Wednesday, September 3, 2014

Global Warming Flat Since 1941


Posted on August 26, 2014 Written by The Australian
The [Aus­tralian] Bureau of Mete­o­rol­ogy has been accused of manip­u­lat­ing his­toric tem­per­a­ture records to fit a pre­de­ter­mined view of global warm­ing. Researcher Jen­nifer Maro­hasy claims the adjusted records resem­ble “pro­pa­ganda” rather than science.
Dr Maro­hasy has analysed the raw data from dozens of loca­tions across Aus­tralia and matched it against the new data used by BOM show­ing that tem­per­a­tures were pro­gres­sively warm­ing. In many cases, Dr Maro­hasy said, tem­per­a­ture trends had changed from slight cool­ing to dra­matic warm­ing over 100 years. — Gra­ham Lloyd, The Aus­tralian, 23 August 2014
The esca­lat­ing row goes to heart of the cli­mate change debate — in par­tic­u­lar, whether com­puter mod­els are bet­ter than real data and whether tem­per­a­ture records are being manip­u­lated in a bid to make each year hot­ter than the last. Marohasy’s research has put her in dis­pute with BoM over a paper she pub­lished with John Abbot at Cen­tral Queens­land Uni­ver­sity in the jour­nal Atmos­pheric Research con­cern­ing the best data to use for rain­fall fore­cast­ing. BoM chal­lenged the find­ings of the Marohasy-Abbot paper, but the inter­na­tional jour­nal rejected the BoM rebut­tal, which had been pre­pared by some of the bureau’s top sci­en­tists. This has led to an esca­lat­ing dis­pute over the way in which ­Australia’s his­tor­i­cal tem­per­a­ture records are “improved” through homogeni­sa­tion, which is prov­ing more dif­fi­cult to resolve. — Gra­ham Lloyd, The Aus­tralian, 23 August 2014
When I first sent Gra­ham Lloyd some exam­ples of the remod­el­ing of the tem­per­a­ture series I think he may have been some­what skep­ti­cal. I know he on-forwarded this infor­ma­tion to the Bureau for com­ment, includ­ing three charts show­ing the homog­e­niza­tion of the min­i­mum tem­per­a­ture series for Amber­ley. Mr Lloyd is the Envi­ron­ment Edi­tor for The Aus­tralian news­pa­per and he may have been con­cerned I got the num­bers wrong. He sought com­ment and clar­i­fi­ca­tion from the Bureau. I under­stand that by way of response to Mr Lloyd, the Bureau has not dis­puted these cal­cu­la­tions. What the Bureau has done, how­ever, is try and jus­tify the changes. In par­tic­u­lar, for Amber­ley the Bureau is claim­ing to Mr Lloyd that there is very lit­tle avail­able doc­u­men­ta­tion for Amber­ley before 1990 and that infor­ma­tion before this time may be “clas­si­fied”: as in top secret. — Jen­nifer Maro­hasy, 23 August 2014
Con­grat­u­la­tions to The Aus­tralian again for tak­ing the hard road and report­ing con­tro­ver­sial, hot, doc­u­mented prob­lems, that few in the Aus­tralian media dare to investigate.
How accu­rate are our national cli­mate datasets when some adjust­ments turn entire long sta­ble records from cool­ing trends to warm­ing ones (or visa versa)? Do the head­lines of “hottest ever record” (reported to a tenth of a degree) mean much if ther­mome­ter data some­times needs to be dra­mat­i­cally changed 60 years after being recorded?
One of the most extreme exam­ples is a ther­mome­ter sta­tion in Amber­ley, Queens­land where a cool­ing trend in min­ima of 1C per cen­tury has been homog­e­nized and become a warm­ing trend of 2.5C per cen­tury. This is a sta­tion at an air­force base that has no recorded move since 1941, nor had a change in instru­men­ta­tion. It is a well-maintained site near a perime­ter fence, yet the homogeni­sa­tion process pro­duces a remark­able trans­for­ma­tion of the orig­i­nal records, and rather begs the ques­tion of how accu­rately we know Aus­tralian trends at all when the ther­mome­ters are seem­ingly so bad at record­ing the real tem­per­a­ture of an area. Ken Stew­art was the first to notice this anom­aly and many oth­ers when he com­pared the raw data to the new, adjusted ACORN data set. Jen­nifer Maro­hasy picked it up, and inves­ti­gated it and 30 or so other sta­tions. In Ruther­glen in Vic­to­ria, a cool­ing trend of –0.35C became a warm­ing trend of +1.73C. She raised her con­cerns (repeat­edly) with Min­is­ter Greg Hunt.
Now the Aus­tralian Bureau of Mete­o­rol­ogy has been forced to try to explain the large adjust­ments. Aus­tralians may finally gain a bet­ter under­stand­ing of what “record” tem­per­a­tures mean, and the cer­tainty ascribed to national trends. There is both a fea­ture and a news piece today in The Week­end Aus­tralian. — Jo Nova The heat is on. Bureau of Mete­o­rol­ogy ‘alter­ing cli­mate fig­ures’ — The Australian
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