Dr Bill,
The following abstract from the 2010 paper I referenced earlier explains the need for data adjustment. Do you find fault in that paper?

"To monitor climate change adequately and determine the extent to which anthropogenic influences are contributing to observed climate change, it is critical to have land temperature data of a high standard. In particular, it is important to have temperature data whose changes reflect changes in the climate and not changes in other circumstances under which the temperatures were taken. There are numerous factors that can affect land temperature records. Among the most common are changes in instrumentation, changes in local site condition in situ (through urbanization or for other reasons), site relocations, and changes in observing practices. All have the potential, if uncorrected, to have impacts on temperature records at individual locations similar to or greater than the observed century-scale global warming trend. A number of techniques exist to identify these influences and correct data to take them into account. These have been applied in various ways in climate change analyses and in major data sets used for the assessment of long-term climate change. These techniques are not perfect and numerous uncertainties remain, especially with respect to daily and sub-daily temperature data."

Tony153... you've scored an own goal.

You've pointed out exactly why Dr Bill has reason to criticise the process. If you adjust the data, and let's face it anyone doing the adjusting is going to adjust their preferred direction, the data has been corrupted.

The final sentence sums it up "These techniques are not perfect and numerous uncertainties remain, especially with respect to daily and sub-daily temperature data."

Tony, you can’t be serious!

Dr Bill said: “Last post; I have better things to do now; and this is bordering on ridiculous.” I agree!

Yet you persist in asking him to comment on a paper by Blair Trewin (his arch nemesis at BoM) and in the process haul in the most stupid comment I have yet seen on this thread – from someone who obviously hasn’t the attention span to read Trewin’s paper, let alone have the capacity to understand or follow what is in it!

Look mate, I understand your good intentions, but Bill has good intentions too (although I would say you are both misaligned).

Nevertheless, OLO is NOT the place to debate the nuances of scientific argument. A forum like this attracts all sorts of fruit-cakes. They not only detract from rational dialogue, they stifle it - that's what forums like this do.

If you really think you can cross swords with Bill Johnston, why don’t you take up his challenge and do the homework he has set – investigate the ACORN-SAT and get back to him?

You won’t because you can’t, at least not here.

Let me put it this way - Bill has an ‘issue’ with not only Blair Trewin but also; BoM; UNSW; CSIRO, ANU, Melbourne and Monash Uni's and other faux-institutes and 'councils' – he neglected to mention CAWCR specifically but it probably is a moot point anyway.

It seems Bill also has ‘pricing’ issues with institutions and journals that would give him an avenue to properly argue his case e.g. Australian and New Zealand Journal of Statistics, or the Journal of the Royal Statistical Society. A shame that Bill’s ‘followers’ can’t bank-roll him – perhaps a case of where are your supporters when you need them?

His arguments won’t really stack up when put under real scrutiny, that’s why. But they sure sound good to conservative hippies, lions, hasbeens and other ideological followers in denial.

ConservativeHippie

Which part of the following can’t you comprehend?

“Far from being a fudge to make warming look more severe than it is, most of the Bureau’s data manipulation has in fact had the effect of reducing the apparent extreme temperature trends across Australia. Cherry-picking weather stations where data have been corrected in a warming direction doesn’t mean the overall picture is wrong.

Data homogenisation is not aimed at producing a predetermined outcome, but rather is an essential process in improving weather data by spotting where temperature records need to be corrected, in either direction. If the Bureau didn’t do it, then we and our fellow climatologists wouldn’t use its data because it would be misleading. What we need are data from which spurious warming or cooling trends have been removed, so that we can see the actual trends.

Marshalling all of the data from the Bureau’s weather stations can be a complicated process, which is why it has been subjected to international peer-review. The Bureau has provided the details of how it is done, despite facing accusations that it has not been open enough.

Valid critiques of data homogenisation techniques are most welcome. But as in all areas of science, from medicine to astronomy, there is only one place that criticisms can legitimately be made. Anyone who thinks they have found fault with the Bureau’s methods should document them thoroughly and reproducibly in the peer-reviewed scientific literature. This allows others to test, evaluate, find errors or produce new methods.

This process has been the basis of all scientific advances in the past couple of centuries and has led to profoundly important advances in knowledge. Abandoning peer-reviewed journals in favour of newspaper articles when adjudicating on scientific methods would be profoundly misguided.”

Just asking.

Dr Bill,

"....It’s shameful that you and your ilk have to hide behind pseudonyms, frightened of the light."

I agree!

So much so that I'm going to comb my magnificent moustaches, use my little grey cells, and dash off to read something by someone who has the training and expertise to explain methods of analysis.

http://www.stat.washington.edu/peter/593/Trewin.pdf

Or, under availability:

"Click for full-text PDF" for Online Access:

http://search.library.wisc.edu/catalog/ocn793132060