Ken Stewart, 19 March 2012
The Bureau’s brand-new, best quality dataset, ACORN-SAT (Australian Climate Observation Reference Network- Surface Air Temperatures) clearly shows the linear trend has been flat for 18 years.
So what of the Climate Commission’s report on “The Angry Summer” , and the Bureau’s apparent fixation with maximum temperatures in the past summer?
In the past, the BOM has been at pains to make clear that trends in climate can only be analysed over long periods of time. See for example, http://www.bom.gov.au/climate/glossary/climate.shtml Three cold months have barely rated a mention in the past for this very good reason. So why all the fuss over three hot months? And if it is now OK for them to use a three month period in this way, surely it is OK for sceptics to point to a “pause” in warming over the past several years. A period of 18 years is 72 times longer than the “Angry Summer”!
In my last post I demonstrated how well Acorn annual mean anomalies from the 1981-2010 mean, match with UAH (the dataseries of atmospheric temperatures since late 1978 compiled by the University of Alabama- Huntsville):
I was astounded that some commenters at the various sites where this was published had doubts about the accuracy of the UAH data. You can’t help some people. That’s why I decided to play the warmists’ at their own game, by using only the Bureau’s own data, which shows, among other things, that there has been zero trend in the data since 1995.
Finally, as the Climate Commission is not likely to mention these, here are some other not so widely known facts straight from Acorn:
- 2012 had the coldest winter minima since 1983
- 2012, at +0.11C, was the 36th warmest year- equal with 1995, just ahead of 1957.
- The past three years- 2010, 2011, and 2012- were the coolest of the decade.
- 2012 was cooler than 9 of the previous 10 years- beaten by 2011. 2011 was exactly at the median anomaly for the past 103 years, at -0.13C, according to Acorn’s homogenised record.
Meanwhile the Climate Commission would have us believe that because a three month period has been a record, this is somehow proof of man-made global warming.
Why? Because that’s all they’ve got left.