As a Queenslander, I am appalled that this fellow conveniently ignores the fact that there was nothing extreme about the recent floods. As readers of this blog know, 1974 was a much bigger rain event in Brisbane. But even it was dwarfed by the 1893 floods.
The problem with the floods this year has been the development of expensive housing and offices on the river flood plains. In 1974, the areas flooded were largely industrial. Sure, the city and residential areas were also flooded and it was a huge disaster. But it didn’t cost anywhere near as much in dollar terms as the recent floods.
It is the economic cost that is extraordinary this time. It has nothing to do with the weather or climate. It has everything to do with local planning laws, expensive residential developments in flood prone areas and the management of the Wivenhoe Dam.
Dr Trenberth has no credibility.
What makes this interesting is it points out something I mentioned in both "The World's Most Stupid Bureaucrat" and "Welfare For Malibu Residents", many of our AGW proponents talk about "the worst flood ever" and similar things, but do so IN TERMS OF COST. Well, if land is developed which previously was not, or new expensive construction goes up (especially in the US where flood insurance encourages such foolishness), then the economic scale of floods will increase, even though the flood itself may be the same scale, or even smaller than previous ones. Thus, we are basing these estimates of "ever worse flooding" on measurements which are largely meaningless. (Not to mention that many places, such as Australia, have only been settled in recent times, and much development is in areas previously not regularly observed, and thus we have no idea what the scale of previous floods were.)
NOTE: This phenomenon is similar to the increase in disability I discussed in "Peanut Butter and Disability", obesity in "Twice in a Row" or the rise in autism I mentioned in "Statistical Artifacts". By measuring things using a shifting proxy, or by defining your target in unusual ways, it is very easy to find anything you want. And, sadly, in many cases, it is not even real dishonesty, those finding these misleading results have deluded themselves, or been deluded by following the practices of those who are knowingly dishonest.
UPDATE (2016/06/18): Actually, it just struck me that the confusion between known reserves and absolute amounts that lies at the heart of most "peak oil" nonsense is another symptom of the same sort of mistake as well. See "A Brief Comment on Oil", "A Thought on Oil Reserves", "Why I Doubt Peak Oil Predicitons", "Why Peak Oil is Laughable", "Rejecting "Peak Oil"", "Greed and the Price of Oil" and "The Consumption Curve".