Global Temperature Update–October 2012
By Paul Homewood
All the four main datasets have now been released for October.
|October 2012 Anomaly||0.29||0.34||0.52||0.69|
|Increase/Decrease From Last Month||-0.09||0.00||0.00||+0.08|
|12 Month Running Average||0.18||0.13||0.43||0.51|
RSS are down, HADCRUT and UAH are unchanged and GISS is up. Is anyone surprised about that?
The 12 month running averages all remain below the 10 year average, even GISS. My guess is that the UAH figures for the year will finish at about 0.17C, as the cooler La Nina affected months of November and December 2011 disappear from the calculations. In this case, 2012, would end up being the 4th coldest year in the last ten.
For devotees of the “warmest decade evuh”, it is worth noting that the start to the new decade, i.e 2011/12, is running cooler than the 2001-10 period. I wonder what their next bolt hole will be? Hottest 12 year period evuh?
Let’s finish by looking at the graphs.
Monthly anomalies are shown in blue, while the red lines are the centred 12-month running averages. (For instance, the 12 month average for Jan-Dec 2011 appears in June 2011.)
None of the sets suggest that temperature trends have done much in the last ten years.
1) The baseline periods used for calculation of anomalies is different for each set, so direct comparisons are not possible. The baselines used are :-
RSS – 1979-98
UAH – 1981-2010
HADCRUT – 1961-90
GISS – 1951-80
UAH have revised their number upwards from 0.33 to 0.34, which I have now amended.