfalling Hurricanes Down 50% Since the 1930s

    […] yesterday I presented U.S. Government data on the 36 most costly hurricanes in U.S. history, which have all occurred since the 1930s. Since the 1930s, hurricane damages have increased dramatically. But, as Roger Pielke, Jr. has documented, that’s due to a huge increase in vulnerable infrastructure in a more populous and more prosperous nation.

    When major US hurricane landfalls inevitably come back into vogue it will be time to polish off the but Chaos bingo square.

  40. Bob Loblaw says:

    mrkenfabian:

    It is the null hypothesis for every single “global warming stopped in 1998/2006/whatever year”, but the contrarians have yet to do the proper statistical test, as far as I can tell.

  41. Brandon, there is a 2018 paper by James Elster suggesting that tornadoes have been getting stronger. I’ll try to remember to post a link tomorrow.

  42. Brandon Gates says:

    AT,

    Thanks, I found it: Elsner et al., 2019, Increasingly Powerful Tornadoes in the United States. Open access.

    It’s cited in AR6 WGI Chapter 12 along with a few others:

    35 Severe wind storm: There is limited evidence and low agreement in observed changes in North American CID indices associated with extratropical cyclones (Chapter 11), severe thunderstorms, severe wind bursts (derechos), tornadoes, or lightning strikes (Vose et al., 2014; Easterling et al., 2017; Kossin et al., 2017). Observational studies have indicated a reduction in the number of tornado days in the US, but increases in outbreaks with 30 or more tornados in one day (Brooks et al., 2014), the density of tornado clusters (Elsner et al., 2015), and overall tornado power (Elsner et al., 2019).

    Chapter 11 of the same report assessing the quality of data and confidence in trends still reads more or less the same as I recall from AR5:

    Severe convective storms are convective systems that are associated with extreme phenomena such as tornadoes, hail, heavy precipitation (rain or snow), strong winds, and lightning. The assessment of changes in severe convective storms in SREX (Chapter 3, Seneviratne et al., 2012) and AR5 (Chapter 12, Collins et al., 2013) is limited and focused mainly on tornadoes and hail storms. SREX assessed that there is low confidence in observed trends in tornadoes and hail because of data inhomogeneities and inadequacies in monitoring systems. Subsequent literature assessed in the Climate Science Special Report (Kossin et al., 2017) led to the assessment of the observed tornado activity over the 2000s in the United States with a decrease in the number of days per year with tornadoes and an increase in the number of tornadoes on these days (medium confidence). However, there is low confidence in past trends for hail and severe thunderstorm winds. Climate models consistently project environmental changes that would support an increase in the frequency and intensity of severe thunderstorms that combine tornadoes, hail, and winds (high confidence), but there is low confidence in the details of the projected increase.

    So I guess we can say there is a finding for an increase in tornado power in the US but not with a lot of confidence. Stories in the media will surely leave out that caveat, so but Alarmism as usual.

  43. angech says:

    ATTP
    “I’m starting to better understand why some reasonable people are often concerned about the way in which the impact of extreme weather events are sometimes framed.”

    How does one demonstrate that climate change has influenced the severity of an extreme weather event?
    Are there politics involved in attributing extreme events and disasters to climate change?
    Should we really be worried about the extreme events which by definition are bad and rare or as
    smallbluemike might say worry more about the persistent long term general effects which are bad?

    These are the questions that arise.
    We have covered this ground a number of times before but it is still relevant.
    Usually it is on the basis of assessment by Roger Pielke Jun v the assessment, usually bad, of a new paper on this subject.

    Attribution.
    Severity [of the event].
    Damage now, compared to past and future.
    Influence [once attribution is established].

    I have argued, in the past, that extreme and severe weather events evade labeling and pigeonholing of these events in a useful manner.
    Better to stick to the overall general changes that occur and cause problems if that is what one is looking for.

    The problem with attribution is that general weather patterns due to climate change do not lead to predictable outcomes.
    Because, weather.

    Every argument that a cyclone or tornado might have been made worse falls on the side that the same changes might have made it better [less harmful].
    The butterfly flapping its wings causes an event that though catastrophic could have been made better or worse by one flap more or less. No one can know. Speculation, worse rife speculation can be entered into but it is always, individually, a coin toss..

    Warming we say has increased in the last 20 years.
    Anecdotally I would say that tornadoes have been less frequent and deadly up till now over the last 15 years and cyclones the same.
    When one calls out these extreme weather events as attributable to global warming now, and uses the example of the last 20 years, the argument falls flat.
    This point can and will be soundly debated but the only result will be noisy opinions.
    Not attribution.

    Damage is another issue which is difficult to qualify for the reasons that ATTP put up plus population growth and the growth of more expensive things to damage.

    Influence is the most interesting.
    Once attribution is insisted upon , and damage, one can look at influence.
    Here the jury has the option of looking at conditions and causation.
    Two questions.
    Does colder weather increase tornado frequency?
    Does warmer weather reduce Hurricane frequency?

  44. Dave_Geologist says:

    Clive. I was there, and more to the point I know it wouldn’t have been.

    Because Science.

    Since you very clearly don’t understand how (recent, last five years or so) extreme event attribution is done, you should probably spend the Christmas holidays reading a dozen or two papers. Papers which you can easily find using Google Scholar. Then you’ll be able to participate in a reasoned discussion, as opposed to just flaunting your lack of understanding.

    A decade ago it was different, but the eternal curse of science deniers and minimisers, whether about climate change or evolution, and especially for those who ignore the science whose name appears in the title of this blog and rely solely on a journeyman grasp of statistics, is that Science Moves On. Inevitably, because science is right and they’re wrong, it becomes clear in due course that they were wrong.

    If something is bound to happen, indeed is already happening barring Divine Intervention, scientists can be confident that if we keep on doing what we’re doing, in due course the signal will emerge above the noise. Just like it has done time after time after time. Extreme event attribution is just the latest card in the shaky show-me-the-stats house to fall. The child in the back of the car saying “are we there yet” or “why aren’t we there yet” will sure as shooting get to its destination, because the adults in the car know the destination and know that they’re on the way there.

