Updated, Saturday 12th February
On 6th January 2022, journalist Mike Foley at the Sydney Morning Herald concluded his reporting on the Bureau’s yet to be released Annual Climate Statement with comment that:
Australia has warmed, on average, by 1.4 degrees since 1910 according to the Bureau of Meteorology, and every decade since that time has been warmer than the ones before. 2019 was the hottest year on record and the seven years from 2013 to 2019 all rank among Australia’s nine hottest on record.
At the beginning of each year, normally within the first week, the Australian Bureau of Meteorology release their annual climate statement for the previous year with comment about how much hotter it is relative to temperatures back to 1910.
Two years ago (9th January 2020) it was reported, for example, in the Sydney Morning Herald: We’ve seen clear trends in maximum, minimum and average temperatures across Australia, said Karl Braganza, head of the bureau’s climate monitoring, adding the country had warmed about 1.4 degrees since 1910, most of it since 1950.
Last year (8th January 2021) the annual climate statement included comment that Australia’s climate has warmed on average by 1.44 degrees Celsius since records began in 1910.
This year (8th February 2022) the annual climate statement includes comment that Australia’s climate has warmed on averaged 1.47 degrees Celsius between when national records began in 1910 and 2020. Though interestingly it was reported as 1.4 in the Sydney Morning Herald a month earlier.
In fact, temperatures in the official ACORN-SAT database have been coming down for the last two years, but the management at the Australian Bureau of Meteorology don’t seem able to acknowledge this reality.
To be clear the quoted warming of 1.4 °C could relate to the period 1910 to 2019 (inclusive), with 1.44 °C being the value based on ACORN-SAT version 2.1 and 1.47 °C being the value based on ACORN-SAT version 2.2. This is the opinion of Chris Gillham, who maintains a wonderful resource at http://www.waclimate.net. He has calculated that ACORN-SAT 2.2’s mean temperature to be 0.77 °C warmer in 2021 than in 1910, with unadjusted (raw) historical values being just 0.25 °C warmer.
The Bureau’s wording is ambiguous – ‘when national records began in 1910 and 2020’ could mean to the beginning, or end, of 2020 – the wording is ambiguous enough that officialdom might not be technically wrong, and the average person might not realize that they are being dubbed out of two years of data; the last two years of data!
The alternative explanation, which I’m giving in this update (Saturday 12th February), is that the 1.4 is actually the linear rate of warming. It is more normally calculated as a rate per year (0.0133) or per hundred years (1.33), but can be calculated as 1.49 °C for the period 1910 to 2021. Using just the ACORN-SAT values to the end of 2020, the value is 1.47, and to the end of 2019 1.45. The rate is continuing to increase because while the last two years have been cooler, considering the values back to 1910 in the ACORN-SAT database, the last two years are on average warmer.
A media release from the Australian Bureau on 6th January 2022 acknowledged 2021 was Australia’s coolest year in nearly a decade, due to the La Nina conditions.
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The feature image is 8 years old, of me/Jennifer Marohasy in the National Archives, Chester Hill (Sydney) checking temperature records from 134 years ago. I made the trip with another mate from the resistance, Lance Pidgeon.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Good comment, Jennifer. A question though. With the growth of cities since 1910, how much of this increase in temperatures can be attributed to the now massive heat islands of steel, glass, concrete and bitumen? It seems to me that a temperature rise does not equate to climate change with the causal culprit being anthropogenic generated co2, but rather anthropogenic created heat islands of city dwellers.
As I recall, between 1942 and about 1951, the Northern Hemisphere endured some seriously harsh winters.
Because of , I suspect, the prodigious amounts of seawater sloshing around the southern hemisphere, the same thing was barely noticeable, in these parts.
The planet can “fall into” an Ice Age in less than a century. It may last for hundreds of years, then take many hundreds to fully recover. NEITHER phase is purely “linear”; lots of “wobbles”, (solar cycles, volcanic activity, falling rocks, etc. Check with the rock doctors and paleo-meteorologists for the minutiae.
Notice the sudden rise of the ‘low level heatwave’ in the weather reports? What is a low level heatwave?
The BoM’s temperature and precipitation averages are fabricated.
Note, Roy Spencer’s latest temperature data from the mid-seventies to the present, for which he has been defunded by Google.
Well now, every thing stopped in 2019 didn’t it? Climate, influenza, mindsets stuck in a time warp. These tricks of vagueness are so lame. I’m looking forward to seeing snow where it’s not snowed before in my lifetime (since 1964).
If the BOM was being run by honest professionals all the climate nonsense would disappear and reflect what people can feel and see ouside their own fronr doors. This deliberate manipulation of climate data does not fool the people and explains why there is such a groundswell of climate sceptisism around the world especially when the people are being robbed blind by green taxes and levies.
The BoM has adjusted most of this century’s temps by around +0.1-0.2C. For instance both 2001 and 2011 were below average annual means but not any more.
Originally, 1914 was +0.5C above average. This has been reduced to +0.1C over the past 10 years due to ACORN adjustments. 2021 was +0.56C – might see this mean be ‘improved’ in a few years.
I am not quite sure what you expect the BOM to say. Two data points out of 110 shouldnt affect the trend, especially as we know they are due to the semi-regular La Nina events.
Data analysis 101 says if you are using for instance a 5 number average then the last two points (20, 21) only go into the average for 2019 and so one could state overall change from the trendline as being to 2020 or 2022.
Its a bit like judging the All ords long term trend based on this weeks performance.