JC interview: hurricanes and global warming

by Judith Curry

My recent interview with David Whitehouse of the Global Warming Policy Foundation on Hurricanes Harvey and Irma and the link with global warming.

The video of the interview:

Transcript:

DW:  First of all – do we understand hurricanes?

JC:  We’re getting a whole lot better at predicting individual storms. This has really been a banner year for long range prediction, and detailed prediction for hurricane impacts. Models like ECMWF {European Centre for Medium-Range Weather Forecasts} and the NOAA models – they’re doing a good job. We understand the basics of how hurricanes form and we have a predicative capability using high resolution global and regional weather forecast models. We don’t understand rapid intensification. Like hurricane Harvey this year – it spun up very quickly, rapidly intensified, in less than 24 hours. We don’t know how to predict that much in advance. But in terms of track and overall intensity, rainfall impacts, we’re getting pretty good at being able to predict that. My company Climate Forecast Applications Network (CFAN) — hurricane forecasting is a big part of what we do, and we’ve have a really good year for our predictions.

DW: What do we know about, looking backward, in the past, what do we know about the rate of change of the intensity of hurricanes, or the frequency of occurrence.

JC:  We only have good satellite data back to maybe 1980. We have some satellite date going back to 1970. But it is of lesser quality. We don’t have long global records. But in the Atlantic, we have pretty good historical records, at least for the landfalling hurricanes. But not necessarily for the total number in the ocean basins. For the satellite record globally, there’s no trend in the numbers or overall accumulated cyclone energy. We have teased out a signal, of increasing percentage of category four and five hurricanes in two of the basins in the Atlantic and the North Indian Ocean. But trying to determine whether this is natural variability or human-caused — we just don’t have a long enough record to tease that out. There are hints of an increasing percentage of category four and five hurricanes, but we don’t have the knowledge or enough data to attribute that to humans versus natural variability.

DW: But some people have said that as a result of hurricane Harvey and Irma, that we live in a warmer world, the oceans are warmer, the sea level is higher, and this is going to make hurricanes more destructive. What do you think of that?

JC: Can they then tell me why we’ve had no major hurricanes strikes in the US for the twelve years preceding Hurricane Harvey? Sea surface temperature is only one ingredient for hurricane development and intensification, and it doesn’t seem to be absolute sea surface temperature, either. You can go back and there were really strong hurricanes in the nineteenth century for example, where surface temperatures were significantly cooler. And there were some horrendous hurricanes in the Atlantic in the early part of the twentieth century, when sea surface temperatures were noticeably cooler. It’s more relative sea surface temperatures and the overall dynamics of the atmosphere that are arguably the key ingredients – not just absolute sea surface temperature itself.

We now have a pretty good predictive capability of individual hurricanes. Our understanding of the climate dynamics of hurricanes is a different story. This is something that’s still a work in progress. There is a lot of debate in the scientific community about this, and we’re only now starting to see some high resolution global climate model simulations trying to sort out what we might see in the future.

There was a paper just published by a Japanese group: “Response of Tropical Cyclone Activity and Structure to Global Warming in a High-Resolution Global Nonhydrostatic Model” by Yohei Yamada et al. in the Journal of Climate. They ran the very high resolution Japanese climate model for the current conditions of perturbed warmer conditions, and they found a significant decrease in the number of hurricanes, but they found an increase in intensity, an increase in the horizontal size, which relates to storm surge among other things, and an increase in precipitation. I just glanced at it literally yesterday – I flagged it to read more carefully. But that may be the best study that I’ve seen of that kind. For the sake of argument, assume that is correct. What is the trade-off for 20% fewer hurricanes for a slight increase in overall intensity. In terms of overall damage. I don’t know what the trade-off is, so it might not be a net increase in actual damage if there’s fewer hurricanes. That’s the state of our understanding right now.

DW:  So, given the models — what the models say — What people might say will happen in the future, how long will it be before we are observationally able to compare what’s happening with the models?

JC: Kerry Emanuel has said that it will be mid-twenty-first century before we’d expect to see any climatological signal in the observations, because natural variability is so large. And weather roulette — sometimes crazy things happen, and then they don’t have anything to do with climate. By the time you have a long enough time — and this is assuming that we have some substantial warming over the next thirty years — if we do have substantial warming over the next thirty years, probably by 2050 we would start to be able to tease out a signal.

But looking at that period, the next 30 years, we’re probably looking at a shift in the Atlantic to the cool phase of the Atlantic multidecadal oscillation. In 1995, after a relatively quiet period in the Atlantic, we flipped to the warm phase of the Atlantic multidecadal oscillation, and that like really juiced-up the hurricanes. And so, at some time, probably in the order of ten years, we’ll see a flip to the cool phase again, and presumably much quieter situation in the Atlantic for hurricanes.

DW: So are those who point to Harvey and Irma as being climate change in action, are they mistaking weather for climate?

JC:  Oh yes, they’re mistaking weather for climate. Harvey and Irma were big storms, but they’re don’t really rank up there with the worst that we’ve seen in the last decade or the last century. There were some horrendous ones earlier in the twentieth century. Including really bad ones that hit Houston and Florida. These aren’t particularly unusual as far as hurricanes go. They’re top-20 kind of storms, but they’re not record-breaking in any way, apart from the overall rainfall from Harvey, which was really more of a fluke from the weather situation that allowed the storm to sit in one place for a very long time. There’s nothing unusual about this hurricane season or about Harvey and Irma. The US had incredibly lucky run of 12 years without a major landfall during this active phase of the hurricane cycle. We were incredibly lucky. Our luck is now broken. But it’s totally expected.

DW: Can I ask you finally about event attribution? Because there are people saying that hurricane Harvey wouldn’t have happened without climate change., there are people say that the heatwave in Russia was made ten times more likely because of climate change, or the drought in America was made X-times more likely. Can I ask you what you think about scientists who try and attribute individual events to climate change in a direct way?

JC:  The group that I like is really the NOAA group in Boulder, who looks at the historical record and tries to see is there anything unusual. Looking back a hundred years, is this exceptional in any way? If it is not particularly exceptional, given the record we have for the last hundred years, then it’s hard to argue that it is human caused climate change. Occasionally we do get genuinely record-breaking events. Then we need to trace back to what was the atmospheric dynamics, and whatever that contributed to that event and you need to tease it out. It needs a lot of detective work.

There is this new movement to use climate model simulations of natural variability, and then with natural variation plus human-caused global warming, but these same climate models they’re using can’t resolve these extreme events. They can’t produce hurricanes, they don’t have the right temperature distributions to provide heatwaves. It is just Voodoo statistics that they’re playing with these models — which do not have the capability to predict these extreme events in the current climate or an unperturbed climate anyways. I’m not very impressed with the model-based attribution arguments. Carefully-constructed diagnostic analysis and comparisons with historical events — to me those are of much more value.