  45. angech,

    How does one demonstrate that climate change has influenced the severity of an extreme weather event?

    Physics. Consider what the event would probably be like in the absence of climate change and compare that to what it would probably be like in its presence. Bit more complicated, but we do have a reasonably good understanding of how climate change is likely to impact extreme weather events and can do analyses to see if an event probably has been infuenced in some way.

  46. Willard says:

    > The Intergovernmental Panel on Climate Change has resolutely maintained that the impacts of human contributions to climate change, including extreme weather events, are not likely to be felt until 2040

    Resolutely indeed:

    Human influence has likely increased the chance of compound extreme events since the 1950s. This includes increases in the frequency of concurrent heatwaves and droughts on the global scale (high confidence); fire weather in some regions of all inhabited continents (medium confidence); and compound flooding in some locations (medium confidence). {11.6, 11.7, 11.8, 12.3, 12.4, TS.2.6, Table TS.5, Box TS.10}

    Source: https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Full_Report.pdf

    To answer Doc’s question more completely a bit of logic might be needed.

  47. Mal Adapted says:

    Jim Eager:

    the strawman argument that “warmists” blame the extreme event on climate change, and then proceed to knock it down, when in reality it is the “warmist” contention that climate change has made the event stronger or worse, or more frequent, while saying nothing at all about it being the cause of the event.

    aTTP, to Clive Best:

    If you think they every association between climate change and extreme events is claiming something like “climate change *caused* this event” then maybe you need to read more carefully.

    Well, I’m confused. Doesn’t the definition of ’cause’ include partial attribution? Every weather event is the result of a hierarchy of influences from proximate to ultimate. No single factor can be the sole cause of any weather, but if our null hypothesis is that climate is in fact changing, then we can say that all weather now is partially caused by climate change (actually, if ‘climate’ is simply ‘statistical weather’, it may be more accurate to say that newly-extreme weather events define ‘climate change’). The goal of attribution science is to quantify the fraction of storm surge height, rainfall total or rate, wind speed, etc. that’s due to global heat accumulation, no?

  48. Mal,
    Yes, maybe “caused” can also mean “partial attribution”. I was just trying to distinguish between climate change having caused some event that would not have occured at all, versus climate change having changed the properties of an event, or made an event more likely than it would otherwise have been. For example, making the precipitation more intense, or sea level rise enhancing storm surge, or a heatwave that should happen once a century happening once a decade, etc.

    The goal of attribution science is to quantify the fraction of storm surge height, rainfall total or rate, wind speed, etc. that’s due to global heat accumulation, no?

    Yes, that’s my understanding.

  49. Joshua says:

    Anders –

    > Consider what the event would probably be like in the absence of climate change and compare that to what it would probably be like in its presence.

    Did you comment on the following paper?

  50. Joshua,
    I haven’t, but I did see it being highlighted on Twitter. It looks interesting. I guess the basic idea is show that your model would actually predict the event, and then use that model to see how increased atmospheric CO2 probably influenced the event. Seems quite reasonable.

  51. Mal Adapted says:

    Joshua, thanks for linking that Twitter thread. I probably shouldn’t get a Twitter account, because it would be yet another temptation to waste time 8^(. The denialist challenges predictably missed the point. For example, Wei.Zhang:

    “If you’re interested in attribution of extreme weather”. I’m not. Attribution studies are simply an assassination of the null hypothesis and doing science in reverse… Starting with the conclusion and working backwards to a pre-determined answer.

    It sounds like Wei needs to adjust his priors. Does he still think the null hypothesis is that the globe is not warming? If he acknowledges that the earth system is accumulating energy, is he saying it must be assumed not to influence weather in Europe?

  52. Clive Best says:

    There’s a pretty good article here.

    https://www.climate.gov/news-features/understanding-climate/extreme-event-attribution-climate-versus-weather-blame-game

    Basically you can estimate how the frequency (1 in a 100 y) for some category of extreme weather event changes with AGW (models), but you can’t attribute an individual event to AGW.

    Cyclones and wildfires have low confidence. Extreme temperatures have high confidence as expected.

  53. Willard says:

    Right on. Basically you can say that bananas are yellow, but you can’t attribute yellowness to any individual banana. For more background:

    The need to distinguish tokens of types from occurrences of types arises, not just in linguistics, but whenever types of things have other types of things occurring in them. There are 10,000 (or so) notes in Beethoven’s Sonate Pathétique, but there are only 88 notes (types) the piano can produce. There are supposed to be fifty stars (types) in the current Old Glory (type), but the five-pointed star (type) is unique. And what could it mean to say that the very same atom (type), hydrogen, “occurs four times” in the methane molecule? Again, the perplexing thing is how the very same thing can “occur” more than once, without there being more than one token of it.

    https://plato.stanford.edu/entries/types-tokens/

    That might not prevent people to believe that the very banana they eat is yellow, however.

  54. The contrarians are good at setting up the debate on their home field and keeping the debate framed in controversy, whether controversy exists in the science or not. The media amplifies the controversy in much the same way that global warming amplifies extreme weather events. Pushing and amplifying controversy is a media revenue stream. The public may want to embrace controversy because embracing the settled science of global warming is likely to lead to societal changes that are difficult and likely to be somewhat painful. It is so much easier to embrace the controversy and hope the flooding/tornado/heat wave etc. slams someone else and leaves you unscathed. Time to slow down on the science for a week or two and enjoy the holidays! We only have a few shopping days left, get busy!

    It might be a good idea not to get dragged into the weeds with the contrarians in terms of going over the science with them over and over. Maybe just cite the attribution studies and dismiss the contrarians in a pithy manner. If a scientist won’t grasp the attribution aspect of global warming and extreme weather events, they are probably just doing what they are being paid to do: create doubt and controversy to delay actions that will damage the parties who want to avoid getting stuck with stranded assets. Merchant of doubt occupation probably comes with an impressive salary. I think you get dental with it, too.

  55. Clive,
    Quite a lot has changed since 2016. There are researchers who are now doing single event attribution. Friederike Otto has made Time’s list of 100 most influential people of 2021 for doing exactly that.

