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« Peer-to-peer review | Main | Beddington's meeting with Pachauri »
Wednesday
Apr132011

Muller again

Pielke Jnr has a partial transcript of Richard Muller's radio interview yesterday.

CONAN: Do you find that, though, there is a lot of ideology in this business?

Prof. MULLER: Well, I think what's happened is that many scientists have gotten so concerned about global warming, correctly concerned I mean they look at it and they draw a conclusion, and then they're worried that the public has not been concerned, and so they become advocates. And at that point, it's unfortunate, I feel that they're not trusting the public. They're not presenting the science to the public. They're presenting only that aspect to the science that will convince the public. That's not the way science works. And because they don't trust the public, in the end the public doesn't trust them. And the saddest thing from this, I think, is a loss of credibility of scientists because so many of them have become advocates.

CONAN: And that's, you would say, would be at the heart of the so-called Climategate story, where emails from some scientists seemed to be working to prevent the work of other scientists from appearing in peer-reviewed journals.

Prof. MULLER: That really shook me up when I learned about that. I think that Climategate is a very unfortunate thing that happened, that the scientists who were involved in that, from what I've read, didn't trust the public, didn't even trust the scientific public. They were not showing the discordant data. That's something that - as a scientist I was trained you always have to show the negative data, the data that disagrees with you, and then make the case that your case is stronger. And they were hiding the data, and a whole discussion of suppressing publications, I thought, was really unfortunate. It was not at a high point for science.

And I really get even more upset when some other people say, oh, science is just a human activity. This is the way it happens. You have to recognize, these are people. No, no, no, no. These are not scientific standards. You don't hide the data. You don't play with the peer review system.

It's good to see Muller banging on about "hide the decline": the scientific establishment and prominent science commentators have, for the most part, maintained a deafening silence on the subject - something that does them no credit.

If you have climbed to the very top of the scientific tree you get responsibility as well as power. That responsibility includes the duty to stand up and speak out when scientists misbehave, particularly where public policy is involved. Fence-sitting, diplomatic silences and vague allusions to "problems" are not sustainable approaches for these people to take. Eventually the truth will get out and then the public will ask "Who knew?" and "Why weren't we told?". Many reputations will then be on the line. Muller's will not be one of them.

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Reader Comments (47)

Well that's one in the eye for Kealey and his woeful "Scientists are and have to be advocates" view, debated here recently.

Apr 13, 2011 at 12:34 PM | Unregistered CommenterNicholas Hallam

Prof. Muller is still "pussyfooting around". Poor mixed up scientists who really do have the science, even if they are just a bit over eager. It's really unfortunate!

I'm looking for words like fraud, criminal, shyster, dud "science", what AGW?

Apr 13, 2011 at 1:53 PM | Unregistered CommenterMichael Lewis

Nicholas, I agree. Just because people are not good at admitting they're wrong, and just because in some cases, it is good to persist with an idea even if it seems to be wrong at first, does not mean that being mendacious is acceptable. It isn't, and Kealey was veering dangerously close to saying that it is. Michael, you'd have to accept that there are not many mainstream and respected scientists saying what Muller is saying. Don't you think that is already something?

Apr 13, 2011 at 2:04 PM | Unregistered Commenterj

" And they were hiding the data, and a whole discussion of suppressing publications, I thought, was really unfortunate."

If unfortunate means lacking a bit of luck, then I think it was fortunate (and inevitabe) that these "scientists" were caught pising in the percolator

Apr 13, 2011 at 2:19 PM | Unregistered Commentergolf charley

Full transcript here.

http://www.npr.org/2011/04/11/135320209/climate-change-skeptic-says-warming-is-real

Quote, Muller, "But the public discussion tends to be not on the key science, but on the spectacular things that the exaggerators tend to say or the deniers deny"

Muller uses the "d-word".

