This summary is from Dr. Pielke at the University of Colorado in his words. I’ll have my own post on some detail not covered here, with links to the SI – data code, etc we are preparing in a day or two. Some may ask why I am not lead author. That was my choice, because the strength is in the statistical analysis, and I wanted it clear that the paper is about that joint work and not about any one person’s efforts. – Anthony
UPDATE: Also, two other posts, by co-author Dr. John Nielsen-Gammon that are must reads are:
The surfacestations paper – statistics primer
Something for Everyone: Fall et al. 2011
Guest post by Dr. Roger Pielke Sr.
Our paper
Fall, S., A. Watts, J. Nielsen-Gammon, E. Jones, D. Niyogi, J. Christy, and R.A. Pielke Sr., 2011: Analysis of the impacts of station exposure on the U.S. Historical Climatology Network temperatures and temperature trends. J. Geophys. Res., in press. Copyright (2011) American Geophysical Union.
has been accepted and is now in press. Below I have presented a summary of the study and its major messages from my perspective. While the other authors of our paper have read and provided input on the information given below, the views presented below are mine. I will be posting on the history of my involvement on this subject in a follow-up post in a few days.
Volunteer Study Finds Station Siting Problems Affect USA Multi-Decadal Surface Temperature Measurements
We found that the poor siting of a significant number of climate reference sites (USHCN) used by NOAA’s National Climatic Data Center (NCDC) to monitor surface air temperatures has led to inaccuracies and larger uncertainties in the analysis of multi-decadal surface temperature anomalies and trends than assumed by NCDC.
NCDC does recognize that this is an issue. In the past decade, NCDC has established a new network, the Climate Reference Network (CRN), to measure surface air temperatures within the United States going forward. According to our co-author Anthony Watts:
“The fact that NOAA itself has created a new replacement network, the Climate Reference Network, suggests that even they have realized the importance of addressing the uncertainty problem.”
The consequences of this poor siting on their analyses of multi-decadal trends and anomalies up to the present, however, has not been adequately examined by NCDC.
We are seeking to remedy this shortcoming in our study.
The placement of the USHCN sites can certainly affect the temperatures being recorded—both an area of asphalt (which is warmer than the surroundings on a sunny day or irrigated lawns (which is cooler than surrounding bare soil on a sunny day) situated near a station, for example, will influence the recorded surface air temperatures.
NOAA has adopted siting criteria for their climate reference stations: CRN 1 stations are the least likely to being influenced by nearby sources of heat or cooling, while CRN 5 stations are the most likely to be contaminated by local effects. These local effects include nearby buildings, parking lots, water treatment plants irrigated lawns, and other such local land features.
To determine how the USHCN stations satisfied the CRN siting criteria and also whether the station siting affected temperature trend characteristics, Anthony Watts of IntelliWeather set up the Surface Stations project in 2007. More than 650 volunteers nationwide visually inspected (and rated) 1007 of the 1221 USHCN stations. The volunteers wrote reports on the surroundings of each station and supplemented these reports with photographs. Further analysis by Watts and his team used satellite and aerial map measurements to confirm distances between the weather station sensors and nearby land features.
The Surface Stations project is truly an outstanding citizen scientist project under the leadership of Anthony Watts! The project did not involve federal funding. Indeed, these citizen scientists paid for the page charges for our article. This is truly an outstanding group of committed volunteers who donated their time and effort on this project!
Analyzing the collected data, as reported in our paper, we found that only 80 of the 1007 sites surveyed in the 1221 station network met the criteria of CRN 1 or CRN 2 sites – those deemed appropriate for measuring climate trends by NCDC. Of the remaining, 67 sites attained a CRN 5 rating – the worst rating. While the 30-year and 115-year trends, and all groups of stations, showed warming trends over those periods, we found that the minimum temperature trends appeared to be overestimated and the maximum warming trends underestimated at the poorer sites.
This discrepancy matters quite a bit. Wintertime minimum temperatures help determine plant hardiness, for example, and summertime minimum temperatures are very important for heat wave mortality. The use of temperature trends from poorly sited climate stations, therefore, introduces an uncertainly in our ability to quantify these key climate metrics.
