Comments on: Neukom’s South American Network

By: Skiphil

Skiphil — Sat, 04 Aug 2012 04:40:53 +0000

There is also a Climategate email in which Neukom tells Phil Jones just how aggressively he tests his "ensembles" of proxies to end up with just the right final recipe: Neukom to Phil Jones on the juggling of recipes ("ensembles") to get to just the SH proxy list he wants for the South American reconstruction

By: stevepostrel

stevepostrel — Tue, 12 Jun 2012 19:34:14 +0000

The authors’ description of their method sounds more like a recipe for a witches’ brew than a statistical technique. I’m surprised eye of newt and kelp from the belly of a pregnant manta ray were not included.

By: Geoff Sherrington

Geoff Sherrington — Mon, 11 Jun 2012 03:41:19 +0000

Much Australian temperature data changed convention from deg F to deg C officially in Sept 1972. The conversion of F to C then back again is ambiguous if there is less than 1 place after the decimal. However, we managed to show that very many – perhaps 30-50% – of official Australian temp records pre-1972 were recorded in whole numbers. This might be one source of difference in error estimates. See
http://joannenova.com.au/2012/03/australian-temperature-records-shoddy-inaccurate-unreliable-surprise/

One would have to examine if this type of complication was present at sea and in other countries. It signals care in the use of USA records collected in F and converted to C.

By: Kenneth Fritsch

Kenneth Fritsch — Sun, 10 Jun 2012 23:10:51 +0000

That varied array of supposed proxies for temperature is what one would expect when a model/reconstruction is over fit with in-sample data. The proxy does not have to be explained in physical terms but merely has to fit the model. I have seen this very process carried out with investment strategies where criterion are used because it provides a large return and not that it makes financial sense.

With 18 coauthors, who I have to assume concur with this selection strategy, the reviewers of the paper, the editors of the journal and the IPCC people reviewing and using this paper, I have to conclude that there are lots of people connected with climate science who have no appreciation what these processes do to the statistics for evaluating a valid proxy. OMG IIWTIT.

By: Richard Drake

Richard Drake — Sun, 10 Jun 2012 22:03:46 +0000

I missed this revelation at the end Ross, until now. Congratulations.

By: timetochooseagain

timetochooseagain — Sun, 10 Jun 2012 20:23:07 +0000

I seems odd to me that Law Dome is considered “South America” at all, given that it’s in Antarctica.

By: ThinkingScientist

ThinkingScientist — Sun, 10 Jun 2012 14:40:19 +0000

That statement “As “best location” we defined the grid cell with the highest absolute correlation with the proxy over the overlapping period (between 70 and 106 years within 1901-2006).” is very general and leaves the authors (and reviewers) wide open to criticism. If I were reviewing that I would have asked:

(a) over what distance from the nominal location of the proxy were they searching for correlations?
(b) Was there a limit on the distance of the search? If so, it should be clearly stated what the limit is and what the basis is for arguing that the distance used is physically meaningful. If there is no limit on the distance of the search the paper should have been rejected on the grounds of spurious correlation.
(c) did they search for the first significant correlation or keep searching for the best correlation irrespective of distance, or up to some maximum distance?

Not specifically stating the search criteria leaves one wondering why not? It could just be sloppy writing and reviewing, or it could be another pea under the thimble.

By: Geoff Sherrington

Geoff Sherrington — Sun, 10 Jun 2012 12:42:30 +0000

Phil, Re money, there could be more than one grant or contract. Perhaps your $340,000 mention is for the first and the $950,000 from the Gergis blog is for one or more of the later. The partner is presumably the Australian Federal Dept of Climate Change, but I can’t see with a short search any category that extends specific research beyond Australia. It might be there, I just can’t see it quickly.

Grants
Title, Role, Funding Source, Scheme, Award Date
Reconstructing pre-20th century rainfall, temperature and pressure for south-eastern Australia using palaeoclimate, documentary and early weather station data. Chief Investigator. AUST RESEARCH COUNCIL. Linkage Projects, 01/01/2009.

Contracts
Title, Role, Funding Source, Award Date
ESTIMATING NATURAL CLIMATE VARIABILITY IN THE AUSTRALASIAN REGION OVER THE PAST 2,000 YEARS: DATA SYNTHESIS FOR THE IPCC 5TH ASSESSMENT REPORT. Chief Investigator.DEPT OF CLIMATE CHANGE. 01/01/2011.
ESTIMATING NATURAL CLIMATE VARIABILITY IN THE AUSTRALASIAN REGION OVER THE PAST 2,000 YEARS: DATA SYNTHESIS FOR THE IPCC 5TH ASSESSMENT REPORT. Chief Investigator. 15/07/2011.

PALAEO RECONSTRUCTION OF RAINFALL AND STREAMFLOW FOR MELBOURNE WATER CATCHMENTS. Chief Investigator. MELBOURNE WATER CORP. 01/04/2012.

Additional Grant and Contract Information
Reconstructing pre-20th century rainfall, temperature and pressure for south-eastern Australia using palaeoclimate, documentary and early weather station data, Australian Research Council Linkage Project LP0990151
http://climatehistory.com.au
From http://www.findanexpert.unimelb.edu.au/researcher/person203094.html

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By: Phil

Phil — Sun, 10 Jun 2012 10:53:45 +0000

How is it that Steve is doing better science than richly funded academic PhD scientists? And he’s doing this on his own time. In comparison, Gergis et al. were given $300,000 to run their flawed 3-year study. Just boggles the mind, really.

I honestly believe that it should be made a criminal offense to announce via media results of scientific studies prior to the studies being independently checked and verified by relevant experts–too much pseudoscience is being released to the public.

All scientific journals must also make data-sharing a prerequisite for getting published. How do we go about making this a requirement at all scientific journals? Write to our political representatives? Start an online petition? I think this is something realistic that we can change.

By: MarkR

MarkR — Sun, 10 Jun 2012 10:35:08 +0000

Same old trick. They find correlations in the instrumental temp period including inverted proxies, then choose those that aggregate to give the flatish historic temps they need. Trouble is the proxies never correlate well with each othe outside the instrumental period chosen. That lack of inter correlation shows that they are not all proxies for the same thing, and they can’t all be proxies for temperature.

Steve: I’d dial back the inverted proxy line of rhetoric. The corals ex ante are believed to have a negative relationship of d18O to temperature so they are not “upside down” in a Mannian sense.