Apr 13, 2011 at 2:21 PM | Unregistered CommenterMac

Loyalty can be a strange thing.
Everyone tends to close ranks when they see colleagues being criticised and that applies to scientists, teachers, bus drivers, priests and soap powder salesmen! (In the last case, even when they are in competition with each other.)
Muller has finally broken cover because (a) he has no dog in this particular fight, not being a member of the Team, and (b) somebody has asked him the direct question and he's come up with an honest answer.
Unless I'm reading between the wrong lines his distress is plain to see but he does understand what has happened and why. That said, I think that he is probably a little naive since it appears, from where I sit at least, that there has been allowed to develop a small clique (25? 30? at most) who now run the climate science establishment. With the politicians (who would sell their grandmothers for power, inflience, and a secure excuse for raising taxes) and an unholy alliance of eco-extremists, enviro-fanatics, neo-Malthusians, and eugenicists it is hard to see which group is calling the shots and which are the "useful idiots".
My second reading of HSI (just completed) confirms my original suspicion, namely that the key players are subject to no proper oversight and when challenged behave exactly like five-year-olds caught with their fingers in the cookie jar. Anyone who has had children will recognise the procedure:
1. No I didn't;
2. Hide the evidence;
3. It was your fault;
4. Lose temper;
5. Break down in tears.
The trouble is their more mature colleagues start from the assumption that by the time they get their PhDs they've grown out of the tantrum stage. Regrettably, not so.

Apr 13, 2011 at 2:34 PM | Unregistered CommenterSam the Skeptic

CONAN: You mentioned Anthony Watts. He runs a website for climate deniers, said he was prepared to accept whatever result your group produced, even if it proves my premise wrong. After your testimony, he said the hearing was post-normal science political theater.

Prof. MULLER: Well, I think Anthony can be forgiven for his ups and downs. I think he has done a great job, a real contribution, and I think his work has proved really essential. Because you look at the photographs of these sites, and you say I wouldn't trust the thermometer there. But by doing it systematically, by going to over 1,000 stations in the United States and documenting them, we now have the data that we need to evaluate how much of an effect these bad sitings have.

And our tentative conclusion, which is what I reported to Congress, is even though these sites can lead to different temperatures, that for the trends, for the thing we called warming, that there does not seem to be a significant effect.

So for example, if you're near a building, it may be warmer, but the rise in temperature from year to year does not appear to be any more than it is for sites that are out on the countryside. That's very important.

Note, once more the "d-word" is uttered.

Note, also, comparing trends from good sites to bad sites does not give any legitimacy to include bad sites. Indeed the process of mixing good with bad, thru averaging, homogenisation and the use of other techniques, ultimately means that everything becomes bad because you can't untangle the good from the bad.

Anthony Watts has done the quality control, if Muller choses to ignore that then he has to give a much better explanation than given.

Apr 13, 2011 at 2:46 PM | Unregistered CommenterMac

I shall be interested to see Muller's argument for the part of recent warming due to human activity - which he says in the full transcript that his team is investigating (though he also appears to anticipate the outcome of this investigation as showing non-negligible human-induced warming).

In the light of recent discussions here on (1) the existence of uncaused trends in complex non-linear systems and of (2) the significance of trends in time series data depending on properties of the underlying model, it will be interesting to see how human causation can be read from the temperature data. I can't think that it could be a very strong conclusion and certainly not one strong enough to get us to take our medicine.

Apr 13, 2011 at 3:12 PM | Unregistered CommenterNicholas Hallam

I don't mind being labelled a 'denier' as long as it is made clear exactly what it is that I am denying.
I suspect Prof Muller considers himself to be an 'honest broker' but so far from his pronouncements I do not think he will go against the prevailing paradigm.
No instrumental measurement expert seems to be involved at all, quality control, calibration etc.

Apr 13, 2011 at 3:20 PM | Unregistered CommenterG.Watkins

'So for example, if you're near a building, it may be warmer, but the rise in temperature from year to year does not appear to be any more than it is for sites that are out on the countryside. That's very important. '

It will be interesting to see this statement justified with the release of the data and methodology as have previously been promised!

