PRESS RELEASE – U.S. Temperature trends show a spurious doubling due to NOAA station siting problems and post measurement adjustments.
Chico, CA July 29th, 2012 – 12 PM PDT – FOR IMMEDIATE RELEASE
A comparison and summary of trends is shown from the paper. Acceptably placed thermometers away from common urban influences read much cooler nationwide:
A reanalysis of U.S. surface station temperatures has been performed using the recently WMO-approved Siting Classification System devised by METEO-France’s Michel Leroy. The new siting classification more accurately characterizes the quality of the location in terms of monitoring long-term spatially representative surface temperature trends. The new analysis demonstrates that reported 1979-2008 U.S. temperature trends are spuriously doubled, with 92% of that over-estimation resulting from erroneous NOAA adjustments of well-sited stations upward. The paper is the first to use the updated siting system which addresses USHCN siting issues and data adjustments.
The new improved assessment, for the years 1979 to 2008, yields a trend of +0.155C per decade from the high quality sites, a +0.248 C per decade trend for poorly sited locations, and a trend of +0.309 C per decade after NOAA adjusts the data. This issue of station siting quality is expected to be an issue with respect to the monitoring of land surface temperature throughout the Global Historical Climate Network and in the BEST network.
Today, a new paper has been released that is the culmination of knowledge gleaned from five years of work by Anthony Watts and the many volunteers and contributors to the SurfaceStations project started in 2007.
This pre-publication draft paper, titled An area and distance weighted analysis of the impacts of station exposure on the U.S. Historical Climatology Network temperatures and temperature trends, is co-authored by Anthony Watts of California, Evan Jones of New York, Stephen McIntyre of Toronto, Canada, and Dr. John R. Christy from the Department of Atmospheric Science, University of Alabama, Huntsville, is to be submitted for publication.
The pre-release of this paper follows the practice embraced by Dr. Richard Muller, of the Berkeley Earth Surface Temperature project in a June 2011 interview with Scientific American’s Michael Lemonick in “Science Talk”, said:
I know that is prior to acceptance, but in the tradition that I grew up in (under Nobel Laureate Luis Alvarez) we always widely distributed “preprints” of papers prior to their publication or even submission. That guaranteed a much wider peer review than we obtained from mere referees.
The USHCN is one of the main metrics used to gauge the temperature changes in the United States. The first wide scale effort to address siting issues, Watts, (2009), a collated photographic survey, showed that approximately 90% of USHCN stations were compromised by encroachment of urbanity in the form of heat sinks and sources, such as concrete, asphalt, air conditioning system heat exchangers, roadways, airport tarmac, and other issues. This finding was backed up by an August 2011 U.S. General Accounting Office investigation and report titled: Climate Monitoring: NOAA Can Improve Management of the U.S. Historical Climatology Network
All three papers examining the station siting issue, using early data gathered by the SurfaceStations project, Menne et al (2010), authored by Dr. Matt Menne of NCDC, Fall et al, 2011, authored by Dr. Souleymane Fall of Tuskeegee University and co-authored by Anthony Watts, and Muller et al 2012, authored by Dr. Richard Muller of the University of California, Berkeley and founder of the Berkeley Earth Surface Temperature Project (BEST) were inconclusive in finding effects on temperature trends used to gauge the temperature change in the United States over the last century.
Lead author of the paper, Anthony Watts, commented:
“I fully accept the previous findings of these papers, including that of the Muller et al 2012 paper. These investigators found exactly what would be expected given the siting metadata they had. However, the Leroy 1999 site rating method employed to create the early metadata, and employed in the Fall et al 2011 paper I co-authored was incomplete, and didn’t properly quantify the effects.
The new rating method employed finds that station siting does indeed have a significant effect on temperature trends.”
Watts et al 2012 has employed a new methodology for station siting, pioneered by Michel Leroy of METEOFrance in 2010, in the paper Leroy 2010, and endorsed by the World Meteorological Organization (WMO) Commission for Instruments and Methods of Observation (CIMO-XV, 2010) Fifteenth session, in September 2010 as a WMO-ISO standard, making it suitable for reevaluating previous studies on the issue of station siting.
Previous papers all used a distance only rating system from Leroy 1999, to gauge the impact of heat sinks and sources near thermometers. Leroy 2010 shows that method to be effective for siting new stations, such as was done by NCDC adopting Leroy 1999 methods with their Climate Reference Network (CRN) in 2002 but ineffective at retroactive siting evaluation.
Leroy 2010 adds one simple but effective physical metric; surface area of the heat sinks/sources within the thermometer viewshed to quantify the total heat dissipation effect.
Using the new Leroy 2010 classification system on the older siting metadata used by Fall et al. (2011), Menne et al. (2010), and Muller et al. (2012), yields dramatically different results.