DW: So we have to wait and see?

JC: We just have to wait and see. In the IPCC Fifth Assessment Report introduced this concept of time of emergence – when you would expect to see the statistics of the future climate breakout from the variability statistics of current climate, then they come up with something like 2050. We are not able to see a signal where the statistics would be genuinely different from what we have now. We’re not able to see that.

I don’t quite understand why it is important to attribute these extreme events other than to hysterically advocate reducing fossil fuels. In terms of trying to figure out how to manage extreme events and reduce our vulnerability, what’s causing it is almost a secondary concern. We’re not preparing for the events we have now, or the events we’ve seen in the twentieth century, let alone for the events that we might see in the latter part of the 21st century. If we have enough money for that extra resilience – wow, that would be great to prepare for even bigger events than we’ve seen. But adapting and preparing for the ones we’re seeing now would be a big step in the right direction to reducing our vulnerability to what we might be facing in the future.

Thinking that reducing fossil fuels is going to help with extreme events on the timescale of the 21st century is a pipe dream. Even if you believe the climate models, and we are able to drastically reduce fossil fuel emissions by 2050, we’re going to see miniscule impacts on the climate and the weather by the end of the 21st century. Any benefits would be realised in the 22nd and 23rd centuries. If we think we have enough wisdom and knowledge to what might happen in the 22nd and 23rd Century — personally I’d rather see us deal with here and now, and maybe focus on what we might be facing out to 2050. That seems a more practical and realistic goal, for what we should be trying to do. That’s my opinion.

Acknowledgement:  Thanks to Larry Kummer for the transcription and some annotations.

 

124 responses to “JC interview: hurricanes and global warming

  1. Dr. Curry,

    Recently, I evaluated some simple statistics from the hurdat data.
    I examined the path of intensification from formation to peak wind speed.
    I was interested to find that in both the Atlantic, but especially in the Eastern Pacific, the majority of tropical cyclones intensify even as the SST of the central point decreases. This is spatial, not temporal, but what do you think this indicates wrt warming and TCs?

    • I am not Dr. Curry, but we do have the same initials.

      There has been a lot of emphasis on water temperatures and hurricanes lately, likely because of the attempt to attribute ‘bad’ storms to human CO2 emissions and warming. There is the assumption that if the water is warmer, the storms will be worse. But the water in most tropical regions is warm enough to support major hurricanes through much of the tropical cyclone season. yet major hurricanes still make up a small minority of all storms.

      As Dr. Curry pointed out, the historical record has a lot of hurricanes just as bad or worse than the ones we had this year, when we believe the water temperatures were cooler.

      Obviously, once the water is warm enough. other factors are much more important in determining tropical cyclone intensity. These factors are in the atmosphere. I believe the answer is largely related to your moniker; turbulent Eddie, or more precisely, a lack of turbulence. Tropical cyclones really hate any kind of shear or turbulence that they are not responsible for. They are surprisingly fragile compared to other large scale atmospheric weather systems, and they are very much allergic to dry air intrusion from any direct at any level.

      The climatological peak of the Atlantic Hurricane Season is September 10th, not because that is when the water temperature is warmest, but that is when the tropical atmosphere, on average, is most conducive for tropical cyclones.

  2. “Abrupt climate changes were especially common when the climate system was being forced to change most rapidly. Thus, greenhouse warming and other human alterations of the earth system may increase the possibility of large, abrupt, and unwelcome regional or global climatic events. The abrupt changes of the past are not fully explained yet, and climate models typically underestimate the size, speed, and extent of those changes. Hence, future abrupt changes cannot be predicted with confidence, and climate surprises are to be expected.” https://www.nap.edu/read/10136/chapter/2

    Unless you grind out the answer they want – as Curry has above – you are benched. Skeptics politicians want one thing from climate science – compliant voices.

    • On the other hand it may decrease the near-term probability of the Holocene Interglacial beginning its long descent into 100,000 years of glaciers everywhere north of the 45th parallel.

      Personally I’d rather Arctic Sea Ice disappear than New York City disappear underneath a glacier. It’s a close call though.

      • Do you think you get to make that choice?

      • I think we are on the verge of descent into the next glacial stage (although maybe not noticeable in the next several centuries). Revisit the Ewing and Donn model. I wrote an article updating that model with newer information on glacial stages and Milanković cycles a couple of years ago: http://kennethpiper.com/global-warming-next-glacial-stage/

      • In rewriting my previous comment that at first failed to post, I neglected to mention that in the Ewing and Donn model, an open-ocean Arctic and glaciation of New York City go hand-in-hand. That is, open water is a necessary precursor of continental glaciation around the perimeter of the Arctic Ocean. There may be ways to engineer our way to a permanently frozen Arctic Ocean (in a human, not geologic time scale) and prevent future glacial cycles, but I wouldn’t want to go there. Fortunately, I won’t have to.

  3. We’re not preparing for the events we have now, or the events we’ve seen in the twentieth century, let alone for the events that we might see in the latter part of the 21st century. If we have enough money for that extra resilience – wow, that would be great to prepare for even bigger events than we’ve seen. But adapting and preparing for the ones we’re seeing now would be a big step in the right direction to reducing our vulnerability to what we might be facing in the future.

    I wonder how often that has to be said.

    • I wonder what it means. What specific new measures are proposed? Are we talking about new government authorities over people’s lives in the name of resilience? There is no way to prevent hurricanes from causing damage. Perhaps we are properly resilient now.

      • The US govt subsidizes hurricane and flood insurance rates in at-risk areas. Just remove the subsidies and do NOT assist in re-building. Let the owners take the risk, not the taxpayers, and a lot of development on the coast would shrink.

  4. Loved your interview at the time with GWPF. Voodoo statistics is a new favorite term, because it is so apt–reminiscent of Feynman’s Cargo Cult commencment address to CalTech.

  5. And we’re not done because Nate is on its way probably towards New Orleans.
    Some records already this year.
    First season with two major hurricane landfalls in the US.
    Harvey produced record rainfall amounts (near 5 feet in places).
    Irma stayed at cat 5 longer than any previous Atlantic hurricane and ranks among the top few in strength ever globally.
    Maria had one of the deepest central pressures seen in the Atlantic.

    Climate change means more of this, not less, as time goes by. Resilience has to account for a frequency change. Insurance and budgets need to be ready for more of these seasons. Planning and rebuilding in prone areas need special considerations of cost-benefit. If the return period is decreasing, that figures directly into the economics of many coastal decisions.

