Robert Vislocky, Ph.D.
Less than a month has passed since the official end of the 2025 hurricane season for the Northern Hemisphere. Interestingly, 2025 statistics show that Accumulated Cyclone Energy (ACE) in the northern hemisphere was roughly 20% below the 1991-2020 mean while the number of major hurricanes and major hurricane days were down about 27% and 36%, respectively, compared to their 30-year averages (shown in parentheses).1
| Basin | Named Storms | Named Storm Days | Hurricanes | Hurricane Days | Major Hurricanes | Major Hurricane Days | Accumulated Cyclone Energy |
| Northern Hemisphere | 66 (60.9) | 273.25 (288.7) | 34 (33.7) | 89.25 (123.5) | 13 (17.9) | 27.25 (43.0) | 455.5 (573.8) |
1Seasonal hurricane statistics from the Department of Atmospheric Science, Colorado State University
https://tropical.atmos.colostate.edu/Realtime/
Despite the otherwise lackluster hurricane season, the climate activist community had their poster child in hurricane Melissa, one of the most intense tropical cyclones in history. Of course the media had a field day blaming it on climate change. Here are some quotes and headlines …
“Hurricane Melissa Is a Reminder of Our Dangerous New Reality as the Climate Crisis Accelerates”
“Manmade climate change clearly made Hurricane Melissa stronger and more destructive”
https://www.sierraclub.org/sierra/hurricane-melissa-reminder-our-dangerous-new-reality-climate-crisis-accelerates
“How Climate Change Turned Hurricane Melissa into a Monster”
https://www.climaterealityproject.org/blog/how-climate-change-turned-hurricane-melissa-monster
“After Melissa, how much stronger will future hurricanes be?”
“Is it time for a Category 6?”
https://www.theinvadingsea.com/2025/11/10/hurricane-melissa-category-6-rapid-intensification-climate-change-sea-surface-temperatures-volo/
“Was climate change to blame for the strength of Hurricane Melissa?”
https://www.bbc.com/weather/articles/c205zwz4yj9o
The last article begs the question …. Did climate change, or more accurately anthropogenic global warming (AGW), really make Melissa stronger? Enter the world of single-event attribution science, where climate change can be shown to enhance any hurricane, even if it’s the only hurricane of the season! All that’s needed is to show that higher water temperatures will intensify existing hurricanes and that water temperatures have increased due to AGW. Just like that the hurricane is proven to be enhanced by climate change. News organizations feed the frenzy by publishing the results without dispute and lawyers take oil companies to court to pay for their part of the damages.
Now single-event attribution science is significantly more complicated than the above over-simplification, and admittedly their methods are quite intuitive and mathematically rigorous. After all, they are based on “peer-reviewed” science (tongue-in-cheek). There are several organizations that specialize on attribution science and ambulance-chase storms around the globe hoping to find a climate change connection. Several of the more prominent outfits include World Weather Attribution, Climate Central, and ClimaMeter. Although their methods differ significantly, all three of these companies determined that human-driven climate change enhanced Melissa’s wind speeds by about 7-10%, which doesn’t seem quite as dramatic or impactful as the news headlines indicated above.
https://www.worldweatherattribution.org/climate-change-enhanced-intensity-of-hurricane-melissa-testing-limits-of-adaptation-in-jamaica-and-eastern-cuba/
https://www.climatecentral.org/tropical-cyclones/melissa-2025
https://www.climameter.org/20251027-hurricane-melissa
Nonetheless, despite their diverse methodologies, all of their single-event hurricane attribution studies contain the same critical flaw. Specifically, they don’t assess the role of climate change in areas where there are no storms to gauge the total effect of climate change on hurricane activity or to see if climate change might have actually prevented an intense hurricane in another location. This point was alluded to at least a couple times in the past on WUWT, for example see Rotter (2023) and Vislocky (2018) below. However it’s an important point that needs to be exposed and repeated often given the meteoric rise in single-event climate attributions.
