This is a small bombshell. I’ve been telling readers about UHI since this blog started. One notable example that I demonstrated by actual measurement is Reno, NV:
Click for larger image
The IPCC reports have minimized the effects of UHI on climate for quite some time.
From Warwick Hughes:
The IPCC drew that conclusion from the Jones et al 1990 Letter to Nature which examined temperature data from regions in Eastern Australia, Western USSR and Eastern China, to conclude that “In none of the three regions studied is there any indication of significant urban influence..” That has led to the IPCC claim that for decades, urban warming is less than 0.05 per century.
A paper in JGR that slipped by last fall without much notice (but know now thanks to Warwick Hughes) is one from Phil Jones, the director of the Hadley Climate Center in the UK. The pager is titled: Urbanization effects in large-scale temperature records, with an emphasis on China
In it, Jones identifies an urban warming signal in China of 0.1 degrees C per decade. Or, if you prefer, 1 degree C per century. Not negligible by any means. Here is the abstract:
Global surface temperature trends, based on land and marine data, show warming of about 0.8°C over the last 100 years. This rate of warming is sometimes questioned because of the existence of well-known Urban Heat Islands (UHIs). We show examples of the UHIs at London and Vienna, where city center sites are warmer than surrounding rural locations. Both of these UHIs however do not contribute to warming trends over the 20th century because the influences of the cities on surface temperatures have not changed over this time. In the main part of the paper, for China, we compare a new homogenized station data set with gridded temperature products and attempt to assess possible urban influences using sea surface temperature (SST) data sets for the area east of the Chinese mainland. We show that all the land-based data sets for China agree exceptionally well and that their residual warming compared to the SST series since 1951 is relatively small compared to the large-scale warming. Urban-related warming over China is shown to be about 0.1°C decade−1 over the period 1951–2004, with true climatic warming accounting for 0.81°C over this period.
Even though Jones tries to minimize the UHI effect elsewhere, saying the UHI trends don’t contribute to warming in London and Vienna, what is notable about the paper is that Jones has been minimizing the UHI issues for years and now does an about face on China. And even more notable is that Jones result are directly at odds with another researcher at Hadley, Dr. David Parker.
It seems that Parker is looking more and more foolish with his attempts to make UHI “disappear” To back that up, the National Weather Service includes the UHI factor in one of it’s training course ( NOAA Professional Competency Unit 6 ) using Reno, NV.
In the PUC6 they were also kind enough to provide a photo essay of their own as well as a graph. You can click the aerial photo to get a Google Earth interactive view of the area. The ASOS USHCN station is right between the runways.
This is NOAA’s graph showing the changes to the official climate record when they made station moves:
Source for 24a and 24b: NOAA Internal Training manual, 2004-2007
What is striking about this is that here we have NOAA documenting the effects of an “urban heat bubble” something that Parker 2003 et al say “doesn’t exist“, plus we have inclusion a site with known issues, held up as a bad example for training the operational folks, being used in a case study for the new USHCN2 system.
So if NOAA trains for UHI placement, and Hadley’s Dr. Jones admits it is real and quantifies it, I’m comfortable in saying that Parker’s claims of UHI being negligible are pure rubbish.
Its all about location, location, location. And climate monitoring stations that are poorly sited and that have been overrun by urban growth clearly don’t give a pure signal for assesment of long term climate trends. This puts a real kink in the validity of the surface temperature data in GISS and HadCRUT and could go a long way towards explaining the divergence between satellite and surface temperatures in recent years.
DJ,
In a field as primitive as climate science it would be quite easy for prof. lindzen to demonstrate that mr. gore, mr. mann et altri have no science to offer, and others like mr. hansen, schneider and media are spreading fears beyond what is declared scientific consensus.
DJ:
As a matter of fact, DJ, you’re wrong once again. Science debates don’t play out in science journals. Not when the debates concern a skeptical argument regarding global warming: click
As even you can see, skeptical scientists are being deliberately stonewalled. The information in that link was taken from another link in the comment by Lucy Skywalker immediately above your post.
The outright fraud that is being perpetrated in the peer-review and scientific publication industry is becoming increasingly well documented. In this particular case, over $7 million in grants were paid out of the public treasury, based on outright global warming fraud.