    • First season since 2005 with two major US landfalls. Irma ranks #7 in intensity (behind several storms from about 100 years ago).

      • (jimmie, ya din’t read da transcrip… ☺)

      • 2005 had no cat 4’s while 2017 has had 2, which has not happened before. Older storms may appear worse only because of infrastructure and warning deficiencies, so that is all anecdotal. Irma is in a similar league with Haiyan (2013) for which they got close to meriting a sixth category. Other storms have not been compared with Haiyan. It does no one any good to downplay prospects for more of these in the future. Warmer waters, higher sea-levels, longer seasons, new areas. It all adds up and is going in one direction. Studies are showing major cat 4 and 5 storms becoming more frequent, and this is no surprise.

      • According to yimmy, the climate changed this year. The sudden onslaught of hurricanes proves it. Everything in the past is anecdotal. Our resident gadfly is predicting even more hurricanes next year. And even more in the year after…yatta yatta yatta. He has been waiting for this opportunity for a long time.

      • (gude tings come to dem dat wait)…

      • Don, the skeptics are hunkered down. WUWT has had probably 20 articles by now on how this is not a sign of climate change. You should read them for a more friendly view if you can’t take the real world.

    • Jim D,

      Climate change means more of this, not less, as time goes by.

      An unsupported assertion. Please provide paleo-evidence to support your belief that there were more frequent and more intense hurricanes when the planet was 2C, 3C, 4C, 5C, 6C, 7C, … up to 13C warmer than now.

      Watch Jim D dodge and weave and avoid the question.

      • Supported by physics and what we know about warmer oceans versus colder oceans just by observations of where the stronger tropical cyclones preferentially form.

      • Typical dodge. Doesn’t address the question I asked. Statement of belief. Zero relevant. valid evidence.

      • If you don’t believe warmer waters support stronger hurricanes, that is your problem, not mine.

      • JimD not supported by physics

      • warmer waters support stronger hurricanes

        That’s not what the physics indicate.

        Here’s the actual formula for the maximum potential intensity of tropical cyclones from wiki.

        As you can see, potential intensity is not a function of sea surface temperature, but rather is a function of the difference of the outflow temperature from the SST divided by the outflow temperature.

        So, warmer waters (Ts) support stronger tropical cyclones, only if the outflow temperature (To) is not warmer also. But remember, tropical cyclones are “warm core systems” to begin with. The very process of the copious latent heat release warms the atmosphere of a hurricane aloft. So To tends to vary with Ts. But also consider that global warming is supposed to create a big hot spot of warming from around 60S to 60N. This reduces the CAPE ( convective available potential energy ) in this equivalent formulation. So conceivably, global warming could suppress cyclone intensity.

        Here’s another thing to consider. Most Eastern Pacific hurricanes intensify as they are moving over progressively cooler waters!

      • TE, that’s what the observations indicate and physics explains. What planet are you on? The strongest hurricanes have had long paths over warm water which has been a necessary condition.

      • TE, that’s what the observations indicate and physics explains. What planet are you on? The strongest hurricanes have had long paths over warm water which has been a necessary condition.

        No, you aren’t reading the equation, nor examining the data.

        In fact, consider the term: (Ts-To) / To
        If Ts and To each rise by 1 degree, (Ts-To) / To actually decreases slightly!

        Also, you’re not looking at Figure 4d. above.

        Hurricanes, especially in the Eastern Pacific, intensify while the SSTs decrease.

        See Figure 6c. and 3c.

        Now, that’s using monthly means of SST, so there could be some bias due to the mixing from TCs. Time permitting, I intend to reproduce using daily data.

      • TE, you are not looking out the window. In the real world the strongest hurricanes occur over the warmest water, and if your equation can’t show that, there is something wrong with it. Look at when the hurricane season occurs. Look where hurricanes occur. It is the SST that is the clue.

      • JimD you’re not getting
        it. Try harder

      • Explain

      • “But also consider that global warming is supposed to create a big hot spot of warming from around 60S to 60N. This reduces the CAPE ( convective available potential energy ) in this equivalent formulation. So conceivably, global warming could suppress cyclone intensity.”

        Not anything like enough to matter it doesn’t.

        SST warming will far overcome a top of Trop warming.
        Study the CC relation.

        I’ll help you….
        Here is the UKMO Tephigram form …

        Take a 30C SALR from 1000mb up to 150mb … it arrives there at at -49C

        Now take a 32C SALR FROM 1000mb to 150mb … it arrives there at -42C
        A 2C delta at surface becomes 7C at 45,000ft.

        Release/transport of latent heat from the ocean via convection. Tops in a TS would be beyond 150mb and so the contrast with the environmental LR even greater.
        In fact NASA have reported that cloud top temps in the eye or Irma reached -83C, corresponding to around 90mb or near 90,000ft.
        Yes, the LH energy burst the Cb tops through the Tropopause into the Stratosphere.

        What delta did the CC relation create there?
        In short, no the empirical physics within NWP models is not wrong.
        And the basic thermodynamic all diagram I’m meteorology that I worked with every day of my professional life is correct.

      • TE:
        Also….
        “As you can see, potential intensity is not a function of sea surface temperature, but rather is a function of the difference of the outflow temperature from the SST divided by the outflow temperature.”

        But T(out) IS a function of T(in) as a direct consequence of the CC (Clausius Claperon) relation anyway …. and as it says and I show above, if T in increases by (say) 2 C then T out will increase by 7C at 150mb.

        “So, warmer waters (Ts) support stronger tropical cyclones, onlyif the outflow temperature (To) is not warmer also..”

        TE – no, no ,no … if SSTs are warmer then the fact is that outflow aloft will be warmer also ( by around 3.5:1 in my above example). The two are tied together.
        And what you are saying is the direct opposite of empirical science and, as Jim says, observation ( not to mention common-sense).
        “So To tends to vary with Ts. ”
        Only in the same sense it does, i.e. Warmer SSTs then warmer To.

      • Tony Banton:

        “TE – no, no ,no … if SSTs are warmer then the fact is that outflow aloft will be warmer also ( by around 3.5:1 in my above example). The two are tied together.”

        Perhaps you glossed over where I wrote above:

        The very process of the copious latent heat release warms the atmosphere of a hurricane aloft. So To tends to vary with Ts.

        You are somewhat conflating changes of a parcel (warming with realized latent heat of condensation), with environmental lapse rate trend of the Hot Spot, modeled by GCMS.

        However, BOTH tend to imply weaker hurricanes!

        The Hot Spot means upper tropospheric temperatures are supposed to warm twice as much as SSTs – this is stabilizing.

        Also consider your parcel analysis above:
        To increases more than Ts,

        in terms of the relevant term of the equation of intensity:

        (Ts – To) / To

        What happens to intensity if To increases more than Ts?

      • “In the real world the strongest hurricanes occur over the warmest water, and if your equation can’t show that, there is something wrong with it.”

        You still haven’t read the reference. The equation isn’t mine, but is from none other than Kerry Emanuel, the advocate of increasing TC strength.

        Consider Figures 3a. and 3b. above. The peak temperature of both formation and peak wind speed is the same 28.5C. It is the same for storms which peaked at Tropical Storm, Hurricane, and Major Hurricane. If SST were that significant, one would expect a greater percentage of Major Hurricanes to peak at a higher temperature. But they don’t. Major Hurricanes peak at the same temperature that Minor Hurricanes and Tropical Storms do.

      • “”You are somewhat conflating changes of a parcel (warming with realized latent heat of condensation), with environmental lapse rate trend of the Hot Spot, modeled by GCMS.”

        No I’m not, as the parcel temp at that pressure level is what takes the parcel aloft of that point (the supposed HS).
        So, as I said SST rise would overcome the HS any inhibition of rising saturated parcel over tropical waters.

        “The Hot Spot means upper tropospheric temperatures are supposed to warm twice as much as SSTs …..”

        However it would need to warm more than 3 times faster (in my example).

        “However, BOTH tend to imply weaker hurricanes!”

        No, as I’ve explained and as empirical science and observation show.

        “Also consider your parcel analysis above:
        To increases more than Ts,

        in terms of the relevant term of the equation of intensity:

        (Ts – To) / To

        What happens to intensity if To increases more than Ts?”

        TE: you have omitted an important part of the equation …. the multiplication of Delta(k).

        Look at your Wiki quote page….
        https://en.m.wikipedia.org/wiki/Tropical_cyclone

        As the storm passes over warmer water then the enthalpy diff between the adjacent air and that in the boundary layer increases, so increasing the multiplyer Delta(k).

        Your bit of the equation relates to Carnot efficiency, which would logically fall with greater internal friction as wind speeds at all levels increase with strength. So yes, efficiency falls but it gains strength. Sat air at 35C has 130 J/Kg enthalpy and at 30C has 99.
        http://www.engineeringtoolbox.com/moist-air-properties-d_1256.html

      • TE, your assumption is that the outflow somehow stays at the same height as the SST warms. It actually gets higher and therefore must be colder, regardless of any lapse rate change, because higher lifted air is always colder. The tropopause height is rather controlled by the SST because that is how high surface-based convection can reach, and with warmer SSTs the surface air can get higher just from its increased buoyancy that Tony Banton is trying to explain to you. So To decreases as Ts increases and it is worse than you thought from your equation.

      • “TE, your assumption is that the outflow somehow stays at the same height as the SST warms. It actually gets higher and therefore must be colder, regardless of any lapse rate change, because higher lifted air is always colder.”

        If you go to the NASA GISS site, you can verify for yourself that the the modeled ( but not verified ) effect of a higher tropopause is somewhere between 100 and 300 m. That’s about 1/3 to 1 degree C of moist adiabtic difference. That’s physically plausible, but not enough to overcome the hot spot, which of course, hasn’t happened during the satellite era, but is modeled.

      • TE, you can’t conflate mean tropopause with actual storms. Stronger storms have colder outflows, and stronger storms exist above warmer SSTs. This outflow is seen as high clouds on satellite images. The lapse rate feedback is nowhere near enough to counter the raised outflow level, otherwise you would favor hurricanes more in the Arctic, if you think it through. Furthermore you would not be able to understand why stronger storms show up with colder tops on satellite images. The mean tropopause might rise in the future too, but that is not useful when looking at individual storms. Also, warmer waters support stronger hurricanes, observably.

      • Clarifying My …
        “….if SSTs are warmer then the fact is that outflow aloft will be warmer also ( by around 3.5:1 in my above example). The two are tied together.”

        By ‘warmer’, I mean that at a given pressure level. The fact that it is warmer at that level, means that it is more bouyant and therefore has greater CAPE, such that it can reach higher levels and break into the Stratosphere (as do Large Cb’s in the Stats, that give rise to tornados).
        Hence the NASA observation of cloud tops at -83C above IRMA at it’s strongest.

        TE: I don’t know what you’re saying here ….
        “That’s about 1/3 to 1 degree C of moist adiabtic difference. That’s physically plausible, but not enough to overcome the hot spot, which of course, hasn’t happened during the satellite era, but is modeled.”

        But look for yourself on my posted Tephigram form.
        Like I said the modeled HS would not stop convection from rising SSTs.

      • “Try harder”

        How about you try.
        Like with some science.
        TE: hasn’t done it – how about you try?
        Hand-waving sky-dragon slaying doesn’t do it my friend.

      • Below is a recent sounding from the airport in Barbados.
        The original sounding is in blue.
        Various ‘what-if’ soundings are in red.
        Figures:
        a.) what if warmed as if the HotSpot occurred but Td remains the same
        b.) what if warmed as if the HotSpot occurred but Td increases per RH
        c.) what if warmed same as sat. era obs, Td remains the same
        d.) what if warmed same as sat. era obs, but Td increases per RH

        Warming, but not humidifying decreases the Convective Available Potential Energy(CAPE).

        Warming, and humidifying increases CAPE.

        Warming, and warming with humidifying by amounts commensurate with the satellite era warming don’t change CAPE very much.

        Warming and also humidifying by some amount between constant absolute humidity and constant relative humidity, a physical possibility, still results in zero change of CAPE.

        Of course, this represents just a what – if. Changes that occur to an actual hurricane profile remain elusive ( anyone got a good sounding from near a hurricane eyewall? ).

    • “First season with two major hurricane landfalls in the US.”??
      OK, it’s only Wikipedia, but “In the 1893 season, two hurricanes each caused over 1,000 deaths.”.
      https://en.wikipedia.org/wiki/List_of_United_States_hurricanes
      Cat 3, Georgia & S Carolina, Aug. Cat 4, Louisiana (& S Carolina cat 3), Oct.

      Bear in mind that some years ago Klotzbach and Gray pointed out that US landfall hurricanes were more strongly asociated with global cooling than with global warming:
      https://i0.wp.com/www.powerlineblog.com/ed-assets/2011/10/Hurricanes0045382.jpg?resize=600%2C467&ssl=1
      Maybe we have now entered a new global cooling period?