Apr 13, 2011 at 3:39 PM | Unregistered CommenterLord Beaverbrook

It'll be interesting to see what happens if the Berkely experiment reaches the conclusion is that they seem to be hinting at, namely that:
1. There is a global warming signal extractable from the data, and that it is caused by man.
2. The data and analysis by the hockey team is deeply flawed and unreliable.

They going to be very unpopular.

Apr 13, 2011 at 3:50 PM | Unregistered CommenterStuck-record

One thing that I thought was interesting in the full transcript was that Muller says:

have created a new project here in Berkeley - we call it Berkeley Earth - that is doing a reexamination of the global warming issue. We are addressing all of the issues that have been raised - all the legitimate issues that have been raised by the people called the skeptics.

If you look at the Berkeley Earth webpage, it is much more specific than that - it says it looks at the surface temperature record. I have lots of sympathy for people like Mac who think that the surface temp records are not right at present - but equally, I think there's no harm in admitting that they might be roughly correct. What would be interesting is if Berkeley really were intending to look at all the issues raised by sceptics.

Apr 13, 2011 at 4:21 PM | Unregistered Commenterj

Sam the Skeptic

"...soap powder salesmen! (In the last case, even when they are in competition with each other.)"

They don't do much competing in Europe.

http://news.yahoo.com/s/ap/20110413/ap_on_bi_ge/eu_eu_detergent_cartel_1

Apr 13, 2011 at 4:45 PM | Unregistered CommenterDreadnought

I wonder if Muller has seen that comparison done by a high-school kid and his dad, where they took all the major population centres in the States, and graphed the temperature trends, and then for each reading took the closest rural reading and did the same thing.

They showed that using two apparently identical geographic sets of readings for the US, there was no significant rural warming over the last century, only urban warming.

I cannot see how this result was possible if as Muller contends, the rural and urban trends are the same.

I wish I could find the link.

Apr 13, 2011 at 5:05 PM | Unregistered Commentersteveta_uk

j

Muller defines three types of people in this process;

1. Exaggerators
2. Skeptics
3. Deniers

Muller also states, "We are addressing all of the issues that have been raised - all the legitimate issues that have been raised by the people called the skeptics"

So who are the skeptics?

Apr 13, 2011 at 5:09 PM | Unregistered CommenterMac

It’s hard to put my finger on the exact reason but I’m not expecting too much from the good professor. He’s obviously enjoying his 15 minutes and is just a bit too smooth on the PR front for my liking.

Pointman

Apr 13, 2011 at 5:30 PM | Unregistered Commenterpointman

Muller seems an intelligent and fair sort of chap, and I'm trying hard to give him the benefit of the doubt, but his statement:-

"So for example, if you're near a building, it may be warmer, but the rise in temperature from year to year does not appear to be any more than it is for sites that are out on the countryside. That's very important."

.... seems to miss out the biggest problem with the temperature stations Anthony has identified - which is that stations which were once in quiet semi-rural situations on the edge of towns are now completely swamped by urban expansion.

A good example would be instruments outside public buildings where only a handful of vehicles would have been parked in the past - but which are now in the middle of large car parks.

Or instruments sited on the edge of small airfields which have grown into airports.

In these situations, "the trend" could obviously be a direct artifact of the surrounding environment and I'm wondering if he missed the point by accident or design.

Apr 13, 2011 at 5:32 PM | Unregistered CommenterFoxgoose

Dreadnought
Yes, I saw that. I'm surprised P&G were caught at that game. Not their style at all. Or never used to be.
Something else to blame global warming for.[ ;>)

Apr 13, 2011 at 5:43 PM | Unregistered CommenterSam the Skeptic

@steveta_uk: is this what you're after?

http://www.climate-skeptic.com/2009/12/urban-biases-on-surface-temperature-records.html

Apr 13, 2011 at 6:05 PM | Unregistered Commenterwoodentop

Woodentop, yes that's the one - does Muller read this site, do you think? I think he would find this quite enlightening.

