2010-08-16 20:00:11Basic rebuttal No.16: Hurricanes aren’t linked to global warming
Graham Wayne

Hurricanes And Climate Change: Boy Is This Science Not Settled!

Argument No.16: Hurricanes aren’t linked to global warming

The current research into the effects of climate change on tropical storms demonstrates not only the virtues and transparency of the scientific method at work, but rebuts the frequent suggestion that scientists fit their findings to a pre-determined agenda in support of climate change. In the case of storm frequency, there is no consensus and reputable scientists have two diametrically opposed theories about increasing frequencies of such events.

The background to these enquiries stems from a simple observation: extra heat in the air or the oceans is a form of energy, and storms are driven by such energy. What we do not know is whether we might see more storms as a result of extra energy or, as other researchers believe, the storms may grow more intense, but the number might actually diminish.

What do the records show? According to the Pew Centre, “Globally, there is an average of about 90 tropical storms a year”. The IPCC AR4 report (2007) says regarding global tropical storms: "There is no clear trend in the annual numbers [i.e. frequency] of tropical cyclones."

But this graph, also from the Pew Centre, shows a 40% increase in North Atlantic tropical storms over the historic maximum of the mid-1950, which at the time was considered extreme:

But while the numbers are not contested, their significance most certainly is. Another study considered how this information was being collected, and research suggested that the increase in reported storms was due to improved monitoring rather than more storms actually taking place.

And to cap it off, two recent peer-reviewed studies completely contradict each other. One paper predicts considerably more storms due to global warming. Another paper suggests the exact opposite – that there will be fewer storms in the future.

What can we conclude from these studies? About hurricane frequency – not much; the jury is out, as they say. About climate change, we can say that these differing approaches are the very stuff of good science, and the science clearly isn’t settled! It is also obvious that researchers are not shying away from refuting associations with climate change, so we can assume they don’t think their funding or salaries are jeopardised by research they believe fails to support the case for AGW. The scientific method is alive and well.

Never mind the frequency, feel the width

So far, all we’ve managed is to document here is what we don’t know for sure yet. But we do know there is extra energy in the system now, so could it have any other effects on tropical storms? Here, the science is far less equivocal, and there is a broad consensus that storms are increasing in strength, or severity. This attribute, called the Power Dissipation Index, measures the duration and intensity (wind speed) of storms, and research has found that since the mid-1970s, there has been an increase in the energy of storms.

Recent research has shown that we are experiencing more storms with higher wind speeds, and these storms will be more destructive, last longer and make landfall more frequently than in the past. Because this phenomenon is strongly associated with sea surface temperatures, it is reasonable to suggest  a strong probability that the increase in storm intensity and climate change are linked.

2010-08-17 15:11:53Great flavor, nice finish


I was actually going to note your virtue in taking this on and then suggest it just be dropped because conclusions are so squishy but you made it into a nice example!

I ran into some information just recently having to do w/a possible increase in N. Atlantic storm intensity; if you want me to dredge up the refs let me know. 

2010-08-17 16:22:04on storm frequency
Graham Wayne

Hi Doug - I'd like the reference for my own links please. I did find some other information but concluded that if I over-egged it, the additional stuff might look a bit suspicious. Glad you appreciate the slant though - had me puzzled for a minute as to how to pull it off.

BTW - if you're generally happy with it, does the rebuttal merit a thumbs up yet?

2010-08-18 02:08:57Yes

I do think it's ready. I'll look for my references; they're recorded in a text file somewhere (hopefully still).
2010-08-19 15:51:17More thumbs required
Graham Wayne
Hey - this one has been languishing. More thumbs required please (or comments)
2010-08-20 04:45:10Bump and ping


Graham I just remembered that I posted those refs in a comment thread. Will find and supply link.

Meanwhile, bump.

2010-08-20 05:52:15Typo - one "that" too much


Hi Graham,

in the last paragraph there is a "that" too much in this sentence:
"Recent research has shown that that we are experiencing more storms with higher wind speeds, ...."

2010-08-20 05:56:18

Could even remove both of those there thats. :-)
2010-08-20 08:45:50Small grammar point
John Russell


"...that there will be less storms in the future"...

Should be "...that there will be fewer storms in the future".

Don't ask me why -- it's just that that's what the grammar books say!  

Otherwise excellent!

I award the order of the green thumb.

Best wishes,


2010-08-20 09:45:16


This is very good, however I'd suggest making the heading:

  • Never mind the frequency, feel the width

To something like

  • Never mind the frequency, feel the intensity

"Width" does not adequately convey the intent of the second half for a lay audience. A lay reader may say "You mean fatter?"

People don't always read the complete text, but scan paragraph headings and take those away as sound bites. Making headings simple, declarative "statements". In an online environment, readers will scan an article first to see if it's worth their time, thus those paragraph headings need to be like mini-post titles... ask if the heading draws the reader in.

Otherwise, a very good summation of the issue. Watts and Nova have been banging on about hurricane/TC frequency the last few weeks as if that disproves the claims of science.

Nice job!

2010-08-20 11:55:57Thumbs up

Good post.  i agree with the above comments.
2010-08-20 19:06:55Corrections
Graham Wayne

Thanks to BaerbelW (and Doug on the same point), JR (after the split infinitive elsewhere, you are rapidly becoming the guardian of our good english, and I for one really appreciate it) and watchingthedeniers. All points now addressed except one...

watchingthedeniers: I didn't change the paragraph head. I know what you mean, but it's a word-play joke really, not intended to be scientifically accurate. I could argue that it is the oddity of the title that would draw in readers, but I have as much proof of that as deniers do about anything at all...  :)

Rockytom: as you pass through various threads, would you consider giving a green thumb to those you are happy with? It really helps to keep the process moving...?

2010-08-20 19:35:29feel the width
John Russell

Agree with graham 'width' is a stand in for intensity to create a wordplay. It's not necessary to change -- everyone knows the autor doesn't actually mean 'width'.  
2010-08-21 18:13:09Any spare thumbs around?
Graham Wayne
2010-08-21 18:19:27thumbs up from me
John Russell


I just realised I've already given you one, Graham. So I better take it back -- but I can't! 

2010-08-21 18:31:31Cool with me...
Graham Wayne
No complaints here mate...still thinking of voting for myself, but it's so damn obvious!
2010-08-25 18:13:14Two thumbs (BUMP)
Graham Wayne
We've all got a thumb to spare, surely?
2010-08-26 04:22:32
Anne-Marie Blackburn
Anne-Marie Blackburn
Thumbs up from me
2010-08-26 13:26:01I like it.


This is a good response.  There seems to be a lack of info regarding trends in extreme weather. 

Anyway, thumbs up for me! Good job.


2010-08-27 01:38:11Comment
Robert Way

Why does the graph end there. cause since then hasn't there been a big drop? I think its important to put a little more into the intensity section as that is more scientifically clear.
2010-08-27 04:01:30Great job of a messy area!

1st line, 2nd paragraph -I think " theses enquiries" should be "these inquiries".
2010-08-27 17:50:59Responses
Graham Wayne

Robert; the PDI is covered in more detail in the intermediate. I think this is long enough already.

Niamhaill: quite right, and thanks!

2010-09-03 17:28:46Published
John Cook

Great article, Wayne, love how you turned it into a teachable moment about the scientific method.