  56. Clive,
    I’ve no doubt that you doubt it.

  57. Clive Best says:

    Check the article again.

    UPDATED OCTOBER 26, 2021

  58. Clive Best says:

    Here is an abstract from one of her recent papers:

    “In October 2020, Central Vietnam was struck by heavy rain resulting from a sequence of 5 tropical depressions and typhoons. The immense amount of water led to extensive flooding and landslides that killed more than 200 people, injured more than 500 people and caused direct damages valued at approximately 1.2 billion USD. Here, we quantify how the intensity of the precipitation leading to such exceptional impacts is attributable to anthropogenic climate change. First, we define the event as the regional maximum of annual maximum 15-day average rainfall (Rx15day). We then analyse the trend in Rx15day over Central Vietnam from observations and simulations in the PRIMAVERA and CORDEX-CORE ensembles, which pass our evaluation tests, by applying the Generalized Extreme Value (GEV) distribution in which location and scale parameters exponentially co-vary with increasing global temperatures. Combining these observations and model results, we find that the 2020 event, occurring about once every 80 years (at least 17 years), has not changed in either probability of occurrence (a factor 1.0, ranging from 0.4 to 2.4) or intensity (0%, ranging from −8% to +8%) in the present climate in comparison with early-industrial climate. This implies that the effect of human-induced climate change contributing to this persistent extreme rainfall event is small compared to natural variability. However, given the scale of damage of this hazard, our results underline that more investment in disaster risk reduction for this type of rainfall-induced flood hazard is of importance, even independent of the effect of anthropogenic climate change. Moreover, as both observations and model simulations will be extended with the passage of time, we encourage more climate change impact investigations on the extreme in the future that help adaptation and mitigation plans and raise awareness in the country.”

  59. Willard says:

    You might think they’re doing that, Clive, but that abstract makes me doubt that you doubt they think they’re doing that.

  60. Willard says:

    And here is a quote from Clive’s source:

    It can’t tell us whether global warming “caused” a specific event. When most people ask if something caused something else—did global warming cause the Louisiana floods?—they want a yes or no answer. But with global warming and extreme events, it’s not a yes/no question.

    Instead, it’s always a question of whether global warming added to the existing mix of ingredients that already make extreme weather happen. Global warming may be a cause for an event, but not the cause—at least not yet.

    https://www.climate.gov/news-features/understanding-climate/extreme-event-attribution-climate-versus-weather-blame-game

    Emphasis in the text.

  61. Clive Best says:

    My source is direct from her Bio

    https://www.imperial.ac.uk/people/f.otto

    simple as that!

  62. Willard says:

    [CLIVE] you can’t attribute an individual event to AGW.

    [A SOURCE CLIVE LIKES] “Global warming may be a cause for an event, but not the cause—at least not yet.”

    The notion of attribution may not imply what Clive makes it imply.

  63. Clive,
    I’m not quite sure what your point is, but you would seem to be illustrating that not every attribution study will conclude that climate change played a big role.

  64. Clive Best says:

    I am trying to bring a little rational discussion to your website.

  65. Thanks, Clive, appreciated. I always trust people who tell me their amazing qualities in their bios.

  66. Joshua says:

    Clive –

    > I am trying to bring a little rational discussion to your website.

    Your sacrifice for the benefit of others is quite touching.

    I’m glad you’re not trying I wind people up and to make arguments to prove that they’re wrong.

  67. Mal Adapted says:

    Clive Best:

    I am trying to bring a little rational discussion to your website.

    By insisting that extreme weather events can have only one cause?

  68. Clive Best says:

    Untrue.

    You seem sensitive to very sensitive to any criticism. Perhaps it is best then to leave you inside your echo chamber.

  69. doctorbunsenhoneydew says:

    Clive ” by applying the Generalized Extreme Value (GEV) distribution” [quoting Otto]

    Also Clive “extreme value statistics” = probability of x-A where A is the normal mean”

    Which is the sort of thing you would say if you had no idea what extreme value statistics (such as the GEV) were.

    Also Clive “I am trying to bring a little rational discussion to your website.”

    The first rule of Dunning-Kruger club…

    [Dikran Marsupial’s alter-ego again]

  70. russellseitz says:

    I am trying to bring a little rational discussion to your website.
    By insisting that extreme weather events can have only one cause?

    Mal, Clive strives to broaden our intellectual horizons, lest the causally challenged attribute the disappearance of islands to the single cause of rising seas without considering the Eschenbach Hypothesis that while sea level is conserved, island buoyancy is subject to erosion by parrotfish.

    https://vvattsupwiththat.blogspot.com/2021/11/covid-authority-blames-sea-level-rise.html

  71. Mal Adapted says:

    Russelll:

    without considering the Eschenbach Hypothesis that while sea level is conserved, island buoyancy is subject to erosion by parrotfish.

    https://vvattsupwiththat.blogspot.com/2021/11/covid-authority-blames-sea-level-rise.html

    LOL, Russell 8^D!

  72. mrkenfabian says:

    Maybe science IS like an echo chamber – scientists lining the walls with sound science muffles the out of phase reverberances of unsound science, thus allowing the standing waves of knowledge to ring clearly.

  73. Willard says:

    > any criticism

    One explicit criticism would be a great idea, Clive!

  74. Dave_Geologist says:

    Nice one Clive:

    “The geological record shows that forest fires happened before man invented fire. Therefore there has never been any arson and all arsonists should have their sentences quashed. Not only that, there have never been any accidental fires started by human fire use and all those accused of manslaughter or property damage through carelessness should be pardoned.”

  75. Chubbs says:

    This tweet refers to last friday’s tornadoes. On wednesday there were record-breaking tornadoes in the upper midwest.

  76. lerpo says:

    “Well actually, the argument(s) most frequently made against the Xtreme Weather meme are:
    1. Extreme weather events are uncommon, hence are not readily amenable to statistical analysis with regards to either strength or frequency”

    That seems reasonable. The folks I’ve seen argue against typically make very strong claims about changes in strength and frequency. For example, Pielke: “no matter what President Obama and British Prime Minister David Cameron say, recent costly disasters are not part of a trend driven by climate change. The data available so far strongly shows they’re just evidence of human vulnerability in the face of periodic extremes.”