While all groups of stations showed warming trends over those periods, there is evidence to suggest a higher level of uncertainty in the trends since it was found, as one example, that according to the best-sited stations, the 24 hour temperature range in the lower 48 states has no century-scale trend, while the poorly sited locations have a significantly smaller diurnal temperature range. This raises a red flag to avoid poorly sited locations since clearly station measurement siting affects the quality of the surface temperature measurements.
The inaccuracies in the maximum and minimum temperature trends do matter also in the quantification of global warming. The inaccuracies of measurements from poorly sited stations are merged with the well sited stations in order to provide area average estimates of surface temperature trends including a global average. In the United States, where this study was conducted, the biases in maximum and minimum temperature trends are fortuitously of opposite sign, but about the same magnitude, so they cancel each other and the mean trends are not much different from siting class to siting class. This finding needs to be assessed globally to see if this also true more generally.
However, even the best-sited stations may not be accurately measuring trends in temperature or, more generally, in trends in heat content of the air which includes the effect of water vapor trends (which is the more correct metric to assess surface air warming and cooling; see). Also, most of the best sited stations are at airports, which are subject to encroaching urbanization, and/or use a different set of automated equipment designed for aviation meteorology, but not climate monitoring. Additionally, the NCDC corrections for station moves or other inhomogeneities use data from poorly-sited stations for determining adjustments to better-sited stations, thus muddling the cleaner climate data. We are looking at these issues for our follow-on paper.
However, we know from our study that the use of these poorly sited locations in constructing multi-decadal surface temperature trends and anomalies has introduced an uncertainty in our quantification of the magnitude of how much warming has occurred in the United States during the 20th and early 21st century.
One critical question that needs to be answered now is; does this uncertainty extend to the worldwide surface temperature record? In our paper
Montandon, L.M., S. Fall, R.A. Pielke Sr., and D. Niyogi, 2011: Distribution of landscape types in the Global Historical Climatology Network. Earth Interactions, 15:6, doi: 10.1175/2010EI371
we found that the global average surface temperature may be higher than what has been reported by NCDC and others as a result in the bias in the landscape area where the observing sites are situated. However, we were not able to look at the local siting issue that we have been able to study for the USA in our new paper.
Appendix- Summary of Trend Analysis Results
Temperature trend estimates do indeed vary according to site classification. Assuming trends from the better-sited stations (CRN 1 and CRN 2) are most accurate:
- Minimum temperature warming trends are overestimated at poorer sites
- Maximum temperature warming trends are underestimated at poorer sites
- Mean temperature trends are similar at poorer sites due to the contrasting biases of maximum and minimum trends
- The trend of the “diurnal temperature range” (the difference between maximum and minimum temperatures) is most strongly dependent on siting quality. For 1979-2008 for example, the magnitude of the linear trend in diurnal temperature range is over twice as large for CRN 1&2 (0.13ºC/decade) as for any of the other CRN classes. For the period 1895-2009, the adjusted CRN 1&2 diurnal temperature range trend is almost exactly zero, while the adjusted CRN 5 diurnal temperature range trend is about -0.5°C/century.
- Vose and Menne[2004, their Fig. 9] found that a 25-station national network of COOP stations, even if unadjusted and unstratified by siting quality, is sufficient to estimate 30-yr temperature trends to an accuracy of +/- 0.012°C/yr compared to the full COOP network. The statistically significant trend differences found here in the central and eastern United States for CRN 5 stations compared to CRN 1&2 stations, however, are as large (-0.013°C/yr for maximum temperatures, +0.011°C/yr for minimum temperatures) or larger (-0.023°C/yr for diurnal temperature range) than the uncertainty presented by Menne at al (2010).
More detailed results are found in the paper, including analyses for different periods, comparisons of raw and adjusted trends, and comparisons with an independent temperature data set.
Questions and Answers
Q: So is the United States getting warmer?
A: Yes in terms of the surface air temperature record. We looked at 30-year and 115-year trends, and all groups of stations showed warming trends over those periods.
Q: Has the warming rate been overestimated?
A: The minimum temperature rise appears to have been overestimated, but the maximum temperature rise appears to have been underestimated.
Q: Do the differing trend errors in maximum and minimum temperature matter?
