Bishop Hill Surfacestations: the punchline
Dec 17, 2015 Climate: Surface 
And what a punchline it is. Anthony has finally published the results of his epic Surfacestations project, and it seems that the surface temperature record is as flawed as we thought. Here's some excerpts from the press release.
SAN FRANCISO, CA – A new study about the surface temperature record presented at the 2015 Fall Meeting of the American Geophysical Union suggests that the 30-year trend of temperatures for the Continental United States (CONUS) since 1979 are about two thirds as strong as officially NOAA temperature trends.
Using NOAA’s U.S. Historical Climatology Network, which comprises 1218 weather stations in the CONUS, the researchers were able to identify a 410 station subset of “unperturbed” stations that have not been moved, had equipment changes, or changes in time of observations, and thus require no “adjustments” to their temperature record to account for these problems. The study focuses on finding trend differences between well sited and poorly sited weather stations, based on a WMO approved metric Leroy (2010)1 for classification and assessment of the quality of the measurements based on proximity to artificial heat sources and heat sinks which affect temperature measurement...
A 410-station subset of U.S. Historical Climatology Network (version 2.5) stations is identified that experienced no changes in time of observation or station moves during the 1979-2008 period. These stations are classified based on proximity to artificial surfaces, buildings, and other such objects with unnatural thermal mass using guidelines established by Leroy (2010)1 . The United States temperature trends estimated from the relatively few stations in the classes with minimal artificial impact are found to be collectively about 2/3 as large as US trends estimated in the classes with greater expected artificial impact. The trend differences are largest for minimum temperatures and are statistically significant even at the regional scale and across different types of instrumentation and degrees of urbanization. The homogeneity adjustments applied by the National Centers for Environmental Information (formerly the National Climatic Data Center) greatly reduce those differences but produce trends that are more consistent with the stations with greater expected artificial impact. Trend differences are not found during the 1999- 2008 sub-period of relatively stable temperatures, suggesting that the observed differences are caused by a physical mechanism that is directly or indirectly caused by changing temperatures...
Lead author Anthony Watts said of the study: “The majority of weather stations used by NOAA to detect climate change temperature signal have been compromised by encroachment of artificial surfaces like concrete, asphalt, and heat sources like air conditioner exhausts. This study demonstrates conclusively that this issue affects temperature trend and that NOAA’s methods are not correcting for this problem, resulting in an inflated temperature trend. It suggests that the trend for U.S. temperature will need to be corrected.” He added: “We also see evidence of this same sort of siting problem around the world at many other official weather stations, suggesting that the same upward bias on trend also manifests itself in the global temperature record”.
The full AGU presentation can be downloaded here: https://goo.gl/7NcvT2
Much more at Anthony's.
Reader Comments (114)
Phil Clarke, as Christians, Muslims and Jews worship the same God, could we have a Consensus approach to resolving most of the world's conflicts?
Obviously those who view Climate Science as a religious faith without scientific proof thought Paris was simply divine, and want the enforcement of interventions.
Heh, unanimous consent to do nothing, and say anything. We have a Winnah!
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As the world will not end in flood, there is plenty of time for reverend golf to pray for our deliverance from willfull ignorance.
The US was always the place to start, given that temperatures there are being highly oversampled spatially from a climatological point of view, allowing the luxury of just discarding any data that needs adjustment.
Bingo.
Thanks to Clipe for reminding us that end-runs around peer review are as old a problem as the polemic abuse of modeling.
Do you really think this is not going to be submitted for peer review? Really?
So even Watts' no doubt carefully-mined stations (He's applied bits of Leroy 2010 he likes and ignored others, such as slopes and shading, no doubt this will be justified when this Watts et al 2012 is eventually fit for publication LOL) . gives a straight -line trend of 2.2C a century.
Where to begin?
Carefully mined? The stations we dropped run far cooler than the ones we retained. Both for the compliant and non-compliant groups. What next? You're gonna say we are anti-cherrypicking?
Leroy 2010 has other considerations than microsite, yes. But we are not interested in those other considerations. Shade? Said shade is usually a direct result of the heat sink, itself. As for slopes and grass length, they are minor considerations, not in any way related to heat sink, and impossible to evaluate with our available tools, anyway. We are interested in the effect of heat sink and heat sink, only. So we use the heat sink evaluation. Why would we do anything else?
Finally, we deliberately chose a period showing an unequivocal strong warming trend. (After all, Microsite effect on trend is our study, and one must have a trend in order to evaluate.) That period covers a CONUS positive PDO period and to infer a longterm global trend from that is -- completely -- misplaced.
In 2007, Watts announced what he thought the data would show before it was even collected - bit of a scientific no-no, huh?
In the science biz, we call that one a "hypothesis".
This time round, maybe the involvement of John N-G and the rigours of peer-review may help to keep him honest,
You don't know what yu are talking about. We brought him in precisely because he did not believe in our hypothesis. It usually helps a paper to have a hypothesis-skeptic on board.
however I note that the trigger for study is Leroy 2010, which has a rating scheme for weather stations, and it seems our heroes are only applying one of Leroy's 5 criteria (Heat sinks) and classifying stations differently - Leroy classes 1-3 out of 5 as 'good', retaining about 90% in France for example - while Watts et al only like classes 1-2, meaning they are trying to estimate US temperature trends using just 92 stations.
NWS siting guidelines state that a sensor is to be placed 100 feet or more from a sensor. That roughly equates to Class 1\2. Any Class 3\4\5 station is non-compliant according to NWS' own guidelines.
In the science biz, we call that one a "hypothesis".
The Earth is warmer than it was 100-150 years ago. But that was never in contention
Just about everywhere that is what we call a 'lie'
My point was, as you well know, your co-author has a track record of accusing the people who curate the surface record of incompetence and malfeasance; accusations that are never retracted even when shown to be Class A BS. So, any 'analysis' from that source is going to be subjected to intense scrutiny for bias.
Not sure that putting out a press release when there were several years of analysis still to do to support the conclusion did much to enhance your reputation in 'the science biz'.
We are interested in the effect of heat sink and heat sink, only.
Hmmm Sure smells like data mining ....
The poster claims that 'It also explains why the cooling from 1999 - 2008 is exaggerated.' But according to the data digitised from the poster, the linear trend in the difference between NOAA and 'pristine' is, over that period, um, zero. So the exaggerated cooling part of the hypothesis is falsified, according to your own data.
BTW, any chance you could publish the data for the chart alongside?
We welcome "intense scrutiny". We have been trying to get it for longer than you can imagine.
The Earth is warmer than it was 100-150 years ago. But that was never in contention
Certainly not by us.
Just about everywhere
Maybe you are hanging out in the wrong places.
that is what we call a 'lie'
Whereas we call making a prediction a "hypothesis" and then testing it by observation and statistical analysis"scientific method". OTOH, I concede your chosen terminology is more snappy.
Hmmm Sure smells like data mining ....
When we are measuring Heat Sink Effect, we use information on heat sink. Not grass length. What do you do, sir?
Meanwhile, I suggest a visit to your otorhinolaryngologist.
Evan jones answered that on WUWT comments. Apparently the trend is 10% lower than satellites; ie closer to what theory predicts.
You can go further than that. According to Christy (also see Klotzbach et al.), LT trend is 10% to 40% higher than surface trend, depending on latitude. So we do more than "closer". We split the uprights -- on the safe side.
The Earth is warmer than it was 100-150 years ago. But that was never in contention
Certainly not by us.
And yet I can download in minutes the 2010 document 'Policy Based Deception' coauthored by Watts which has as its opener:
Instrumental temperature data for the pre-satellite era (1850-1980) have been so widely, systematically, and uni-directionally tampered with that it cannot be credibly asserted there has been any significant “global warming” in the 20th century.
http://scienceandpublicpolicy.org/images/stories/papers/originals/surface_temp.pdf
Which kinda shows Watts, at least has no difficulty in talking out of his hat. In the 'science biz', you are meant to withdraw your conclusions if they are falsified, especially if they imply malpractice. Perhaps you could have a word to avoid this continuing embarrassment? LOL.
We welcome "intense scrutiny". We have been trying to get it for longer than you can imagine.
That assertion would carry more weight if you released some of the data, say the stations that go to make up the 'good' subset. I for one, would be interested in knowing what happens to the result if you extend the data range to present day to include the recent surge ….
Instrumental temperature data for the pre-satellite era (1850-1980) have been so widely, systematically, and uni-directionally tampered with that it cannot be credibly asserted there has been any significant “global warming” in the 20th century.
Which does not state there has been no warming for the last 100 - 150 years. It is a comment on NOAA method.
That assertion would carry more weight if you released some of the data, say the stations that go to make up the 'good' subset.
I for one, would be interested in knowing what happens to the result if you extend the data range to present day to include the recent surge ….
Well, you'd have a much smaller set of unperturbed stations, of course. I think it unimportant: The El Nino blip is way too short to judge to examine this. And the overall trend from 2005 (when CRN came online) if flat. You can't quantify a trend divergence if there is no trend from which to diverge.
(But you could if you liked. Some even may.)
That assertion would carry more weight if you released some of the data, say the stations that go to make up the 'good' subset.
Yes, quite. All will be available on publication, in easy to assess Excel format. That will be the first stage of pedal to metal independent review. All cards face-up on the table You can be there if you like. Anyone can play, all are welcome.