You’re on the criminals’ side of the argument, DJ. And your argument has been reduced at last to: “…media norms which give people the false impression that the ‘sceptics’ have science to offer.”
Pathetic.
I realize this is OT for this particular article, but there are some interesting articles here ( http://www.mitosyfraudes.org/Ingles/Crista.html ) about the Antarctic ozone hole, including discussion of the complexities of the Antarctic vortex. ( http://www.mitosyfraudes.org/Ozo/vortex.html ). There is some passing discussion of global warming theory there as well.
I’ve found that many parallels can be drawn between the dishonest way the world has been tricked into abandoning useful chemicals such as DDT, and CFCs, and the new nonsense about CO2.
It has been argued that the loss of DDT for control of disease carrying insects, and CFCs for safe, reliable refridgeration, have cost millions of lives around the world. How many people will the CO2 scare cost?
I think this paper is also related to the Aerosols issue as well.
With the asian brown cloud happening, they have to be able to explain why temps in China and India are not falling right now. In fact, if you look at the current February Anomaly at Hadley Centre (Jones’ agency), Asia is the big hotspot on the planet.
http://hadobs.metoffice.com/hadcrut3/index.html
They should have seen a decline in temps recently with less sunlight getting down to surface (a recent paper put the effect at -4 W/m2 right now, significantly larger than the GHG forcing to date).
There is a new Aerosols database that has been produced and the climate modelers desperately need to build bigger Aerosols impacts into the models.
It makes no logical sense to include these bigger numbers if the area and the latitudes that should be cooling off the most right now due to effect are, in fact, warming faster than anywhere else.
Hence, the exclusion of London and Vienna as well from the new urban heat island estimates since these areas have had a significant reduction in Aerosols – there is not enough warming in these two cities to fit in both UHI and an increase in temps due to declining Aerosols.
Aerosols up, temps up, big UHI impact – Aerosols down, temps flat, no UHI impact to account for.
Jones has not been known to take a hit for the Team before but since he was one of the original authors which set the UHI impact at just 0.05C and it now turns out to be based on “iffy” data and it doesn’t fit where they need to go now, he has put forward the new UHI proposal.
A hypothetical question: If an AGW promoter began to realise that “things are not as bad as previously thought” and/or ” a diminishing number of peer-reviewed scientists now accepts that AGW is real”, thereby suffering a crisis of faith; would he/she tell the world about it, or just quietly disappear?
My point? Perhaps there are now a lot fewer AGW promoters out there “than previously thought”.
“DJ (13:51:43) :
>someone obviously failed spelling……
Neil, perhaps you might tells us how large the UHI island effect must be to explain global warming given earth’s geography.
I look forward to your response.”
When you cast aspersions that we have all failed geography, I thought you might have had your own post in order seeing the obvious intellectual superiority you are implying for yourself. However, as to your question.
I didn’t fail geography at school, in fact I even managed to stumble on and get a university degree as a Bachelor of Architecture, in which there was a modicum of science relating to buildings and building materials. A subject called Building Science as I recall.
Please see Anthony’s transect across Reno at the very top of this thread, which is an actual experiment (as opposed to a computer model) taking continuous temperature measurements on a drive across and back from one side of Reno to the other. It clearly shows around 5 – 6F difference from the centre to the rural outskirts. Lets take GISS as an example. Apparently there is some very minor form of adjustment, around 0.05C for UHI effects in their algorithms. But the majority of the stations used by GISS are in medium to large cities and at airports as well at sewage treatment plants, and rural stations have been steadily dropped off the list. Total stations now used by GISS have dropped significantly in recent years. Therefore it is not hard to see, especially with the very low % of well sited stations in the USHCN that Anthony has documented, that the medium/large city temperatures, along with poorly sited stations, tend to dominate the record. This is how I see the UHI effect not being given sufficient credence in the temperature record.
Oh, and last time I looked at the temperature metrics there has been cooling for the last decade.
How does all this mesh with the temperature records of non UHI areas that show warming over the past century?
p.s. where did the other thread go? A correction would have been brave and honest… but deleting it and sweeping it under the carpet?? Now how will all the sceptics who read it on much less credible blogs than this one learn that it was in fact an incorrect article that made fraudulent claims about temperature records… ahh well. Obviously this is in the wrong thread and will get deleted, fair enough, but those who count will read it at least;)
Reply: It appears to be currently under revision, but I don’t know. I would appreciate you’re toning it down a bit. I’ve been quite lax with you up til now ~ charles the moderator.
