Monday, January 24, 2011

All summer in a day*

Yesterday was a lovely summer's day in Brisbane; the first in 3 months it seems. So, being the last day of the school holidays, we went down to the Gold Coast and had a nice time at the beach. Water temperature was warm; no bluebottles; the sun was out but the air did not feel too hot. Lovely.

As for recent Queensland weather generally, I note that Andrew Bolt had quoted another blogger claiming that a report by Queensland's Office of Climate Change barely mentioned "floods". It turns out that this relates to merely one chapter of the report, and as Tim Lambert says, it's another case of climate change skeptic gullibility.

In terms of the climate change debate, I have never paid all that much attention to the particular regional rainfall changes for Australia forecast by CSIRO and the like. I just always assumed that regional forecasts under climate models were going to be more rubbery than the general effect of increased heat waves, which I consider a big enough worry. This explains why I wasn't really aware that there had been predictions of both extended droughts and intense rainfall under AGW. But as Tim Lambert notes, the report Bolt tries to slur as being warmenist propaganda that puts the emphasis all on drought, has this:
Climate change is also likely to affect extreme rainfall in south-east Queensland (Abbs et al. 2007). Projections indicate an increase in two-hour, 24-hour and 72-hour extreme rainfall events for large areas of south-east Queensland, especially in the McPherson and Great Dividing ranges, west of Brisbane and the Gold Coast. For example, Abbs et al. (2007) found that under the A2 emissions scenario, extreme rainfall intensity averaged over the Gold Coast sub-region is projected to increase by 48 per cent for a two-hour event, 16 per cent for a 24-hour event and 14 per cent for a 72-hour event by 2070. Therefore despite a projected decrease in rainfall across most of Queensland, the projected increase in rainfall intensity could result in more flooding events.
Very prescient, as it turns out. (Not to say that you can directly attribute any particular extreme weather event to AGW yet.)

Last week, I pointed out a different paper which indicated the same thing (modelling indicates longer droughts but broken by intense rain) at Catallaxy, a.k.a the "centre right" blog where climate science goes to die. This was followed by the glib "so, everything's consistent with AGW" response that shows that even though a weather event may (after all) be consistent with climate modelling of some years ago, they will insist on claiming that it either isn't, or that it doesn't matter.

I think that Tim Flannery's role as a populariser of AGW has something to do with this, in that he seemed to love making statements that gave the impression that Australian cities were facing pretty much continual drought since the last one started about a decade ago. But again, I simply haven't paid him much attention, and skeptics who harp on about him are in one sense fighting a straw man.

Meanwhile, a fight has broken out at Judith Curry's blog about attributing extreme weather to AGW, and the Queensland floods get a particular going over. (Read from here down). Curry did do one thing useful, and linked to this site, which has a lot of links to papers over the years looking at extreme rainfall over the decades in Australia.

Andrew Bolt's also been an enthusiastic promoter of the idea that poor management of the water flows out of the Wivenhoe dam was the real cause of this flood. He is following the lead of The Australian's Hedley Thomas, who has been running a story kicked off by an engineer with no experience in hydrology, although others (not directly involved in Wivenhoe) have come out offering some sort of support. Of course, now that an enquiry is underway, the proper thing to do is to give it a rest. I personally expect that there will ultimately be no blame put on the Wivenhoe dam managers at all, nor on any politician. One media report noted last week that the dam inflows that led to the floods were enough to fill it in a day (something I would not have thought possible.) I simply find it very hard to believe that in those circumstances it is at all likely that the outflow decisions could have done anything other than make a very minor difference to the flood height.

However, if I worked for SEQ Water, I would consider both Hedley Thomas journalistic campaign, and Bolt's anti climate change politicisation of it, to both be offensive smear campaigns. No, wait: I don't need to work for SEQ Water to be very annoyed with Bolt's line of argument. (Sure, you can say that I've already admitted that I didn't have knowledge of the drought and flood AGW papers either, but then I'm not the one running an anti climate science campaign in a national newspaper, and being completely careless of informing myself about facts.) Bolt is running not just with the line that the dam operators were at fault, but it was the insidious effects of "warmenism" that led them to not let out enough water in case we were left without enough drinking water. Oddly enough, while Bolt was saying this, John Quiggin quickly shot from the hip and suggested that maybe the dam should be operated at 75% capacity when a wet summer is forecast. While I expect Quiggin may well change his mind, it certainly shows there is at least one "warmenist" who takes a line contrary to what Bolt would suggest.

I bet the reality turns out to be this: the dam has always been intended to run at 100% supply for drinking water if possible, and population increases since it started operating in 1985, and a recent drought which led to the dam getting dangerously low meant the policy continued to make a lot of sense. "Warmenism" will have nothing to do with the policy existing to this day.

We'll see if I am right or wrong.



* I knew the title was from a science fiction story, but I couldn't remember anything about it. Turns out it was particularly apt:
The story is about a class of school children on Venus, which in this tale is a jungle world of constant torrential rainstorms, where the sun is only visible for only two hours every seven years. Such an occurrence is imminent.

3 comments:

Anonymous said...

"... as Tim Lambert says, it's another case of climate change skeptic gullibility."

Steve;

Not for nothing, but you're getting your AGW science from Lambert who hasn't published for a decade according to his bare UNSW website and links to a truffle farmer in NZ about climate science.

How much lower can you go.

JC

Steve said...

JC, what the hell does Lambert's publishing record have to do with the ability to read a government report - in full?

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