https://wattsupwiththat.com/2023/07/11/extreme-weather-attribution-or-just-sharpshooting-in-texas/
https://wattsupwiththat.com/2018/12/07/wildfire-attribution-study-full-of-smoke/
As it is right now, single-event attribution science is the equivalent of a pathologist performing an autopsy on one victim who passed away as a result of an allergic reaction to a vaccine and concluding that the vaccine is causing excess deaths. After all there’s no denying how the person died or the science used in determining the cause of death. But such a superficial analysis is incomplete because the total efficacy of the vaccine hasn’t been taken into account. Was a study performed to see if the vaccine saved thousands or millions of other lives from a deadly pathogen, or whether people who took the vaccine perished at a lower rate than those who did not take the vaccine? Until those additional analyses are completed there would be no way to determine the *overall* role of the vaccine on human health based on just that one autopsy. Similarly, there’s no way single-event attribution science can measure the influence of climate change on the totality of hurricane activity. Sure, there’s probably little doubt that AGW enhanced water temperatures made Melissa up to 10% stronger, but it can’t measure whether climate change is increasing overall hurricane activity unless additional analyses are completed. Even more preposterous is it’s entirely conceivable in a hypothetical season where only one hurricane occurs that single-event attribution science could still ascribe a portion of that hurricane’s strength on climate change!
Now this notion (that climate change can occasionally prevent extreme storms from forming) may seem preposterous to those who think that climate change can only create more “storm energy” and make everything worse. However, there are some known mechanisms as a result of climate change that can actually stabilize the atmosphere and potentially offset some of enhanced storminess that’s found through the single-event attribution studies. For one such example, it’s well known that arctic amplification is reducing the north-south temperature gradient which, in turn, could reduce the strength of cold fronts in mid-latitudes. Perhaps this is a reason why powerful tornadoes (EF3+) have decreased substantially since the 1950s. In terms of hurricanes, it’s pretty clear that the vertical lapse rate is also lessening with climate change as there appears to be more warming aloft in the 850-700 mb layer than at the surface across tropical latitudes (see graph below).2 This could cause an increase in ambient stability making it more difficult for hurricanes to form in the first place. Perhaps this could explain why overall hurricane frequencies are slightly down but the proportion of major to total hurricanes is up (i.e., the more stable air decreases the odds of initial hurricane formation but the warmer sea surface temperature increases its intensity once one forms). The point is there are a myriad of physical mechanisms in which climate change could impact hurricanes, some factors can make them worse, and perhaps some could make them less impactful. Without a deeper analysis we just won’t know the total impact of climate change on hurricane activity, and we certainly can’t assess that through a forensic analysis of one storm. Climate models are of little help as they can’t resolve hurricanes or reproduce our atmosphere accurately (otherwise seasonal hurricane forecasting would be easy), and single-event attribution models don’t provide an answer either as already pointed out.
2 Temperature data from NCEP/NCAR Reanalysis Project and NOAA Physical Sciences Laboratory
https://psl.noaa.gov/data/timeseries/
This is why I feel that trend analysis right now is the best way to determine the broader impact of AGW on hurricane activity. However which trends should be computed? One trend would be to estimate the cyclonic energy of each hurricane in the US Landfalling Hurricane database.3 This calculation is simply the annual sum of the squared sustained wind speeds for each hurricane at landfall. The cyclonic energy estimate is similar to the ACE index except in this case it’s just computed at landfall, not over the life of the storm, and I didn’t divide by 10,000 like the ACE. The advantage in using the landfalling hurricane database is its long history back into the 1800s so hurricane activity can be viewed through a wide lens as it impacted the United States. Certainly by the late 1800s most coastlines were populated enough that it would be unlikely to miss a big tropical cyclone, so this would be a fair starting point.
The chart below shows the running 5-year cyclonic energy totals ending at the year shown. Although there’s been a lot of choppiness the most recent couple of decades, the overall trend (dashed line) actually shows a slight but probably statistically insignificant decline. Most importantly there’s no strong evidence that climate change is making US landfalling hurricanes worse. Even the more active periods after 2000 were on par with some of the active periods in the late 19th century through the middle of the 20th century.