REPLY: No pleasing this guy. He complains if it’s up, complains if it’s not. He just assumes he knows the reason and then proceeds to denigrate based on that. Could in be that I’m attempting to get in touch with Lorne Gunter? Could it be that I’m editing it and I don’t want people like yourself, poised to pounce, to read it mid-edit since WordPress autosaves while edits are going on?
Matt, you’ve lost the right to criticize now, since you just assumed you “know” and proceeded to comment on my “bravery and honesty” without having one iota of information to back up that claim. Also, although you would apparently like it to be so, I won’t edit Gunters words until he does so. He’s the author, the correction should lie with him. – Anthony Watts
Should it be removed under revision? It was being revised while still posted yesterday.
My hunch is that it has warmed, just not as much. One of the possible reasons why we had such a jump in temps is station drop out. That can screw up a clean research project any day of the week. The variables related to station temperature are numerous, which would require a large sample size in order to avoid false positives (nonrandom variation) and handle expected random variations in order to calculate significant trends. If your sample size changes dramatically, and in a consistent way (IE rural station dropout) midway through your data collection period, any results have to be suspect. You cannot rule out false positives.
‘Is there something fundamentally different in Chinese cities – I think not.’
Agreed. But what is distinctive is that the period in question (especially the latter half) experienced extremely rapid urbanisation across China – possible the most extensive and rapid urbanisation ever in history. And of course, while the impact on recorded temperature has been the most marked in the region, it has also contributed to inflating the global average, just as all previous periods of urbanisation in different parts of the globe have done. These have all incrementaly inflated the global average and (as someone pointed out: once a city warms it stays warm) that inflation continues to be present.
It would be interesting to trace the history of GISS global hotspots and compare them to the historical record of regional urbanisation. More importantly what needs to happen (and Hadley now has a duty to make this happen), is that all instances of UHI inflation need to be expunged from the record. My bet is that this would make comments like “2008 was the nth warmest in history” sound much less alarming.
Here is the experiment I want to see:
–Select a sample of cities with a variety of conditions. Windy, non-windy, desert, jungle, tundra, agricultural, sheltered, open, whatever. Mix and match.
–Use surface level sensors, as we are primarily interested in UHIE on the USHCN network. (This is important.)
–Sensors would be placed at varying points in the cities, and CRN-compliant sites outside (upwind, downwind, and crosswind).
–You’d need maybe a hundred sensors. Maybe 200, depending on your sample size. Standard-issue MMTS units would be preferable, but, OTOH, it might be more practical to use the self-contained, fully automated (and much cheaper) stuff. In quantity you could probably snag those for maybe $100 to $300 per unit.
Also, cheaper, better equipment would allow both hourly measurements and a Tmax/Tmin calculation. And they store the data automatically, so no need for daily readings and (joy of joys) no missing records. No FILNET. So long as the equipment is compatible, you’d probably get more experimental bang for the buck than by going the non-MMTS/Nimbus route.
–Run the experiment for at least a full year, making sure the stations were properly maintained and that the microsite remains constant.
This begs untested theory, variable atmospheric layers, what have you, and measures UHI effect the same way the GHCN does. In your face, down and dirty, and strictly empirical.
Until this is done, we WON’T REALLY KNOW.
Funding, anyone?
Oh, finger problem. Before someone picks it up and nitpicks, make that “2008 was the nth warmest on record”
what is the percentage of sites that are in urban vs. non-urban locations for GISS and HadCRUT?
For the US (USHCN):
Rural: 820
Suburban: 287
Urban: 113
REPLY: Unfortunately, many of the “rural” sites have serious microsite bias issues. – Anthony
‘Funding, anyone?’
For experimental, empirical climate research? Now that would novel. But someone might then miss out on their supercomputer upgrade.
I believe the best measurement of the total heat in the Earth climate system is by measuring the temperature of the water near the ocean floor away from strong currents. Find the places around which the various currents circulate and measure the temperature there near the ocean floor.
The temperature there will be very stable, not moving between day/night and probably not seasonally either. Any change you get in temperature should give you a very accurate picture of overall change in the Earth’s climactic temperature. No UHI problems, no siting problems, no weather problems. It just is what it is.