      • Katrina was only a 3 and caused 1000 deaths. It depends on circumstances. However, I think there are efforts by skeptics to dismiss that there have been two cat 4 landfalls this year as not being related to the warmer oceans. Good luck with that.

    • Harvey event rain total set a new record for lower 48 states. Intensity wasn’t close, that belongs to Claudette in 1979…also in SE Texas. Forty three inches in 24 hours, it remains the US record for 24 hour rainfall.

    • Jim, there are no reliable statistics before the satellite era for “length of time a storm was a cat4.” There are no reliable statistics except for storms that made landfall. I would doubt instrumental readings anyway from the 19th or early 20th century. So we don’t know reliably much about peak wind speeds even at landfall.

      • Yes, and this dashes the hopes of skeptics who say with some certainty that we have seen all this before and try to dismiss it on that basis. There is also a difference between large storms every 50 years, and large ones every ten years. This is a subtlety that many miss.

      • Well, I think some skeptics like Muller have looked at land falling hurricanes and have seen no change. Looking at ACE though requires a lot of modeling.

      • Jim D, So how do you compare current seasons with historical seasons before satellites and flying Doppler radars? It is impossible to say what those instruments would have found if they existed before the 1970’s, but we can reasonably figure out what we might have observed this year if we only had the same technology that existed in the pre-Doppler/pre-satellite decades. This would primarily be ground based wind and pressure readings.

        When we do that, the intensity of this year goes significantly lower. IN fact, most of the major hurricanes making landfall this Century would not show up as major hurricanes at landfall, based on the old sampling methods.
        The only rational conclusion is that the past was significantly under sampled compared to today. The past was worse than we expected.

        As a climate crisis skeptic, I am not dismissing the severity of the storms this year, but even the under-sampled records of the past show that this year was very much in the sphere of natural climate variability. In other words, we have seen this before and I say that with certainty. It is all in the records, even though they are undersampled.

      • The skeptics have dismissed the scientific part that warmer surface temperature permit stronger storms to occur. Even a degree or two makes a large difference to what kind of storm can be supported.

    • Just not seeing your reasoning.

    • The ‘skeptics’ are going to be occupying an increasingly tiny islet as reality overwhelms them.

      Even satellite data they’ve been championing gives us a new monthly record…without El Nino.

      http://www.drroyspencer.com/2017/10/uah-global-temperature-update-for-september-2017-0-54-deg-c/

      The Version 6.0 global average lower tropospheric temperature (LT) anomaly for September, 2017 was +0.54 deg. C, up from the August, 2017 value of +0.41 deg.

      • Ahhh….lighthouse. I find it amusing that you try to dismiss your opponents by selecting the temperature of one month, when your opponents have a 30 year record of temperatures warming about half to one third of what the models projected.

        A record warm September says nothing about why it was record warmth. We have probably been regularly setting record warm months for the last 250 years, when compared to the Little Ice Age. Humans have not had any responsibility for the first 200 of those years. How much are we responsible for now? That is impossible to say.

        On the other hand, the Pause alone falsifies the AGW Theory as it is currently written. Since the current theory does not recognize natural climate variability in the form of natural ocean and atmospheric cycles, cosmic rays and who knows what else, a pause in warming for 15 years while CO2 continued to climb unabated, would be impossible; yet it happened. Theory falsified. Climate sensitivity to CO2 in the theory is too high, and the theory needs an overhaul.

        That overhaul would result in the calling off the crisis, which would be true to the science and a great relief for most of humanity, but not those in academia, the media and politicians/bureaucrats, so science will be denied for as long as these groups can deny it, and perpetuate the idea of a crisis for their benefit. This is not a conspiracy. It is a paradigm. And those in the paradigm probably tell themselves they are doing the right thing, even as they incrementally go against their own conscious ‘for the cause’. This should not be hard to believe. Human history is little more than this very process repeating over and over again. It would be unusual if it was not happening.

      • The reason the 30-year temperature shows no pause is that the previous 15 years had a warming rate of 0.3 C per decade. The 15-year temperature is all over the place, but the 30-year temperature has risen steadily at nearly 0.2 C per decade since about 1980. There is a reason climate needs 30 years to define it. This goes for its trends too.

  6. Hurricane season peaks in early september. Do we similarly know when SSTs peak?

  7. Judith,

    I share your opinion on this:

    I don’t quite understand why it is important to attribute these extreme events other than to hysterically advocate reducing fossil fuels.

    Thinking that reducing fossil fuels is going to help with extreme events on the timescale of the 21st century is a pipe dream. Even if you believe the climate models, and we are able to drastically reduce fossil fuel emissions by 2050, we’re going to see miniscule impacts on the climate and the weather by the end of the 21st century.

  8. ”Throughout history,” Dr. Philip Stott observed back in August 2008 (“More On Cognitive Dissonance — The End Of The World Is/Is Not Nigh!”), “many competing cults have attempted to predict dire catastrophes for the Earth.” Stott asks, “What happens when the predictions fail?”

  9. Jim D writes :”If you don’t believe warmer waters support stronger hurricanes, that is your problem, not mine.”

    Did you even bother to read J.C.’s take on this?

    Q:But some people have said that as a result of hurricane Harvey and Irma, that we live in a warmer world, the oceans are warmer, the sea level is higher, and this is going to make hurricanes more destructive. What do you think of that?

    A: Can they then tell me why we’ve had no major hurricanes strikes in the US for the twelve years preceding Hurricane Harvey? Sea surface temperature is only one ingredient for hurricane development and intensification, and it doesn’t seem to be absolute sea surface temperature, either. You can go back and there were really strong hurricanes in the nineteenth century for example, where surface temperatures were significantly cooler. And there were some horrendous hurricanes in the Atlantic in the early part of the twentieth century, when sea surface temperatures were noticeably cooler. It’s more relative sea surface temperatures and the overall dynamics of the atmosphere that are arguably the key ingredients – not just absolute sea surface temperature itself.

    • How do we guess the strength or sea surface temperatures for hurricanes 100 years ago? This is just guesswork and anecdotes. Warmer waters make conditions more favorable for stronger hurricanes and this is known as long as we have reliable observations to match these together. It is a tricky fact for skeptics to deal with, and Judith’s attempt was not convincing, relying as it does on no observed quantitative support. As for no big hurricanes in recent years, that is conflating weather with climate. Warmer water is a necessary but not sufficient conditions for strong hurricanes. On average, the ones you get would be stronger than if the water was 1 C cooler.

      • The trend is her pet hiatuses go poof, and then it’s a retreat to the negative phase of the AMO will eventually arrive. Says who? Why? With ACO2 above 400 ppm, what will cause the negative phase of the AMO to come back? What will the negative phase of the AMO look like? How does she know it has not already happened? It’s analysis by charts.