3 Hurricane landfall data from NOAA’s Atlantic Oceanographic & Meteorological Laboratory
https://www.aoml.noaa.gov/hrd/hurdat/All_U.S._Hurricanes.html
Unfortunately, the use of the US landfalling hurricane dataset to uncover a trend is not without criticism as it only looks at only a small subset of the total hurricane picture. Specifically, the dataset leaves out non-landfalling hurricanes and storms in basins outside the Atlantic. The US landfalling dataset also does not include measurements of hurricanes over their entire life cycle but rather only a snapshot at landfall. Those are all fair criticisms but sadly the ability to detect a trend using all the available hurricane data becomes a challenge as the ability to remote-sense and detect hurricanes over the open oceans has increased greatly over time. As a result historical hurricane data over the open oceans are subject to potential observational biases, more specifically under-sampling biases going back in time, which can significantly distort the real trend. Many hurricanes were missed prior to 1970 due to the lack of 24/7 global satellite coverage. During the 1970s and 1980s satellite technology evolved considerably, and it wasn’t until the 1990s that aircraft reconnaissance could measure surface wind speeds with high accuracy. Despite increased coverage over the last quarter of the 20th century, a number of very short-lived tropical cyclones over the open waters were still likely missed or their intensity underestimated prior to 2000 as remote-sensing and detection technology gradually improved. Since 2000, there have been a plethora of new tools available to observe hurricanes including scatterometers, GPS dropsondes, stepped frequency microwave radiometers, etc., that weren’t available earlier. Landsea and Blake (2021) discuss on the National Hurricane Center’s blog site, Inside the Eye, the evolution of technology for monitoring tropical cyclones and its impact on counting storm totals (see first link below). Below that are links which further describe the evolution of weather satellite and aircraft recon technology.
https://noaanhc.wordpress.com/2021/06/30/was-2020-a-record-breaking-hurricane-season-yes-but/
https://www.nesdis.noaa.gov/our-satellites/related-information/history-of-noaa-satellites
https://www.hurricanescience.org/science/observation/aircraftrecon/index.html
With that preface in mind, shown below are plots of annual ACE values for all tropical cyclones in the northern hemisphere and the globe during the post-satellite era.4 However, as mentioned above, since detection technology improved significantly over time, and because it’s a relatively short time period overall, the trend in the ACE may be sensitive to the year the graph is started. Therefore, several graphs are provided with different starting dates: 1971, 1980, 1990, and 2000. Note that hurricane data was available for the northern hemisphere and the globe beginning in 1971 and 1980, respectively.
Results show an upward trend in accumulated cyclonic energy for the northern hemisphere in the chart starting in 1971. However every chart with a starting point from 1980 onward shows a slight decline in ACE for both the northern hemisphere and the globe. In light of all of these graphs it’s certainly difficult to make a case that AGW is making hurricanes more powerful and destructive, at least on large time and/or space scales, especially considering the fact that it seems like every successive year in the past couple decades a new record is set for the “hottest year ever recorded”. One would think that if hurricanes were becoming significantly worse from global warming that solid confirmation signals would show up in these charts. Of course this is contrary to the news media articles and the attribution reports from the climate cabal. However, it is consistent with IPCC reports which expressed low confidence in long-term trends in tropical cyclone intensity, frequency, and duration. In the least, it is hoped that these analyses will at least draw doubt and speculation to the efficacy of single-event attribution science which has serious flaws. It is further hoped that word will spread of this speculative science to lawyers and judges so that unnecessary and costly lawsuits can hopefully be avoided.
4 Data from the Department of Atmospheric Science, Colorado State University
4 Data from the Department of Atmospheric Science, Colorado State University
https://tropical.atmos.colostate.edu/Realtime/
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The only thing becoming worse is more and more people choosing to live in harms way (on sand bars, flood plains, and in inadequate structures. We should learn from history.
Looks like my graphs at the end got chopped off. Here they are.
These too.
The article got fixed, thanks Charles.
I believe a hurricane is a revolving storm, not a result of “climate” in any way, shape, or form.
Another pointless post from an ignorant and gullible author. Energy associated with “cyclones” cannot be “accumulated” or “stored”. Future states of the atmosphere cannot be predicted any more skilfully than a smart 12 year old can do.
If this is what the author is trying to convey, albeit in a somewhat roundabout way, then obviously I agree.
This wasn’t an article on cyclone mechanics. ACE is just a commonly used metric to guage hurricane strength through the life of the storm. It’s not meant to imply the accumulation of energy with the storm just like the popular phrase “greenhouse gasses” doesn’t mean they work the same way as a greenhouse.
The point of the article was to expose the flaw in single event attribution studies that are being used to blame bad storms on climate change so they can sue big oil.
“Climate” can change nothing, and anybody who “attributes” anything to “climate change” is obviously ignorant and gullible. Likewise, anyone who believes them.
As to “so they can sue big oil”, I think I get the gist of what you mean. Hopefully, there will be at least some judges who are not as ignorant and gullible as some might hope. Even better, some might even realise that adding CO2 to air does not make thermometers hotter, which seems the basis for all sorts of nonsense, leading to such bizarre outcomes as ignorant and gullible (not to say mindless) protesters waving placards saying “Stop Climate Change!”.
Man, you never do let anything as trivial as reality impact your opinions, do you.
Reminds me of the saying, “often wrong, never in doubt.”
Maybe you could explain what you really mean to say, but I doubt it. Are you a “climate scientist”, perhaps?
Michael, you are way off base on this one calling someone else “ignorant and gullible”.
The term “accumulated” in this context refers to the cumulative cyclonic energy on a year-to-date basis. It is not a physics representation, but rather just denotes how the statistics are reported.
Personally, I find it quite a useful data series. If you think some ocean basin has been particularly active (or quiet) recently, then it is very easy to look at the shape of the curve and compare the activity to the historical averages.
Well, the author says
It seems to be a “commonly used metric” of the “climate science”, meaning different things to different people. Neither meaning seems particularly useful. If it’s a “measure of energy”, why not use commonly accepted units – of energy?
Sorry, but your “clarification” isn’t helping me. In my worthless opinion, the author is ignorant and gullible, and I can provide reasons to support my opinion if the subject of it so desires.
And that’s your opinion. Worth exactly as much as mine – in my worthless opinion, of course.<g>
Fascinating how the quotes you choose, completely refute claims you made.
Your rant:
Your quote:
is from the post. I even said “Well, the author says . . .”.
If you believe he is ranting, don’t blame me.
If a hurricane has nothing to do with temperature, why do hurricanes form mostly in the summer.
Only a few people are stupid enough to think that ACE means the energy of the storm itself is accumulating. What it means is that the numbers are accumulated. That is, the energy from all of the storms in a season are added together in order to create a single number for the entire season.
If you want to find someone ignorant and gullible, I suggest you find a mirror.
Michael is a one-trick pony. I am reminded of Nick, who likewise grabs onto one small thing and clings to it like a dog with a Frisbee (I hope you like animal metaphors), entirely missing the substance of an argument. Mikey’s need to denigrate rather than enlighten surely suggests a deep-seated insecurity.
This subject is a nuanced one, and speaking in absolutes is generally unhelpful. OK, I will stand with one absolute. There is no climate crisis. OK, two. No one knows enough about the climate system to make definitive statements about how it functions.
Why ask me? I didn’t say any such thing. You have either confused me with me someone else, or you are just confused in general.
Maybe you could quote my exact words? That would help avoid misunderstandings.
Nice post! And thanks for the links.
To me, attribution of extreme weather always seems to be circular reasoning. Since “climate change” can cause hot, cold, wet & dry conditions, one would be surprised only if the attribution came back as no effect. Your take is that we should look for “negative” effects on weather events,
to which I agree. But we should only look at events that have been both detected & attributed [as per AR6 Table 12.12 ].
And the Vaccine analogy was interesting. That reminded me that while vaccines can help, they can also hurt, so they should never be mandatory.
According to the alarmists, “climate change” can cause hot, cold, wet, and dry.
Even more amazingly, the dry is only ever predicted to land on the driest places. Climate change advocacy seems never to predict that an arid region could receive beneficial rain from these changes.
It is like a random coin flip that always lands on the “you lose” side!
I think the rubes are finally starting to question whether the alarmists are flipping a fair coin.
I always have a laugh when I see things of this sort. These sorts of “studies” are completely pointless – smart 12 year old standard, and nothing more. For example, a smart 12 year old can say that smartly applying a tourniquet saved a life. I admit to being ignorant and gullible, which is why I accept some vaccines, and reject others. For example, 5th and subsequent COVID vaccine injections.
I’m sure an expert could “explain” why I contracted COVID shortly after my 4th vaccination, and tell me that the vaccinations “saved my life” (add another “saved life” to the list?), but how do I know the “expert” isn’t ignorant and gullible himself!
Feynman said “Science is belief in the ignorance of experts”. Feynman was caught out badly, and wasted a lot of time due to taking an “expert’s” word for something that turned out not to be true. Once bitten, twice shy.
I agree that vaccinations should not be mandatory. If this results in the unvaccinated being persecuted or ostracised, them’s the breaks.
You got 4 Covid injections? Now that’s gullible. Chuckle.
As I said, I admit to being ignorant and gullible. I don’t suppose you might tell me something I don’t already know? Are you trolling or just stupid?
You should number your figures so we can properly complain about them. /s
“Most importantly there’s no strong evidence that climate change is making US landfalling hurricanes worse.”
There’s absolutely no evidence at all that ‘climate change’ is making US landfalling hurricanes worse.
We must stop using the catastrophist’s twisted interpretation of language.
The ‘climate’ you are in is the result of weather patterns caused by geography, which in turn is the result of tectonic plate movements, volcanoes & erosion over billions of years.
Climate doesn’t cause anything; it is a result ...
Of the average of (at least) 30 years of weather patterns in a particular area.
The UK has a Northern Temperate Marine climate, the same as our ancestors who built Stonehenge, except we are several degrees colder.
Most importantly, there’s strong evidence that weather patterns are cyclical.
That is an observation we should all make more often. Forests don’t cause trees.
A second meaning of the word “climate” has been surreptitiously added to the language. It is a favorite rhetorical trick that allows one to say something that seems sensible and uncontested when in fact you mean something entirely different. It is a linguistic trojan horse. In the UK we recently needed a supreme court decision to reinstate the old meaning of the word “sex” when reading documents written before the new meaning slipped in.
“Climate” in the mouths of activists means…well I don’t know what it means to them, but it isn’t the word we grew up understanding. Maybe it just means “higher CO₂ concentration”.
Agree that climate change isn’t a force that causes anything. But it’s a catch 22. If I say AGW then some will argue there’s no proof that humans are causing any warming. Thus in the article I mix around the use of AGW or climate change to make enryone unhappy!
“Climate change” Is weather change by definition. Climate change cannot cause weather change, that’s the cart before the horse.
From the article: “sure, there’s probably little doubt that AGW enhanced water temperatures made Melissa up to 10% stronger,”
I have a great deal of doubt about that.
There is no evidence that human-produced CO2 or any other source of CO2 is causing ocean temperatures to get hotter.
There is no evidence that CO2 is measurably warming the Earth’s atmosphere and there is no evidence that CO2 is warming the Earth’s oceans.
The sun warms the oceans. The oceans are not unusually warm.
There is no link between CO2 and any weather phenomenon.
Yeah I could’ve said possible instead of expressing high confidence. However when I was writing that the goal was to point out that even if that attribution analysis was technically correct that the whole method misses the bigger picture and is flawed.
When they claim there were 66 hurricanes this past season they lose all credibility. Slapping a name on every half assed collection of clouds over water has totally destroyed any claims to accuracy all these agencies ever had.
From the article:”…broader impact of AGW on hurricane activity.”.
How can something that doesn’t exist have an impact on anything.
The main point, that alarmist analysis never attempts a fair and comprehensive cost/benefit consideration, is well taken. However, assuming that either can be properly assessed in the case of tropical cyclones is in the context of human influences is itself flawed. No one knows enough about how the system operates to do so.
From the above article:
“. . . the climate activist community had their poster child in hurricane Melissa, one of the most intense tropical cyclones in history.”
Yeah, that “community” just cannot understand that a single data point CANNOT be used to establish a trend . . . in regards to climate, or any other physical or theoretical topic.
What was it, the 1935 Labor Day Hurricane that was just as intense and impressive as Melissa?
I am going from memory and have not verified the date.
Another analogy I thought of as I’m watching a hockey game is waiting for a team to give up a goal and then doing an attribution study on the goal against to see which player is to blame. But does that mean the player is bad overall for the team? Only a deeper analysis can determine that (ie, does he make more good plays than bad plays). These hurricane attribution studies are the same. They cherry pick a bad hurricane and apportion a % of the blame to climate change without assessing whether hurricanes overall have become worse over time with global warming. Big flaw, IMO.
Some very convincing numbers here, but naturally the mainstream media was guaranteed to bypass them in favor of over-publicizing Melissa and making their usual unsupported predictions that such storms will be more frequent because of human activity featuring higher levels of fossil fuel consumption. Except no one’s going to scale back this use because it might cause a minuscule increase in temperature averages or a couple more violent weather events.
A lot of good information. Of coarse I am disappointed that the article is about climate change rather than added CO2 in the atmosphere. Climate change is a meaningless term, everybody knows the climate changes, it always has. The question is does more CO2 in the atmosphere change climate? I say no, it has a modest warming effect most noticeable at night and I understand that the long wave radiation coming back to earth can’t raise ocean temperatures.
Yeah I was probly too loosy-goosy with the ‘climate change’ phraseology vs. saying CO2 or global warming. Guess I’ve been reading too many scare monger articles from the media, lol.