A: They matter quite a bit. Wintertime minimum temperatures help determine plant hardiness, for example, and summertime minimum temperatures are very important for heat wave mortality. Moreover, maximum temperature trends are the better indicator of temperature changes in the rest of the atmosphere, since minimum temperature trends are much more a function of height near the ground and are of less value in diagnosing heat changes higher in the atmosphere; e.g see .
Q: What about mean temperature trends?
A: In the United States the biases in maximum and minimum temperature trends are about the same size, so they cancel each other and the mean trends are not much different from siting class to siting class. This finding needs to be assessed globally to see if this also true more generally.
However, even the best-sited stations may not be accurately measuring trends in temperature or, more generally, in trends in heat content of the air which includes the effect of water vapor trends. Also, most are at airports, are subject to encroaching urbanization, and use a different set of automated equipment. The corrections for station moves or other inhomogeneities use data from poorly-sited stations for determining adjustments to better-sited stations.
Q: What’s next?
A: We also plan to look specifically at the effects of instrument changes and land use issues, among other things. The Surface Stations volunteers have provided us with a superb dataset, and we want to learn as much about station quality from it as we can.
================================================================
UPDATE: Since some people seemed unable to divine the link upstream, the pre-print version of the paper, posted on Dr. Pielke’s website is available here:
http://pielkeclimatesci.files.wordpress.com/2011/05/r-3671.pdf
– Anthony
UPDATE2: Dr. John Nielsen-Gammon, Texas State Climatologist and co-author, weighs in with his post:
Something for Everyone: Fall et al. 2011
As you may have heard, the long-awaited peer-reviewed analysis of the results of the SurfaceStations.org project has finally been released. I can’t wait to see the dueling headlines. Some will argue that the take-home message should be: Poor Station Siting Strongly Effects Temperature Trend Measurements, and will laugh at the idea that we can say with sufficient accuracy what has happened to our climate. Others will argue that the take-home message should be: Poor Station Siting Has No Effect on Temperature Trend Measurements, and will laugh at all the effort expended on a null result. Both sides will find solid evidence for their points of view in the paper. How can that be? How can one paper support opposing conclusions?
…
Here, in brief, are the answers: The poorest sites tend to be warmer. The minimum temperatures are warming faster at poorer sites than at better sites. The maximum temperatures are warming slower at poorer sites than at better sites. The adjustments reduce the differences by about half. The two effects are roughly equal and opposite so the mean temperature is rising at about the same rate across sites of different quality while the diurnal temperature range shows the biggest difference across sites.
On the one hand, this seems to be confirmation of the quality of the temperature record. All types of sites show the same mean temperature trend, so there’s no change necessary to our estimates of observed historical temperature trends in the United States.
On the other hand, there are several warning flags raised by this study. First, station siting is indeed important for the maximum and minimum temperature measurements. Second, the adjustments are only partly correcting the temperature record. Third, since the adjustments use data from all surrounding stations, there’s the danger that the mean trends are dominated by data from the poorer stations. (Less than ten percent of the USHCN stations are sited well enough to be considered appropriate for climate trend measurements.) Finally, and perhaps most important, are we really so lucky that the rest of the world would also have its poorly-sited stations have erroneous maximum and minimum temperature trends that just happen to be equal and opposite to each other?
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Richard M
You might be intersted in these few article on UHI from my own web site.
http://climatereason.com/UHI/
Many weather stations move with surprising frequency and may become engulfed by urbanisation. Therefore a series of different micro climates ares often being recorded which may bear no relation to the one that the station started out in.
Many will argue that it is the anomaly that is important and provided these are consistent such aspects as you mention aren’t crucial.. Some of us disagree with that…
Tonyb
It looks like we are back to Satellite temperature records.
@Latitude on May 11, 2011 at 6:16 pm
Re: So, what gives?
Regarding the 1989 article about global cooling, that is consistent with what I have seen in the temperature record for roughly 1890 to 1990. I wrote about this on my blog under the topic “Abilene Effect.” In short, there were some very cold and unusually frequent winters in the late 1970s and early 1980s. From the point of view in 1989, those five or six cold winters skewed the temperature trends downward, leading to the conclusion that the Earth was entering a global cooling period.
