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Atlantic Hurricane Numbers Decreasing Despite Increases In Atmospheric CO2

February 1, 2017

By Paul Homewood




From GWPF:


Study of historical hurricane occurrences in the Gulf of Mexico and the Caribbean Sea, during the period 1749 to 2012, reveals that “the hurricane number is actually decreasing in time.”


Paper Reviewed

Rojo-Garibaldi, B., Salas-de-León, D.A., Sánchez, N.L. and Monreal-Gómez, M.A. 2016. Hurricanes in the Gulf of Mexico and the Caribbean Sea and their relationship with sunspots. Journal of Atmospheric and Solar-Terrestrial Physics 148: 48-52.


Although some climate alarmists contend that CO2-induced global warming will increase the number of hurricanes in the future, the search for such effect on Atlantic Ocean tropical cyclone frequency has so far remained elusive. And with the recent publication of Rojo-Garibaldi et al. (2016), it looks like climate alarmists will have to keep on looking, or accept the likelihood that something other than CO2 is at the helm in moderating Atlantic hurricane frequency.

In their intriguing analysis published in the Journal of Atmospheric and Solar-Terrestrial Physics, the four-member research team of Rojo-Garibaldi et al. developed a new database of historical hurricane occurrences in the Gulf of Mexico and the Caribbean Sea, spanning twenty-six decades over the period 1749 to 2012. Statistical analysis of the record revealed “the hurricane number is actually decreasing in time,” which finding is quite stunning considering that it is quite possible fewer hurricanes were recorded at the beginning of their record when data acquisition was considerably worse than towards the end of the record. Nevertheless, as the Mexican research team indicates, “when analyzing the entire time series built for this study, i.e., from 1749 to 2012, the linear trend in the number of hurricanes is decreasing” (see figure below)….


Figure 1. Annual hurricane count in the Gulf of Mexico and Caribbean Sea over the period 1749-2012. Red line indicates the linear trend. Source: Rojo-Garibaldi et al. (2016).

  1. Ian Magness permalink
    February 1, 2017 11:34 am

    Best hide that before Mr T gets hold of it.

    • Harry Passfield permalink
      February 1, 2017 1:12 pm

      On the other hand, make sure Myles Allen gets to see it. He may come to the conclusion that MM GW is responsible for a decrease in hurricanes etc (and why shouldn’t it?)

  2. Tim Hammond permalink
    February 1, 2017 11:39 am

    No doubt the red line numbers are correct, but once again it looks more like a “random” pattern with very high variability. There’s even a hint of cyclicality to my eye, so I would be really hesitant to claim a declining trend.

    But it’s clear there’s no upward trend. More interestingly, what causes the high variability? If we cannot explain that, how can we claim to know enough about the climate to say the science is settled?

    • Tim Hammond permalink
      February 1, 2017 11:41 am

      PS. I mean what is the underlying cause, not the basic energy cause.

      • February 1, 2017 1:34 pm

        It’s in the link:
        ‘Hurricanes in the Gulf of Mexico and the Caribbean Sea and their relationship with sunspots.’

      • ray permalink
        February 2, 2017 9:08 am

        “…basic energy cause…”

        That is interesting because it shows the almost universal misunderstanding of what causes an episode of high winds. THERE IS NO basic energy cause – at least not in the way assumed (of course, moving air has kinetic energy.)

        The general circulation in the whole atmosphere possesses energy of motion and a certain amount of angular momentum. The air is gently swirling (has a curl in vector terminology.) A hurricane represents a CONCENTRATION in that swirling. It is just like the spinning skater who draws her arms into her body.

        The proximate cause of the hurricane is evaporation from warm seas into regions of mild depressions and subsequent release of heat into the air so that it rises and attracts MORE of the gently swirling air. Of this transfer of heat only 1 part in 200 goes into accelerating wind.

    • Broadlands permalink
      February 1, 2017 2:27 pm

      Tim… temperatures (and precipitation) are the same. Simply take a fairly long time series and do a year-to-year change by subtracting each year from the previous year. Take those results and plot them. Then do the linear regression. It may not be technically random, but very close? If I knew how to post a chart here I’ve got many, hemispheric, regional.