Using Leroy 2010 methods, the Watts et al 2012 paper, which studies several aspects of USHCN siting issues and data adjustments, concludes that:
These factors, combined with station siting issues, have led to a spurious doubling of U.S. mean temperature trends in the 30 year data period covered by the study from 1979 – 2008.
Other findings include, but are not limited to:
· Statistically significant differences between compliant and non-compliant stations exist, as well as urban and rural stations.
· Poorly sited station trends are adjusted sharply upward, and well sited stations are adjusted upward to match the already-adjusted poor stations.
· Well sited rural stations show a warming nearly three times greater after NOAA adjustment is applied.
· Urban sites warm more rapidly than semi-urban sites, which in turn warm more rapidly than rural sites.
· The raw data Tmean trend for well sited stations is 0.15°C per decade lower than adjusted Tmean trend for poorly sited stations.
· Airport USHCN stations show a significant differences in trends than other USHCN stations, and due to equipment issues and other problems, may not be representative stations for monitoring climate.
###
We will continue to investigate other issues related to bias and adjustments such as TOBs in future studies.
FILES:
This press release in PDF form: Watts_et_al 2012_PRESS RELEASE (PDF)
The paper in draft form: Watts-et-al_2012_discussion_paper_webrelease (PDF)
The Figures for the paper: Watts et al 2012 Figures and Tables (PDF)
A PowerPoint presentation of findings with many additional figures is available online:
Overview -Watts et al Station Siting 8-3-12 (PPT) UPDATED
Methodology – Graphs Presentation (.PPT)
Some additional files may be added as needed.
Contact:
Anthony Watts at: http://wattsupwiththat.com/about-wuwt/contact-2/
References:
GAO-11-800 August 31, 2011, Climate Monitoring: NOAA Can Improve Management of the U.S. Historical Climatology Network Highlights Page (PDF) Full Report (PDF, 47 pages) Accessible Text Recommendations (HTML)
Fall, S., Watts, A., Nielsen‐Gammon, J. Jones, E. Niyogi, D. Christy, J. and Pielke, R.A. Sr., 2011, Analysis of the impacts of station exposure on the U.S. Historical Climatology Network temperatures and temperature trends, Journal of Geophysical Research, 116, D14120, doi:10.1029/2010JD015146, 2011
Leroy, M., 1999: Classification d’un site. Note Technique no. 35. Direction des Systèmes d’Observation, Météo-France, 12 pp.
Leroy, M., 2010: Siting Classification for Surface Observing Stations on Land, Climate, and Upper-air Observations JMA/WMO Workshop on Quality Management in Surface, Tokyo, Japan 27-30 July 2010 http://www.jma.go.jp/jma/en/Activities/qmws_2010/CountryReport/CS202_Leroy.pdf
Menne, M. J., C. N. Williams Jr., and M. A. Palecki, 2010: On the reliability of the U.S. surface temperature record, J. Geophys. Res., 115, D11108, doi:10.1029/2009JD013094
Muller, R.A., Curry, J., Groom, D. Jacobsen, R.,Perlmutter, S. Rohde, R. Rosenfeld, A., Wickham, C., Wurtele, J., 2012: Earth Atmospheric Land Surface Temperature and Station Quality in the United States. http://berkeleyearth.org/pdf/berkeley-earth-station-quality.pdf
Watts, A., 2009: Is the U.S. surface temperature record reliable? Published online at: http://wattsupwiththat.files.wordpress.com/2009/05/surfacestationsreport_spring09.pdf
World Meteorological Organization Commission for Instruments and Methods of Observation, Fifteenth session, (CIMO-XV, 2010) WMO publication Number 1064, available online at: http://www.wmo.int/pages/prog/www/CIMO/CIMO15-WMO1064/1064_en.pdf
Notes:
1. The SurfaceStations project was a crowd sourcing project started in June 2007, done entirely with citizen volunteers (over 650), created in response to the realization that very little physical site survey metadata exists for the entire United States Historical Climatological Network (USHCN) and Global Historical Climatological Network (GHCN) surface station records worldwide. This realization came about from a discussion of a paper and some new information that occurred on Dr. Roger Pielke Sr. Research Group Weblog. In particular, a thread regarding the 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, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res.
2. Some files in the initial press release had some small typographical errors. These have been corrected. Please click on links above for new press release and figures files.
3. A work page has been established for Watts et al 2012 for the purpose of managing updates. You can view it here.
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Note: This will be top post for a couple of days, new posts will appear below this one. Kinda burned out and have submission to make so don’t expect much new for a day or two. See post below this for a few notes on backstory. Thanks everybody! – Anthony
NOTE: 7/31/12 this thread has gotten large and unable to load for some commenters, it continues here.