Apr 13, 2011 at 6:24 PM | Unregistered Commentersteveta_uk

Muller has drifted from the point here. It is not the temperatures or the trends that are of interest but the cause of the trends that is. One such cause - step.changes - was to be dealt with in the yet-to-be announced code, UHI was to be another hence involvement of Anthony Watts.

Muller was to direct the programme to achieve its aims, not to second-guess it. Very worrying so far and I am beggining to doubt its ultimate relevance as signal in the current noise.

Apr 13, 2011 at 8:01 PM | Unregistered Commentersimpleseekeraftertruth

One of the concerns I had regarding Muller's testimony was that while he did caution that BEST findings to date were preliminary (based on 2% sampling of data), this would result in a takeaway that eliminates/obscures the preliminary nature of their results. Given the "framing" by NPR, it would seem that this concern is not unwarranted:

First, the URL contains filename: /climate-change-skeptic-says-warming-is-real (fairly minor but ...)

Second, the intro on the page:

During a Congressional hearing on climate science, physicist Richard Muller was expected to testify on the side of climate change skeptics. Instead, Muller announced his team found a warming trend. Muller says scientists are often challenged to insulate findings from political pressures. [emphasis added -hro]

Sounds far from preliminary to my ear.

And third, from Conan's on air intro:

Representative EDDIE BERNICE JOHNSON (Democrat, Texas): There seems to be some attitudes that there is an elaborate hoax orchestrated by the scientific community on global change. Based on your work, the three of you, do you agree that the global temperatures are rising and will continue to rise, and that greenhouse gas concentrations are at least partly to blame?

CONAN: Those at the witness table that day included Richard Muller, a professor of physics at Berkeley, considered by some as a climate skeptic. When he responded in the affirmative to both those questions, he found himself in the middle of a debate where emotion and politics intersect with science.

If one didn't know better (and it's not unreasonable to assume that many NPR listeners might not), one might be inclined to conclude "Oh, gee ... here's a skeptic who agrees that the consensus is right".

This, combined with Muller's sidestepping (as opposed to correcting) Conan's labelling of Anthony Watts as a "denier" leaves me somewhat uncomfortable with Muller's performances.

Apr 13, 2011 at 9:11 PM | Unregistered Commenterhro001

Muller gave every indication that he is a salesman at the Senate hearings and the product he is pushing is Muller. I am sceptical of his intentions so far, but I will read carefully any findings the Best team eventually produce.

Apr 13, 2011 at 9:33 PM | Unregistered CommenterAlexander K

Steveta_uk


I wonder if Muller has seen that comparison done by a high-school kid and his dad, where they took all the major population centres in the States, and graphed the temperature trends, and then for each reading took the closest rural reading and did the same thing.

They showed that using two apparently identical geographic sets of readings for the US, there was no significant rural warming over the last century, only urban warming.

My understanding is that IF the urban records actually comprise a succession of trends broken up by small step changes, then the algorithm will possibly be looking at temperature differences - not sure what time difference would be used here - and discarding differences which are considered to be outliers. Using this sort of approach each of the step changes might be identifiable and thus be discarded but the unbroken trend measured between each pair of step changes could possibly still be comparable to the trend in an unbroken record from a rural station.

I hope this makes sense.

This also solves the situation where a station is relocated, and it also solves the situation where negative temperatures e.g. -20 deg are occasionally recorded as positive e.g. 20 deg.

Presumably they have other "tricks" (in the nicest sense of the word) to handle a few other anomalies too, but the biggest plus will hopefully be the transparency of approach and the ability to test for residual bias much more easily. Especially if the database is built from Day 1 with those goals in mind at the outset.

Apr 13, 2011 at 10:41 PM | Unregistered Commentermatthu

Is it so surprising that BEST’s preliminary result shows a warming trend?

Some commenters here are uncomfortable with fitting trends to the data so instead let’s smooth out the noise with a 5 year running mean and look at the general shape of the curves:

GISTEMP, HADCRUT, UAH, RSS five year means:

Same shape but a vertical separation. This goes away when the records are re-baselined for a more correct comparison. GISTEMP and HADCRUT use different baselines to UAH and RSS which take their mean from the 32 year period of satellite observations.

GISTEMP and HADCRUT rebaselined for accurate comparison with UAH and RSS:

This is the basis for the Wood for Trees temperature index:

http://woodfortrees.org/plot/

This explains how it was done and needs to be read if you are going to disagree with all this:

http://woodfortrees.org/notes#wti

The correspondence between the satellite measurements of tropospheric temperature and the surface temperature measurements is clear. This indicates that the surface data are broadly correct.

BEST is working with the same data, so BEST is going to produce something recognisably similar to the existing surface temperature reconstructions.

This requires no betrayal, or deceit. Muller may indeed be enjoying his 15 minutes, but nothing suggests that he has ‘torqued the science’.

Apr 13, 2011 at 11:06 PM | Unregistered CommenterBBD

"Eventually the truth will get out and then the public will ask 'Who knew?' and 'Why weren't we told?'."

Thanks not least to you, the truth did get out about Climategate, nearly eighteen months ago. Plenty of us were hopping mad about the MMGW scare for years before, but with nothing like your articulacy.

The problem now is that Climategate is all the way back in 2009. Mann is trying to crush dissent with libel laws. (Considering how far English libel law favours the plaintiff, it's a bit odd that "Professor" Phil Jones hasn't resorted to them.) Some Chief Scientific Advisor spouted some utter drivel, just the other day. about global wombling, or some such, obediently repeated, ad nauseam, by the broadcasting wing of the public sector party.

The trouble is that the alarmists are like that Hammer movie monster who always gets up again. They lose all of the arguments, literally on a daily basis, courtesy of you, Donna Laframboise, Joanne Nova, Antony Watts, Steve McIntyre, Ross McKitrick and many others, but they never stay down, because they are backed up by what they imagine to be infinite amounts of taxpayers' money. Clue to Professor Beddington: there is only a finite number of taxpayers, so you probably ought to understand that their finances are limited, too.

Apr 13, 2011 at 11:08 PM | Unregistered CommenterOwen Morgan

A lot of people are trying to put words into Watt's mouth and hoping that UHI will explain everything away. here is what his soon-to-be-published paper says, according to his testimony to Congress:

"Temperature trend estimates vary according to site classification, with poor siting leading to an overestimate of minimum temperature trends and an underestimate of maximum temperature trends, resulting in particular in a substantial difference in estimates of the diurnal temperature range trends. The opposite-signed differences of maximum and minimum temperature trends are similar in magnitude, so that the overall mean temperature trends are nearly identical across site classifications. Homogeneity adjustments tend to reduce trend differences, but statistically significant differences remain for all but average temperature trends. Comparison of observed temperatures with NARR shows that the most poorly-sited stations are warmer compared to NARR than are other stations, and a major portion of this bias is associated with the siting classification rather than the geographical distribution of stations. According to the best-sited stations, the diurnal temperature range in the lower 48 states has no century-scale trend."

My take is that WEatts no longer believes thatsiting issues not affect the mean temperatures but only the max and min readings. Will mac and co please stop foaming at the mouth? Their guru has spoken.

Apr 13, 2011 at 11:14 PM | Unregistered Commenterdiogenes

And aventually we will all be dead Mr. Morgan.

Apr 13, 2011 at 11:22 PM | Unregistered CommenterGeorge Steiner

@BBD

"Is it so surprising that BEST’s preliminary result shows a warming trend?

No.

The BEST study is to identify any anomalies in the data that influence trends and adjust for them, publish their work transparently and produce a cleaned data set.

If that is successful, their results can be utilised to look for any anthropomorphic signal. That is the way I understood it and (still) hope for it to progress.

