Monday, 14 December 2009

FIDDLING THE DATA, BIG TIME

This report looks at one set of data for Darwin, Australia. By looking at how this data has been 'adjusted' the author reveals a great deal about the kind of fiddles that may have been going on elsewhere. I'm sure that once all the raw data is put out in the open there will be many experts pouring over it and it will be interesting to see if they turn up many more blatant attempts to produce 'warming' by 'adjustment'.

Here's another data set this one for Nashville, Tennessee. Once again the article from Watts Up With That illustrates the way the raw data has been adjusted for no obvious reason, other than to show a clear warming trend.

And Orland also shows the 'adjustment' effect.

10 comments:

Dan Olner said...

http://www.ncdc.noaa.gov/crn/

http://www.youtube.com/user/greenman3610#p/u/11/dcxVwEfq4bM

Which shows that even Watts own selected set of US stations matches the standard temperature record.

Also: why, and how, could so many different scientists in so many different countries falsify climate data? I can't see why they would, or how? There are so many datasets all pointing in the same direction, I find myself baffled how these stories keep on getting traction.

Derek Tipp said...

It is not that many scientists have done this, it is actually only a very small number. As you can see from the examples shown, it is done in the guise of 'enhancement'. Most scientists probably don't look closely at the raw data, but accept that the 'enhancement' is done for genuine reasons. As Watts says, it is at least odd that these changes have been made. If there are genuine reasons then they should be explained publicly. The world of statistics is very murky - hence the saying "lies, damned lies and statistics".

These examples speak for themselves. Let the scientists explain themselves. I wait with interest, though so far I have heard nothing but vague excuses.

Have you got any explanation for the data above being adjusted in the way it was?

Dan Olner said...

"If there are genuine reasons then they should be explained publicly."

For adjusted records, they usually are. E.g.

http://www.ncdc.noaa.gov/oa/climate/ghcn-monthly/images/ghcn_temp_overview.pdf

Which includes:

"A great deal of effort went into the homogeneity adjustments. Yet the effects of the homogeneity adjustments on global average temperature trends are minor (Easterling and Peterson 1995b). However, on scales of half a continent or smaller, the homogeneity adjustments can have an impact. On an individual time series, the effects of the adjustments can be enormous. These adjustments are the best we could do given the paucity of historical station history metadata on a global scale. But using an approach based on a reference series created from surrounding stations means that the adjusted station's data is more indicative of regional climate change and less representative of local microclimatic change than an individual station not needing adjustments."

(via http://bit.ly/7c23GJ)

The overall point being: if you want to attempt an accurate measure of global changing temperature, there are going to be adjustments. I agree they should be transparent, but a) as above, they usually are, b) you can compare any adjustments to other data pretty easily e.g. the CRN and Watts' own selection of US weather stations above *both* match the US overall pattern, and as the above says, any adjustments are usually tiny when compared to overall changes.

I'd like to know what you think of the term "smoking gun" when applied to these things? Do you agree - that is, do you think these WUWT articles somehow falsify the overall temperature record? Do you agree with the authors' statement that he's found -

" - indisputable evidence that the 'homogenized' data has been changed to fit someone's preconceptions about whether the earth is warming?"

Dan Olner said...

Oh, just found a comment from a scientist actually working on the Darwin station:

http://larvatusprodeo.net/2009/12/11/how-low-can-you-go/#comment-843553

Do you believe this person is actually doing what Eschenbach claims - fiddling data to give a warming trend?

Derek Tipp said...

Well, Dan, these examples are "a smoking gun" in the sense that they appear to show manipulation of data with no obvious acceptable explanation. I do accept that there are many places which have become slightly warmer over the past century, but if the warming has been exaggerated then A) it is not the serious problem that it is being made out to be, and B) It calls into question the integrity of the scientists doing the work.

I believe that government-funded climate scientists start out by accepting that man-made global warming is a fact. They then produce evidence to back this up. Their job depends on this. True science should allow all results to be treated equally. The suppression and denigration of scientists who dare to challenge the so-called consensus is wrong.

Dan Olner said...

I think it does come down to this - I see no reason not to trust most scientists, and you - I think - see no reason to trust them, since their pay packet depends on govt money.

I'll have to come back to this - it's an assertion that we can probably test. But I just want to go back to the actual data. It's a point I've already made, but I don't know if you had a chance to look at the data in question -

Oh! Links not working in Firefox! More shortly, sorry...!

Dan Olner said...

So -

http://www.ncdc.noaa.gov/oa/about/response-v2.pdf

The NOAA's response to Watts' critique of US temperature data. See the graph on p.3 - it compares the 70 stations verified as good by Watts' network and compares to all 1200 US stations. As near as dammit, they're the same.

Question: if scientists had been deliberately tipping the data to show a warming trend that wasn't there, that would show up in a difference between Watts' selected "good" stations and the whole record, wouldn't it? What explanation do you have for the two datasets being pretty much identical? I find th most straightforward explanation appealling - no-one has been falsifying records for US weather stations.

Derek Tipp said...

I can only speak for the data highlighted in the examples in my post. I simply don't know about other individual stations. It is not that I am arguing that there has been no warming, simply that there appear to be attempts to exaggerate the effect in some stations.

I do not deny that there is a little warming over the past century, may be as much as 0.7C. I believe this could be largely natural, with only a small contribution from greenhouse gases.

Dan Olner said...

OK: You say above "if the warming has been exagerated"... let's say you have a hypothesis, then: "some stations have been adjusted to show a false warming trend." Do you agree, firstly - as the NOAA graph above shows, comparing Watts' own "good" stations to the whole US record - that any adjustments made make no material difference to the level of measured warming?

Also take a look at:

http://www.realclimate.org/index.php/archives/2009/12/are-the-cru-data-suspect-an-objective-assessment/

- where they've done a proper randomised test. No material difference between raw and adjusted CRU data.

Derek Tipp said...

How do we know what adjustments may have been made to some of the 'good' stations, or to some of the others? This is not about the urban heat island effect. It is about dubious adjustments and only a complete check of all the data will reveal the extent of it. So far we have seen a number of apparently doubtful ones which require explanation. These may be the exceptions or there may be others. We need answers, which so far are not coming.