    It may be true that trends are difficult to discern for infrequent events. Are there folks making that argument while not also claiming that there certainly are no trends in strength or frequency?

  77. dikranmarsupial says:

    “That seems reasonable. ” perhaps you should have read further – statistics does have appropriate methods for the study of extremes (extreme value theory). Sadly Prof. Pielkes Sr and Jr both seem to have a rather weak grasp of statistics. The former doesn’t understand statistical power analysis and the latter doesn’t understand “not signficant” does not mean “is not happening” – which is a pretty fundamental error.

  78. Joshua says:

    Dikran –

    I’m certainly not able to interpret the application of extreme value theory.

    But it is my (very basic) understanding that given the low frequency of extreme weather events, it would be difficult to interpret trends with much certainty unless you have a very long sampling period.

    Are you saying that’s not the case or doesn’t apply? If so, could you attempt a dumbed-down basic explanation of where I’m wrong?

  79. Bob Loblaw says:

    Dikran:

    I am not sure I would make such a strong statement about the Pielkes not understanding statistics. An alternative explanation is that they understand it perfectly well, but they are playing to an audience that does not understand it and they can get away with saying stuff that is not true because the audience will like it.

  80. Joshua says:

    To be clear, that question is completely independent of the nonsense peddled by some of our “skeptic” friends.

  81. Bob,
    This discussion that this post by James Annan highlighted might suggest that you’re being somewhat generous (in the first part of your comment, at least 🙂 ).

  82. Joshua says:

    Dikran and Bob –

    > I am not sure I would make such a strong statement about the Pielkes not understanding statistics. An alternative explanation is that they understand it perfectly well, but they are playing to an audience that does not understand it and they can get away with saying stuff that is not true because the audience will like it.

    From where I sit, neither explanation is seems satisfactory. I can’t evaluate their understanding of stats myself, but the idea that they don’t understand statistics seems implausible to me. Neither does it seem plausible to me that they’re explicitly intending to use their understanding of statistics to fool people who lack that understanding.

    More plausible to me – they understand stats (even if not at the level of stats experts) and actually believe their arguments are correct. (That doesn’t mean that I think their arguments are correct. RPJr., in particular, I’ve seen make what I consider to be some rather half-assed arguments and then engage poorly with critique of those arguments with a notable unwillingness to actually interrogate what he’s presented).

  83. Joshua says:

    Or let’s put it this way – irrespective of how well he understand stats, it seems to me that RPJr. may well overestimate the extent of his understanding, and is prone to personalizing critiques of the validity of his statistical analyses (not an unusual trait, BTW).

  84. Joshua,
    One of my biggest criticisms of RPJ has become that he is a science in society scholar who appears not to understand the ways in which science is social.

  85. Joshua says:

    Anders –

    Yes. It’s hard to avoid the impression that he deliberately provokes the reactions he gets (from both sides of the climate divide – praise from “skeptics” and scorn from “realists”). The repeated patten is easily predictable, so if it’s not deliberate and in skms way desired, why doesn’t he change his approach? It would be easy to do.

    An inability to see what’s going on doesn’t seem likely, as he’s so invested in looking at the society/science interface.

    I try to avoid arguing from personal incredulity but I really do find it perplexing.

  86. Joshua,
    I should probably stop this discussion now. Apparently I have a vendetta against RPJ and am partly responsible for why he now has a small windowless office 😉 .

  87. dikranmarsupial says:

    ” they understand stats (even if not at the level of stats experts)”

    The error made by Prof Pielke Jr is a very basic mistake that a scientific user of statistics really should not be making. The error made by Prof. Pielke Sr is a little less basic, but it is far from “expert” level statistics.

    I’m not a mind reader, I try to assume the interpretation that puts people’s motivations in the best light that is consistent with the observations, in the hope that others are doing the same for me. It goes against human nature somewhat though.

    Having said which, in my exchanges with them, both Pielkes have been resistant to criticism. It is interesting to consider whether the Dunning-Kruger correlation is caused by ignorance leading to over-confidence or over-confidence limiting ones ability to learn things (or a bit of both).

  88. Joshua says:

    Dikran –

    So Anders says that particikar discussion should end. I’ll just say that even knowledgeable people can sometimes make basic mistakes they shouldn’t make. Even doers make mistakes sometimes 😉

    What’s more informative for me (particularly as someone who can’t evaluate technical arguments) is how people handle obvious mistakes when they make them, or handle critiques. When I can’t evaluate a technical argument, I try to use information related to how people respond, to help inform me about probabilities.

  89. dikranmarsupial says:

    Joshua – indeed. We all make mistakes, as Montaigne says – we are all but blockheads, and embracing your inner blockhead (and not being crushed by your mistakes) can help avoid making it your outer blockhead too often.

  90. russellseitz says:

    ATTP: Anyone who has been involved in the climate debate will probably be aware that there are a number of people who have spent many years claiming that natural disasters have not been impacted by climate change.

    You’re too kind— There are numbers of people who have spent many centuries claiming natural disasters cannot arise form anything other than Acts of God

    https://vvattsupwiththat.blogspot.com/2021/12/no-one-believes-in-climate-denial.html

    Willard should give Because Noah a bingo card of its own

  91. lerpo says:

    “perhaps you should have read further – statistics does have appropriate methods for the study of extremes (extreme value theory).”

    Perhaps that’s the case. Either way, we also have physics to help inform us of what may come.

    To me, it would be refreshing if there is a contrarian making the case that we don’t have enough data yet to know the trend.

    Typically (as in the case of Pielke) they will claim that there certainly is no trend. Even Thomas Fuller was willing to make unambiguous claims about trends way back in 2015: “Global drought has decreased since 1901.” Curiously the link he provided as proof claimed only “no long-term trend”.

  92. Bob Loblaw says:

    “More plausible to me – they understand stats (even if not at the level of stats experts) and actually believe their arguments are correct

    The Venn diagram for those two categories has no overlap.