Apr 13, 2011 at 11:29 PM | Unregistered Commentersimpleseekeraftertruth

Lord B

"it may be warmer, but the rise in temperature from year to year does not appear to be any more than it is for sites that are out on the countryside"

So how did it get to be warmer? Sounds like a flat contradiction to me.

Apr 14, 2011 at 12:09 AM | Unregistered CommenterJames P

James P

Please look again at the big picture. Why are the satellite data in good agreement with the surface data?

(links at 11:06pm above)

Apr 14, 2011 at 12:25 AM | Unregistered CommenterBBD

I'm not sure I understand Muller's point about the temperature rise year on year being the same for cities and urban areas. Surely that depends on your starting point? If an urban site has already gained it's temperature then if you measure it and compare it to 1980 it may show a slight rise in temperature, ir you measure it against it's total record, it should, say since 1900 then it is almost certainly going to show a higher rise in temperature. Intuitively you have to believe that if 80+% of the sites in the US, which make up a large part of the data set for GATA are badly sited then the there will be an effect on the overall 20th century rise in temperatures.

In my mind there is no doubt temperatures are rising around the globe, they have been since the end of the Little Ice Age and there's no reason for them to stop now, so we'd expect the 30 year anomoly to go up. The question is, is there a factor in there exaggerating the 20th century rise.

Having said that it's only an academic question, the belief in AGW seems so entrenched now that the government will still be announcing initiatives, and George Monbiot telling us it's what global warming looks like, when glaciers have covered Scotland and most of England.

Apr 14, 2011 at 8:06 AM | Unregistered Commentergeronimo

This new post by Willis Eschenbach,

http://wattsupwiththat.com/2011/04/13/second-best/#more-37904

is worthwhile linking here as he tackles most of the points raised here.

Apr 14, 2011 at 8:45 AM | Unregistered Commentersimpleseekeraftertruth

The AGW community is still selling miracles.
The issue is not if we have had some warming. The issue is if the warming we have had in the past ~150 years is unusual, dangerous, or leading to unusual or dangerous conditions in climate.
The Trenberthian hypothesis, which Muller seems to accept implicitly, is so useless as to be non-falsifiable,
Yet this seems to be what the majority of climate scientists and their followers are using as a starting point.
We have indeed entered the age of stupid.

Apr 14, 2011 at 9:48 AM | Unregistered Commenterhunter

The video of the father-son science project debunking the UHI-no-impact claims of the believers was posted at the Climate Skeptic blog site.
I have just asked the host if he could re-post a link to it.

Apr 14, 2011 at 10:00 AM | Unregistered Commenterhunter

Muller and others are wrong about the impact of UHI. Since we were initially led to believe that the 2% preliminary results, a 1.2C rise, are based on Japan (we still don't know for definite - nothing by BEST has been released) here is a temperature graph of Tokyo dating back 100 years.

http://en.wikipedia.org/wiki/File:HeatIsland_Kanto_en.png

As noted, "the temperature of Tokyo has gone up more than surrounding since about 1920. And, the temperature goes up in the city from Tokyo to the inland (Kumagaya and Maebashi) compared with the city along the sea (Katsuura and Yokohama)."

It is only by site-by-site local comparison that you can detect problems like UHI, greenfield versus urban, and then decide what to do with the urban data ( I would bin any and all UHI affected data)

Further Muller uses the definition "rural" to distinguish between it and urban. That is wrong, for rural site data can be and are affected by the impact of agriculture (water, types of crops, animal farming, etc). There is a need to distinuguish between greenfield-rural and agricultural-rural. Again only by site-by-site local comparison would you be able to detect any differences between greenfield-rural and agricultural-rural data.

Finally, since Anthony Watts ( who Muller now deems to be a denier) has done all the quality-control leg work on establishing good sites for bad in the US it seems obvious that BEST should concentrate all its efforts on the US surface data. There is a lot of knowledge and expertise on the US data sets, McIntyre has done a lot of critical work on them giving us invaluable insight into how errors are made in handling these data-sets.