    • John F. Hultquist permalink
      February 1, 2017 6:52 pm

      … with very high variability …

      This is common with things that are rare. Big rainfalls in deserts, lightning hitting a smallish area over time, and many others are not “normal” distributions. That they are not makes many statistical aspects beyond the Stat-100 class.

  3. February 1, 2017 11:45 am

    Like a lot of other examples of “evidence of climate change”, claims that hurricanes are increasing seem to be based on recent data (since the 1960’s and 1970’s) without taking into consideration earlier data.
    The trouble is, those of a less sceptical disposition, blindly accept that evidence, without checking the full facts for themselves.
    Scientists who do this are, either intentionally or unintentionally. guilty of confirmation bias.
    Unfortunately, most of the media are now incapable of challenging this “evidence”.

    • Mike Jackson permalink
      February 1, 2017 4:26 pm

      Since the post-1980 global warming scare is largely political — in the widest sense of the word which encompasses “scientists” protecting their income stream — it is hardly surprising that a whole forest of cherries have been picked in order to support the Cause.

      Evidence to the contrary has been blatantly ignored for the last 30 years and where it hasn’t been ignored those who propound it have been vilified.

      This paper is of considerable interest because it identifies a long-term decline in Atlantic tropical storms. Whether Tim Hammond is correct in suggesting cyclicality I wouldn’t know but neither would I know whether this decline is necessarily a good thing for the planet or mankind in the longer term.

      But while the sceptics use the data to challenge the paradigm (reasonably enough) and the warmists simply ignore anything that doesn’t equate to it we will never learn anything useful on the subject, assuming there is something useful to learn.

  4. Bloke down the pub permalink
    February 1, 2017 12:17 pm

    The increasing hurricanes idea was always one of the daftest to come out of the AGW lobby. Their theory predicts that warming in the high latitudes will be greater than in the tropics which will reduce the difference between the two regions and therefore the energy gradient that causes storms. Fewer hurricanes is actually proof of global warming, but I suppose they can’t get the population scared by saying that.

  5. February 1, 2017 2:14 pm

    But if the US gets 2 hurricanes next year it’ll be a 100% increase. Can you imagine the headlines. They went off the deep end last year with one.

  6. CheshireRed permalink
    February 1, 2017 2:46 pm

    Another AGW fail, then. At this rate Paul you’re gonna need a bigger website.

  7. Athelstan permalink
    February 1, 2017 5:05 pm

    So, all naturally if you get the drift, as the earth gently warms more CO₂ is released into our atmosphere and concentrations increase though only relatively at PPM. The graph shows a decline in the incidence of Hurricanes as atmospheric CO₂ concentrations rise, therefore the correlation is directly inverse and conflicts with all alamist propaganda which states emphatically that,

    “we’re all doomed and yes folks it’s all your fault and and and more HURRICANES TOO will result!”…………………… which is specious nonsensical hyperbole and nothing else!

    It must be also reflected on, this sample is limited to the Carib and Gulf. Evidently, severe category 1 – 5 tropical cyclone events are not exclusive to only the Gulf and Carib, therefore we can with wobbling certaintly say not so much, but then, realists always pragmatic aver we must continue to observe, annotate and experiment because – the science is never settled – now is it?

    • February 2, 2017 1:02 pm

      ‘The graph shows a decline in the incidence of Hurricanes as atmospheric CO₂ concentrations rise, therefore the correlation is directly inverse’

      Whoa! Correlation is not necessarily causation, whether direct or inverse. There’s already a study linking hurricane and sunspot behaviour – again, the previous sentence applies – so we can’t pronounce with any certainty (by saying ‘therefore’) how it all works 🙂

      Of course these ideas can be on the table for further study.

  8. February 1, 2017 5:57 pm

    Reblogged this on Climate Collections.

  9. February 2, 2017 1:10 am

    Reblogged this on Climatism and commented:
    Rather inconvenient news for promulgators of CO2-induced Climate Change fear, doom and gloom…

  10. ray permalink
    February 2, 2017 9:18 am

    It has been terribly disappointing for the Met Office that their propaganda wheeze of naming storms has flopped completely this year. After 11 storms in 15/16 (cue prepared headlines of “Angus smashes terrified Britain – expect one-a-day for ever because of your evil burning of fuel to keep warm”) there have only been three little ones this winter.

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