On Sunday profile on ABC Radio on Sunday 29 March, the Director and CEO of the Bureau of Meteorology was interviewed. The whole interview is here:
For a scientist who claims to be only interested in science and not in advocacy, he certainly sounds like a fervent Global Warming Enthusiast.
Here is the feedback I sent to the Bureau.
“[THESE QUESTIONS ARE DIRECTED TO DR. BOB VERTESSY, WHO WAS INTERVIEWED ON ABC RADIO ON SUNDAY]
Dear Dr Vertessy
I was interested to listen to your interview on Sunday Profile on ABC Radio yesterday, 29 March 2015. I was particularly interested in your comments regarding public criticism of the Bureau’s adjustments to temperature data, and on the increasing frequency in heatwaves.
Several times you stated that the adjustments “make no difference at all” to temperature trends, that the raw temperature data “tell exactly the same story”, and that we see “the same result (in temperature trends) for the whole continent” as for raw data.
You also stated that heatwaves are becoming “one of our most serious natural disasters”. They are “a bit of a silent killer- it’s the number one cause of death.” You also said, “We are probably seeing of the order of five times as many very serious heatwaves today as we did in the middle of last century.”
I have some questions.
Q.1: Can you please supply me with a reference to your data that show that the number one cause of death is heatwave? I was sure it was cardio-pulmonary disease usually associated with very cold weather, with mortality rates much higher in winter than summer. Perhaps you meant heatwaves are the number one cause of death when compared with other natural disasters, which is debatable. This was not at all clear and must surely have misled some listeners.
Q.2: Can you please supply me with a reference to your data that show five times as many very serious heatwaves today compared with the middle of last century? Could you also please tell me your criteria for a very serious heatwave.
For the next question I refer you to Table 1 on page 14 of On the sensitivity of Australian temperature trends and variability to analysis methods and observation networks (CAWCR Technical Report No. 050), R.J.B. Fawcett, B.C. Trewin, K. Braganza, R.J Smalley, B. Jovanovic and D.A. Jones , March 2012 (hereafter CTR-050). This shows that quadratic change in mean annual temperatures from 1911 to 2010 in adjusted data of the ACORN-SAT network (+0.94C) is 36% greater than in the ‘unadjusted’ data of the AWAP network (+0.69C). For maxima, the change is 38.9%, and for minima is 34.1%. In this paper the authors claim that the rise in unadjusted data is “somewhat smaller” than in ACORN-SAT.
Q.3: In what way can 38.9%, 36%, or 34.1% difference in quadratic change be interpreted as “no difference”, “exactly the same story”, or “the same result”?
Perhaps you should have told your listeners that the similarity was only since 1955, and that before this, raw data show temperatures (especially maxima) were cooling, but then 60 years is not such a long climate record for making trend analyses, and this may be confusing to those who cannot understand more than a simple climate narrative.
In the Concluding Remarks of CTR-050, p.50, the authors state that “further work will be undertaken to characterise in more detail these changes, particularly at the monthly and seasonal level”.
Q.4: When can we expect to see the results of this further work published on the ACORN-SAT website? If it is available elsewhere please refer me to it. I am particularly interested in any difference in quadratic change in summer maxima between AWAP and ACORN-SAT, as this is relevant to heatwave analysis.
I look forward to your reply.”
For an explanation for my interest in comparison with AWAP data, see my analysis of monthly and seasonal differences in trends between AWAP and Acorn from October last year. My calculations indicate a 200% increase in trend in summer maxima.
One might think that if Australia wide there has been a five-fold increase in the number of very serious heatwaves, there should also be some discernible increase in the number of very hot days.
To illustrate my incredulity about this claim, here is the timeseries graph of very hot days (BOM definition: >40 degrees Celsius) straight from the Bureau’s website:
The linear trend (for what it’s worth) shows an increase of 0.02 days per decade. That’s 0.2 of a day per hundred years, or 2 days in 1,000 years. Scarey hey.
I will be following up on the hot days and heatwaves analysis in coming posts.