Evertything seems to be in place for BEST to carry out as a first step an extensive and comprehensive review of the US temperature record. Being seen to do that right in an open and transparent way would lend credibility to BEST, credibility that Muller's recent words have badly dented and eroded.

Apr 14, 2011 at 10:22 AM | Unregistered CommenterMac

BBD

Perhaps the explanation is Watts's conclusion about "the opposite-signed differences of maximum and minimum temperature trends" although I always thought that urban locations gave greater maxima (hence the phrase UHI).

Airport tarmac is famously hot, but maybe it just seems that way when you boarded the plane in England...

Apr 14, 2011 at 11:46 AM | Unregistered CommenterJames P

I suggest people read these two articles to get some handle on the known problems with surface data.

http://www.john-daly.com/ges/surftmp/surftemp.htm

http://www.uoguelph.ca/~rmckitri/research/jgr07/M&M.JGR07-background.pdf

If you have the strength try reading this.

http://www.uoguelph.ca/~rmckitri/research/jgr07/M&M.JGRDec07.pdf

Quantifying the influence of anthropogenic surface processes and inhomogeneities on gridded global climate data Ross R. McKitrick and Patrick J. Michaels

Received 26 January 2007; revised 3 May 2007; accepted 8 November 2007; published 14 December 2007.

Local land surface modification and variations in data quality affect temperature trends in surface-measured data. Such effects are considered extraneous for the purpose of measuring climate change, and providers of climate data must develop adjustments to filter them out. If done correctly, temperature trends in climate data should be uncorrelated with socioeconomic variables that determine these extraneous factors. This hypothesis can be tested, which is the main aim of this paper. Using a new database for all available land-based grid cells around the world we test the null hypothesis that the spatial pattern of temperature trends in a widely used gridded climate data set is independent of
socioeconomic determinants of surface processes and data inhomogeneities. The hypothesis is strongly rejected (P = 7.1  1014), indicating that extraneous (nonclimatic) signals contaminate gridded climate data. The patterns of contamination are detectable in both rich and poor countries and are relatively stronger in countries where real income is growing. We apply a battery of model specification tests to rule out spurious correlations and endogeneity bias. We conclude that the data contamination likely leads to an overstatement of actual trends over land. Using the regression model to filter the
extraneous, nonclimatic effects reduces the estimated 1980–2002 global average temperature trend over land by about half.

As I keep saying deriving simple linear trends means you are not looking at the data.

Apr 14, 2011 at 1:19 PM | Unregistered CommenterMac

Mac

Why do the satellite trends match so well to the surface trends if the surface data are contaminated with UHI?

And before we go round the mulberry bush again with 'but they diverge' etc. REMEMBER that the likely divergence is a more rapid rate of increase in surface temps compared to tropospheric temps. In other words, the opposite of the hypothesised effect of GHG forcing.

Please read (I mean really read, not skim) my comment at 11:06pm yesterday, including the link to the explanation of how the four records are re-baselined for accurate comparison.

I am absolutely certain that you are not clear about this, or you would not maintain the position that you do.

As I keep saying deriving simple linear trends means you are not looking at the data.

While I absolutely dispute this, as you know, I prepared the comment I'm referring you to using only running means. Not a trend line in sight. This was for your benefit and also Cumbrian Lad's.

Apr 14, 2011 at 6:51 PM | Unregistered CommenterBBD

I have things to do this evening, so no comments for a while now. But one last thought: if the surface temperature records are contaminated with UHI and trend artificially high as a consequence, this might bring observations in line with hypothesis again.

Reducing the rising trend in T for LST vs tropospheric T would give us the divergence expected from GHG forcing, with tropospheric T trending higher than LST.

But it would do so at the expense of the claimed rate of LST warming. Which already falls below the lower bound of 0.2C/decade derived from the multi-model mean so central to the estimation of climate sensitivity as 3C or higher per doubling of CO2.

