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Roger -----------

Your arguments are entirely sound. As the RealClimate piece on Peer Review indicated, science advances in slow measured steps. Peer reviewed papers are built on a foundation of previous peer reviewed papers which are cited in their bibliography.
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Unfortunately this slow process means that momentum shifts in science come only with difficulty. When someone like Dr. Trenberth proposes a hypothesis which has no previous history of peer reviewed publication, it is (rightly) very difficult to perform the rigorous analysis required to pass peer review.
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Nevertheless, momentum shifts do take place regularly. This is because good scientists do not close their mind to new evidence, nor to the possibility that their own conclusions might be overridden by this new evidence.
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I think it is only a matter of time until peer reviewed papers emerge which support Dr. Trenberth's position, which is now nothing more than a hypothesis. There is already a significant body of evidence that could serve as the basis for such a paper. I'd like to elaborate a bit:
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The evidence comes from climatology -- the daily frequency of storms:
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In the tropical North Atlantic the Tropical Storm Frequency (http://www.ems.psu.edu/~nese/f11_3_2.htm ) peaks sharply around 12 September. This corresponds with the time of peak heating at the latitudes (5 to 10 N) where tropical storms are spawned. One need only compare the frequency of hurricanes on 12 Sept with the frequency on 12 August or 12 October, for example, and ask what factors cause this difference. One of the primary factors is the heating and resultant sea surface temperature.
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Similarly, one can compare the Atlantic basin with the Tropical Northwest Pacific. That part of the Pacific produces the most frequent and strongest hurricanes on Earth. An analysis of why this Pacific basin has more storms than the Atlantic basin is likely to point to the fact that Sea Surface temperatures are warmer there at the latitudes where Tropical Storms form. Since both basins experience the same solar input, but one produces warmer water (and higher air humidity) as a result of basin size and configuration, this provides further evidence that sea surface temperatures and air humidity cause the difference between the two basins.
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It is not unreasonable to conclude from this evidence that warmer sea surface temperatures (SST) and higher humidity cause a greater daily frequency of storms.
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So assuming that it has been established through other peer reviewed papers, that GHG warming will produce greater SST and humidity in the tropical northern ocean basins in early September, then one can fairly confidently conclude that there will be a greater daily frequency of tropical storms.
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I believe that Landsea's approach, of searching for a trend in storm frequency ignores the sort of climatological evidence I've cited above. Nevertheless, his methodology is sound, based on the data he used and the methods by which he analyzed them: The high year-to-year variability of storms produces a large "noise" level, above which a clear signal of Greenhouse warming has not yet emerged.
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What I predict will happen in the future is that a few papers will emerge that examine the evidence more from a climatological and process-study point of view: I've suggested the climatological approach above -- process studies (regarding what makes hurricanes form and what sustains them) have already been done which rather clearly point to the fact that warmer SST's and higher humidity do produce more and stronger storms. The result of putting the two ideas together provides strong **circumstantial** evidence that we can expect more tropical storms in a GHG warmed world.
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It is entirely possible to get peer reviewed papers accepted which are based on strong circumstantial evidence, particularly when some direct evidence is also emerging (namely, the unusually high frequency of North Atlantic Tropical storms since the mid/late 1990's, for example). As said, I expect to see these papers arriving at a peer reviewed journal near you -- possibly even in time for the release of AR4.
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-- Pete Wetzel, Ph. D., 1978 Atmospheric Science, Colorado State University. Trained in the understandin of tropical storm processes by Dr. Bill Gray (http://typhoon.atmos.colostate.edu/ ). Specializing in the parameterization of land-atmosphere interactions for Global Climate, Regional Mesoscale, and Local Cloud Resolving numerical weather prediction models.

Sorry, the links didn't work -- try these:

http://www.ems.psu.edu/~nese/f11_3_2.htm

http://typhoon.atmos.colostate.edu/

Trenberth´s hypothesis is absolutely reasonable. At the most basic level, Thermodynamics explains it all. We were expecting weird climate since many years. It is, unfortunately, possible a scientifically explanation of these severe events. Sometimes we don´t understand excellent scientists like Landsea ..
Well.. maybe we are not experts in this particular extremely complicated Science. Climatology will have never the possibility to take into account in models all and every one of the million of real events that take place on the Earth (so many marginal, unknown ones which add a lot, maybe).
I hope we have not to wait too much for papers suppporting Trenberth´s views being written.
His point of view is much understood, at least empirically, by many Scientists and people with common sense.

May a layman comment briefly?
One must regognize the value of peer review, but one can also notice that there is a lot of research that is part of the climate controversy where the "peers" are chosen by the research author or a very supportive editor,or even the owner and ideological dictator of a publication. A recent case was the von Storch blowup a year or so ago, followed by his resignation when the owner was not sufficiently impressed by his adverse views, and the journal seems to have sailed along since without benefit of improvement. Then there is the publisher of the M&M paper whose only apparent standard is whoever puts out a line she favors, and the ensuing climb down by Science which seems to have left it to reviewers to explain why nothing further should be done except that Mann should perhaps let the bad guys see all the data, so that apparently peer review does not include doing that, or even taking a close look at the study concerned if they are busy, as one reviewer complained. And then Science puts its bets on von Storch, who contributes a devastating attack on Mann (that Mann is not even given a chance to read prior to publication).

Tell me of something nasty that the skeptics have done that is worse than all that. The only item I can think of is that the majority of climate scientists are the white hats and the skeptics are the black hats. Just look at their funding, their associations, and their often hilariously brainless arguments. We really do not need the help of statistical science to reach a conclusion on that one.

Not that I am complaining about all this. The climate scientists are in the "happy" position that whatever modest conclusions they draw from their studies, supporting evidence is likely to land at their front doors with the morning media .

I believe it is reasonable to say one must hope the scientists will insist upon maintaining high standards in their work. But they should form and stay loyal to alliances among themselves (IPCC), stop giving the rest of us these ego displays like we are seeing now between von Storch and Mann, and pour their venom instead into attacks on the enemy.

Yes we do need good science. But we do not need wimps who panic and start to qualify themselves out the back door as soon as corporation funded academic whores start snarling. There will be no gentlemen in this fight. Garry Culhane

So we have strong supporting evidence that hurricane intensity will increase with global warming,this being: hurricane frequency is greater during september than august/october. Well gosh that's demolished the skeptics. Why not demolish them some more by comparing September to March. Perhaps if we were told the exact increase in frequency and the exact increase in hurricanes and the exact increase in sea temperature we could come to some useful conclusions.
Meanwhile a simplistic counter-argument of my own. Given that vedlocity increases with the square root of energy (E=.5mv^2) my calculations show that a 1 C increase in average temperature gives .1% increase in average windspeed, ie unmeasureable. Highly simplistic I know! But so is saying that higher temperatures must increase storminess

A lot of these arguments represent tautologies. Hurricanes must become more frequent and stronger because of global warming. The fact that this past year had a number of strong storms proves that there is global warming. This is an unreasonable leap in logic. There is no evidence that there was a significant or unprecedented change in the number of hurricanes. Even the current, flawed GCM's would not predict an increase in hurricane activity at this point in the global warming cycle. They would place such changes several decades in the future. The most crucial point is that there is no peer reviewed science that "proves" anthropogenic global warming exists. I suggest that anyone who is convinced should read up on the "Maunder Minimum" and the "Little Ice Age".