Comments on: Treadgold and the NZ CSC: dogging a fled horse

By: Climate Conversation Group » NIWA disowns Salinger thesis

Climate Conversation Group » NIWA disowns Salinger thesis — Mon, 05 Apr 2010 10:31:07 +0000

[...] NIWA’s national temperature series. Back in February he became offended and quite agitated. NIWA’s word was enough for him so on their behalf he waded loyally into the Coalition and me for having the temerity to doubt the [...]

By: Climate Conversation Group » Dog legs it after Hot Topic

Climate Conversation Group » Dog legs it after Hot Topic — Thu, 11 Feb 2010 11:10:55 +0000

[...] Renowden, in a recent post at his Hot Topic blog, apart from a flash of genuine humour in the heading (”dogging a fled horse”) offers [...]

By: Phil Scadden

Phil Scadden — Wed, 10 Feb 2010 22:44:54 +0000

For actual study of the drivers on glacier snowline in NZ setting then try http://geology.gsapubs.org/content/34/2/121.abstract

By: Billy T.

Billy T. — Wed, 10 Feb 2010 22:03:30 +0000

But that is much harder work… And it means that other scientists then can criticize any mistakes I might have made. That’s not very nice for me… Much easier to go through their work and find something – anything – to criticize. And if they wrote odd comments in their ‘code’ it’s even more funny…

Seriously though… if anyone is actually interested in the process Phil describes, Tamino at Open Mind is doing exactly this on his blog – step by step replicating the global temperature index from the raw data. It will be interesting to see how closely his final result matches that of the existing indices.

By: Phil Scadden

Phil Scadden — Wed, 10 Feb 2010 20:21:36 +0000

This fuss is an example of a meme floating around scientists covering their tracks by not providing worksheets, code, etc. for “audit”. I think its mostly a ploy because those doing the screaming wouldnt know how to audit the code anyway, but beside the point. I think normal best practice when uncertain about another scientist’s results is different and frankly better.
If possible, you would redo the measurements/sampling from scratch. Obviously this is often not practical (only one set of historical temp readings – you dont have time machine; expensive to drill another well in identical position etc). Failing that, you would start with raw data and redo analysis with your software according to what you think best methodology is. Now if you get significantly different results, then at that point, you would start to examine the other person methodology in some detail to see if you can reproduce. Getting different results from slightly different methodologies can be very instructive and tells you something about reality (i.e. get ready to publish a paper). This is the likeliest outcome. It would only be if you cant reproduce the result using the stated methods that you would be contacting the author to find out what is going on. And you would probably go a long way down that road of checking methods before starting to compare codes. An error in the computer code is usually the least likely explanation for a surprising result. Now famously, this is what happened between RSS and UAH, but it was very unusual in that it turned out to be a bug with UAH code. I cant think of another example off the top of my head.

Someone who cant recreate the analysis from methodology papers isnt qualified to audit a result.

NZC”S”C kinda went down that road making their own analysis from raw data, apparently without understanding the need for homogenization of temperature station data. So far I would say this mostly reflects badly on their competence to doing such an analysis but by all means redo the homogenization using published methods. But as to question of bias that might creep in, I know who I would trust more.

By: Phil Scadden

Phil Scadden — Wed, 10 Feb 2010 19:13:17 +0000

The snowline varies with ESNO, but look at the trend. That is what distinguishes climate from weather. I think you will find snowline is heavily temperature dependent too.

I struggle with your default position which appears to be:
a/ the experts in this data cant be trusted and biased. We need some clueless amateur to analyse the data instead.
b/ NZ cant possibly be warming whatever the rest of the world is doing so data must be wrong.

Now why do you think this? If I am wrong about your thinking, then why the tone of posts?

By: Rob Taylor

Rob Taylor — Wed, 10 Feb 2010 13:25:36 +0000

I take your point. Australis – the real world is part of the conspiracy too!

By: Australis

Australis — Wed, 10 Feb 2010 11:07:37 +0000

Okay – so some detail on Hokitika adjustments has finally been released. (And I thought this blog said everything had been disclosed last year). Will look forward to examining it.

The snowline fluctuates. Driven by changes in precipitation.

By: Phil Scadden

Phil Scadden — Wed, 10 Feb 2010 09:10:52 +0000

Try READING the material in the link I gave you from NIWA. Again, what is missing here that you think should be. As to NZ warming being a myth – what about the snowline then? Is that doctoring of photos if it is not caused by warming.

By: Macro

Macro — Wed, 10 Feb 2010 07:23:02 +0000

He didn’t understand it first time round – Or more to the point didn’t WANT to understand it. I can’t see Australis accepting the obvious this time either. It doesn’t fit in with his world view.