Enterprising climate scientists, though, have used that same cold period (1975 to 1985) to show a WARMING trend up through about 2000.
see http://sowellslawblog.blogspot.com/2010/02/abilene-effect-and-anomalies.html
There are so many holes in the CO2-causes-warming premise that it is no wonder that nothing goes right for those who predict catastrophe. As just one example, cold winters around 1980? But, CO2 causes WARMER winters – IPCC says so!
Sea levels rising due to thermal expansion and melting polar ice? Oops, Antarctic and Greenland ice masses are increasing, and the Pacific Ocean level is decreasing.
Snow is a thing of the past? Oops, there was snow just this past weekend at Lake Tahoe in California — with more snow on the way this weekend.
But, at least to me, the clincher is the fact that CO2 does not perform in a uniform manner, but appears to have no effect on come locations. How can so many sites in the US have zero warming, or even a cooling trend over roughly a 100 year time span, when neighboring cities have “global warming” due to CO2? Even using the climate scientists’s own data (HADCRUT3) and their anomalies to compare trends rather than absolute temperatures, one sees warming in some places but cooling in others. Physics does not allow arbitrary behavior – CO2 has to either heat everything up, or not heat any at all. This is especially true where the cities are all in the same hemisphere, all in the same general range of latitude, and all in the same general range of longitude. The lower 48 states in the USA all qualify for that last sentence.
As an example, Winnemucca, Nevada has a gently rising trend of 0.53 degrees C per century. Yet a neighboring city, Reno, has a trend almost 5 times greater at 2.55 degrees C per century. For another example, Abilene (Texas) shows a slight cooling trend of (minus) -0.19 degrees C per century, while its neighbor, El Paso, shows a slight warming trend of 0.71 degrees C per century.
Even if differences can be measured to say CRN 3,4,5 station measure warmer (higher than CRN 1,2 stations) at night and the opposite during the day it would be incomplete to argue long-term trends since site history seems to be lacking. It is only looking at the siting of now not the 30 or 115 year record (lawn and certain cropping areas return cooler but if for the reporting period the site has always had that then it should matter little in the long-term trends). Trends in sites where we know usage has not changed in the least is of most interest to me as was shown by Warwick Hughes in places like canefields just outside of Mackay, it has always been a canefield since the temperature has been recorded there and showed minimal warming (but was adjusted by almost 1oC due to being classed Urban and other places at airports being classed as Rural, go figure).
Well done to you Anthony and all the other volunteers involved in this exercise though, more representitive results are at least something that will come out of this.
Richard M
“The results may be reasonable from a purely scientific perspective. If heat is being captured during the day and released at night, then that heat is not present during the day to influence the high temperature for the day. Something to consider.”
First lets be clear. There IS a UHI effect. We have many examples of this. In satillite imagery, in isolated site studies, and in transect studies.
Here is what these studies show.
1. the UHI effect is NOT spatially uniform. In fact some parts of a city or semi urban zone can be COOLER than the surrounding rural area. This is due primarily to canopy cover. See the study on portland or the studies on large european cities. What this means of course is that while the entire urban area as an averaged WHOLE is warmer, you will find what Oke called “cool parks”
2. The UHI effect depends upon the rural surroundings. See Oke
3. The UHI effect is not uniform in time. Very simply, some days are prone to more UHI than others. So a city may be warmer than the surrounding rural on one day, but the same temp on a different day. What drives this?
A. cloud cover
B. rain
C. season
D. wind.
So many readers here seeing a daily snapshot of UHI ( say 3C warmer) fail to realize that this is a low frequency occurence. let’s make an extreme example. If UHI happened one day of the year, a 10C warming would disappear in the yearly average.
If UHI only impacts Tmax at a site, then its impact is HALVED. why? because we look at Tave (Tmax+Tmin)/2.
So lets do a sample back of the envelop guesstimate just to show you the problem.
Tmax gets a 3C bias on sunny windless days.
Tave will show a 1.5C bias on sunny windless days.
if 10% of your days are sunny and windless then you can see how a big 3C effect gets diminished in a monthly and yearly average.
Finally, Not ONLY does the heat have to be released at night, BUT it has to be release at precisely the right time. what time? well when the thermometer records Tmin.