      • Jim D
        “How do we guess the strength or sea surface temperatures for hurricanes 100 years ago”

        Great comment.
        Can I break it out every time you use or misuse a Paleo reference in future?
        FYI the word is estimate, not guess in a scientific discussion, as in having some substance to it.
        So have people estimated the strength of hurricanes a hundred years ago, Jim D?
        Yes.
        Did they take the SST back then?
        Yes.
        Random quote
        “The researchers compared ocean-temperature data collected in the 1870s by the Challenger vessel with modern data collected by the Argo project,”

      • For paleo we have evidence of widespread high CO2 levels when it was globally warm. For individual hurricanes we have no clue what their SST was where they tracked, and there is no paleo data to help with that either. It’s a weather/climate difference. Pointwise history is a lot harder than global history, but you knew that.

      • Jim D
        “Warmer waters make conditions more favorable for stronger hurricanes and this is known as long as we have reliable observations to match these together”

        Chris Mooney . As one has to endlessly repeat, no individual storm is causally attributable to a changing climate.
        Brad Plumer
        global warming may lead to stronger hurricanes, although this gets complicated, since climate change can also affect wind shear that suppresses hurricanes.)
        As climatologist Katharine Hayhoe points out, seasonal hurricanes are a natural part of the weather system in the Gulf coast, and attributing the cause of a single storm entirely to climate change is currently an impossible task. “Once you get down to a small regional level, hurricanes are so rare and random that you would not be able to detect a robust trend even if there was one,” says John Nielsen-Gammon, Texas’ state climatologist.

        Agreement.
        Warm waters cause Hurricanes.
        Hard to have one in winter, Jim D.
        That is why there is a season.
        But attributing more to more warmer water?
        You did not say that but you mean it.
        Like saying temperature must go up in synch with CO2 ( it does) without looking at negative feedbacks albedo changes and natural variation ( So it does not go up anywhere as much as expected, shame).
        Hurricanes are dependent on the rate of change in the temperature of the hot water Jim D .
        If the overall temperature is hotter it must change temperature more slowly as it gets hotter in summer. Hence the rate of change causation factor is diminished. The hot pools needed to cause a rate of change do not have the oomph to start a hurricane.
        Such a shame really. All that extra water vapour and nothing to give it a kick off.
        The real joke is that less hurricanes could be a sign of a warming world but all the alarmists want disasters to happen.
        Al Gore turned science on its head by predicting devastation when he should have been preaching quietus.
        And one and sometimes both sides have fallen for it.

      • No, warmer water permits stronger hurricanes, and is a necessary but not sufficient condition for them, is what I have said. Larger warm pools like the West Pacific are also more productive of hurricanes than smaller ones like the Atlantic. You need to take into account realities like this in your argument. Hurricanes occur at the peak of SST, so I don’t see how rate of change has much to do with it. There are always seasonal changes and always peaks.

      • But attributing more to more warmer water?
        You did not say that but you mean it.

        How utterly ridiculous can you get?

      • Geoff Sherrington

        Jim D,
        Are you postulating high water temperatures a century ago, to account for strong hurricanes then?
        Others are telling us that global warming has made oceans warmer in that time.
        You get these contradictions when you try to guess to bolster a failed hypothesis. Geoff

      • Hurricanes, like any type of storm, have existed through the centuries. The only thing changing with warmer global ocean temperatures would be their average intensity and the frequency of more intense ones.

      • The only thing changing with warmer global ocean temperatures would be their average intensity and the frequency of more intense ones.

        Probably doesn’t matter much.

        There’s a lot more variability than there is trend in the ACE:

      • It’s at least a step to acknowledge trends, because with these trends come added real costs and needs for mitigation, adaptation, and resilience that can’t be just ignored. Insurance industries and governments dealing with coastal areas are highly aware of this.

      • For example, Houston. Three recent 100-year floods. Time to do something.
        https://www.huffingtonpost.com/entry/houston-prepare-for-climate-change_us_59d7f773e4b046f5ad984a71

  10. “But some people have said that as a result of hurricane Harvey and Irma, that we live in a warmer world, the oceans are warmer, the sea level is higher, and this is going to make hurricanes more destructive. What do you think of that?”

    You didnt answer the question.

    I will make it easy

    Given two worlds.

    A> the world with a sea level as it is today, with hurricanes like we have today
    B> a world with sea level 1 foot higher, with hurricanes like we have today

    Which world will suffer more damaage from huricanes.

    Note This question has nothing to do with the past. This question has nothing to do with increased or decreased hurricanes.

    Nothing to do with models, or arguments about unprecidented, or new records.

    Just a simple question: Would a future, similar in all ways to today, except for Sea level diference, suffer more damage or less damage do to sea level rise.

    • Houston is sinking a foot per decade due to groundwater withdrawal. NOLA’s sea level rise problem is large, but only a fraction is attributable to AGW. Etc.

      • Miami’s spending more and more money just to pump the water from their streets.

        https://slate.com/business/2017/10/massive-october-king-tide-gives-miami-another-taste-of-climate-change.html

        Flooding from King Tides increased 400% between 2006 and 2016.

      • The whole city has dropped a foot? That’s alarming. Send them an email because they are not aware of that.

        How do you know that Harris County subsidence has not actually improved Harris County drainage?

      • 10 ft since 1920, in parts of the city

      • And I can drive you right to them.

      • The whole city has dropped a foot? That’s alarming. Send them an email because they are not aware of that.

        Either your memory or your comprehension are failing (it happens to us all I guess, but try more leafy green vegetables):

        How do you know that Harris County subsidence has not actually improved Harris County drainage? Good question – things are rarely black and white. But given the distribution of the subsidence, I would suspect that things have improved for the high ground and the expense of the low-landers which are both in more of a bowl and collecting even more runoff.

      • Lol. You should give up data analysis.

      • NOLA’s problem is that the Army Corps of Engineers has kept the Mississippi River from building a more stable delta. A professor of mine once joked: The Corps of Engineers said, “If God had meant for the Mississippi River to change its course, He wouldn’t have given us concrete.” The long bird-foot “delta” has raised the river level relative to the city. Lake Ponchartrain’s setting as a dead-end embayment open to the east is a constant problem because of the westward storm surge at the lead edge of hurricanes from the south (e.g., Katrina and Nate).

      • If one builds a city largely on reclaimed swamp land a certain amount of flooding is too be expected. You should also expect the area to continue to settle as you keep pumping out ground water. I was amused when some one in NASA blamed further settling during the flood on gravity depressing the crust. Whilst this undoubtedly played a part, its very minor in comparison to simply adding water into a partially dry swamp. You only have to look at venice for evidence of that. Its not the crust. Its the mud…..

