Global Temperature Updates–August 2012
By Paul Homewood
This post is the first of a regular monthly series, which will bring the latest global temperature numbers from the four major datasets – GISS, HADCRUT, UAH and RSS. For ease of access, it can also be located on the category bar at the top of the page, under “Global Temperature Adjustments”.
As well as giving the latest monthly figures, I will be keeping track of the 12 month running averages. This, hopefully, will smooth out monthly fluctuations and give a better idea of longer term trends. Currently I believe we tend to be over fixated on calendar year figures, which can change significantly from year to year with ENSO changes and other factors. Use of running averages will remove this concern.
The links below give access to each of the four datasets.
So, first of all, let’s look at the actual numbers for August. HADCRUT numbers are still not available for the month, so I will update these in due course. However the running averages of the other three sets are all either at or below the 2002-11 baseline. (HADCRUT were also below in July).
|August 2012 Anomaly||0.26||0.34||N/A||0.56|
|Increase/Decrease From Last Month||-0.03||+0.06||+0.09|
|12 Month Running Average||0.16||0.18||0.50|
Global Temperature Anomalies – Degree Centigrade
A quick note at this stage :-
1) Each dataset uses a different baseline to calculate their anomaly from, and this is one reason the numbers vary so much and, of course, cannot be compared directly. For information, the periods used are :-
RSS : 1979-1998
UAH : 1981-2010
HADCRUT : 1961-1990
GISS : 1951-80
Now let’s take a closer look at the 12 month running averages.
Again, the current position suggests temperatures are at, or below, the run of years between 2002 and 2007.
I had hoped to include a section illustrating how the four datasets had diverged over the years, but will have to delay this until the HADCRUT data is in.