In many cases this is the early morning. NOW, if we integrated temperature every 5 minutes we would see the increase in nighttime temps as heat is released, but since we take only one value (the lowest value recorded) then all the UHI heat could be released BEFORE tmin is recorded. So, the nights are warmer for a while, but eventually they reach a tmin which is not effected by UHI. When you think about the whole problem, you quickly becme aware that UHI is not a simple thing to discover in the temp record.
As some commenters compare UAH with CRU, here is what would be expected:
There is no reason to believe, UAH and CRU trends should be same same. Similarly, everybody expects Arctic trends to be higher than global trends.
Over land, UAH trend should be 1.1 times higher and over oceans 1.6 times higher,, resulting in an overall trend increase by approx. a factor of 1.5.
As the UAH trend is actually lower than CRU, there is a HUGE discrepancy between these datasets.
http://blogs.agu.org/wildwildscience/files/2009/11/2009_Klotzbach_etal6.pdf
http://hurricane.atmos.colostate.edu/Includes/Documents/Publications/klotzbachetal2010.pdf
Steve, it is very disturbing to see you use the word “deny” for aspects of climate science that are disputed. That is the type of tactic I would expect from an alarmist.
I don’t see the arguments you presented (1+2) as the norm. The LIA is only mentioned in the context of the MWP or when used to define the starting point of the instrumental record.
Most people who argue for the existence of the MWP do so based on extensive scientific evidence,
http://www.co2science.org/data/mwp/mwpp.php
The question of whether the MWP was warmer than today is very relevant to determine if there is any cause for alarm.
Regardless the debate becomes largely irrelevant once it is acknowledged that any current warming is “unremarkable”, which I believe it is. This is why the unprecedented argument is critical for proponents of mitigation policies.
@Rex
Indeed. All good points / questions. Nice Autumn day in Perth 24C and blue sky in the middle of a huge record breaking drought in SW WA ,unlike the rest of Australia. So very aware of local variability / issues.
However the main game here is the carbon tax. I won’t go into how crazy this tax is (others are far more eloquent). The issue the taxers are saying is that temps are rising due to CO2 therefore we have to reduce the CO2 by taxing “polluters”. CO2 concentration is taken as a global number in popular discussion. So a global temp (probably the mean) is a simplistic number (I agree) to allow communication to the proletariate.
A small poll here in Perth found that
CO2 comprises less than 1/20th of one percent of the earth’s atmosphere – it is a trace gas. Just 7% of respondents knew that CO2’s concentration was under 1%; a sizeable 44% saying more than 10% concentration and 21% saying CO2 represents more than 50% of the atmosphere (Stephen L. Harper April 29th 2011 I think posted here and at Jo Nova’s site)
So imho we have to keep things simple (even if inaccurate to some degree) to communicate with a population with that level of understanding.
Which is why this Surface Stations work is so important (back on topic). We need to know and trust that at least the temperature numbers come from a sound base and are valid over a long time frame.
@Poptech,
Another reason we know that the current temperature state (warmer) is not without precedent is the ancient hunter whose body was discovered in the Alps a few years ago, after a glacier had partially melted. It would appear that the ancient one had been mortally wounded by an arrow and died in the Alpine pass. Either he dug a hole down and into the glacier, fell into a crevasse in an existing glacier, or his body was later covered by snow that turned into a glacier. As he was not wearing cold-weather clothes, it would appear he was later covered by snow that turned into a glacier.
It’s a bit hard to believe that today is warmer than then, as the glacier has only now receded to the point that the body could be discovered.
steven mosher says:
May 12, 2011 at 5:06 pm
Richard M
“The results may be reasonable from a purely scientific perspective. If heat is being captured during the day and released at night, then that heat is not present during the day to influence the high temperature for the day. Something to consider.”
First lets be clear. There IS a UHI effect. We have many examples of this. In satillite imagery, in isolated site studies, and in transect studies. [snip]
Well Steve, that’s all very nice, but I was referring specifically here to the micro-site situation of lower daytime temps and higher nighttime temps of poorly sited stations. From there I went into a discussion of UHI, maybe I didn’t break the two apart clearly.
The thought I was trying to get through is possibly the microsite situation has a reasonable cause AND, IN ADDITION, ALSO was masking a more substantial UHI effect than we realize.
Steve Mosher: See the study on portland….
I’d like to look at this. Any chance you have a link? Portland, Maine? Oregon?
steven mosher says:
May 12, 2011 at 5:06 pm
In addition to your points there is also the fact that if there is no trend in the UH contribution then UH cannot affect the temperature trend at a given location.
Typos:
“… both an area of asphalt (which is warmer than the surroundings on a sunny day or irrigated lawns (which is cooler than surrounding bare soil on a sunny day)”
[Missing “)” after “day”]
“Menne
atet al (2010).”[and there should be a period after “al”]
I note the abstract of the paper ends with this statement:
“According to the best-sited stations, the diurnal temperature range in the lower 48 states has no century-scale trend.”
But climate scientists and the climate models never said it should did they? And the reason why? because both daytime and night-time temperatures are increasing. Why is that? Because of the blanketing effect of greenhouse gases, which warm the planet by trapping radiation both night and day. What you’ve drawn attention to is an observation which is a powerful piece of evidence that global warming is because of greenhouse gases, and not the sun, because any in any model where you increase solar forcing, daytime temperatures increase relative to night-time temperatures.
Well done Anthony for drawing attention to this important piece of evidence for AGW.
Richard S Courtney said:
“And, as is usual with the most interesting of studies, the findings are not what anybody could have predicted.”
Well they certainly don’t support the hypothesis that global warming is an artefact caused by poorly sited stations and the urban heat island effect.
Since others have looked at this data, and shown in peer reviewed papers that removing poorly sited stations makes absolutely no difference to the long term trend of global warming – I think the result of this paper is precisely what they predicted, and they’ve been vindicated.
There is now much moving of goalposts. The observation about no trend in diurnal temperature range based on the best quality stations is inconsequential and a distraction from the clear admission that the claim that global warming is an artefact from it’s main proponent. It is always possible to make ‘interesting’ observations if you trawl through enough, but you can’t say such observations vindicate your hypothesis unless you made a hypothesis beforehand. What we see here is a clear example of blasting a barn door with a shotgun. drawing a target around a cluster of pellet holes and claiming to be a sharpshooter. To say that ‘it matters quite a bit’ that diurnal temperature range is underestimated by poorly sited stations as Pielke Sr does is post hoc rationalisation for the exercise. If indeed ‘it matters quite a bit’ why did was the importance of this drawn to our attention before the exercise was undertaken. The obvious fact that the underestimate means that if anything, the true situation regarding global warming is worse than stated is something that neither Roger Pielke or Anthony Watts thinks ‘matters quite a bit’ otherwise why not draw attention to obvious conclusion.
As for it being ‘fortuitous’ that errors cancel out – that’s a remarkable way to justify a null result. There are errors in the measurement of any physical phenomenon, and the entire field of statistics has been developed in order to deal with them. Measurements always vary around a mean, typically in a Gaussian bell curve – and to blame this on fortuitous ‘luck’ if the result doesn’t please you is simply sour grapes.
However I am pleased to see that the authors of this paper are now taking an interest in the rest of the world. It wasn’t so long ago that claims were being made that there hadn’t been any increase in global temperature since the 1930’s, on the basis of a outlying data point from the 2% of the globe that is the USA. Good luck with extending the surface stations project to the rest of the globe though. I think you’ll find that McDonalds car parks and unfortunately sited air conditioning units are in short supply in the Antartic, Chile, the Australian Outback or Siberia, not to mention the 70% of the Earth’s surface that is covered in water.
Whilst I commend the citizen science exercise that Anthony set in motion, and the submission of a paper for peer-review, I also think the attempts to spin this into something positive for the ‘sceptics’ really are rather desperate.
Dean Morrison,
The current trend goes back to the LIA, well before the start of the industrial revolution. Further, temperatures declined for thirty years, between 1940 and 1970 – right in the middle of the industrial revolution. And the current very mild natural warming cycle is nothing new.
Even Phil Jones shows that the current trend is not unusual. Since the trend goes back to at least the beginning of the LIA, your conjecture that GHGs make a measurable difference fails, and the null hypothesis remains unfalsified.
Dean Morrison, the paper discusses microsite problems, not UHI. These stations might also be impacted by UHI and the degree is still an open question. In fact, it’s possible the better microsites could exist in more significant UHI areas. Could be one reason for the results.
Might not be the best time to uncork that champagne.
Anthony Watts, in the June 2010 you made a tour of Australia in which you gave an interview at the ABC which included this:
“Dr Pielke, his research group and myself are now in the process of finishing a paper for submission to a peer reviewed scientific journal that illustrates what we found in the way that siting difference has affected the US temperature record. And I can say with certainty that our findings show that there are differences in siting that cause a difference in temperatures, not only from a high and low type measurement but also from a trend measurement and a trend calculation…..
Michael Duffy: In which direction does the bias lie? Are you suggesting that the temperature has not got as hot as the American official historical record suggests?
Anthony Watts: That’s correct. It’s an interesting situation. The early arguments against this project said that all of these different biases are going to cancel themselves out and there would be cool biases as well as warm biases, but we discovered that that wasn’t the case. The vast majority of them are warm biases, and even such things as people thinking a tree might in fact keep the temperature cooler doesn’t really end up that way. ”
So, what changed?
You would probably know that your interview was extracted by Andrew Bolt, a very popular (and politically influential) “skeptic” blogger in Australia.
Do you have any concern about correcting the false impression you gave about the forthcoming results, even at a time you said the paper was close to its finalisation?
REPLY: Apparently you and the folks at Deltoid missed this, but that’s understandable when you want to play the denigration game that goes on there, or “rubbishing” as you call it. The fact is, you folks would “rubbish” the conclusions no matter what they were. Here’s a must read to help you understand should you choose to:
Something for Everyone: Fall et al. 2011 John Nielsen Gammon
As you may have heard, the long-awaited peer-reviewed analysis of the results of the SurfaceStations.org project has finally been released. I can’t wait to see the dueling headlines. Some will argue that the take-home message should be: Poor Station Siting Strongly Effects Temperature Trend Measurements, and will laugh at the idea that we can say with sufficient accuracy what has happened to our climate. Others will argue that the take-home message should be: Poor Station Siting Has No Effect on Temperature Trend Measurements, and will laugh at all the effort expended on a null result. Both sides will find solid evidence for their points of view in the paper. How can that be? How can one paper support opposing conclusions?
Read it all here: http://blog.chron.com/climateabyss/2011/05/something-for-everyone-fall-et-al-2011/
The simple and most indisputable fact about the USHCN surface network is clearly shown in this chart.
http://surfacestations.org/Figure1_USHCN_Pie.jpg
Only 1 in 10 meet climate station siting requirements by the NOAA adopted CRN rating, and the vast majority have a warm bias based on the Climate Reference Network rating system error magnitude numbers. There’s no mistaking that. At the time of that interview, and today, that statement remains true. Note the paper was submitted in October 2010, not June. Analysis by John N-G didn’t commence until we completed all the survey QC, and that took quite a bit of time.
In a couple of days, I’ll have my writeup and you can practice your “rubbishing” further on that. Be sure to heed Dr. Neilsen-Gammon’s writeup first though. – Anthony
Smokey – you say with confidence that the trend goes back to the ‘Little Ice Age’?
How do you know this? Do you have secret access to an unimpeachable temperature record stretching back centuries on which to base such a statement? Or perhaps you feel able to accurately reconstruct global temperatures with great precision on the basis of some Viking sagas about a failed colonisation of a few villages a few centuries ago?
I think us scientists will stick with the surface temperature record from thousands of sites around the world, which is confirmed not only by cutting edge satellite technology, but also by Anthony Watts. Feel free to stick with mythology if you prefer, but don’t expect to be taken seriously.
Richard M – you say that the paper concerns itself with ‘microsite problems, and not the UHI’. I’m afraid that quite simply you are wrong. The hypothesis put forward by Anthony Watts and others is that global warming is merely an artefact caused by a systematic problem of poorly sited stations falsely showing a global warming signal because of increasing urbanisation and the Urban Heat Island effect. Anthony’s paper shows no such signal, and confirms several other pieces of work which show that station quality is not responsible for the globally observed trend of warming. Furthermore, by pointing out that there is no increasing trend in diurnal variation, Anthony points to a powerful piece of evidence that such warming is because of greenhouse gases, and against the hypothesis that it is because of increased solar activity. We should be grateful to Anthony for exposing his work to peer review, but I’m afraid it confirms not only what is already known, but the predictions of climate models. If you have a hypothesis that something has been missed, or that something is Anthony’s work, then you are free to conduct your own research, and if you feel it supports you hypothesis, to submit you evidence for peer review. However your postulations alone do not count as evidence, and do nothing at all to counter the overwhelming established scientific evidence for global warming.
Dean Morrison,
You’re not really up to speed, are you? Here’s a chart of the gradually rising temperature trend since the LIA. The CET record is as ‘unimpeachable’ as any you will find anywhere.
As you can see, my statement was based on empirical evidence, not on Viking sagas, etc. But nice try at misdirection, and thanx for playing.☺
Smokey – the data you presented doesn’t include the Little Ice Age which you mentioned. The scales are arranged to deliberately downplay the increasing rate of warming since 1880. In the Central England Temperature record there is no statically significant warming from 1660 to 1890, and if anything there is a slight cooling trend. Since then there has been steadily increasing warming, with a plateau in the middle of the last century, followed by warming at an increasing rate. The same general picture is true of all of the data sets you show, and therefore the red lines that have been put through those charts are deliberately misleading. Globally the upward trend in temperature is detectable only from about 1880 – and not as you say from the ‘Little Ice Age’. If you want to provide evidence for your assertion you need to show there was significant global warming during the period 1660- 1880. That’s assuming of course you are going to use actual temperature measurements, rather than paintings of ice fairs… 😉
Dean Morrison,
First you claimed that my view was based on Viking saga and paintings of ice fairs, etc., while disregarding the links in my previous comment. Then when I posted charts of the clearly rising temperature trend line from the LIA, you bizarrely claimed that it shows a cooling trend. The obvious conclusion is that your mind is already made up, the science is settled, and all evidence that contradicts your world view is simply rejected. It is clear that none of the facts I could provide would make any difference to you.
That being the case, I won’t bother. Arguing against cognitive dissonance is fruitless. But now it’s my turn to ask you a question, since you claim to be one of “us scientists”: can you provide any empirical, testable evidence, per the scientific method, showing global damage due to CO2? No one else has been able to, but maybe you can.
Congratulations Anthony et al. Don’t I recall that the worst of the warming trends was supposed to be manifested in higher minimum (night-time) temperatures? It seems to me that the difference in trends between poorly-sited and well-sited surface stations in your study is telling. I’m looking forward to your further analysis of this report.
Dean Morrison
I am absolutely incredulous that you can make the assertions you did to Smokey (8.21 and previously)
This is my web site;
http://www.climatereason.com
In it I collect historic temperature records dating back to 1659. I have also written a number of articles on the increasing warmth from the low point of 1607.
There were ups and downs of course (a period from 1698 to 1730 was very similar to today) but basically there has been a slow and unremarkable warming captured in CET and other records.
I would respectfully suggest you read a few books by such as Hubert Lamb-the first Director of CRU. He was certainly aware of this long term warming and dated the retreat of the glaciers to around 1750. A good one is;
‘Climate, History and the Modern World’ ISBN 0415-12735-1
Here is a Blow by Blow account of the steady rise in warmth throughout the 19th century;
http://wattsupwiththat.com/2010/12/05/has-charles-dickens-shaped-our-perception-of-climate-change/
As it happens my next article is called ‘The long slow thaw’ and deals with this gradual warming from 1607. Fortunately we have a wealth of diaries, church records, crop records and instrumental records etc that show this centuries old rise very clearly and demonstrate that it didn’t start at 1880.
If you are American and would like to search the articles on my web site you will see two from me that noted the steady warming in the US in the 19th century and comments on the oddity of James Hansen commencing his records just as the temperature turned down temporarily, thereby missing out on the preceding warmth and accentuating the slope of the subsequent rise.
Incidentally, CET in 1659-the first year of CET- was exactly the same as 2010-the last year of the record at 8.83C
tonyb