        As to sea level rise. There are both dry and submerged harbours all around the world that illustrate that this is always changing. The key is to build better and more sensibly. The rate of sea level rise does not appear to have changed very much in recent history. Obviously there are number of opinions and papers on this. Some of the team based ones are scarier than others, but then they always are.

    • Steven Mosher: Would a future, similar in all ways to today, except for Sea level diference,

      Since a future would not have all ways similar except for sea level difference, any answer is untestable and irrelevant to the decisions that we face.

      Do you not see the asymmetry in demanding answers from others without answering questions put to you?

    • simple question to a simple brain.
      Some things are not meant to be.
      If sea level had risen a foot more compared to today We would all be living in different buildings with different adjustments made to coastal fortification (cue Holland).
      Seeing people build in a manner equivalent to their perceived risk and ability to do something about it or not the rusks are the same.
      The sea cannot come up a foot higher if the buildings are already a foot higher can it?
      People don’t choose to have increased risk and insurance companies don’t acquiesce.
      In other words damage, financially and emotionally will be the same. Physically you cannot damage something already a foot under water can you. So physical damage has to be different in the two different worlds and they cannot suffer comparable hurricanes ever because the conditions that create them are irretrievably altered by the different coastlines currents and water mass, to name but a few.
      The question is not simple, it is meaningless.

    • RE: Steven Mosher
      “Would a future, similar in all ways to today, . . . damage do to sea level rise.”

      Would that future include; continue building on the coast (wherever the coast maybe) particularly coasts where hurricanes have hit before &/or often; and continue building on flood planes, particularly flood planes where floods have hit before &/or often? Of course it will.

      I’m guessing the future will be very similar in all ways to today. Those with money will want to be ‘on the coast’. Those with less will buy where they can afford to even if it means a new development that was once considered a flood plane but not mentioned in the brochure.

      More damage? Of course it will. Money will be forever ‘on the coast’ (wherever the coast maybe). And new development will continue on flood planes. Coastal mansions are getting bigger and more expensive as they get more expansive. Flood planes continue to be developed in-spite of our current knowledge of present day risks.

      There are solutions to many present and potential future problems. Buyer beware, is one of them.

    • Mosher,

      What would we do if the oceans dropped a foot and the beach was now 500 feet away? We would move.

      We cannot choose the sea level we want, but we can and we will adapt to whatever level it is, just like we adapt to all changes. We are really good at it. It is very puzzling that this obvious fact is almost entirely ignored when people try to warn us of climate change as if it is the one thing that we simply cannot adapt to, despite all the evidence to the contrary.

  11. JCH: “With ACO2 above 400 ppm, what will cause the negative phase of the AMO to come back? What will the negative phase of the AMO look like? How does she know it has not already happened? ”
    It’s very easy: make a regression of the NA-SST on the forcing and the result will look similiar to this:https://curryja.files.wordpress.com/2016/12/slide3.png?w=500&h=375 .
    For more details of the impacts on TCR see https://climateaudit.org/2017/06/19/the-effect-of-atlantic-internal-variability-on-tcr-estimation-an-unfinished-study/

    • Something causes what you call the negative phase of the AMO. What is the cause?

      • The same causes as in the past, the AMOC and others. If you believe that the changes of the past won’t work in the presence ( and the future) it would be voodoo, wouldn’t it? For more information I gave the link!

      • So you do not know what causes the changes in the AMO. How do you know that the cause of the positive AMO proximate to WW2 is the same as the current positive phase? You don’t.

      • I think I saw this on the information highway: a butterfly can flap its wings cause a climate shift, but 403 ppm ACO2 can’t do a dam thing.

      • Here is sort of what it would look like. I provide this because school children in England may seldom see it like it was in the good old days.

      • JCH: You missunderstood the butterfly-comparison. IF the climate system would be chaotic the flip of a wing could change the whole system. BUT this is not the case, that’s why our climate is NOT chaotic. The comparison also describes the frontiers of weather models. These are unable to describe the system because they get chaos if one wants informations for more than 10 days or so ahead.
        The role of the AMO is described in many studies, you should read more and witie less.

  12. Judith Curry:

    ”Thinking that reducing fossil fuels is going to help with extreme events on the timescale of the 21st century is a pipe dream.”

    I agree with your statement above. I agree with scientists who have stated that climate sensitivity can not be distinguished from zero. In addition, according to geological and recent observations longer trends of climate follow trends of climate temperature and not vica versa; https://judithcurry.com/2017/09/26/are-climate-models-overstating-warming/#comment-859082 .

    As far as I am aware, hurricane storms are someway related to increases of sunspots. For instance during the Harvey hurricane the the increase of sunspots made sun activity higher, and the higher activity of sun made magnetic fields change, which made cosmic rays to globe lessen. As cosmic rays catalize formation of water drops from water vapor, the lessened water drops makes smaller cloud cover in atmosphere, and the smaller cloud cover makes irradiation of sun to globe increase and sea surface water warm.

    • Sunspot activity alters the sun’s spectrum. UV-B for instance increases while near infrared decreases during high activity. The shift represents a 10% reshuffling of power in different frequency bands. Total solar power only changes about 1% in the meantime. The power spectrum is important because different wavelengths are absorbed in different layers of the earth system. UV-B is mostly blocked in the ozone layer while near infrared penetrates until it hits clouds, water, or dirt.

    • I correct the defective sentence ” In addition, according to geological and recent observations longer trends of climate follow trends of climate temperature and not vica versa”: instead of ‘longer trends of climate’ must be: longer trends of CO2 content in atmosphere.

    • “I agree with scientists who have stated that climate sensitivity can not be distinguished from zero.”

      You’re agreeing with the empty set there. No scientist has ever claimed that!

      • See the link above:
        “There is a lot of scientists, who, on the bases of experiences of their own, are agreeing with your statement on the ‘uncertain and exaggerated’ climate sensitivity adopted by IPCC. Especially I appreciate Nir Shaviv’s princible, too: do not believe any solution of problem if you have not scrutinized that yourself! And concerning the climate sensitivity, he agr
        ees with you: the climate sensitivity adopted by IPCC is highly uncertain and exaggerated. Scafetta and Lindzen say, that it is lower than 1 and 0.5 C, but they do not state any lowest value. Wojick, Arrak and Cripwell have said that it can not be distinguished from zero, with which I agree, too”.

      • VP

        Trying to disprove a negative can be a real bummer, VP. In fact, I remember the time when I was trying to prop up an old drunken derelict on his barstool at a Cleveland tavern when he told me he was a scientist and he said exactly that. Disprove away.