Stephen Wilde (07:42:59) :
A problem arises in that if UHI effects could account for much if not all of the observed warming then where does that leave the supposed effects of a high level of solar activity and a positive PDO with an exceptional dominance of El Nino during the same period ?
Large troubles a head… but the more honest info comes out the better.
Anthony’s stations project is one.
MattB (18:55:09) :
How does all this mesh with the temperature records of non UHI areas that show warming over the past century?
It’s being worked on!!!!!
Charles……..LOL 🙂
Satellite measurements are adjusted and calibrated using surface temp records.
Dr. Christy says not. Him I trust.
But bear in mind that what the sats are measuring is lower troposphere (etc.) by microwave proxy. That is not a direct measurement and lower trop is expected to increase at a faster rate than surface (1.2 to 1.4 depending on latitude). Those conversions are problematic.
My my,
This little hot-bed of [snip] is hilarious. Don’t you guys realise that REAL climatologists have long since thought of, quantified, refined and included the (very small) discrepancies due to UHI effects? Try reading a bit wider people. As Matt B asked, (that’s not me, by the way), what do you make of the fact that the clear heating trend remains unaffected when you take out the urban stations and just consider the unchanged rural ones? (with sufficient data point densities of course).
It astounds me repeatedly how similar this movement is to the creationist one, so much so that I would warrant there’s some interesting studies to be done. Straw men, half truths, outdated data, cherry picking, ‘arguments of the gaps’ ad homs, and an INCREDIBLE paucity of peer-reviewed ground-breaking published work from one side. By and large, REAL scientists don’t do this if they care about their reputations, but then that’s just the point isn’t it – it’s easy to cry out from the sidelines when you’ve never been able to create a reputation through an honest day’s work in the first place. And from what I’ve seen, there’s a distinct lack of [snip] willing to put their money where their mouth is when real bets are proffered by scientists who have an inkling of what they’re talking about.
And Crosspatch, nice idea but unfortunately the ocean floor (or near to it) is not just some static entity that is necessarily representative of the globe as a whole. It has its own microcosm of temp gradients, salinity changes, current directions/patterns, localised responses to the state of the crust below it and, most specifically, it lags centuries behind any surface changes anyway. No, the wonderful global surface averages that have been so carefully compiled over the decades, in combination with ever-improving proxies for the past are the best we have to go on and are highly valuable at that.
My hunch is that it has warmed, just not as much.
That’s my impression. My belief is that heat sink has exaggerated the warming trend. But for heat sink to exaggerate warming, there has to be warming in the first place.
REPLY: Unfortunately, many of the “rural” sites have serious microsite bias issues. – Anthony
Don’t I know it!
US Dropouts (my expanded list). Based on B91 filings. (There are a handful more on my “I have my hopes of getting their locations” list. Perhaps a half dozen.)
US Dropouts:
Rural: 70
Suburban: 21
Urban: 21
Bearing in mind what Anthony has said, above. A huge majority of those rural sites are real stinkers. (Same can be said for the entire lot, for that matter.)
It astounds me repeatedly how similar this movement is to the creationist one, so much so that I would warrant there’s some interesting studies to be done.
Urgh.
Analogies are all very well.
Shall we now consider how similar the other side of the argument is to the Revelationists? (The ones who bring a New Truth, separate the sinners from the righteous? Judgment, Rapture-ins, population reduced to eco-acceptable levels . . . end of the world Tuesday, next?)
But being an atheist (agnostic on my better days), I’d just as soon stick to the science.
And I think we all should, too.
Matt Bennett says:
You guys in the AGW movement are not very inventive when trying to put us sceptics down, are you?
For the record, I find Evolution a compelling explanation for the state of life on the Earth today, although abiogenisis is an open question at the moment.
Also, to forestall any other silly epithets you might throw my way, I am married to a person with a different skin color to mine and I have two daughters who I read books on paleo and poetry to when they were children, and I expect them both to get degrees in technical areas.
You also say:
Be more specific. Since they do not have the information that Anthony has compiled on sites across the US, and since they deny that UHI has any real influence, how can they have adjusted for it? How about in Siberia?
What is a REAL climatologist, BTW, or is that just an appeal to authority?