Today on ABC Radio’s Country Hour, there was an interview by Lydia Burton with a grazier from the Longreach district in Central Western Queensland, which has been having some pretty hot weather this summer, as has most of Western Queensland.
Peter Whip is from Royston near Longreach and says over the last 50 years he has noticed an increase in the amount of days over 35 degrees and that is a real concern for all landholders.
“In the last couple of years we have had some really long hot dry spells when the feed quality has been terrible and we have seen cattle conditions slip really quickly.
“That is certainly something that is changing over time and….it is something that in 20 years time it will be a significant impact.”
The gist of the segment was that cattle were struggling in the heat, with so many days above 35 degrees Celsius, and especially with days over 40 degrees, let alone 45 degrees.
As I have said before, I have close links to agriculture. My parents, grandparents, and great-grandparents were farmers; one brother still farms, another is retired, and my brother-in-law is a farmer also. As well, several nephews and nieces are on the land or in agri-business. I have great sympathy for those on the land at all times, especially in drought conditions.
However, is there any evidence that Longreach is having an unusually hot spell, or that Longreach is getting hotter, or that it will get hotter in the future? And how could an intrepid rural reporter check the facts against one grazier’s anecdote?
The very simplest check would be on Longreach’s mean maximum temperatures. From November to February, the mean monthly maximum is never below 35 C, so we might expect many days to be well above 35 C. Longreach Aero’s highest ever maximum was back on 28 January, 1990, at 47.3 C.
Let’s have a look at the number of days above 35 C, 40 C, and 45 C. I’ll do this for 180 day periods, which will capture days in a single summer, but not two. I use the official ACORN dataset, plus daily data right up to yesterday, 1st March, straight from the Bureau of Meteorology, so there can be no accusation of cherry picking or of using “unreliable” raw data.
Fig. 1: Number of days in summer above 35 C at Longreach.
And for the last 50 years….
Fig. 2: Number of days in summer above 35 C at Longreach since the summer of 1964 -65.
What about the length of heatwaves? The next plot shows the number of days in a row where the temperature has exceeded 35 C.
Fig. 3: Number of consecutive days above 35 C at Longreach.
Mr Whip may be a little mistaken. Since 1965, and since 1910, there appears to be no trend in the number of days above 35 C in Longreach, and there is no trend in the length of heatwaves.
But the ABC is always talking about extremes- what about days over 40 C?
Fig. 4: Number of days in summer above 40 C at Longreach.
Fig. 5: Number of days in summer above 45 C at Longreach.
Now Lydia Burton is a good rural reporter, I frequently listen to her on the Country Hour and the Rural Report, but if only she had checked the facts, she could have saved her listeners a lot of angst. Instead, “our” ABC continues to peddle nonsense about dangerous climate change.
It’s no wonder that people have lost faith in the ABC.