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davidmhoffer says:
The history of such “crowd sourcing” here does not give one reason to be so optimistic. For example, consider this post on WUWT by Roy Spencer: http://wattsupwiththat.com/2008/01/28/spencer-pt2-more-co2-peculiarities-the-c13c12-isotope-ratio/ It turns out that the main result that “Significantly, note that the ratio of C13 variability to CO2 variability is EXACTLY THE SAME as that seen in the trends!” is not significant at all since it is rigorously mathematically equivalent to what was deemed not significant. However, nobody discovered this fact until about a year later when tamino looked into it.
My guess is that, in this case, there may enough critical looks at Anthony’s paper to discover the flaws. (The issues around the surface temperature record is not something that I have followed closely, but I think that Peter Ellis’s comment may be the best so far here in that regard: http://wattsupwiththat.com/2012/07/29/press-release-2/#comment-1047576 ) However, whether Anthony and the WUWT community at large will clearly acknowledge the flaws that are identified is another question.
And, that speaks to the main problem with a place like WUWT: Lots of things here are shown to be incorrect by people (including myself) but since much of the readership is not capable of judging the actual scientific arguments, the incorrect science remains undebunked in the eyes of many here. This is what makes it somewhat different than what happens in the scientific community in the peer-reviewed journals where the good science does tend to win out in the end.
I read the paper, and it has some obvious problems. The most obvious is the lack of comparison between the USCRN and the different classes of stations in this paper. The USCRN should be the “gold standard” for station temperature measurements. If there are siting issues, you don’t need decades of data to spot the problem. The siting issues should be detectable, even with only 4-5 years of daily data. Since almost all of the USCRN stations now have over five years of data, correlating the Tmax and Tmin against the data from the various classes of “selected” stations in this report should be the obvious first step in identifying siting issues.
Menne et.al. (2010) did this with the homogenized data from different subsets of stations, and found very strong correlations with the entire USHCN dataset (r2 = 0.98 for Tmax, and r2 = 0.96 for Tmin). The failure of Watts et. al. (2012) to complete the same exercise, should be rectified prior to publication. If the findings regarding siting in this paper are accurate, then the Class 1 and Class 2 sites should correlate strongly with the USCRN station data, and Class 3, Class 4, and Class 5 stations should have significantly lower correlations with the USCRN stations.
If the correlations for the different station Classes identified in this paper are not substantially different enough to explain the large differences in decadal trends, then some of the other adjustments are likely responsible for the differences. For example, changes in time of observation, adjustment for a move of a station that was previously sited next to a heat source to a better location (that now allows the station to be classed as Class 1 or 2), switch to a different temperature measurement device or system, etcetera, could explain why smaller classes of raw data don’t track well with the overall trend calculated from homogenized station trend data.
Not addressing the USCRN data is a serious shortcoming for this paper.
wmsc
The Southwest has experienced very rapid growth in county population
between 1970 and 2008.
See: http://www.globalchange.gov/images/cir/pdf/southwest.pdf
I can see the necessity of doing science by press release these days, still, this method is deeply flawed and should be eradicated as soon as practicable.
On the other hand, issuing pre-releases of a paper even before it is submitted to a journal for publication, is laudable, especially if it is done through a proper revision control system and all contributions are made readily visible (and are archived).
I believe these two requirements could be made compatible by appending an appropriate & obligatory Intellectual Property Statement to such pre-releases, which would effectively prohibit references to it in the MSM until such time it is actually deemed “published” by the authors.
I think this practice should be promoted by all means, and those who are slow to comply are to wear a dunce cap for life.
“New study shows half of the global warming in the USA is artificial.”
For a press release, I would call it artifactual, not artificial. Artificial could be interpreted as being “man made” by some lay people.
Woke up thinking about that title (it’s only 6:20 am here in NSW). If it’s not already suggested, how about:
“WARMING IN THE USA ARTIFICIALLY DOUBLED.”
Now, off to read from comment 680 onward and to catch up on everything else that’s happened since I went to bed last night… 🙂
This must be a joke right? There is not a single illustration of trend uncertainty incurred by altering the number of stations or their spatial locations, no bootstrapping, Monte Carlo analysis, nothing. My six grader could do a more robust analysis for a middle school science project. I mean, the term “uncertainty” is found once in the whole manuscript… as part of a reference title.
This is a very significant paper. The next step is to get it in the mainstream media and that will be tough, at least it will here in the UK. The last significant change to the data that made it was when Steve McIntyre calculated that the hottest year on record in the USA was in the 1930’s.