That climate sensitivity argument... again.

Apr 14, 2011 at 7:44 PM | Unregistered CommenterBBD

Anyone wishing to check my assertion that the satellite data are in good agreement with the surface temperature data can do so. Here are with further examples of accurate re-baselining from the excellent Climate Charts & Graphs blog:

UAH and GISTEMP compared

UAH and RSS compared

The satellite record validates the surface temperature record both in general interannual variability and multi-decadal trend.

The argument that the surface temperature data are significantly in error either in terms of interannual variability or multi-decadal trend fails.

Mac and others: if you wish to continue to claim otherwise, you must show clearly why the above analysis is incorrect.

Apr 15, 2011 at 2:41 PM | Unregistered CommenterBBD

Re BBD

Satellites see UHI as well. That's nicely imaged here:

http://www.nasa.gov/mission_pages/terra/news/heat-islands.html

Apr 16, 2011 at 7:57 PM | Unregistered CommenterAtomic Hairdryer

Atomic Hairdryer

Agreed.

But it doesn't address the question posed at 2:41pm. Bear in mind that UHI isn't warming the troposphere.

Apr 16, 2011 at 10:15 PM | Unregistered CommenterBBD

Ah, possibly slightly different questions :)

If surface temperature records and satellite derived surface temperature records agree, then that's a good thing but does not eliminate potential UHI effects. I'd disagree and suggest that UHI would warm the troposphere as well. I'm still curious how much, and how much measuring has been done regarding the effects. UAH seems pretty reliable given it's been tested against radiosonde data and TLT, TMT and TLS data are available. I'd like to see comparisons of urban radiosondes vs satellite observations for the same area. We know urban locations are warmer than rural, and that heat must go somewhere.

If the question's about tropospheric warming though, then the only measurements that really work are the radiosondes and satellites because the surface stations can only measure the surface layer. UAH's TLT trends are still lower than GISS or Hadleys, but they're not really measuring the same thing. It seems to me that to answere whether predictions for tropospheric warming are true or not, we need more satellites or more radiosondes.

Apr 17, 2011 at 11:51 AM | Unregistered CommenterAtomic Hairdryer

UAH's TLT trends are still lower than GISS or Hadleys, but they're not really measuring the same thing. It seems to me that to answere whether predictions for tropospheric warming are true or not, we need more satellites or more radiosondes.

I'm comparing TLT satellite data from AQUA Ch 5 (600mb layer) with HadCRUT and GISTEMP.

All the detail is now on the Discussion thread.

I think you need to back up the assertion that UHI is capable of significantly (ie measurably) warming the global troposphere.

Apr 17, 2011 at 12:12 PM | Unregistered CommenterBBD

The difference in trend between UAH, RSS, GISTEMP and HADCRUT is trivial:

GISTEMP, HADCRUT3, UAH and RSS from 1979 – present (full satellite record).

Trends (degrees C):

GISTEMP 0.5 (0.528)

HADCRUT3 0.5 (0.489)

UAH 0.45 (0.451)

RSS 0.5 (0.518)


GISTEMP runs warm because of the high anomalies it calculates for the Arctic by interpolating land surface temperatures over sea surface area.

The vertical separation between the curves is an artefact of the different baselines used to derive the anomalies. See Discussion thread.

If you take GISTEMP's methodological shortcomings into account, the difference in trend between the surface and TLT measurements is trivial.

So UHI is not a major factor and the surface temperature records are validated by the satellite observations.

Apr 17, 2011 at 12:25 PM | Unregistered CommenterBBD

Correction.

Wrong numbers above. Apologies. Those are the temperature increases over the period calculated from the trend.

This is what I should have used:

Decadal trend 1979 - present (degrees C):

GISTEMP 0.16

HADCRUT 0.15

UAH 0.14

RSS 0.16

Apr 17, 2011 at 10:40 PM | Unregistered CommenterBBD

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