US Atmospheric Scientist Sees No Link Between Accumulated Cyclone Energy And Global Warming Over Past 30 Years

Atmospheric research scientist Dr. Philip Klotzbach at Twitter here tweeted a chart showing that accumulated cyclone energy (ACE) has not risen at all in 30 years, despite earlier massive hype and hollering by climate scientists and media, who insist “man-made” global warming is causing more frequent and intense cyclones.


In fact Klotzbach’s plot above shows that there has even been a modest decline.

So I tweeted a question to Dr. Klotzbach, and he was kind to answer as follows:


As the reader will note, Klotzbach does not see any link between cyclone activity and global warming over the past 30 years.

If we roughly plot CO2 levels vs ACE, no statistical analysis is needed to tell us that there is no correlation, except of course that rising atmospheric CO2 concentration might be causing a little bit less cyclone activity (which is the OPPOSITE of what is claimed by alarmists):


Plot of ACE since 1980 vs atmospheric CO2 concentration. ACE has dropped a bit. CO2 chart from NOAA.

Global temperatures have also risen since 1980 (many arguing it has more to do with ocean and solar cycles, and less so with CO2). Yet, here as well a temperature increase over the period has not led to a rising trend in cyclone activity.

The paper Dr. Klotzbach refers to can be seen here. He writes in the abstract:

Ten years ago, Webster et al. documented a large and significant increase in both the number as well as the percentage of category 4 and 5 hurricanes for all global basins from 1970 to 2004, and this manuscript examines whether those trends have continued when including 10 additional years of data. In contrast to that study, as shown here, the global frequency of category 4 and 5 hurricanes has shown a small, insignificant downward trend while the percentage of category 4 and 5 hurricanes has shown a small, insignificant upward trend between 1990 and 2014. Accumulated cyclone energy globally has experienced a large and significant downward trend during the same period. The primary reason for the increase in category 4 and 5 hurricanes noted in observational datasets from 1970 to 2004 by Webster et al. is concluded to be due to observational improvements at the various global tropical cyclone warning centers, primarily in the first two decades of that study.

Globally, the year 2015 saw brisk cyclone activity, and thus has caused the trend since 1985 to be less steeply downward.


11 responses to “US Atmospheric Scientist Sees No Link Between Accumulated Cyclone Energy And Global Warming Over Past 30 Years”

  1. Top US Scientist Sees No Link Between Cyclones & Global Warming Over Past 30 Years - Principia Scientific International

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  2. Kenneth Richard
    “The impact of climate change is seen in slightly decreased intensities in landfalling cyclones (about 5 hPa) resulting from the competition between warming provided by the climate change scenario and modest cooling around the storm center induced mainly by dynamic cooling. An additional impact is that cyclone tracks tend to shift poleward.”
    “Any changes associated with warming of the surface compared to a smaller temperature rise in the lower-troposphere (and resultant changes in atmospheric stability) have not produced detectable impacts on intensification rates of tropical cyclones in the North Atlantic basin.”
    “No significant correlation was found between the typhoon activity parameters and local SST. In other words, an increase in local SST does not lead to a significant change of the number of intense TCs in the NWP, which is contrary to the results produced by many of the numerical climate models.”
    “[T]he period between AD 1600 to 1800 had many more intense or hazardous cyclones impacting the site than the post AD 1800 period.”

  3. A C Osborn

    Historically I think you will find a Colder Climate produces more severe weather etc not warmer.
    This business of a Warmer Ocean/Atmosphere has more energy is not what it is about.
    It seems to be the differential between Tropics and Poles that produce more energy for storm systems.

    1. Mindert Eiting

      Could that be the reason of the super cyclone lasting for centuries on the very cold planet Jupiter?

  4. Stephen Wilde

    Interestingly, my contention is that more GHGs mean that the convective overturning of an atmosphere need work less hard to move energy back to the surface prior to radiation to space so on that basis a slight reduction in global cyclonic energy would be the correct system response to a slight increase in the radiative capability of the atmosphere.

  5. Harry Dale Huffman

    Old news…

    “Hurricane/Tropical Storm Strength, 1851 – 2010”.

    A mere 1 degree rise in global mean temperature (that claimed by climate scientists for the last century) would not be discernible as a rise in average cyclone energy. And with the so-called “pause” in the global warming going back 20 years, what good is looking at only the last 30 years anyway? My simple analysis went back through the full record of Atlantic tropical storms and hurricanes, from 1851 through 2010.

    So the academics, like Dr. Klotzbach, are well behind on the learning curve. That is what paying attention only to the peer-review-passed literature gets you.

  6. Bitter&twisted

    So what’s new? Climate “scientists” lie.
    They lie to keep the grant money flowing.
    They never let facts get in between their snouts and the money trough.
    In short they are fraudsters.

  7. AndyG55

    Climate scientists LIE.. Especially when they instructed to do so.

    Here is the latest FABRICATED FARCE from NOAA

  8. DB

    Colin Zarzycki of NCAR looked at high-resolution modeling of tropical cyclones (TCs). He focused on the phenomenon called ‘cold wake’ where the churn from TCs brings up colder sub-surface water.

    Including cold wake in his models, he found a reduction of 5-9% in the number of TCs. More significantly, the number of strong storms (Category 4 and 5) was reduced by 65%.

  9. Dr Tim Ball-Climatologist

    I would like to tell you of my latest book, “Human Caused Global Warming”.
    The Biggest Deception in History.
    Available on ‘’ and ‘Indigo/Chapters’.

  10. Mad Dog

    “US Atmospheric Scientist Sees No Link Between Accumulated Cyclone Energy And Global Warming Over Past 30 Years”
    Possibly because while you can make up and manipulate Global Warming data, it’s much harder to fake a Hurricane.

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