  93. izen says:

    Setting aside how little or much AGW influenced the occurrence and severity of the Illinois and Kentucky tornados, the impact of vulnerability/resilience was evident in the socio-economics of the deaths allegedly caused by the warehouse and candle factory requiring the workers to keep working when the storms approached.

    As resilience often seems to be associated with improving the conditions of the individual rather than the profitability of the system perhaps that has to be one aspect of resolving climate change impacts along with ceasing the release of CO2.

  94. Brandon Gates says:

    I’ve been reading papers Friederike Otto where she is either lead author or co-author, and where the subject is attribution of human causes to individual events, or methods papers generally describing how to do the same. My reading list comes from the citations mentioning her in AR6 WGI Chapter 11, Weather and climate extreme events in a changing climate. There are some fifty papers meeting these criteria; I’ve sampled perhaps 10% of them, enough to feel comfortable identifying some recurring themes:

    1) Extreme event attribution is heavily dependent on how events are defined.
    2) A given method and definition may obtain significant results in some regions but not in others.
    3) While there may be good physical rationale for expecting certain extreme events to increase under climate change, physical models often fail to reflect that expectation, or give significantly different results when applied to a given event.
    4) For certain event definitions in particular regions, attribution methods can be quite robust thus increasing confidence in the correctness of their conclusions.

    I give one example of a paper which touches on these themes, and which obtains a successful attribution to human-caused climate change (emphasis mine):

    Otto, F. E. L., van der Wiel, K., van Oldenborgh, G. J., Philip, S., Kew, S. F., Uhe, P., et al. (2018b). Climate change increases the probability of heavy rains in Northern England/Southern Scotland like those of storm Desmond—a real-time event attribution revisited. Environ. Res. Lett. 13, 024006. doi:10.1088/1748-9326/aa9663.

    7. Conclusion
    During the days immediately after an extreme weather event with large impacts, like the floods in the UK following heavy rains around 5 December 2015, the question arises what role climate change has played. Using real-time observations and weather analyses, historical data, reanalyses and climate model output, we can now give a first scientific assessment of the effect of climate change in a relatively short time. The analysis here shows that the real-time estimates are robust for this kind of extreme weather event. For the analysis of the heavy precipitation event in Northern England and Southern Scotland caused by the storm Desmond we used three independent methods: a statistical analysis of observed trends, coupled climate model simulations and a large ensemble of regional climate model simulations. In this case, a lack of observations of the event precluded us from establishing the return period of the event with accuracy, but statements can be made about relative return periods under various scenarios. Based on the available data at the time, it appeared to be very roughly a one in one hundred year event when averaged over a large region, but with an uncertainty range from about 20 years to many hundreds of years. Locally return periods may be very different from this. With more observations becoming available a month and more after the event the return period was revised to be in the order of 5 years.

    The increase in likelihood of the event does not depend strongly on the return period and was found to be in good agreement between the three methods.

    For the event defined over the large region in section 2.1 to enable comparison with models and with the revised return period, the best estimate is 59% increase in risk with a larger uncertainty range that includes 0 and has an upper bound of 250%. Taking also into account that Desmond was not a one-off storm but was followed by two others also leading to extreme precipitation and flooding, the whole month of December was analysed as well, resulting in an increase in risk that is higher than the daily precipitation but also with larger quantitative discrepancies between the methodologies.

    The reanalysis of a real-time attribution event shows that it is possible to provide a robust first-guess quantification of the role of anthropogenic climate change in an extreme rainfall event in a temperate climate zone with high day-to-day and low interannual variability. This is in particular important as it highlights that real-time attribution can be done even when station data of the event is not available. Putting the one day event in the context of a whole wet month also shows that the attribution question with respect to daily extremes is very different to that of very wet months. These results highlight again the strong dependency of attribution results on the event definition and thus the importance of accessible observational data.

    We should be justifiably skeptical of contrarian claims that all or a majority of near-real-time attributions of an extreme event to climate change are politically-motivated black magic, especially when evidence given for same are based on cherry-picked papers. Even better than my cursory review of papers by this one author is reading the summary tables in Chapter 11 where examples of low confidence are effectively frequent as higher confidence attributions and projections.

  95. Willard says:

    > this kind of extreme weather event

    That ought to please Clive!

  96. ATTP sez …

    “sea level rise enhancing storm surge”

    That is an abjectly FALSE statement.

    SLR, to date, has only affected nuisance coastal flooding appreciatively. Those same nuisance flooding elevation numbers carry forwards into storm surges of 3-10 meters. Millimeter and centimeter numbers do not magically change into multi-meter numbers unless you believe in magic! :/

    Oh and don’t ever confuse FoO numbers with the underlying monotonic SLR. As SLR does not concern itself with frequency of occurrence (FoO).

  97. doctorbunsenhoneydew says:

    “That is an abjectly FALSE statement.” odd then that it is not difficult to find journal papers that suggest otherwise.

    Sea levels are currently rising at about 3cm per decade and accelerating (see paper mentioned above). 3cm is 1% of 3m, over the course of a century (the scale on which we need to think about climate change) that would be at least 10%. That seems to me to be completely consistent with “sea level rise enhancing storm surge” [emhpasis mine].

    I suspect that part of the issue is that SLR will make sea defences (e.g. Thames barrier) designed to protect against a 1-in-N year storm surge event fail to provide that level of protection, especially when changes in the hydrology cycle may be an issue as well.

  98. Chubbs says:

    Link below is a good, relatively short, primer on extreme event attribution.

    “The emerging field of extreme-event attribution (EEA) seeks to answer the question: “Has climate change influenced the frequency, likelihood, and/or severity of individual extreme events?” Methodological advances over the past 15 years have transformed what was once an unanswerable hypothetical into a tractable scientific question”

    https://www.cell.com/one-earth/fulltext/S2590-3322(20)30247-5

  99. Ben McMillan says:

    As usual, Tamino has useful stuff on sea level rise:

    https://tamino.wordpress.com/2021/11/29/sea-level-rising-fast/

    Some of the exposed locations have local sea level rise significantly faster than global averages (e.g. due to subsidence). This doesn’t help much with the erosion of barrier islands that normally would help to protect the coastline during extreme events.

  100. My understanding, which may be wrong, is that you don’t need a lot of sea level rise to potentially have a big impact on storm surge. Maybe I’m using the wrong terminology, but if you have some protection against storm surge then you just need to exceed that level to potentially have a lot of impact.

  101. Chubbs says:

    The paper I linked above has a graphic showing the impact of sea level rise on the hurricane Sandy surge in NYC.

  102. I don’t think we need to worry much about SLR and storm surge as long as the Thwaite holds steady as it has through the warming so far.

  103. Pingback: How to Do Things with Claims | …and Then There's Physics

  104. Brandon Gates says:

    Mike, not sure if you’re being sarcastic, but Thwaites has been making headlines recently: Scientists warn Antarctic glacier could collapse, raise sea levels at least a foot.

    Scientists are warning an Antarctic glacier could collapse and cause sea levels to raise at least a foot in the next decade.

    The scientists said Monday at the American Geophysical Union the Thwaites glacier, which is the size of Florida, could collapse in the next three to five years.

    The ice shelf holding the glacier in place is quickly developing cracks due to the warm water hitting it, according to the scientists.

    Popular media accounts I’ve seen don’t mention that breakup of the glacier itself will take somewhat longer, a prediction which is itself deeply uncertain. Science does a little better:

    With several seasons left in the ITGC campaign, researchers will be able to watch as the shelf disintegrates—and they’ll have to retrieve their instruments before the ice cracks, with several fissures only 3 kilometers away from their former campsite. The ice shelf failure will be a warning that Thwaites, and the rest of the West Antarctic Ice Sheet, could begin to see significant losses within decades, especially if carbon emissions don’t start to come down, Pettit says. “We’ll start to see some of that before I leave this Earth.”

    So we may have several decades before the world ends, unless the thing has already passed a tipping point.

  105. You are almost there Chubbs.

    The riddle is this: How can SLR have a return period? Short answer? It can’t! SLR is monotonic and does not ever have a return period on human timescales.

    Every time I see one of those frequency of occurrence graphs (FoO) I go … what a bunch of ignorant climate scientists, as you never mix a periodic function with an abjectly non-periodic function and then call the final product a return period or frequency of occurrence graph.

    The ENTIRE graph has been shifted uniformly by ~0.5 meters. I call it one of climate sciences d’oh moments. The storm surge proper has not changed one iota.

    I have now pointed this basic flaw several times at this blog. I will continue to do so until such time as [Snip. Please chill. -W]

  106. exactly right. lots of buzz about Thwaites breakup, with “some scientists saying the Thwaites glacier, which is the size of Florida, could collapse in the next three to five years.” My guess is that these “scientists” are exaggerating the rate of collapse and it will probably take decades. Plus, Florida is not all that big. So, yeah… as you say… several decades before the world ends.

    And, I live about 100 miles from the coast line, so rising sea level or storm surge won’t mean that much to me even if it did happen in just a few years.

    As Everett notes, maybe a bit more nuisance coastal flooding.

    Yeah, maybe a little bit of sarcasm, but no whining!

    Cheers

  107. Brandon Gates says:

    Mike, I’m on your wavelength now. Upon review the first article I quoted seems to have mistook collapse of the ice sheet holding Thwaites back with collapse of the glacier itself. Expect addition of this episode to examples of #butMedia, #butAlarmism and #butTenYears contrarian concern trolling.

  108. mrkenfabian says:

    We should expect low lying places already at risk of occasional tidal inundation to be most affected – and people with limited ability to build better or move elsewhere to be most impacted within relevant time frames. For more affluent nations it probably impacts costs rather than existence – insurance, construction, borrowing, comparative (but not necessarily absolute) property prices – and quite narrowly; it will be site specific, with institutions like insurance companies and building regulators doing their homework and having a good idea of specific risks for each specific site. Which may be low or entirely absent within the lifetime of buildings for a specific site that may still be at absolute risk later.

    None of this seems difficult to understand but the “but coastal property prices are booming, people must not really believe in global warming” arguments are very commonplace – short term property prices being a poor proxy for long term global climate change.

  109. Brandon Gates says:

    Everett,

    > Millimeter and centimeter numbers do not magically change into multi-meter numbers unless you believe in magic!

    I don’t believe in magic but I do believe in geometry and erosion:

    Willis said sea level rise accelerates and exacerbates the natural coastal erosion that’s continually taking place in locations like Ocean Isle Beach. “Sea level rise literally eats away at a coastline, making it more vulnerable to floods,” he said. “While floods happen naturally, it’s sea level rise that causes them to gradually begin topping natural barriers—like wetlands, mangrove forests and saltwater marshes—and even human-built barriers that typically protect coastal areas around the world from flooding. All of a sudden, that flood that you used to be protected from is now wiping you out.”

    It’s the same story all over the world. You may not be able to eyeball sea level rise at your local beach, but its effects are being felt in many ways. Willis says a good rule of thumb is that every inch of sea level rise results in the loss of about 2.5 meters (100 inches) of beach, though recent studies suggest beach losses around the globe could happen even faster.

    Emphasis in original.

    Multiply meters of beach by hundreds of thousands of kilometers of shoreline by the relatively high market value of that real estate, note that locally bursting valuation bubbles propagate destructive waves of their own, and it becomes easy to see that some nuisances are probably best avoided if at all possible.

  110. angech says:

    Thanks, appreciated.

  111. EFS,
    Are you suggesting that storm surge is always defined relative to current sea level?

  112. Brandon Gates says:

    AT, he’s equivocating on the meaning of the x-axis in Chubbs’ plot.

  113. Nathan says:

    There’s also the impact of rising seal levels on local aquifers, lifting the water table and priming the local area to flooding through greater saturation of the ground prior to the storm event. The higher water table also limits infiltration and delays surface flows draining to the sea.
    so it’s a compounding impact.

  114. doctorbunsenhoneydew says:

    I think EFS is missing the fact that the title of the graph is not “storm surge in New York City” but “storm surge flooding in New York City” [emphasis mine].

    “The riddle is this: How can SLR have a return period? Short answer? It can’t!”

    Of course, nobody is saying SLR has a return period, but that flooding due to storm surge (enhanced by SLR) has a return period.

