As Hurricane Dean works its way through Mexico, we are reminded of the debate between those who link Hurricanes with global warming, and those who don’t. Scientists Chris Landsea of NOAA and Greg Holland of UCAR find themselves on opposite sides of the debate. Holland has recently claimed that tropical storms have doubled due to global warming in a new paper with Peter Webster. Landsea has also published a recent paper entitled Counting Atlantic Tropical Cyclones Back to 1900. Holland is quoted as saying, “….my sense is that we shall see a stabilization in frequencies for a while, followed by potentially another upward swing if global warming continues unabated.” Landsea’s response was to call Holland’s research “sloppy science.”
Roger Pileke Jr, who has several publications on Hurricanes co-authored with Chris Landsea, waded into the debate by asking Webster for his data. Webster told him in no uncertain terms to recreate it himself, so he did.
The storm data set used is divided into halves, each 51 years long:
1905-1955 (51 years) and 1956-2006 (51 years).
The official HURDAT data looks like this:
1905-1955 = 366
1956-2006 = 458
Holland/Webster 2007 looks like this using their storm-count underestimate correction:
1905-1955 = 417
1956-2006 = 458
Landsea also uses a storm-count underestimate correction:
1905-1955 = 529
1956-2006 = 527
It all comes down to which correction is correct.
William Gray has his say here.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Currently sitting at Mooloolaba watching 4 metre swells and lightning – looks like something akin to Dean is here as well!
Jim: Sit tight. Try finding a taller sand dune on the Pacific sea front otherwise. Reckon you will feel safer up at old Buderim?
These mod canal estates are already a bit sus. Currimundi inlet is a future weak point like Twin Waters.
Good luck finding the airport hey
Balanced newspaper article in the UK Independent:
The Big Question: Are there more hurricanes, and are they the result of global warming?
http://environment.independent.co.uk/climate_change/article2881385.ece
Gadzooks – an article indicating controversy. And in the Independent ! Post it on the wall.
Will the readership cope with the confusion?
I am interested to know what Landsea’s conclusion is but this is all the information in the abstract:
Climate variability and any resulting change in the characteristics of tropical cyclones (tropical storms, subtropical storms, and hurricanes) have become topics of great interest and research within the past 2 years [International Workshop on Tropical Cyclones, 2006]. An emerging focus is how the frequency of tropical cyclones has changed over time and whether any changes could be linked to anthropogenic global warming.
And the conclusion is?
When does a teeter totter exercise on a seesaw become boring?
Pielke Jr’s conclusions from comparing HW2007 with the Landsea paper:
1. Given how crucially the results of HW2007 depend upon a yet-to-be completed reanalysis, aggressive and loud public claims to absolute certainty (in any direction) are way overstated.
2. Extension of a still-uncertain analysis of trends to claims of conclusive attribution to greenhouse gas emission may be supported by other available research but is not at all by HW2007, at least not according to anything even remotely resembling the IPCC’s approach to detection and attribution. I doubt that the detection threshold has been achieved, pending a proper uncertainty analysis.
3. Was Landsea justified in claiming that HW 2007 were “sloppy”? HW could of course easily resolve this by releasing their dataset for all to see (don’t hold your breath, by we shall see), but my analysis suggests pretty strongly that they did not follow the procedures that they described in the paper, exactly as alleged by Landsea. For a paper broadcast around the world as being policy relevant, this is unfortunate, to say the least.
4. Should the American public have new and increased concerns about increasing hurricane landfalls, as compared to recent years? Maybe, but HW2007 do not make this case. In fact, their paper does not even discuss landfalls!
5. Until the research community can satisfactorily explain the relationship of basin-wide activity with landfall rates, any suggestion that landfalls will continue to increase (or even decrease!) in future years remains speculative at best and at worst, a dramatic overstatement of what science can provide at this time. There is marginal skill in forecasting basinwide activity on a seasonal basis, and no skill at predicting landfalls at any timescale (greater than 5 days;-). I welcome corrections if this assessment is incorrect (but I don’t think that it is).
6. And it probably needs to be said that it is already well documented that there has been a dramatic increase in activity 1995-2006 as compared to 1970-1994. This is widely accepted and its causes are debated. But it is not the focus of HW2007 which claims to discern a heretofore unseen trend from 1905-2005.
Bottom line? Landsea was absolutely correct about the sloppiness, which is inexcusable. The jury is still out on trends, though uncertainty seems sure to persist for a while, despite the loud and aggressive claims to the contrary.
Yea well Pielke would say all this wouldn’t he. He seems to be railing about absolutely everything. Yet another contrarian pretending not to be.
And what’s this diversion on landfalls about. Can’t they write their own research papers.
No word from Jim?
Pielke Jr frustrates both sides of the AGW argument, but he is well published, particularly in Hurricane science. The upshot is that no-one should be making strong statements about a link between hurricane frequency/intensity and global warming. The problem with records is always the fact that recent records are better than historical records, so we can’t really compare like with like.
PS – we’re back to the unfortunate and unnecessary practice of withholding data, which blights climate science.
So is Webster claiming to have published “peer reviewed” research? If so, who were these peers? And what sort of credibility can that process have if the core material has not been forthcomming?
Webster’s main crime is not being sloppy, the refusal to provide the data is an unambiguous demonstration of a willingness to be selective with the facts. In my days in the headhunting business that was all that would be needed to earn the bum a 8 minute interview and a roaring silence.
It’s Holland and Webster – at least try to familiarise yourself with the very basics.
Read the paper – of course not.
Luke
all you have to do is put up the science, and watch it completely ignored, to see what makes up the level mainstream denier debate.