In previous posts I’ve examined the Australian Bureau of Meteorology’s temperature records.
In this article, I examine the Bureau’s practice of ignoring data prior to 1910. I also look at the adjustments the Bureau has made to the original data. ACORN-SAT is the adjusted temperature record. CDO is, supposedly, the ‘raw’ data.
Here’s a few samples from the full article:
This graph shows all of the weather stations used by the BOM for ACORN-SAT but with the pre-1910 data included.
Two things stand out:
1. There was rapid warming from 1860 to 1900, much more than the little bit of warming seen since 1900.
2. 1900 was the hottest year since records started in 1860.
The adjustments make the period 1910 – 1950 appear colder.
There is nothing special about the years 2013 and 2014. I’ve shown four decimal places on the temperatures. In reality, we’d be lucky to measure to the nearest degree. So in 1900, the average maximum temperature was 27 degrees Celsius. In all the other years, the maximum average temperature was 26 degrees Celsius. No big deal.
Unfortunately, I’m lead to the following conclusions:
1. The year 1900 is likely to have been the warmest on record.
2. The rate of warming from 1860 to 1910 it much larger that any warming experienced in the recent past.
3. There was a systematic downward adjustment of temperature records prior to 1950. This makes more recent temperatures appear warmer by comparison.
It’s may be coincidental that both the decisions to eliminate pre-1910 data and to systematically adjust pre-1950 temperatures downward, support the hypothesis of human-induced global warming.
If it is a coincidence, it’s a mighty big one.