Update: Dr. Roger Pielke Jr. says via email “the fake photo is perfectly appropriate” and adds this update to his report on Grinstead from last year:
Today Grinsted et al. have another paper out in PNAS in which they follow up the one discussed below. They make the fantabulous prediction of a Katrina every other year. They say in the new paper:
[W]e have previously demonstrated that the most extreme surge index events can predominantly be attributed to large landfalling hurricanes, and that they are linked to hurricane damage (20). We therefore interpret the surge index as primarily a measure of hurricane surge threat, although we note that other types of extreme weather also generate surges such as hybrid storms and severe winter storms. . .
As I showed in this post, which Grinsted commented on, the surge record does not accurately reflect hurricane incidence or damage. Another poor showing for PNAS in climate science.
– Anthony
Guest Post by Willis Eschenbach
Anthony has commented on the recent paper by Grinsted et al. in his post called “Model predicts more storm surge, but they use what appears to be a fake photo in the press release“. The original study Abstract is here, but the paper has not yet been published. Fortunately, the supplementary material with their summary data is online here. This is the relevant quote from their Abstract (emphasis mine).
We find that warm years in general were more active in all cyclone size ranges than cold years. The largest cyclones are most affected by warmer conditions and we detect a statistically significant trend in the frequency of large surge events (roughly corresponding to tropical storm size) since 1923. In particular, we estimate that Katrina-magnitude events have been twice as frequent in warm years compared with cold years (P < 0.02).
Their claim from the abstract is that historically, warmer years have larger storm surges from cyclones … which seemed doubtful to me. So I got their “Surge Index” data from their Supplementary Information, and took a look. Figure 1 shows the results. I have plotted the size of the surge against the temperature anomaly for the month in which the surge occurred.
Figure 1. Surges plotted against the HadCRUT3 temperature anomaly for that month. PHOTO: Wolf Rock Lighthouse
Well … that sure doesn’t show what they claimed. There’s absolutely no trend in that at all. In particular, “Katrina sized events” (storm surge >= 113) are more common and larger in the colder months, not the warmer months. So having failed there, let me try something else …
They talk about warm and cold years, not warm and cold months. I’ll give that one a try. Figure 2 shows the previous Surge Index results compared to the temperature for that year, rather than for the month … or it will as soon as I go calculate, create, and shoot Figure 2 … OK, here it is.
Figure 2. Surges plotted against the HadCRUT3 temperature anomaly for that year.
That didn’t help in the slightest. Again, no trend in storm surge index with respect to temperature. And again, “Katrina sized” events with a storm surge 113 or greater are more common in the colder years.
So I fear that I can’t replicate their results. They may be using some very sophisticated analysis … but in my experience, if a trend were actually present, it would show up in one of the two charts above.
What am I missing?
Regards to everyone,
w.
DATA: Spreadsheet with the values is here.
[UPDATE] A reader points out that the paper is now available here.
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If I were an emergency planner, I’d be more worried when temperature anomalies diverged from 0.20. That’s the takeaway message.
Clearly you’re mistaken, or a shill of Big Oil, or something, cuz Al Gorezeera said there’d be no Arctic ice left by 2013.
(do I really need a /sarc?)
Willis, try infilling “missing” data. You’re neglecting the storm surge of fake data.
Russ in Houston says:
March 19, 2013 at 7:02 am
“Why are we using Katrina as an example storm? Most of the damage that was associated with the storm was caused by a leeve failure. It wasn’t over topped, it failed due to improper construction and maintainance.”
The damage to New Orleans was as you say. However, there was major damage in Mississippi and Alabama due to a Cat 5 like storm surge.
Kasuha says:
March 19, 2013 at 5:11 am
Kasuha, it may well be that a “warm year” determined by global temperature anomaly is too narrow … but that’s what they are doing. They list it out in the document and the SI. I just couldn’t replicate it …
w.
TimTheToolMan says:
March 19, 2013 at 5:34 am
Dang, the Marcott-Shakun method, why didn’t I think of that?
w.
brad says:
March 19, 2013 at 6:59 am
I plotted both by month and by year … take another look.
w.
They could have seen the data as a “bathtub” curve in which case higher temperature would ultimately trend upward in surge index. I do not advocate that view as more data is needed and consideration for more drivers should be made. I also see that if it is indeed a bathtub curve that the global cooling scenario is just as bad, if not worse. . .
I have noted something.
As their “climate science” fails and they can no longer produce actual science (if they ever did) that backs their position what they have done is switch the purpose of “science papers”.
“Science papers” are now just an arm of the propaganda efforts. The claim that their propaganda is based on a “science paper” makes their silliness seem realistic. So expect a huge upsurge in junk science papers that will be given quick press and wide public distribution — then quickly forgotten to be replaced by yet another junk science paper and then another and another — all shrilly touted and as quickly forgotten.
Debunking these papers needs to be done but as propagandists they are only interested in the immediate headlines. Lots and lots of shouting hides the calmer voice speaking truth. God, but we are dealing with people who are real garbage.
Eugene WR Gallun
Their relationship was probably with the AMO. Just by eyeballing it, when comparing the AMO vs. Chris Landsea’s Power Dissipation Index (PDI), I can see a relationship. The PDI had lower values when the AMO was negative during the 70’s and 80’s.
http://rogerpielkejr.blogspot.ca/2012/11/us-hurricane-intensity-1900-2012.html
http://en.wikipedia.org/wiki/File:Amo_timeseries_1856-present.svg
Of course, Tamino maintains that the AMO is a response to temperatures, so why you aren’t picking up this relationship using HadCRUT is a mystery.
Kudos to Kurt, DavidL and Ferd for their comments. The paper reads as an attempt to find evidence to support a pre-existing agenda. Thats worse than useless. Even the definition of “surge” is likely useless for several reasons. The “parameterization” of surge is suspect due to conflating unknowns. You can’t quantify something without understanding it.
Eg. Coastlines are too variable to assume a “surge” quantity as a linear function. People have naturally settled along coasts in “surge prone” areas, such as harbors. And avoided cliffs.
The papers measurements of “surge” are post-hoc. Good science would make the hypothesis based on a clear definition, then establish a method to observe, and quantify the “surge” over time.
Delightful as always. Keep up the good work.
The Marcott-Shakun Method. I’m suddenly reminded of the Schartz-Metterklume Method. There are similarities…
I wonder if homogenising the surge data would work or was that pasteurising it, I forget…..
[snip. Invalid email address. — mod.]
The reason for all of this push to get another hockey stick into AR5. The big upswing graph is the only thing a lot of undeveloped countries leaders can follow, got to have an easy to see graph for all those who have very little science training.
It gets them the votes from the floor they need, they (hockey sticks) help to stir up the masses, to generate the “tax redistribution of income method” for skimming some/most of the money as it passes through the UN.