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
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
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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tegirinenashi: “It is much easier to follow just two stations, not subject to UHI”
As BEST says, one third of the stations in their record show cooling. The problem with using only two records is that it is very easy to claim that they are cherry picked.
But I do think you have a point. I think if we could find 50 stations around the world that were pristeen; never moved, never had their elevation changed, no construction around them, continous record for fifty years, and simply used their averaged raw output, I would trust that result more than all of the over processed data that we currently call global temp records. The trick would be to identify those pristeen stations before you ever looked at their records. And then trust their result after you do get their record. That way you would avoid allowing yourself to cherry pick.
Izen: The point is not that three groups find the same trend in the same data, its that NONE of the studies show any significance difference in trend between urban and rural sites.
That’s because the rural sites aren’t rural. The only requirement for a site to be classified as rural is that it not have more than 50% build coverage. That makes many suburbs rural. The requirement also says that for urban areas, the over 50% build must be contigous with no breaks for a minimum of one square kilometer. That also means that many small cities are classified as rural. And the growth rate in small cities and suburbs can be higher than in highly built urban areas where there is little room for more build.
Tilo says
I think if we could find 50 stations around the world that were pristeen; never moved
Henry@Tilo
Good point. 50 should be enough. So far I have looked at 15.
I also did include islands and coastal cities in my sample,
remember that earth is 70% water, so to take only samples on inside landmasses is a no-no, because you might get a biased signal
http://wattsupwiththat.com/2011/10/20/pielke-sr-no-surprise-about-best/#comment-774632
izen says:
October 22, 2011 at 2:53 am
If you click on “raw data” you get data:
http://www.woodfortrees.org/data/uah/from:1997/to:2011/trend/plot/uah/from:1997/to:2011
#Time series (uah) from 1978.92 to 2011.75
#Selected data from 1997
#Selected data up to 2011
#Least squares trend line; slope = 0.0116653 per year
1997 0.0650968
2011 0.228411
#Data ends
#Number of samples: 2
#Mean: 0.146754
So, 1.17°C per century, that isn’t too steep, down in the noise really. How does that compare to the earlier recovery from the LIA?
Tito;
I also recall seeing recent info that the UHI effects start very small, and are almost logarithmic (diminishing returns). The first level of habitation build-up does most of the work; thereafter it’s gilding the lily.
Clarification: UHI effects start with very small towns, …
Henry;
Will 600 in the US do?
http://wattsupwiththat.com/2011/10/24/unadjusted-data-of-long-period-stations-in-giss-show-a-virtually-flat-century-scale-trend/#comment-776101
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.”
Interesting to watch Zeke. Especially as there seems to be a correlation between the rise in stations and the rise in temperature 😉
Henry@Dave Springer
You remember that thing we discussed some time ago?
You said that the oceans only gives up 20% of its solar heating which would explain matters with the CO2.
I did some checking and testing on this. It did not work out as you predicted.
I think you are wrong.
In the case of the leaf chart here:
http://wattsupwiththat.com/2011/03/24/the-earths-biosphere-is-booming-data-suggests-that-co2-is-the-cause-part-2/
I am finding an extraordinary correlation between warming in the red areas and actual cooling in the blue areas. In other words, if you pick a blue area, you will find mean temperatures declining,
if you pick a red area you will mean temperatures rising.
So, seeing that the overall chart shows more red (the earth is blooming) it explains the extra warming noted of the past decades. It is more vegetation that traps more heat.