    [Snip. Let’s try to play the ball here. -W]

  115. [Please try to reword your last comments in a more constructive manner, Everett. -W]

  116. I’m not entirely sure what the disagreement is, but this might be apt 😉

  117. ATTP,

    There is a real difference. Storm surge is always defined as an event based value using the then current RSL. This is always done weather the vertical datum it the Mariana Trench, the LGM or Mount Everest.

    You also appear to be unfamiliar with how FoO or return period plots are constructed and how wrong it is to simply lift the plot vertically. I drew my 1st one in 1976. We came upon this climate science trick of lifting the plot vertically in 2012. This then leads to a disproportionate change in the FoO or return period as the x-axis in nonlinear and always exaggerates the actual invariant return period due to storm surge proper.

    What Willard removed was all true too. I did not save those particular comments however.

  118. EFS,

    There is a real difference. Storm surge is always defined as an event based value using the then current RSL. This is always done weather the vertical datum it the Mariana Trench, the LGM or Mount Everest.

    Yes, I do get this. All I was suggesting is that – all else being equal – sea level rise will probably influence the impact of storm surge, even if – technically – it doesn’t change the quantitative measure of storm surge. It’s hard to see what’s objectionable about this.

    You also appear to be unfamiliar with how FoO or return period plots are constructed and how wrong it is to simply lift the plot vertically.

    Yes, I’ve no doubt this is true. I haven’t ever suggested otherwise.

    What Willard removed was all true too. I did not save those particular comments however.

    I don’t think the suggestion was that it wasn’t true. The request was to rephrase it in a way that was more constructive.

  119. doctorbunsenhoneydew says:

    “Are you suggesting that storm surge is always defined relative to current sea level?”

    I think storm surge is defined relative to the predicted tide (e.g. NOAA), and and sea levels rising increase the predicted level of the tide. However the graph is of flooding related to storm surge, which arguably isn’t (as it would presumably be land that is not normally underwater, even at high tide).

    I suspect climate change will contribute the the surge as well, by making the storm more vigorous, rather than by sea level rise, but that is irrelevant if the discussion is about damages caused by storm surge.

    My only view on the appropriate way to say things is to avoid insults and adopt some humility when disagreeing with a whole research community, as it makes it easier to see/acknowledge when you are the one that is in the wrong (but perhaps didn’t express that clearly).

  120. doctorbunsenhoneydew says:

    EFS: “You also appear to be unfamiliar with how FoO or return period plots are constructed and how wrong it is to simply lift the plot vertically. “

    If the storm surge level is independent of sea level and they combine additively, then it is not clear to me why the level of a 1-in-n year flood will not rise by 1m if sea levels rise by 1m.

  121. doctorbunsenhoneydew sez ,,,

    (1) NOAA does not have the coastal mission statement but USACE does.

    (2) Oh and look up epoch for NOAA is 19-years (to cover at least one full cycle of the Lumar nodal period of 19.6 years). There are any number of vertical datum one can use but MSL is usually updated every ~19 years. The current fixed verytcal datum for the US is NAVD88.

    (3) Just like WMC, I take no prisoners, ever.

  122. 18.6 years NOT 19.6 years (in the above)

  123. doctorbunsenhoneydew says:

    EFS, you have not answered my question. I am not talking about the change in return time of an n-meter flood. I am asking why the level of a flood of a given return time does not increase by 1 meter if sea levels rise by 1 meter.

  124. Design storm surge today = 10 meters
    Design water level today = Zero meters

    Design storm surge in 2121 = 10 Meters
    Design water level in 2121 = 1000 meters

    Long story short? Do not ever assume a stationary and ergodic and iid system in the presence of a known non-stationaty component. And a FoO is just that, its basic assumption is a stationary system. D’oh!!! :/

  125. doctorbunsenhoneydew says:

    You still have not answered my question. This is about physical flood levels, not designs.

  126. I have already discussed vertical datum. That is a non issue. All vertical datum are fixed.

    We also have the SLR curve, it is also fixed into a suitable probabilistic fashion. So in 100 years it is one meter and in 1000 years it is 100 meters.

    You already have your answer(s) so that there is never a need to discuss SLR in a FoO or return period format. Never. Ever. Period. Full stop. :/’

  127. EFS,
    Maybe I can try and phrase Dikran’s question in a different way. If the return period is independent of sea level rise, then if you consider a 1-in-n year storm surge event, does the height of that storm surge event – relative to a fixed level – increase by 1m if there is 1m of sea level rise?

  128. All designs are based about physical flood levels (real or assumed). Period. Full stop. :/

  129. Ah, so we have been there done that before. And yes, I did think so from the get go.

    When you know who get’s PO’ed it only leaves us to infinite regress. I have had it at this point. Sock puppet indeed.

    I have to stick to formal definitions. SLR = SLR with or without storm surge.

  130. doctorbunsenhoneydew says:

    “You already have your answer(s) so that there is never a need to discuss SLR in a FoO or return period format. ”

    This is obviously incorrect. If we are discussing the return period for a particular level of flooding in New York City, then the “vertical datum” is set by the level if of the land surface in NYC (as it is the depth of water above that level that is being recorded). If the sea level rises relative to the land surface, then a rise in sea level is obviously going to reduce the return time of an n-meter flood.

    I think the problem here is confusing the return time of a flood level with the return time of a storm surge level (I am assuming that the latter is essentially constant, for the sake of simplicity).

  131. doctorbunsenhoneydew says:

    “Sock puppet indeed.” I clearly stated who I am up-thread.

    You still haven’t answered my question, you won’t convince me you are right and the research community wrong by not answering my question, but I won’t ask it again.

  132. Also, let me go back to what I said. I said “sea level rise enhancing storm surge”. Maybe I should have said “sea level rise enhancing the impact of storm surge”. This seems a reasonable inference, even if storm surge is defined relative to sea level rise.

  133. So instead of talking about the poors and LULC, let us talk about attribution analyses.

    So, in the past are there cases where attribution analyses due to climate change go below 0%?
    So, in the present (and even more so in the far future) are there cases where attribution analyses due to climate change go above 100%?