Theo Goodwin says:
July 30, 2012 at 12:54 pm
Anthony Watts has accomplished a heroic task that began with his weather stations website and culminated in yesterday’s brilliant reintroduction of empiricism into the science of weather station siting and the science of temperature reading comparisons.
This has nothing to do with his blog.
It is well and good that Anthony’s actions call forth more than excellent analysis and tightly controlled comments.
I did not advocate ‘tightly controlled comments’, just elimination of some of the chaff. But I guess we set the bar at different heights.
If you want to make clear the ramifications of this paper, how about a subtitle:
“Climate databases skewed. Thousands of papers erroneous.”
Andyj says:
July 30, 2012 at 4:05 am
EVAN!
leading zero before a decimal point:-
“REPLY – Thought about it, then decided that since every starting number there would be a zero, anyway, why bother? ~ Evan”
Please Wiki “decimal” & IEEE 754-2008
It’s the standard.
Sorry but we want this to work and be totally bullet proof.
*
YES! You need those leading zeros. PLEASE, do it right (don’t let this paper be thrown out on a technicality).
Well done. I hope your paper gets the most robust scrutiny both at this stage and through formal peer review. Not because I want it to succeed or fail in order to support my perspective on this matter but because it really is time that we had a decent benchmark to work from and attempts to continue to present the existing methodology as accurate and fit for purpose resemble the Croquet game in Alice in Wonderland.
That’s so 20th century.
Perhaps unsurprisingly, the BBC gives emphasis to Muller and Mann and includes only a late and tiny mention of Antony’s work.
http://www.bbc.co.uk/news/science-environment-19047501
How about “bundling”?
[SNIP: Policy. -REP]
Small deal.
From the last slide of the ppt station siting:
”(It is difficult, however, to be certain of the true effect thanks to the relatively small number of Class 1,2, rural, non-airport stations.)”
I remember reading that a lot of the reporting sites were being discontinued. Does anyone know if it’s mostly these type of sites?
(With the volumn of comments on this post and my PC that is just a few years to young to belong in a museum, I second the suggestion of opening a “New Study, volumn 2” post.8-)
NOAA’s initial response:
http://dotearth.blogs.nytimes.com/2012/07/30/a-closer-look-at-climate-studies-promoted-before-publicatio/#more-45511
Hi guys (Evan, Anthony, et al): Me again.
I’d like to second a question/comment raised by an earlier commentator, James, yesterday at 1:46 PM.
He writes:
“What is the motivation behind using the new siting methodology ? Are there pros and cons to using it ? Could using the new methodology in some way create a (counter intuitive) bias such that trends would be *under*estimated ? Are there good reasons based on the laws of thermodynamics for assuming that one methodology is better than the other ?
Why wasn’t it adopted widely in other studies ? Were reasons given or is it simply too new to have made an impact ?
I realise that answers to the some of the above questions may be found in the reference list. However, like the journalists who read this, I don’t have a great deal of time and would prefer the authors to defend their work. I suggest that answers to the above questions (+ other relevant questions popping up here) be placed in a FAQ section. This work *will* be attacked and readily available well motivated responses are needed.
On another note, its not enough that a method is simply “endorsed”. The CAGW methodology is endorsed by the community and accepted by governments worldwide. To claim the method is endorsed is a useful statement but the argument shouldn’t be overused.”
I would like to second that!! I’ve already earmarked this as an area for *legitimate* criticism of the paper–by which I mean, if someone starts raising concerns about the selection of Leroy 2010 methodology, I would expect Anthony et al to provide a thoughtful, detailed response.
And, frankly, saying “this method is endorsed” is, ahem, argument by authority. I don’t accept it from warmists, and I don’t accept it from skeptics, either. I understand the rationale for including it in the press release, but I think there really needs to be a more thorough discussion of this issue somewhere (perhaps in an FAQ, as James suggested).
Thanks!
Johna
Absolutely fabulous work. Well done and thank you!
John M
questingvole says:
July 30, 2012 at 12:12 pm
The BEST thing about the BBC coverage of the Muller story is the illustration… of a weather station array right next to a runway!!!
Do you have a link which shows this? Thank you to whomever will post it as a reply to this request.
I remember when Watts first published his data on site quality rankings:
Mosher and his poodle John V were straight in trying to discredit it. See Watts first post on this at Climate Audit in 2007: http://climateaudit.org/2007/09/12/ushcn-survey-results-based-on-33-of-the-network/
Mosher has always been determined to be wrong on the idea that site quality hasn’t impacted the quality of the temperature record. Likewise his insistance that CO2 has any correlation to temperature. Clever, but wrong.
Does this information not call into question all temperature data sets worldwide at this moment even before some journal publishes this paper? This should be stunning stuff to those who have never looked into the “adjustments” issue. Positively stunning I would say.