A few days ago I had a post that discussed a couple of papers that questioned the relevance or otherwise of a “global average temperature” and whether this measure actually had any scientific basis. In that post I analysed Adelaide’s January temperatures for the period 1888 to 2018 in 10 year intervals.
In order to be complete I have analysed temperatures for the same period in blocks of 5 years. The purpose was to see whether maximum and minimum temperatures have changed very much and to look at whether we are having more “hot” days than in the past.
The data is from the Bureau of Meteorology and has been partitioned into 5 year intervals. For each interval I found the maximum and minimum temperatures, the “range” of temperature and the number of days above 38 degrees C. This analysis covers the full years in the 5 year blocks of time, not just the summer months. The results are summarised in the table below and under that is a graph showing the changes with time. Once again my Excel skills result in red for minimums and blue for maximums however that is where I am with technology.
The greatest temperature range is 45.5 degrees in the period 1978 to 1982 and the highest temperature recorded, (46.1), is in the period 1938 to 1942 – it was actually in 1939. The graph below shows the changes with time. In order to keep the X axis within bounds the time periods are numbered from 1 to 26 and can be referenced in the table and the Y axis is temperature in degrees C.
The reason for looking at temperature range is because that is what we all live within. If I “averaged” the highest and lowest temperatures I get 24.4 degrees which is meaningless as a comparison when the maximum range over the 130 years is 48.7 degrees, (from +46.1 to -2.6).
When looking at the frequency of “hot” days I chose 38 degrees as the measure and counted the days that were equal or greater. Out of a record of 47,400 odd points there were 745 days that met this criterion. In the total record this amounts to about 1.6%, say 1.6 days in every hundred is 38 degrees or above, remembering the absolute maximum was 46 degrees and that there were only 2 days in the record above 45 degrees.
It is interesting that in the 1898 to 1902 period we had the greatest number of days above 38, (62) and recent times show about half that number. The 25 year period 1898 to 1922 averages around 43 days above 38 C and the same number of years from 1993 to 2017 averages around 27.
So, far from warming, the climate in Adelaide looks remarkably consistent over the past 130 years and I suspect other places are just the same. There are some ups and downs but climate/weather is chaotic and not amenable to forecasting very far into the future.
There is no “global climate” as the earth has a temperature range from +60 to -80 degrees, (140 degrees), so to talk of representing “climate change” by some dubious, statistically constructed, heavily manipulated and scientifically wrong “global average temperature” is simply wrong and probably fraudulent.