    Oh and what is up with using two (or even three) significant digits for published attribution studies. I mean, come on already, one should never use excessive significant digits wherein the analyses inherently contain such large uncertainties (at least that is what I was taught in kiddiegarden).

  134. Willard says:

    Everett,

    You changed your name a few times already over the years, so you’re the last person who should complain about sock puppets. I trashed your comments because they were insulting. You can’t hide insults behind “but it’s all true.”

    Kindergarten teaches social cues, not mathematical tricks.

  135. Brandon Gates says:

    doctorbunsenhoneydew,

    > If the storm surge level is independent of sea level and they combine additively, then it is not clear to me why the level of a 1-in-n year flood will not rise by 1m if sea levels rise by 1m.

    It’s actually worse than you thought:

    Arns, et al. 2017, Sea-level rise induced amplification of coastal protection design heights:

    Here, we use hydrodynamic modelling and multivariate statistics to show that shallow coastal areas are extremely sensitive to changing non-linear interactions between individual components caused by SLR. As sea-level increases, the depth-limitation of waves relaxes, resulting in waves with larger periods, greater amplitudes, and higher run-up; moreover, depth and frictional changes affect tide, surge, and wave characteristics, altering the relative importance of other risk factors. Consequently, sea-level driven changes in wave characteristics, and to a lesser extent, tides, amplify the resulting design heights by an average of 48–56%, relative to design changes caused by SLR alone.

  136. Brandon Gates says:

    Everett,

    > This then leads to a disproportionate change in the FoO or return period as the x-axis in nonlinear and always exaggerates the actual invariant return period due to storm surge proper.

    The curves on Chubb’s log-linear plot are … not a line. Up to now you you have simply asserted that whatever function generates those curves is wrong without really explaining why, and critically, have not offered the right way to do it. You can be safely ignored until you do so, backed with citations.

    ***

    > So, in the past are there cases where attribution analyses due to climate change go below 0%? So, in the present (and even more so in the far future) are there cases where attribution analyses due to climate change go above 100%?

    How you do the legwork yourself, and tell us why it matters, instead of handing out homework assignments.

  137. angech says:

    …and Then There’s Physics says:
    I’m not entirely sure what the disagreement is, but this might be apt
    Lovely graph.
    perfect agreement.
    think I stand on both ends at once too often.

  138. Dave_Geologist says:

    Some workers use the term Storm Tide, not Storm Surge, to make the confluence of both explicit.

    Accounting for tropical cyclones more than doubles the global population exposed to low-probability coastal flooding

    Abstract
    Storm surges that occur along low-lying, densely populated coastlines can leave devastating societal, economical, and ecological impacts. To protect coastal communities from flooding, return periods of storm tides, defined as the combination of the surge and tide, must be accurately evaluated. Here we present storm tide return periods using a novel integration of two modelling techniques. For surges induced by extratropical cyclones, we use a 38-year time series based on the ERA5 climate reanalysis. For surges induced by tropical cyclones, we use synthetic tropical cyclones from the STORM dataset representing 10,000 years under current climate conditions. Tropical and extratropical cyclone surge levels are probabilistically combined with tidal levels, and return periods are computed empirically. We estimate that 78 million people are exposed to a 1 in 1000-year flood caused by extratropical cyclones, which more than doubles to 192 M people when taking tropical cyclones into account. Our results show that previous studies have underestimated the global exposure to low-probability coastal flooding by 31%.

    Whatever you call it, it ain’t getting any better.

    Methods
    General approach
    Storm tides are driven by the combined effect of storm surges and tides. To estimate the RPs of storm tides, we followed three main steps (Fig. 5). First, we separately simulated TC surge levels, ETC surge levels, and tidal levels. Second, at each output location, we stochastically combined TC and ETC surge levels with random tidal levels to obtain TC and ETC storm tide levels, respectively. Third, we calculated the exceedance probabilities for TC and ETC storm tides using Weibull’s plotting position formula and probabilistically combined the two to obtain storm tide RPs.

  139. I have been watching the King Tides in Puget Sound for many years and I can tell you that a high tide, low barometric pressure, a little bit of wind and rainfall on land adjacent to the Sound can create a significant amount of flooding under current conditions. Sea level rise is just going to be one more contributor to shoreline flooding and the costs are going to be significant. Many of us have been telling the City of Olympia that they need to do some serious planning around sea level rise, but it appears this might be a lesson learned the hard way. I like the name storm tide. Maybe that will help connect the dots on more of the variables that drive flooding.

    We have time to plan as long as the Thwaites holds up. We would get pushed a bit if the Thwaites collapsed, but that seems unlikely. Here is a pretty recent quote and news story about the Thwaites:

    “Scripps Institution of Oceanography scientist Jeffrey Severinghaus opens the video pointing to someone’s gradually rolling a large round boulder down a hill: Stop pushing a few moments, and the boulder may pause, may sit in place. But in time, the pushing gets to the point that the boulder sets apace on its own. Severinghaus calls that a “runaway positive feedback,” something to be avoided. Is that runaway prospect inevitable? he asks rhetorically. “We are possibly in a collapse right now,” he says. “but I would say it’s not very likely.”

    https://yaleclimateconnections.org/2020/11/can-shearing-of-thwaites-glacier-slow-or-stop-if-humans-control-greenhouse-gas-emissions/

    I realize the story is a year old, but I am guessing we have been working hard at cutting emissions in the year since that story was published because we are not a dumb species. We are very clever and know when and how to make essential changes.

    Happy holidays!

    Mike

  140. David B Benson says:

    smallbluemike writes “We are very clever …”
    To work with Nature as opposed to against, irrespective of how clever, I recommend reading
    “A Natural History of the Future” by biologist Rob Dunn, published recently by from Basic Books.

  141. gator says:

    EFS
    “Design storm surge today = 10 meters
    Design water level today = Zero meters

    Design storm surge in 2121 = 10 Meters
    Design water level in 2121 = 1000 meters”

    Is this essentially you saying SLR doesn’t matter for storm surge because people in the future will just build bigger walls?

  142. Pingback: Cumulative and (probably) irreversible | …and Then There's Physics

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