Dr. Roger pielke confirms a point made in comments in my earlier post on BEST about all data coming from a single source, which is the National Climatic Data Center. (NCDC)
By Dr. Roger Pielke Senior
Comment On The Article in the Economist On Rich Muller’s Data Analysis
On Climate Etc, Judy Curry posted
which refers the Economist article
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
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.