Comment On The Article in the Economist On Rich Muller’s Data Analysis

Update October 21 2011

I have posted these comments on Watts Up With That, Climate Etc and Blackboard

“Zeke Hausfather – I realize that he has a much larger set of locations, but many of them are very short term in duration (as I read from his write up). Moreover, if they are in nearly the same geographic location as the GHCN sites, they are not providing much independent new information.

What I would like to see is a map with the GHCN sites and with the added sites from Muller et al. The years of record for his added sites should be given. Also, were the GHCN sites excluded when they did their trend assessment? If not, and the results are weighted by the years of record, this would bias the results towards the GHCN trends.

The evaluation of the degree of indepenence of the Muller et al sites from the GHCN needs to be quantified.

Perhaps they have done these evaluations. However, from my reading of their work, I have not yet seen it.”

Zeke Hausfather says:
October 21, 2011 at 12:05 am
Dr. Pielke,

I believe the BEST results using all 39,000 stations can be found here: http://berkeleyearth.org/movies.php

As Mosh mentions, the data and code is also available for download.

Zeke Hausfather says:
October 21, 2011 at 1:10 am
Stephen Brown,

Inasmuch as it shows values comparable to HadCRUT using a much larger set of stations (39,000 vs 7,000), I’d consider it a validation. The BEST folks have an updated comparison graph using all stations (rather than just the GHCN stations included in the draft paper) here: http://berkeleyearth.org/analysis.php

Zeke – I still would like to see an analysis of how much added geographic location the other stations (non-GHCN) covered, as well as their time record length. Roger

Nick Stokes says:
October 21, 2011 at 7:13 am
rpielke says: October 21, 2011 at 6:22 am
“What I would like to see is a map with the GHCN sites and with the added sites from Muller et al.”

In a comment at Judy Curry’s I mentioned a KMZ file which shows the 36700 BEST stations in Google Earth. I’m hoping to extend this to show GHCN also, much as you suggest, when Ive been able to get the years of observation for the BEST sites.

Nick Stokes – This is an excellent resource. One of the key questions is the extent that the Muller et al analysis added sites in order to expand the geographic coverage. If the data is from mostly the same geographic regions, the added data would not be expected to add much beyond GHCN. Roger

——————————————–

On Climate Etc, Judy Curry posted

Berkeley Surface Temperatures: Released

which refers the Economist article

A new analysis of the temperature record leaves little room for the doubters. The world is warming

The Economist article includes the text

There are three compilations of mean global temperatures, each one based on readings from thousands of thermometers, kept in weather stations and aboard ships, going back over 150 years. Two are American, provided by NASA and the National Oceanic and Atmospheric Administration (NOAA), one is a collaboration between Britain’s Met Office and the University of East Anglia’s Climate Research Unit (known as Hadley CRU). And all suggest a similar pattern of warming: amounting to about 0.9°C over land in the past half century.

The nearly identical trends is no surprise as they draw from mostly the same raw data!

I discussed this most recently in my post

Erroneous Information In The Report “Procedural Review of EPA’s Greenhouse Gases Endangerment Finding Data Quality Processes

The new Muller et al study, therefore,   has a very major unanswered question. I have asked it on Judy’s weblog since she is a co-author of these studies [and Muller never replied to my request to answer this question].

Hi Judy – I encourage you to document how much overlap there is in Muller’s analysis with the locations used by GISS, NCDC and CRU. In our paper

Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res., 112, D24S08, doi:10.1029/2006JD008229. http://pielkeclimatesci.files.wordpress.com/2009/10/r-321.pdf

we reported that

“The raw surface temperature data from which all of the different global surface temperature trend analyses are derived are essentially the same. The best estimate that has been reported is that 90–95% of the raw data in each of the analyses is the same (P. Jones, personal communication, 2003).”

Unless, Muller pulls from a significanty different set of raw data, it is no surprise that his trends are the same.

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