  13. I’m really impressed by the advances in hurricane modelling. This seems to be an area in which high quality data and sophisticated modelling within a relatively constrained field is beginning to become credible.

  14. There was a paper just published by a Japanese group: “Response of Tropical Cyclone Activity and Structure to Global Warming in a High-Resolution Global Nonhydrostatic Model” by Yohei Yamada et al. in the Journal of Climate. They ran the very high resolution Japanese climate model for the current conditions of perturbed warmer conditions, and they found a significant decrease in the number of hurricanes, but they found an increase in intensity, an increase in the horizontal size, which relates to storm surge among other things, and an increase in precipitation

    There is a number of papers from the Japanese researchers, where the simulations result in a decrease in TC in a warming world and an increase in a cooling world eg.
    http://onlinelibrary.wiley.com/doi/10.1002/2015GL064929/full

    Another aspect is the role of aerosols (anthro and natural) and the constraints on TC generation that arise.

    http://blog.pnas.org/2017/10/journal-club-aerosols-global-warming-may-dampen-cyclone-activity-in-some-regions/

    An important outcome in moisture (rh etc) experiments is invariance.
    With midlatitude storms here the horizontal scale reduces,whilst the vertical increases eg booth

    https://link.springer.com/article/10.1007/s00382-012-1472-3

    • Actually according to this ….

      Waters between 26 & 28C
      Having an anomaly of ~ +2C

      http://www.nhc.noaa.gov/text/refresh/MIATCDAT2+shtml/111439.shtml?

      “Although the ocean is not too warm, the shear is low and the
      upper-troposphere is cool. These factors should provide some
      low-octane fuel favoring slight strengthening, and Ophelia is
      still expected to become a hurricane at any time within the next 12
      hours. Extratropical transition is likely to start between day 3 and
      day 4, and Ophelia is anticipated to remain a strong cyclone over
      the northeastern Atlantic.”

    • RE: Jim D
      “. . . For 2017, this just becomes another in a growing list of unusual and unfortunate events. . . .”

      Isn’t 2017 somewhere in 9th or 10th as far as hurricanes go? Doesn’t seem unusual at all. What else was on your list?

      • CA fires, various US floods of which Harvey and Irma are just two, and that is just the US. Two cat 4 US landfalls in one year is unprecedented.

      • CA fires, various US floods of which Harvey and Irma are just two, and that is just the US. Two cat 4 US landfalls in one year is unprecedented.

        Please. Making repeated exaggerations and obvious confirmation bias about every last current event is what rightly raises suspicions about advocates. Thinking people can see through the unfounded claims.

      • Re: “Please. Making repeated exaggerations and obvious confirmation bias about every last current event is what rightly raises suspicions about advocates. Thinking people can see through the unfounded claims.”

        What raises my suspicions is when people discuss “suspicions about advocates,” while displaying ignorance about what the scientific literature shows. Reminiscent of how anti-vaxxers and AIDS denialists would claim “suspicions about advocates” about mainstream, evidence-based virology and immunology, even as they displayed willful ignorance of what the scientific literature showed in those subjects.

        Anyway:
        “Anthropogenic warming has increased drought risk in California”
        “Contribution of anthropogenic warming to California drought during 2012–2014”
        “Emergence of heat extremes attributable to anthropogenic influences”
        “Increasing drought under global warming in observations and models”
        “Global warming and changes in drought”

      • TE, I suppose being among the warmest years ever measured is random chance to you too. These temperatures have consequences, and what I listed are among the expected ones, not even exaggerations.

      • “But three papers on the California drought — which, like the ones about Australia, were published in the Bulletin of the American Meteorological Society — were divided on a link to climate change, with only one seeing a clear connection.”

      • Fires have number of long term causes. Land use. Go or no go fire suppression.

  15. To provide some scientific content here:

    The hurricane prediction was that hurricane intensity would increase. Which it has. See, for instance, the following sources which discuss this at a laymen’s level:

    Youtube: “11. Climate Change — Hurricanes, atolls and coral”
    Youtube: “What We KNOW About Climate Change – Kerry Emanuel” from 37:54 – 38:58

    To repeat myself: the prediction was one of *increased hurricane intensity, and decreased hurricane frequency*, resulting from increased wind shear (from global warming) limiting hurricane formation:

    “Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming Environment”
    “The dependence of hurricane intensity on climate”
    “Simulated Increase of Hurricane Intensities in a CO2-Warmed Climate”
    “Simulated reduction in Atlantic hurricane frequency under twenty-first-century warming conditions”
    “Increased tropical Atlantic wind shear in model projections of global warming”

    “Modeled Impact of Anthropogenic Warming on the Frequency of Intense Atlantic Hurricanes
    […]
    The model projects nearly a doubling of the frequency of category 4 and 5 storms by the end of the 21st century, despite a decrease in the overall frequency of tropical cyclones […]”

    “Observed and projected decrease in Northern Hemisphere extratropical cyclone activity in summer and its impacts on maximum temperature
    […]
    Climate models project a decrease in summer cyclone activity, but the observed decreasing rate is near the fastest projected.”

    “Intense tropical cyclone activities in the northern Indian Ocean
    […]
    Over these 3 months, the vertical wind shear is too strong to allow a significant intensification of storms.”

    There’s some research suggesting that anthropogenic climate change has not significantly affected total hurricane frequency, but has augmented hurricane intensity:
    “Recent intense hurricane response to global climate change”

    This paper suggests that anthropogenic forcing has augmented hurricane frequency, intensity, and cost incurred from the hurricanes:
    “Economic losses from US hurricanes consistent with an influence from climate change”

    This paper compares the data to results in models:
    Knutson et al. 2010: “Tropical cyclones and climate change”
    http://users.clas.ufl.edu/adamsp/Outgoing/ForJJandLaura/Knutson2010Nature%20Geoscience-2.pdf

    And this review discusses increased hurricane intensity in various regions of the world:
    Walsh et al. 2016:
    “Tropical cyclones and climate change
    […]
    For example, a summary of trends in the lifetime maximum intensity of TCTCs [tropical cyclones] in various ocean basins is shown in Figure 1, for the period 1989–2009. Globally, there are modest significant trends in this quantity (at the 90% level), but individual basins have greater significance.”
    https://pdfs.semanticscholar.org/361c/cdfcbeef1bf639c5528fe4d8cb5fa00453f3.pdf

  16. This blog is about dead. Its death confirms it was driven by hyperbolic US climate change policy not science.

    Climate Ball Final Score: Sanity 1, Alarmists 0

    Thanks for playing!

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