Skip to content

Increasing Hurricane Intensity Study Fatally Flawed

January 30, 2021

By Paul Homewood



Last May this story was being widely covered:



Stronger, deadlier and more frequent — that’s the trend scientists at the National Oceanic and Atmospheric Administration (NOAA) have seen in the past few decades, and they expect that trend to continue in the years to come, according to a new study.

Researchers at the University of Wisconsin and NOAA analyzed satellite data of tropical cyclones over the last 40 years and found category 3, 4 and 5 hurricanes were becoming increasingly common, CNN reported. Decade after decade, the likelihood of major global storms has increased, according to CNN.

“The change is about 8% per decade. In other words, during its lifetime, a hurricane is 8% more likely to be a major hurricane in this decade compared to the last decade,” James Kossin, author of the study, told CNN.



The statistician William Briggs published a rebuttal on his website this week, which was written by Greg Kent and attacked the statistical basis of the Kossin study. You can read it here.

The study looks at the period 1979 to 2017, and compares 1979-1997 with 1998-2017

Kent makes one crucial observation, without realising its true significance:

The pervasive erroneous calculations in the original paper and the invalid claim of statistical significance are not the only issues with Kossin et al. There is also reason to question whether the 10% increase in the proportion of major hurricane force winds was a global or largely regional phenomenon. Kossin et al presented results for each of the hurricane basins around the world. The data shows that the global results are driven largely by a single basin, the North Atlantic. The proportion of major wind speeds increased by 72% in the North Atlantic, far more than in any other hurricane basin. Western Pacific, which accounts for over 40% of the major hurricane force winds over the last 4 decades, showed a smaller proportion of intense storms in the later period (indicating a negative change). The other basins either showed no change at all between periods or the change was so small as to fail tests of statistical significance at traditional levels of confidence.

There is actually a very good reason why there have been more intense hurricanes since 1998 than before – the Atlantic Multidecadal Oscillation or AMO. Here’s what NASA have to say about the AMO:



The AMO was in cold phase between 1979 and 1995, and has been warm ever since. So the increase in hurricane intensity has nothing whatsoever to do with “climate change”, and instead is a consequence of natural ocean cycles.

In any other field of science, peer review would have spotted this fatal flaw in Kossin’s paper, which would never have been published.

  1. Ben Vorlich permalink
    January 30, 2021 11:59 am

    Well spotted Paul, missed both by Kossin and his peer review mates and then Kent & Briggs when doing their rebuttal.

    Unfortunately unless this is broadcast with a fanfare of trumpets the original conclusion remains in everyones memory

    • Chris Morris permalink
      January 30, 2021 5:04 pm

      Ben – it would have helped a lot if you had actually read the Kent paper at Briggs’ site. Down in the text it stated:
      “The increased proportion of major storm “fixes” is statistically significant only in the North Atlantic basin. Unfortunately, the North Atlantic basin contains only a small percentage of global hurricanes (i.e., about 12% of global major-hurricane force winds) and is heavily influenced by natural variation. The cut-off year between Kossin et al’s two periods (1997/1998) occurs within a year or two of a flip of the Atlantic Multidecadal Oscillation (AMO) from a cool period to a warm period, and it is widely known that the AMO has a substantial impact on the intensity of North Atlantic basin tropical cyclones.”
      which means Kent did spot it. I also suspect this is why Paul wrote what he did.

      • January 30, 2021 5:55 pm

        I actually did not read it that far, Chris!!

      • Chris Morris permalink
        January 30, 2021 6:23 pm

        Oh well Paul, maybe great minds think alike and you just spotted a link before the paper wrote about it. Sort of like solving a murder mystery before the author has got to the end of Chapter 2.

      • Phoenix44 permalink
        January 30, 2021 8:45 pm

        So was that why the periods were chosen?

        I am always deeply suspicious of comparing periods in this way unless there is actually periodicity and so you are comparing two distinct cycles. If there has been a trend, then why can’t you just show the trend?

        The paper looks to be essentially fraudulent. Thre is no trend outside of the Atlantic and that is explained by a well-known and acknowledged phenomenon. That is trivially obvious yet still they publish.

      • Chris Morris permalink
        January 30, 2021 11:35 pm

        It is quite obvious why they wrote the paper and then published it, Phoenix. It is all part of Project Fear. They needed something for Glasgow to show that AGW or whatever the current name is happening and that it is bad!!! Sea level rise doesn’t work, so hurricanes become your go to disaster.
        This paper will (or would until Kent, Briggs and our blog host shot it down in flames) be part of the plan to win over the increasingly sceptical unwashed. Even then, the alarmists are likely to still use it. Google came up with over 60k hits. The man (or woman) in the street notices their power costs have gone up, their gas heating is threatened and carless days are mooted. They can’t afford electric cars and probably don’t have a garage to store it in anyway, then how will it be charged every night? They will start to ask questions about the sacrifices being made and why China gets a free pass., Despite what the activists think, people vote with their wallet. Tell everyone that zero carbon will cost them as little as 10 quid extra a week and see how quickly support disappears.
        What is the bet it will be strongly referenced in Glasgow? Zombie papers have a life of their own. How many still quote Mann 1998?

  2. Ron Arnett permalink
    January 30, 2021 12:52 pm

    I thought everybody figured all this out a long time ago after Hurricane Katrina.

    Gore with his claims America was going to be obliterated by similar hurricanes every second day which instead turned out to be the final blow of the active season. That was replaced by the quiet period and is now following the cycle towards an active period.

    Hell, even I know about the AMO. How can these people not know? El Nino, La Nina, Polar Vortex, Amo. the Gulf Stream, the Japanese current ….the list goes on. None of them are constant over an extended period. What were they doing in University? Studying critical race theory?

    You don’t need a so called science expert fancying himself as a glorified weatherman spouting nonsense to know which way the wind is blowing.

  3. MrGrimNasty permalink
    January 30, 2021 1:27 pm

    Robert Downey Jr, another hypocritical hyper-rich deluded moron.

    At least he admits (unintentionally?) his real aim is to ride the climate cash wagon.

    2018 Malibu burning woke him up to climate – is he really so ignorant, he can’t even remember/be bothered to check for, fires in the 1980s/90s. Yes 2018 was big, but mainly for various man-made reasons other than climate change, but Malibu burning is normal, not climate change.

    1958 fire, only 2 years after big 1956 fire.

  4. January 30, 2021 1:32 pm

    I did a few posts on tropical cyclones and they may be of some interest here.

  5. Broadlands permalink
    January 30, 2021 1:57 pm

    “The Washington Post headline claimed that “The strongest, most dangerous hurricanes are now far more likely because of climate change.”

    Climate change is now a buzzword-synonym for human-generated CO2 primarily from fossil-fuel use. Where is any correlation between hurricane or tropical cyclone intensity and atmospheric CO2?

    • Gary Kerkin permalink
      January 30, 2021 8:43 pm

      Carbon dioxide is increasing at a relatively constant rate. It will correlated, therefore, with anything that is in a positive increase mode. However, as we know, and as as we keep saying: correlation is not causation. But the two words begin with “c”, are about the same length (11 vs 9), and look much the same. Perhaps the real reason for the confusion is poor education in the English language!

    • Tom O permalink
      February 1, 2021 5:29 am

      Actually, “climate change” is a safe harbor for their eco ship. It absolutely covers everything, be it hot or be it cold, dry or wet, real or imagined.

  6. Tim Spence permalink
    January 30, 2021 6:52 pm

    Questioning each dodgy report is one thing, stopping the conveyor belt of dodgy papers is another. It really is the Borg we are up against.

Comments are closed.

%d bloggers like this: