A couple of days ago there was a guest post from Russ Steele citing a California study “Feeling the Heat” on global warming that just didn’t seem to add up. One of the stations cited as having climate change related warming was Reno, NV. So, I decided to do a field experiment to test this. The results show clearly that UHI exists in Reno.
Here is what Russ wrote a couple fo days ago:
Feeling the Heat was published by Environment California a non-profit group a few weeks ago, claiming 2007 was the tenth warmest year on record and that the mountain west was experiencing above-average temperatures. Full report here: Download feeling_the_heat_ca.pdf One of the examples given for the high western temperatures was Reno Nevada with a average temperature of 55.3 degrees in 2007, four degrees higher than the 30 years average temperatures from 1971 to 2000.
…Up front in the EC report the author dispatches UHI as having any influence on the climate change, citing studies by Easterling, PD Jones and Parker…
Well I decided to test this myself tonight, since I’m driving through Reno on my return home, I arranged an overnight stay. With me is my NIST calibrated data logger, NIST Calibrated temperature probe, a vehicle mounted Gill IR shield, my laptop computer, and my trusty vehicle. See my previous post “Road Kit”
I chose Virginia Street as the transect route, since it remains relatively straight, level, and crosses all of Reno, including the built up southern suburbs and downtown. It is the original “main street” for Reno.
Here is the result of my South to North transect driving Virgina Street overlaid on a Google Earth image oriented to match the timeline of the transect:
Click for larger image
The weather tonight was perfect. Light winds, clear skies.
Here is the data from the Reno airport ASOS, which also happens to be a USHCN climate station:
Time Temp Dew RH Wind Wind Vis WX Sea Level Altimeter Station
Point Dir Speed Pressure Setting Pressure
(PDT) (f) (f) (%) (mph) (miles) (mb) (inches) (inches)
1:55 am 44 25 47 CALM 10.00 CLR 1023.0 30.30 25.788
12:55 am 48 24 39 CALM 10.00 CLR 1023.4 30.31 25.797
11:55 pm 51 23 33 WSW 3 10.00 CLR 1023.7 30.31 25.797
10:55 pm 54 23 30 S 6 10.00 CLR 1024.1 30.32 25.805
For those interested, I have the raw source data from my datalogger in CSV form for the South to North Reno transect here. (PDF)
Note the placement of the airport, which has it’s ASOS weather station used in many climate studies essentially in the north end middle of the airport. The Reno UHI bubble does extend into this area.
Click for a larger image
I also did a reverse transect, driving the same route in reverse immediately. Plus a route near the airport. I’ll have more tomorrow, its 2AM and I’m tired.
UPDATE:
Jeff Id inquired in comments “how is it mounted to the car?” Here is the answer:
The temperature sensor (inside the Gill IR shield) mounted on the vehicle using an improvised window mount.
Also, the time of night that I made the transect (11:15PM to 11:39PM) allowed me to maintain a nearly constant speed during the transect due to the lack of traffic. Plus Virginia street has stoplights set for all green unless there is cross traffic. I was fortunate to have to stop only once during the entire drive, and that was in the downtown area. I kept an eye on the temperature reading during the stop, and no change was recorded.
I’ll have a complete post in the next day, still catching up from my trip.
Excellent stuff Anthony.
Up to 10 degrees F difference, quite amazing. And what does GISS most generously allow in their adjustments for UHI? less than 1 degree I believe.
Why oh why can’t there be a full blown study on UHI to put the facts out there clearly about the impact of UHI ? – wait, I think I know the answer!
Look forward to seeing your follow ups.
Neil
http://www.ncdc.noaa.gov/oa/climate/research/ushcn/#urbanization
Reno after homogenization
Even the BBC weather forecasters (and by extension the Met Office and Hadley Centre) accept large UHI effects. At least one of the BBC overnight forecasts earlier this year predicted a 4C temperature difference between rural areas and towns and cities in the UK. Rural areas where predicted to be -4C and town and cities 0C.
I wonder if they will sacrifice accuracy for AGW correctness and narrow that gap in their predictions this winter.
This is tremendous. This stuff cannot be refuted.
Thanks,
Mike
This brings up something I’ve been thinking about over the past week or two regarding GISS, which seems to be the ‘official’ dataset referred to by the media (and thence the rest of the world, since the media is supposed to be the public’s eyes and ears for what’s going on in the world while we’re living our daily lives).
The oceans have lost a huge amount of heat content in the el ninos of the past 10-15 years, which have sometimes come one right after another. The 2007 one may have wrung out the last of was accumulated since the 80’s, since temperatures dropped like a rock when then one was done.
IF Svensmark is right, the oceans will be slow to replenish that heat given the cosmic ray situation that NASA was on about a couple of weeks ago. The oceans might spend the next ?? number of years shaded by a lot more nice fluffy clouds than they’re used to.
Those clouds will also change the earth’s albedo, and not only will the oceans be slow to warm back up, everything else will be slower to gather heat as well.
IF there is anything to the what the solar guys are saying (sorry Leif, speculating here), and Solar Cycle 24 turns out to be a dud, if they’re right then that will contribute further to the general cooling.
A hockey stick may be a bad way to describe temperatures over the past 1000 years, but its not a bad representation of human population growth. That will demand land-use changes in the form of more agriculture land use, and in many parts of the world, that means fewer forests and urban areas.
This will also contribute to changes in earth’s albedo, not to mention how much extra wood will get burned for heating if things stay cool for an extended period.
People tend to migrate toward cities and suburbs, which will expand accordingly, and more and more of those nice rural temperature stations will become absorbed by expanding urban areas.
Which will have a direct impact on the GISS temperature set because thanks to its proponents’ continual “dispatching” of UHI as a factor, and its owner’s propensity for adjusting it in a way that matches his models, global temperatures might be dropping off a cliff for several years before the media, our window on the world, even notice that anything is happening.
They did a real good job noticing problems with the Reno’s UHI, right? Ha.
So thanks Anthony, for keeping UHI front and center for us. Without your work I don’t think anyone would know just how serious and widespread that issue is.
I see something similar every day I drive across Charlotte, NC. I start my commute in rural Kings Mountain, drive throught Charlotte, and wind up in rural Midlands, NC. I see, every day, at least a 5-6F increase in temperature as I drive through.
Oops, above I meant “…fewer forests and MORE urban areas…”
Could not make things much clearer than that — regarding the potential of the UHI effect to disturb a multi-decade temperature record.
If you watched the recent BBC ‘Climate Wars’ series you will recall that the presented did an excellent demonstration of UHI at Las Vegas. He simply measured the temperature, drove into the city and measured the temperature again. It was several degrees higher.
The really odd thing is that he did not refute this in any way. But what he failed to mention is that the IPCC gives a ludicrously low value for the UHI effect. If the UHI is far larger, as seems almost certain, then a very simple logical conclusion flows from that: the global temperature trend over the last few decades has been exaggerated. Last year Michaels and McKitrick demonstrated a very significant UHI effect. They concluded that if UHI were properly taken into account then the real warming over recent decades is only a half of the normally stated amount.
The presenter is a scientist and seemed a reasonable person. But it never seemed to occur to him that his own demonstration of UHI refuted his own arguments.
As I understand it, the main argument against strong UHI involves windy and windless days. It seems a bizarre argument, bearing in mind that all you have to do is grab a thermometer and measure the UHI yourself, as Anthony has done.
Chris
A couple comments, tongue in cheek:
1) You took measurements with a weather station mounted over a paved road? That’s as bad as a USHCN station in a parking lot, maybe worse!
2) “I also did a reverse transect, driving the same route in reverse immediately.” Next time, consider turning the car around. However, your actions would be considered normal in Boston on one-way streets, at least it is among taxi drivers.
A little more seriously, I don’t have hard data, but I’ve noticed that between my usual parking place at work (shaded in the afternoon, at the bottom of a short hill going up to self-storage place) and the Turnpike heading north, I’ll see a 2-3 F rise. Some of it may be from sun, the temperature sensor is in the exterior rearview mirror, but I think most is from the hillside and car being in the shade at work.
At the hour you were driving, the solar effects would be quite different.
What about altitude affecting the start and finish readings?
One month ago, the UK Met Office made this statement –
25 September 2008 The Met Office forecast for the coming winter suggests it is, once again, likely to be milder than average. It is also likely that the coming winter will be drier than last year.
http://www.metoffice.gov.uk/corporate/pressoffice/2008/pr20080925.html
How are they doing so far?
29th October 2008 Arctic blast turns large swathe of the UK white as London sees first October snowfall in 74 YEARS
http://www.dailymail.co.uk/news/article-1081135/Arctic-blast-turns-large-swathe-UK-white-London-sees-October-snowfall-74-YEARS.html
ASOS data, reformatted, minus date and max/min temps:
Time Temp Dew RH Wind Wind Vis WX Sea Level Altimeter Station
Point Dir Speed Pressure Setting Pressure
(PDT) (f) (f) (%) (mph) (miles) (mb) (inches) (inches)
1:55 am 44 25 47 CALM 10.00 CLR 1023.0 30.30 25.788
12:55 am 48 24 39 CALM 10.00 CLR 1023.4 30.31 25.797
11:55 pm 51 23 33 WSW 3 10.00 CLR 1023.7 30.31 25.797
10:55 pm 54 23 30 S 6 10.00 CLR 1024.1 30.32 25.805
ASOS data, reformatted, minus date and max/min temps, this time with spaces changed to :
Time Temp Dew RH Wind Wind Vis WX Sea Level Altimeter Station
Point Dir Speed Pressure Setting Pressure
(PDT) (f) (f) (%) (mph) (miles) (mb) (inches) (inches)
1:55 am 44 25 47 CALM 10.00 CLR 1023.0 30.30 25.788
12:55 am 48 24 39 CALM 10.00 CLR 1023.4 30.31 25.797
11:55 pm 51 23 33 WSW 3 10.00 CLR 1023.7 30.31 25.797
10:55 pm 54 23 30 S 6 10.00 CLR 1024.1 30.32 25.805
If that doesn’t work, I give up….
So, common then somebody, just when is Solar Cycle 24 going to start in earnest?
Dr Hathaway & the Solar Prediction Panels & others seem to be having little more than wild stabs at it. First it was Autumn 06 definitely & wild & furious to boot peaking in 2010-2011, Spring 07 for sure, probably Autumn 07, looks like Spring 08 now, well, Autumn 08 has come & we’re heading into the “gone” phase as winter overtakes us, speculation about Spring 09 has been dabbled with even less confidence than previous “Guessing Games”. With all that brain power & computer power I would have thought someone would hit the nail on the head.
And are the Arctic temperatures +5°C higher up there or are they lower?
Have clever & powerful people embarrassingly succumbed to being little more than Medieval prophets, adjusting dates when their “end of the world is nigh” prediction fails, rushing back to the crystal ball for anther check, perhaps it was a speck of dust on the other side of the glass that threw them out, then making another prediction to compensate!
Guess what, yet another UK University study has claimed with great accuracy that Solar variations have little or no impact on climate! I wonder which Sun they’re looking at. Hmmmm! and the band played “Believe it if you like!”, as my late father used to say.
The UHI is estimated to be just +0.05C on average across all temperature monitoring stations. I guess they are assuming that there are enough rural stations with no UHI to offset the urban stations which are impacted by UHI.
But let’s just do some basic math with that assumption. The Reno UHI looks to be 5F to 6F or 3C, which is pretty typical for a large city (Reno might be a little small to get into the large city category but Anthony’s measurements show the same impact none-the-less.)
If Urban stations have an average +3.0C UHI and the average UHI across all stations is only +0.05C, then the number of rural stations must be 98.3% of the total number of stations and the urban stations must be only 1.7% of all stations.
Change the UHI to just 1.5C for large cities and we still end up with 3.3% of stations are urban and 96.7% are rural.
Obviously, the math doesn’t work here because the number of urban stations is a large fraction, approaching half, of the total and the UHI average should be closer to 1.0C.
Anthony,
Thanks for providing first hand, the chance to see science in action…it’s fascinating to witness things like this unfold.
Jim
A simple question that perhaps Anthony can answer based on his meteorological experience.
Why don’t we calculate average surface temperature using the techniques meteorologists use to produce those nice temperature gradient maps (isobars? I am not sure of the exact term)?
Use the known temperature points to interpolate a temperature field for all lat/lons, and then sample that field at regular grid points. This corrects for UHI quite naturally, as the vast majority of grid points in a regular sampling grid would be rural. Sure, UHI would influence the overall average, but urbans areas would probably represent just a few percentage of the sample points. Lacking a good way to remove UHI from the temperature signal (other than ignoring urban areas altogether), this would seem to be the best way to handle it.
“I see something similar every day I drive across Charlotte, NC. I start my commute in rural Kings Mountain, drive throught Charlotte, and wind up in rural Midlands, NC. I see, every day, at least a 5-6F increase in temperature as I drive through.”
This mornings drive:
6:45 33F at the house
7:20 38F at the intersection of I85 and I77 in Charlotte (LOTS of concrete/asphalt)
7:50 29F in the parking lot at work.
I see this EVERY day. My commute covers 60 miles accros 3 counties. Those that refuse to acknowledge UHI effect are the true deniers.
Come on, guys. No one denies UHI is real. The question is: does urbanisation affect trends over large periods of time for a significant number of stations. In the case of the Reno airport, which probably started very rural in the thirties and is now in a very large area of concrete and asphalt, this is very likely. And there are sure to be many other stations like it, leading to the IPCC underestimating the effect on the trend.
But just driving through the city proves absolutely nothing about whether the Reno time series is compromised by urbanisation or not. It just proves that the Reno station is not measuring the temperature that would’ve been had the city not been there. But to say something meaningful from a climate perspective, you need to compare the Reno trend to the trend of a nearby station outside of the UHI-bubble. Or you’d need data from the same trip half a century ago, that would be informative as well.
REPLY: Ared do your research before spouting off. Parker and Petersen claim UHI is insignificant, clearly it is not. EC says Reno UHI is insignificant, clearly it is not. The National Weather Service uses Reno’s UHI in their own training manual, so clearly it impacts the sensor.
http://wattsupwiththat.com/2008/01/10/how-not-to-measure-temperature-part-46-renos-ushcn-station/
It shows up as a hot spot in USHCN contours done by Steve McIntyre.
http://www.climateaudit.org/?p=1748
Clearly UHI exists in Reno. I’m not interested in a long debate on this, as I’m on the road. – Anthony
Anthony, Helmut Landsberg would have been proud of you for illistratiog the urban climate so well.
“But just driving through the city proves absolutely nothing about whether the Reno time series is compromised by urbanisation or not.”
Okay…non-scientist here again, so humor me.
From my perspective, if you show me a graph that shows, in general, that things have increased over all, and I say “But what about this thing called UHI?”, and you say “We’ve accounted for that with a formula, and that effect is Xdeg, which we’ve used to adjust all the values.”, and someone goes and actually MEASURES it, and it turns out to be Z, not X, then it calls the whole graph into question, at least for me.
“Into question” being the operative term…
Jim
Near-record cold, and mountain snow
Snow is accumulating this afternoon in the North Carolina mountains, and the rest of the Carolinas is shivering in the first cold outbreak of the season.
http://www.charlotteobserver.com/local/story/283717.html
Right Ared,
It means nothing whatsoever. I was wondering how long it would take for someone to say that.
I wonder if the name A Red means anything.
Mike B.
A couple of thoughts. What was the day like in Reno? Was it clear and sunny with only a light wind? What about a cloudy day followed by a clear evening? Or a clear day followed by a cloudy evening? Or a foggy day or a high wind day? It is interesting to see that the UHI exists, but how often does it exist and to what magnitude? — John M Reynolds
I ride my bicycle everywhere, day and night. On calm, clear nights there is often a 10-15 degree difference between a bike trail through a 20 meter wide greenbelt, and the surrounding neighborhoods with asphalt and brick.
Which is, of course, ridiculous. Using one site to adjust another has no relevance in reality.
And in Manila, it seems :^))
http://calsun.canoe.ca/News/gallery/earth/2008/10/28/7231861.html
Great visual. Not knowing how your equipment was set up, it did raise a question. Did you maintain a constant speed throughout the trip? For example, if you were driving slower in one area could heat from your car have raised the temperature?
REPLY: Relevant question. The Gill IR shield prevents a lot of this, I tried very hard to maintain 35-40 mph through the transsect, and that partly why I chose this time of night…all the stoplights go green on Virginia street at this late hour. The one time I did hit a red light due to cross traffic, I watched the sensor reading carefully while stopped, no change. – Anthony
Let me suggest that you make your first reference to UHI in each post be “Urban Heat Island (UHI),” so that people like me, who aren’t familiar with the term don’t have to do a search and scroll to find it. Good work in checking these things out.
re Steven Mosher
I interpret the graph you linked as showing that the UHI effect for Reno has indeed been adequately accounted for by NOAA’s homogenization process?????
That’s fascinating. When driving roughly that same route in mid winter, after there has been snow, I notice the snow cover is the inverse of this transect, more or less. This cannot be attributed solely to elevation, as the elevation change along the transect is not that great.
Jim, Mike, global warming is about the planet being warmer now than it was a certain time ago. Suppose Reno already had reached its current size & shape 50 years ago. Would the UHI effect have been the same as it is today? Probably very close. So would the UHI have affected the long-term trend? Hardly.
Now, what Anthony has done, is prove that Reno has a UHI, beyond a shadow of a doubt. The IPCC does not deny that, look at page 237 for AR4:
“Urban heat island effects are real but local, and have not biased the large-scale trends.”
So in order to prove the IPCC wrong, you have to prove that UHI’s have affected trends, not just that they are real, because the IPCC already agrees to this. In order to prove that the UHI has affected the trend, you need to either compare the current UHI-bubble to the bubble 50 years ago, or you have to proof that the trend in Reno is different from the trend in a nearby station outside the UHI-bubble. Otherwise you are arguing over something that everybody already agrees upon.
Having ridden a motorcycle for most of the last 40 years, i can attest to UHI firsthand. Colder in rural areas, and significantly colder in low lying rural areas.
Alan the Brit (05:45:20) :
So, common then somebody, just when is Solar Cycle 24 going to start in earnest?
Dr Hathaway & the Solar Prediction Panels & others seem to be having little more than wild stabs at it.
Made in March 2007:
http://www.leif.org/research/When%20is%20Minimum.pdf
SC24 so far:
http://www.leif.org/research/Region%20Days%20per%20Month.png
Not related to this post, I just wanted to call your attention to the following:
U of OK decertifies professor over Global Warming skepticism
A popular professor of environmental geology seems to be under attack by the University of Oklahoma because of his skepticism over global warming this month.
In October Dr. David Deming, a teacher for the U of OK for over a decade, was informed that his “general education” certification was being revoked for his class. This will result in many students passing over his class when they choose their classes in the future.
Too bad the wizards of smart at the climate center couldn’t do this and produce scientific data instead of gibberish that supports the hoax.
I notice that instead of measuring the UHI affect, the climate center try to estimate it. As others state, the actual measurements don’t support the estimate, nor does the math.
Sort of like the effeect of the sun is so small as to not be a factor. Wanna bet.
There are two different points at issue here:
1. UHI effects on temperature readings
2. The increase in the UHI effect over the last century.
Presumable UHI affected temperature readings a century ago also. If rural temperature readings increased 0.65 degrees over the last century, say from 14 to 14.65 C, and if urban readings increased 0.7 degrees over the last century, say from 16 to 16.7 C, then the 0.05 C adjustment would be correct. What would be needed to verify the adjustment one way or the other would be to get comparison tables of rural readings and urban readings for various regions extending over the century.
I suspect the increase in urban temperatures over rural temperatures over the last century has been a lot more that 0.05 C, but current readings of urban temperatures doesn’t settle the argument one way or the other.
Ric Werme (05:07:28) :
the temperature sensor is in the exterior rearview mirror, but I think most is from the hillside and car being in the shade at work.
Minor point but we had a discussion with a mechanic a few weeks ago. All or almost all cars have the sensor up just behind the grill so we see a rapid temp change as we drive thru different areas. The mirror is just the digital readout area, or in the Ford Fushion the readout is down by the a/c controls.
@ared (07:47:32) :
1) Anthony started http://www.surfacestation.org to determine if the data from the surface stations is even reliable. It is increasing looking like it is not and the bias is on the warming side do to poor siting.
2) UHI is not limited to big cities, as is supposed by many. Example: Cooperstown NY and Maryland NY are practically next to each other but Cooperstown shows a marked warming trend in the past 100 years, but Maryland shows a cooling trend for the same period. Both are considered rural stations. You can access the U.S. Historical Climatology Network (USHCN) Data Set and graph stations for yourself at http://www.co2science.org/data/ushcn/ushcn.php. However… I strongly suggest you bear in mind point #1 and visit http://www.surfacestation.org to check if the site has been surveyed and if a trend bias due to siting/operation was identified.
3) We all agree that the IPCC acknowledges that UHI is a factor that needs to be backed out, but the disagreement is if the amount of adjustment by the IPCC reflects the true UHI/Siting Bias.
Ared, the trend (which is cooling as of today) is significantly less than the UHI of 3-4C,
So in fact, my guess is that earth has not warmed in 30 years or more.
And satellite records show that. Ground based temps are totally contaminated.
This comment doesn’t relate to this UHI article, but I find it interesting that the Wikipedia article on global cooling shows the W. Antarctica Peninsula warming dramatically during the 1965-75 period, during a period of global cooling. It makes one wonder what was driving such warming. Could it be that something else is operating there, maybe volcanic activity or something else?
Dee, I know all this. I’m just making the point that knowing the size of one UHI at one moment in time does not prove the IPCC wrong. You need to know how UHI develop over time and what effect many of them have on long-term global trends to say something usefull about whether 0,05 per century is wrong or not.
UHI London,
London experiences a phenomenon called the Urban Heat Island effect (UHI), which means the centre of London may be up to nine degrees warmer at night than the surrounding countryside.
http://www.london.gov.uk/mayor/environment/climate-change/london.jsp
UHI Hong kong,
After analyzing the data, PolyU researchers found that there was an average temperature difference of 7° to 8°C between urban and rural areas in a winter night, and the maximum difference could be as high as 12°C.
http://www.polyu.edu.hk/cpa/polyu/hotnews/details_e.php?year=all&news_id=1435
UHI at Beijing and Wuhan stations
Implications of temporal change in urban heat island intensity observed at Beijing and Wuhan stations
“In summary, temporal trends of annual and seasonal mean SAT for time periods of 1961~2000 and 1981~2000 at Beijing and Wuhan stations and their nearby rural stations are all significantly positive, and the annual and seasonal urban warming for the two periods for Beijing and Wuhan stations is also positive and significant. The annual urban warming at the city stations can account for about 65~80% of the overall warming in 1961~2000, and about 40~61% of the overall warming in 1981~2000.
http://www.agu.org/pubs/crossref/2007/2006GL027927.shtml
If 50% of the weather stations are urban, given these examples being the norm for that 50% the UHI effect must surely wipe out the majority of the reported warming, 0.05%, pull the other one.
Ared,
The biggest issue is credibility. The IPCC is supposed to be so expert on the subject of golbal warming that we must incur trillions in costs and consign the world’s poor to a future bereft of any chance of improvement (re: death, disease, starvation, etc) on the basis of their expertise.
The IPCC says that UHI effect is very small. The IPCC is wrong. This should jeopardize their credibility. Note also, the IPCC relies on a famous study for their view that the effect is small. When asked for access to the data used in the study, the author said that the dog ate his homework. Yet, the IPCC continues to rely on the eaten homework instead of the many, many observations of the UHI. One would hope that such reliance reflects on the IPCC’s lack of credibility.
If they can’t get the basics right, they ain’t experts. At least, not nearly expert enough to damn billions of people to lives of unnecessary misery, disease and death.
I wonder how many desk bound NCDC/GISS types ever engage in such field work as you regularly undertake.
One has to wonder how many of the stations in the USHCN are impacted by the UHI besides the obvious siting problems you’ve exposed at the surfacestations project.
And yet, despite all these problems, it seems the data provided by satellite is still being treated almost as a novelty. Turf battles can be so petty…
ALAN D. MCINTIRE (08:05:25) :
says, Presumable UHI affected temperature readings a century ago also.
Take a look Alan,
http://www.john-daly.com/stations/stations.htm
stan, the IPCC doesn’t say that the UHI effect is small. It says that after correcting for the effect, the impact on global trends is small.
And Anthony, I’m disappointed at your reply as it is obvious I’m not attacking your work, merely the unwarranted conclusions drawn from it by others, whom I specifically name in all but my first reply.
REPLY: Be disappointed all you like, it worries me not, but your version of “obvious” may not be the perception of others, nor can you expect them to glean that perception unless you clearly spell it out as to whom you are disagreeing with. The simple fact is that you haven’t done your homework on the UHI history of Reno, of which there is quite a bit. I’d kindly suggest that you read up on it. – Anthony
ared, look at the datat collected thus far at surfacestations.org. Closing in on half the stations in the US reveals a minimum of 5 deg. F bias. The remaining stations will have to have a strong negative bias to offset this, and that isn’t physically possible. This is the source of GISS temperatures, Hansen’s record of warming.
Ared,
As noted on this site recently, GISS says that the UHI in Manhattan is less now than it was 100 years ago. Does anyone really believe that? Manhattan?! (and not the one in Kansas)
As the various articles showing temperature histories of certain towns which have been cited here in the recent past show, there simply is no way that the UHI can be as small as the IPCC maintains. On the one hand, the Greens have screamed about the horrors of urban sprawl (all that concrete and asphalt!). But the IPCC tells us that it is minimal. BS.
The temperature records are garbage. The “adjustments” to temp data, the infilled data, the changes to past data, the poor siting that no one ever bothered to check, the “dog ate my homework” studies, the SWAGS, the secrets, the refusal to share data — it’s a massive, sloppy mess. As Steve Mc has pointed out, this garbage would get a stock promoter sued for fraud. No one could possibly get a new drug approved with science this sloppy. No one would even bother to try.
But we’re going to alter the course of world history on the basis of this crap!?!?
Weather Underground offers a great way to measure UHI real time in many cities around the world. This view of private weather stations in Denver on a still, clear winter morning around dawn, frequently shows the outlying areas (of equal elevation) 15-30 degrees colder than downtown.
http://www.wunderground.com/wundermap/?zip=80002&magic=3&wmo=99999
Lief Svalgaard:-)
Thanks for that. What I was aiming at was that there were several predictions in 2006 that it was about to start back then, & it was supposed to be fast & furious, & worse than its predecessor Cycle 23! Yet all the evidence seen here & on other sites suggest that it is stuttering along a bit like an old car being churned into life with a flat battery & a grinding starter motor, never quite firing up but only managing an almost got there! I conceded that it may have officially started, but no fireworks as yet with only 14-18 months or so to go!
However, I willing defer to your good self as an expert in this subject. I’m an engineer not a solar physicist, but having witnessed 30 years of adult life of claims, predictions, projections, assessments, of all sorts of things in life, many based/reliant on the latest technology, & usually coming to nothing much in the end. I suppose you could call me sceptical about many things!
@Steve Keohane (09:12:41) :
I hypothesize the following:
What is important about siting bias is that it is not likely to be a fixed distortion of the data (ie, the biased station always reports 5 degree higher no matter what is the actual temperature).
The bias should be a percentage of the ambient (and actual) temperature, so that as temperature goes up, the bias grows. This percentage may also be variable. This behavior would make a modest positive trend from the PDO or regional UHI and magnify the trend, not just the temperature. It could also amplify a cooling trend, showing the surface cooling faster than reality.
So a station that shows a 5 degree bias now may have only shown a 3 degree bias in 1975 when the planet was slightly cooler.
Just another reason I trust the satellite data over the surface data.
ared is missing the boat entirely:
“Suppose”?? FYI, the U.S. has added ~100 million people since the late ’70’s, when the population was around 200 million. Now the U.S. population is over 305 million. Almost all of that increase has occurred in urban areas.
In his statement above, ared presumes that no population increase has occurred in Reno over the past 50 years. Those of us who visit Reno know that its population has exploded during that time. The recorded rise in urban temperatures track that population increase.
It is not clear if ared is deliberately trying to misrepresent the UHI situation, or if he is simply ignorant of the problem of corrupted data. If it is the latter, clicking on the SurfaceStations link on the upper right section of this page would begin an extremely educational process. But if the former is the case, ared had best be prepared to be set straight by the majority of folks here who understand the “adjustment” shenanigans going on at the UN/IPCC, the NOAA, GISS, etc.
ared,
You may feel like quite a few folks are ganging up on you, and I am sorry if that is the impression. Nevertheless, this blog site is full of people who have done a lot of research on UHI, what adjustments are made in GISS for UHI, what the IPCC says about UHI, and how the IPCC has responded to UHI challenges.
Although the IPCC acknowledges the existence of UHI, it dismisses concerns about UHI in two ways. First, it says UHI is small and refers to two studies (questionable studies in my mind) that say UHI is small while ignoring other studies that say that UHI is large. Second, it says that the UHI has already been accounted for in its selected temperature data sets, but IPCC authors ignore convincing studies that show UHI is vastly underestimated and not adequately handled. For example, if UHI is adequately handled, then temperature trends should not depend upon the economic development around the themometers — but temperature trends are extremely highly dependent upon the economic development.
There might be an interesting question of the burden of proof. You seem to suggest that it is the responsibility of skeptics to prove that UHI is biasing the trends. (And many skeptics have whole-heartedly accepted the challenge and believe that they have done just that.) Meanwhile, it seems just as legitimate — or even more legitimate — for AGW pessimists to have the responsibility prove that UHI is not biasing the trends. After all, AGW pessimists propose massive and costly measures which just in their infancy have proven to be laden with immense negative unintended consequences.
(To be sure, some AGW pessimists have argued that it is up to the skeptics to prove that altering the atmosphere’s chemistry will not have dire consequences for the earth. That could be an interesting question for exploration in another posting.)
Many feel that a legitimate approach to examine the UHI effect is to look at satellite data. This data trend shows that temperarture trends are consistent with PDO phases (and major volcanoes) — the satellite data trend is not consistent with a dominating influence of monotonic increases in CO2.
“Come on, guys. No one denies UHI is real.”
Yes, they do…
UHI effects are well known and accounted for.
If the “it’s just UHI” folks were correct, then the global hotspots would by and large be over areas with lots of development. They are not.
Interesting work Anthony.
It would be interesting to plot speed traveled (or time spent at stoplights/stopsigns per 1/4-mile) as an additional parameter on the graphic. If I remember correctly from my past trips to Reno, the origin of your transect is relatively open road with few stopsigns, the latter portion of your transect has stoplights and idling cars at nearly every block (and tall casinos/hotels on the side). I wonder what is the effect of travel-speed and the heat of your (and neighboring) automobiles on the temps?
As a trivial sidenote, to all contributors to this Blogg (I’ve held my tongue on so many previous posts)..”data” are plural, “datum” is singular…”data are”, “datum is”.
Again, interesting project Anthony.
John D.
The important thing about this method is that it shows that you can get real UHI numbers. You can use these numbers to _accurately_ adjust the surface stations for UHI. This method needs to be carefully repeated all over the country/world.
I wonder if it would be useful if Google to added a good temp sensor to their StreetView cars.
One more note, previous commenters have mentioned the possible affect of elevation on the transect itself (~500′ difference?). But perhaps as important is proximity to the base of Mt. Rose, which is very near the transect origin, and quite removed from the terminus. Mt. Rose is ~7,000 feet elevation and nightime downslope flow of cold air may contribute to the cooling of the transect origin just as UHI contributes to heating of the transect terminus? It would be interesting to repeat such a transect elsewhere in the Great Basin with similar topography without a City at it’s end. Just wondering. Complex world out there.
coby: If the “it’s just UHI” folks were correct… Straw man argument, coby. No one here says that “it’s just UHI”. Nice try.
Coby, Steven Mosher, it appears from the EC article that they’re using the red line from your graphs, not the fully-adjusted green line. If so, they’re counting UHI, big time. Did I miss something?
Barrow, Alaska. Population 4500. 70 thermometers. 4 year study.
http://www.geography.uc.edu/~kenhinke/uhi/Hinkel&Nelson_JGR-A_2007.pdf
This study is strictly concerning UHI. Microsite issues are not addressed.
How is it IPCC ignores studies like these, yet rely on creative mathematical iterations to wipe out UHI and poor siting effects?
Coby, your claim that UHI is “accounted for” is absurd and simply a scripted response typically found in pro-AGW propaganda blogs. There is no way without comprehensive studies such as above that UHI can be quantified.
Alan the Brit (09:26:16) :
Thanks for that. What I was aiming at was that there were several predictions in 2006 that it was about to start back then, & it was supposed to be fast & furious, & worse than its predecessor Cycle 23!
I know, but not everybody was predicting that. The forecasters with the best track record [such as it is] have been predicting a weak, ‘sputtering’, ‘lowest in a 100 years’ cycle 24, e.g. http://www.leif.org/research/Cycle%2024%20Smallest%20100%20years.pdf
coby (10:28:04) : said,
UHI effects are well known and accounted for.
If the “it’s just UHI” folks were correct, then the global hotspots would by and large be over areas with lots of development. They are not.
YES THEY ARE,
Urban heat island and population growth in Addis ababa.
Both minimum and maximum temperature trends examined together with urban increase during the period between the late 1960`s and 2000. The total population increase in the 18 years (1967-1984) was 739,581 and the annual mean maximum temperature in the same period became warmer by 1.7 degrees C. The annual mean temperature attained it`s peak in 2000, the urban population
was also at it`s highest in that year.
http://www.geo.uni.lodz.pl/~icuc5/text/P_6_11.pdf
UHI in Saskatchewan’s two largest cities, Saskatoon and Regina.
Nocturnal air temperatures in the city centres of Regina and Saskatoon are, on average, 3–4°C warmer than in the surrounding countryside; and under ideal nocturnal heat island conditions, urban-rural temperature contrasts, measured at the same time, can reach 6–8°C. In spite of the abundance of parks and open spaces in Regina and Saskatoon, both cities exhibit a discernible heat island influence. It is expected that heat islands of lesser intensity may be detectable in smaller cities and towns throughout Saskatchewan.
http://esask.uregina.ca/entry/urban_heat_islands.html
I suggest you read this and look at the thermal image in pic 4.
http://www.urbanheatislands.com/
Dee, I agree with your assesment. I was only refering to the temperature classifications (CRN) given to sitings made at surfacestations.org. That seems to me to be a conservative estimate as the CRN number is the minimum bias. Recalculating, I was in error, the average minimum bias is 3.5 F or 1.95 C. This has to account for some of the ‘warming’ we have seen.
Pretty Cool Pic there Anthony; how does one get to inherit one of these field kits so that the necessity of driving is put to some use ?
Now This: “j oshv (06:06:45) :
A simple question that perhaps Anthony can answer based on his meteorological experience.
Why don’t we calculate average surface temperature using the techniques meteorologists use to produce those nice temperature gradient maps (isobars? I am not sure of the exact term)?
Use the known temperature points to interpolate a temperature field for all lat/lons, and then sample that field at regular grid points. This corrects for UHI quite naturally, as the vast majority of grid points in a regular sampling grid would be rural. Sure, UHI would influence the overall average, but urbans areas would probably represent just a few percentage of the sample points. Lacking a good way to remove UHI from the temperature signal (other than ignoring urban areas altogether), this would seem to be the best way to handle it.
Now you have me bamboozled JoshV. You want to take some actual measured “known” temperature points; and then you want to “interpolate” (based on what scientific or mathematical justification?) to get a grid of made up “data” which we now pretend is real, and then you want to make up some more data for some more points and somehow you have a cascade of increasing information content ?? And from that you are going to compute a really accurate average. Simply wonderful; can you really do all this if say you only have two real starting temperatures ?
The whole problem with GISStemp and all lookalikes, is that the sampling process; which is supposed to be a gathering of actual real data from the real planet; is faulty.
You cannot increase information by interpolation, unless the function you are interpolating is bandlimited to that appropriate to your sampling rate.
Anthony’s little cross town jaunt points out the enormous amount of information that is just thrown away by the climate modellers.
I only have to watch any of the SF Bay area’s 6PM news weather to see that temperature fluctuations, are wild compared to the numbers that are reported as typical. You can ignore the highs and the lows if you wish, but the planet does not, and its various surfaces radiate in some way roughly proportional to either the fourth or fifth power of the absolute temperature (all the time). Fourth power if you are only interested in the total flux emitted, but fifth power if you also are interested in the spectral peak which is important for figuring out GHG absorptions.
It is easy to show, that if at some point the temperature goes through some sort of cyclic change (say daily) about a mean (integrates to zero about the mean), then the integral of the 4th (or 5th) power of the cyclic function, which would roughly correspond to total radiation emitted (4th power); that the total is ALWAYS larger than taking the 4th power of the average temp and using that to compute a radiation total for the cycle.
When you examine this for the annual change during a comlete solar orbit, or even on a 24 hour daily basis; not to mention the -90 to +60 c global temperature extremes(surface), the total emitted radiation is somewhat greater than if you just take the global mean temperature and use that as your total radiation baseline to apply “forcing” to.
I did put out a short essay on that to some people, but5 you can easily do the math for yourselves.
GCMs may be climate models; they just aren’t the models of any planet that is of interest to us. No planet I know of has the sun directly overhead at every point on the planet continuously throughout its whole yearly cycle, so that it uniformly illuminates the entire surface all the time at some constant insolation rate. (I have devised a ZEMAX model of a spherically enclosing sun with a surface that emits uniformly over a very restricted solid angle (0.5 degrees) from the normal at every point on its surface. From any point on the internal planet surface, you can look directly at the zenith and see a 1/2 degree angular diameter sun all the time.)
Hullo, Steve Goddard.
How do you like the rumors going ’round that we are the same person? (Or maybe we are both just mythical virtual constructs of El Reg?) #B^1
Further evidence: Steven Goddard = St. God?
For that matter, how many John Philip(s) ARE there . . . ?
Just wait till the Red King wakes up!
So, common then somebody, just when is Solar Cycle 24 going to start in earnest?
We’re still waiting for action from the House of C’mons.
Anthony,
Thanks for providing first hand, the chance to see science in action…it’s fascinating to witness things like this unfold.
Nobody beats the Rev!
The question is: does urbanisation affect trends over large periods of time for a significant number of stations.
Good question. The answer would appear to be “yes”.
See McKitrick and Michaels (2008) and LaDochy et al. (Dec. 2007).
Increase in trend [sic] is exaggerated by around a factor of two.
That’s how heat sinks work: If there is a warming trend, it is exaggerated. The converse is, of course, that a cooling trend is exaggerated, as well, as the heat sink effect “undoes” itself.
Also what appears to be happening is that suburban and exurban creep (not to mention microsite violation) are overtaking the rural stations. SHAP is obviously not accounting for this (SHAP, believe it or not, is a POSITIVE adjustment–no lie!) This causes an entirely spurious inflation of trends.
ared (07:47:32) :
“So in order to prove the IPCC wrong, you have to prove that UHI’s have affected trends, not just that they are real, …”
The Ipcc advanced the theory, therefore they have to prove it. The ipcc has to prove that uhi’s have not affected the trends and that anthropogenic emissions of CO2 have adversely affected the global environment in a way.
ared (08:27:31) :
“Dee, I know all this. I’m just making the point that knowing the size of one UHI at one moment in time does not prove the IPCC wrong. You need to know how UHI develop over time and what effect many of them have on long-term global trends to say something usefull about whether 0,05 per century is wrong or not.”
What data proves the Ipcc right?
ared (08:46:44) :
“stan, the IPCC doesn’t say that the UHI effect is small. It says that after correcting for the effect, the impact on global trends is small.”
The ipcc is forced to correct for the effect to prove their foregone conclusion.
all of this discussion about global warming/climate change is beside the point. The original al gore/ipcc attack was on anthropogenic co2. we have allowed the discussion to be diverted to global warming/climate change, which would occur if there was no human life on the planet. It is the political attack on the cycle of life with the intent to control, through taxation, our freedom, to live life to its fullest, that must be confronted. Why be defensive about the “straw man” of global anything. The attack by al gore/un is on the american way of life. we are too prosperus and must be restrained by the elites of the world.
I would appreciate some response to the visuals I posted here, and the complete lack of correlation between temperature anomalies and urbanization. If UHI is significantly skewing the global warming signal, then there would have to be a correlation betweeen warming regions and urbanized regions. There is none!
Gary Hladik :
Regarding this page: http://www.ncdc.noaa.gov/oa/climate/research/ushcn/#urbanization
I think it is poorly worded but it does in fact say that the greem line is the result of the processing algorithm used in HCN version 2 data. They say that no individual correction is applied because the general algorithm detects the step change and false warming from urbanization.
So, if my reading is correct, it is green line, not red.
Here is a graph of the NOAA GHCN data fro Reno showing unadjusted (blue) and adjusted (red). http://www.appinsys.com/GlobalWarming/climgraph.aspx?pltparms=GHCNT100AJanDecI188020080900111AR42572488000x
NOAA adjustments remove some of the older warming but not the recent warming.
Here is a graph comparing Reno with the 3 closest stations listed as rural in the NOAA GHCN database since 1970. http://www.appinsys.com/GlobalWarming/climgraph.aspx?pltparms=GHCNT100XJanDecI197020080900410AR42572488000x42572488001x42572488003x42574501004x
Reno shows substantially more warming than the rural stations.
Coby, you are way behind the curve. Start out by reading the old threads on this blog, starting at the beginning. Biases are not limited to urban settings. In fact, the term “UHI” is a misnomer. It should be “AHE” – anthropogenic (direct) heating effect. Such effects can be seen in locations that are “lights = 0”
Go catch up, then come back here.
are people not aware that the satellite records show a similar amount of warming as the surface records over the past 30 years?
bob, people are quite aware of the satellite temps. But upon closer inspection the satellite records show a much more pronounced cooling trend while the surface trends like GISS temp now only show a leveling off of the temperature rise
Troposphere, however, is supposed to heat faster than the surface. It hasn’t been.
And there’s a still controversy on how to convert satellite data into surface temps. At some latitudes, it’s a 1.4-1 conversion. At others, it’s 1.2-1.
(Having said that, satellites are probably more reliable than surface stations, which are poorly sited and ridiculously adjusted.)
Also, GISS is a bit of an outlier, and diverges from the satellite record over the last decade.
” evanjones (14:21:16) :
Troposphere, however, is supposed to heat faster than the surface. It hasn’t been. ”
Evan; obviously we’re not asking the right questions. Let me rewrite your statement for you.
‘ The troposphere hasn’t been heating faster than the surface; some theories claim it should; so they are obviously wrong, and should be dismissed.
Wouldn’t it make sense for the government to spend a little time and money to audit all the weather stations before we spend a lot of money on correcting a problem that is not there, or is exaggerated?
I know and appreciate what Andy has done along these lines, but what is wrong with making sure the surface stations are what we think they should be?
I have been thinking about proposing a state wide science project for all the elementary schools. Each school should have its own weather station, monitored electronically and manually. Teams at the schools could collect the weather data and then analyze and publish the results. Each school could publish the results on a single website. It would be interesting to see what we could learn about UHI from this study.
Big benefit: kids could learn about the real science of measuring and reporting results of those measures. Perhaps it might even stimulate some interest in science, math, and computers?
Another note along the lines of UHI. There were some references to a Jones on this topic earlier. It seems I recall the Jones paper was used by the IPCC to reject UHI as a major contributor to the measured temperature trends attributed to greenhouse gases. Wasn’t there some sort of scandal regarding the loss of the data used in the Jones paper? Does anybody else recall that?
Over at my blog I’ve made a simple graphical illustration of Reno’s population growth over the last 50 years and how this compares with the difference in Reno’s termperature and that of its neighbors (that latter image courtesy of Alan Cheetham @13:23:27.
I think this explains the reason why one can be highly suspicious of reported temperatue increases in Reno given the location of the temperature sensor
Where would a UHI effect precict most of the warming to be observed? I’ll guess India, China and Coastal sunbelt cities of America, Europe and Australia.
Where do the climate models predict most of the warming? Far northern wilderness areas of Russia Europe and Alaska.
Where does Giss show most of the warming? Far northern wilderness areas of Russia, Europe and Alaska.
How often have I heard the following from the AGW Camp.
“… natural variation can only explain a part of the observed warming, CO2 is the only thing that could have caused the rest of the warming – therefore CO2 is the culprit…”
If (as demonstrated by Anthony’s evidence) UHI is a much larger factor and the observed warming has been exaggerated then the actual warming may well be back in the range that natural variation is sufficient to explain.
I look forward to the arguments from the AGW Camp who visit this site to explain how and why the demonstrated UHI effect is “not relevant” to the AGW discussion.
Surely this impact of UHI is testable.
Table 1: All rural stations – map a trend over the 20th Century.
Table 2: All city stations – map a trend over the 20th Century.
Compare map 1 to map 2; If UHI is a factor – the trend lines should be different and capable of demonstrating by how much.
Also use the original raw data.
Has this been done?
I can confirm the UHI. I live downtown in Mannheim, Germany, a city with 300 000 inhabitants.
And in clear sky nights temperatures are easily 6°C above the temperatures of the airport that is outside of the city. On rainy nights its just about 1°C warmer.
Actually it works to grow subtropical palm trees on my balkon – something that usually doesn’t work in Germany.
“6:45 33F at the house
7:20 38F at the intersection of I85 and I77 in Charlotte (LOTS of concrete/asphalt)
7:50 29F in the parking lot at work.”
And again on the way home:
5:30 57F at work
6:00 60F at I-85/77 interchange in Charlotte
6:30 53F in my driveway
No UHI detected at all…..
REPLY: Maybe you’d like to be the next person to run a transect?
-Anthony
Scientists Predict Big Solar Cycle Dec. 21, 2006: Evidence is mounting: the next solar cycle is going to be a big one. Solar cycle 24, due to peak in 2010 or 2011 “looks like its going to be one of the most intense cycles since record-keeping began almost 400 years ago,” says solar physicist David Hathaway of the Marshall Space Flight Center. He and colleague Robert Wilson presented this conclusion last week at the American Geophysical Union meeting in San Francisco.
http://science.nasa.gov/headlines/y2006/21dec_cycle24.htm
Jack Simmons,
Yes. Jones said the dog ate his homework. [in essence] His excuse was that he didn’t save any of his data.
coby:
You can keep reposting that link all you want, but don’t you think a blog like that, with the heading “Whores To Industry”, might have a slight axe to grind?
Look at this map of major errors in surface station temperature data: click
Now explain to us why we should rely on data from surface stations that routinely have errors greater than 5 degrees C?
Evan; obviously we’re not asking the right questions. Let me rewrite your statement for you.
‘ The troposphere hasn’t been heating faster than the surface; some theories claim it should; so they are obviously wrong, and should be dismissed.
No, I haven’t said that. But it does call their conclusions into question. They could be partially right or wrong. (But they can’t be completely correct.)
Wouldn’t it make sense for the government to spend a little time and money to audit all the weather stations before we spend a lot of money on correcting a problem that is not there, or is exaggerated?
You are not the first to ask that. (And I hope not the last.)
Compare map 1 to map 2; If UHI is a factor – the trend lines should be different and capable of demonstrating by how much.
The problem is that the rural stations are even more corrupted by site violations than the urban stations. The effects (according to Leroy 1999, which are used by the NOAA/CRN) are quite similar to UHI.
Over six out of seven stations have severe violations (CRN3 or worse), quite apart from the UHI issue.
Patrick Henry (16:11:09) :
Scientists Predict Big Solar Cycle Dec. 21, 2006: Evidence is mounting: the next solar cycle is going to be a big one. Solar cycle 24, due to peak in 2010 or 2011 “looks like its going to be one of the most intense cycles since record-keeping began almost 400 years ago,”
It better start building soon as 2010 is not far away. I think Hathaway is getting nervous already. BTW, why bring up this old prediction? which seems to be less and less relevant for the [so far] anemic solar cycle 24.
Urban heat islands developing in coastal tropical cities, 2005
http://www.puc.state.pa.us/electric/pdf/dsr/dsrwg_sub_ECA-EOS.pdf
Thanks Evan,
How many stations would we have left, if we restricted the test to only those that were “in fact” well sited according to the defined standard?
Would the number be enough to allow for a reasonable test?
Perhaps the test can’t be run as there is insufficient quality data?
(More uncertainity surrounds the AGW Data…)
G
[…] adjustment for the UHI in Reno is -1 degree not -10 degrees. This is common. See UHI is real, in Reno at least for […]
Where does Giss show most of the warming? Far northern wilderness areas of Russia, Europe and Alaska.
How many weather stations per 1,000,000 square miles? 5? 10?
Go to this page.
http://data.giss.nasa.gov/gistemp/station_data/
Click on Alaska
FIVE stations with 2008 data.
Chris Wright (04:51:23) :The presenter is a scientist and seemed a reasonable person. But it never seemed to occur to him that his own demonstration of UHI refuted his own arguments. Cynical me says that was a neat way of making the majority (who don’t check figures – and maybe that includes himself) believe that UHI WAS properly catered-for. It was adjacent to him showing Spencer had got the satellite temps wrong (as they seemed to show up “too much” cooling)… See how much misinformation is implied in this short space… that Spencer was “wrong”, that the satellite records are still untrustworthy, and that the high UHI he measured has been allowed for… so folks, temperatures are RISING…
“Maybe you’d like to be the next person to run a transect?
-Anthony”
Love to Anthony. I drive from rural, though a 1+million population city, back to rural twice each day. Email me if you’d like. I had just been going of the thermometer in the car. Accurate? Not likely. But you don’t need accuracy to measure a change. And the car thermometer changes 5-6 degrees everytime I drive through Charlotte and out the other side….
Hi, coby. Thanks for re-checking.
The reason I still think the EC report is using the un-homgenized data (red line) is that they say 2007 is about four degrees above the 1971-2000 average but only the tenth warmest year. Now the graph only goes to about 2005 or 2006, but if EC used the green line, a four-degree-above-average 2007 would be the warmest, or maybe second-warmest green-line-year; it would be a prominent spike on the green line.
On the red line, however, four degrees above “average” would still be below several previous measurements. So it still looks like EC is using the straight, unadjusted airport readings (they mention no corrections) and therefore not accounting for UHI. That doesn’t surprise me, because the green line just isn’t terribly alarming. 🙂
I wonder if the UHI effect is responsible for more than the skewing of GISS records.
If we add in 200 yrs of forest clearing could the planet actually be warming from our man made stored energy?
We had a sign in the calibration lab I worked in:
ONE TEST IS WORTH A THOUSAND EXPERT OPINIONS
The UN/IPCC relies on always-inaccurate computer models [their “expert opinions”], which explains why their Assessment Reports are so outlandish.
Here’s something refreshing: a young science student who decided to do his own urban heat island experiment: click
The apoplectic comments by the helpless alarmists are almost a pleasure to read.
I believe that there are more forests now than in 1900 (in the US anyway). The conversion from wood to fossil fuel saved the forests. New England was pretty well clear cut for building materials and firewood. Last time I looked, there were more trees than you could shake a stick at.
(So to speak)
Steamboat Jack
Anthony,
This experiment could be expanded – in a fashion similar to surface stations.org. Volunteers collecting transects such as yours across multiple cities of many different sizes at different times of year, etc. You might be able to collect a large enough data set to quantify the UHI effect is such a way that a reasonable UHI correction could be made according to city size & station location within that city. At the very least, it would provide a large data set to prove the UHI effect is real (& commonly large).
An observation I have made here in Denver is that the UHI effect appears to be larger on drier days – which might imply that it is not only a radiative effect but also a moisture effect – with all the “urban irrigation”, there is also a latent heat component with the additional urban moisture.
Somethings to consider anyway….
Anthony’s data seem to a non-scientist the basis of pure science. Anthony, your being there and recording the difference in temperature from a rural to an urban setting is the real thing, IMHO. Experientially, everyone knows that we get hotter when we drive from a beautiful, rural area to the equally, but differently, fascinating city. What I think scientists ought to add to our knowledge of climate change is now much help UHIs will add to global warming. UHIs might be a much larger contribution than CO2 to global warming, of which we might need a great deal in the near future as we move into global cooling. Just sayin’.
I have also heard the “more forests now” statement but don’t now how to check it. Many residential areas have a lot more trees than the land did when it was farm fields. People also don’t seem to realize that practically the entire Eastern forest died when the chestnut blight hit in the early 1900’s. Chestnut was the dominant tree in the Eastern US much like redwoods in the West. The forest we have today is not only more extensive, it is made up of completely different tree species.
To be a little more specific about the science we might need in the future — there are mega-urban areas, and metropolitan urban areas, and urban areas, and cities, and towns, etc. What percentage of the land mass of the globe are these developed areas compared to the land mass of undeveloped areas, and what percentage of increased temperature does each add to their section of the earth (there are probably more specific questions that can be asked). Then we can find out what the developed areas, in their specificity, add to global warming. If the conclusion is that they are significant “pollutants” in terms of global warming, then we can ban developed areas from the earth. On the other hand, if we find that they help to keep the earth warm and happy, perhaps we can keep them.
Bottom line. We need the best science regarding temperature we can get. We do not have it as yet, as Anthony has clearly shown in his experiment.
Jon Jewett (19:09:48) :
‘I believe that there are more forests now than in 1900 (in the US anyway). ‘
I forget the study, as it was aprox. 10yrs ago, but for New England, you are absolutely correct. The study mentioned that 200yrs ago, New England was basically clear-cut farmland, and that there are MANY more trees here now than there were 200 yrs ago.
Jim
This satellite pic of the earth at night clearly shows mans impact and coverage as far as urbanization.
http://www.cobybeck.com/illconsidered/images/earthlights.jpg
And if we are to believe this website over half of the worlds forests have disappeared.
http://www.globalchange.umich.edu/globalchange2/current/lectures/deforest/deforest.html
The site states almost half of the forests have disappeared in the USA but do mention recovery in some areas.
But if UHI’s are contributing to actual global warming it must be on a small scale or we would not be experiencing the current cooling.
What a demo, there is no way GISS can correct accurately for this kind of clear effect. How is the sensor mounted in the car?
I continued my posts on Tamino’s ARMA analysis here
http://noconsensus.wordpress.com/2008/10/30/dont-get-fooled-againagain/
REPLY: see the update photo showing the mount – Anthony
Evan,
I wasn’t aware of the rumours, but last time I checked I wasn’t you.
However, I hear that you can switch identities, friends, political philosophies and birthplaces at the last minute – if you are running for president of the USA.
coby (12:43:24) :
Perhaps it’s just the scale, but the green line is so flat, you could argue that there is no warming, at least in Reno.
Or if you are voting in Ohio! #B^1
And I’m not kidding. That’s actually a rumor! Or that you are actually Steve McIntyre. Or that we are the fevered alter-egos of Andrew Orlowski, courtesy of El Reg.
Andrew, I’ve met.
But as no one has ever seen us both in the same room, maybe I really AM you!
How many stations would we have left, if we restricted the test to only those that were “in fact” well sited according to the defined standard?
Would the number be enough to allow for a reasonable test?
Perhaps the test can’t be run as there is insufficient quality data?
Maybe not. Only 13 % of the 500+ observed stations are CRN1 or 2 rated. Only 4% are CRN1. And some of those have seen urban areas grow around them, so they’re not a constant.
However, La Dochy did a study of California stations
LaDochy, Medina, Patzert. 2007. Recent California climate variability: spatial and temporal patterns in temperature trends. Climate Research, 33
ABSTRACT: With mounting evidence that global warming is taking place, the cause of this warming has come under vigorous scrutiny. Recent studies have lead to a debate over what contributes the most to regional temperature changes. We investigated air temperature patterns in California from 1950 to 2000. Statistical analyses were used to test the significance of temperature trends in California subregions in an attempt to clarify the spatial and temporal patterns of the occurrence and intensities of warming. Most regions showed a stronger increase in minimum temperatures than with mean and maximum temperatures. Areas of intensive urbanization showed the largest positive trends, while rural, non-agricultural regions showed the least warming. Strong correlations between temperatures and Pacific sea surface temperatures (SSTs) particularly Pacific Decadal Oscillation (PDO) values, also account for temperature variability throughout the state. The analysis of 331 state weather stations associated a number of factors with temperature trends, including urbanization, population, Pacific oceanic conditions and elevation. Using climatic division mean temperature trends, the state had an average warming of 0.99°C (1.79°F) over the 1950–2000 period, or 0.20°C (0.36°F) decade–1. Southern California had the highest rates of warming, while the NE Interior Basins division experienced cooling. Large urban sites showed rates over twice those for the state, for the mean maximum temperatures, and over 5 times the state’s mean rate for the minimum temperatures. In comparison, irrigated cropland sites warmed about 0.13°C decade–1 annually, but near 0.40°C for summer and fall minima. Offshore Pacific SSTs warmed 0.09°C decade–1 for the study period.
http://www.int-res.com/abstracts/cr/v33/n2/p159-169/
This study, however, does not specifically take into account microsite violations, so we have a hanging vairable in play.
Vote early and vote often!
I’ve met Andrew as well, and I am sure he is not me. I have received e-mails from you which I did not send, so I am quite certain that you are not me. And St. Steve McIntyre’s statistical analysis typically go completely over my head, so I am 100% certain I am not him.
Didn’t one of the presidential candidates say this in his book?
“I chose my friends carefully. The more politically active black students. The foreign students. The Chicanos. The Marxist professors and structural feminists.”
No friends who cling to guns and religion? Or capitalists? Or military people? Or Americans who are proud of their country? Or people who have ever had a real job?
Evan and Steve,
Obviously – Neither of you are each other – now that should clear it right up…
That’s only a theory.
Hey Evan – thanks for that – interesting.
Steve, just read your last post, especially the part in italics… hmmm very worrisome – in fact I’m alarmed. (no really – I am).
This is bad for Australia too.
Graeme,
“I chose my friends carefully” Wright, Ayers, Rezko, Farrakhan, Jackson ….. ?
Here’s the flip side:
Ross R. McKitrick, Patrick J. Michaels , JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, DECEMBER 2007, Quantifying the influence of anthropogenic surface processes and inhomogeneities on gridded global climate data
http://www.agu.org/pubs/crossref/2007/2007JD008465.shtml
Abstract
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 × 10−14), 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.
Received 26 January 2007; accepted 8 November 2007; published 14 December 2007.
Evan, Steve,
Thanks.
Of course there is UHI in Reno… NCDC used Reno as the example on the USHCN V2 roll out… they clearly admit it
Graeme Rodaughan (21:42:31) :
I’m offended – with one exception that I’ve nearly completely forgotten about no one has accused me of being someone else. Therefore, I wish to categorically state that I am not the poster who goes by the name Lucy Skywalker. Just because we’ve both written web pages that are good introductions to this sorry field doesn’t mean that they’re both mine. Or hers. But they are ours.
Hey, the clouds outside are breaking up, thank you Graeme. Speaking of which, that was a pretty weird storm here in the east a couple days ago. Odd wind patterns, no lake effect, at least at first, while it was snowing in upstate New York and Philly suburbs (away from the dreaded UHI), Boston was warmer than Atlanta but eventually cooled down on a cold south wind. Gonna be an interesting next few years.
One thing strikes me. The IPCC claims that UHI is almost negligible and cites some studies that are almost laughably weak. I’m sure Anthony wouldn’t claim his test to be a rigorous scientific test. And yet, almost certainly, if those tests could be done world-wide as a fully funded scientific experiment they would confirm what Anthony – and many others – had found.
So the obvious question is this: why aren’t the scientists doing this? By making repeated, accurate measurements along routes that pass across urban areas then a very accurate picture of the strength of UHI should emerge. It would be persuasive because it was based on real measurements. To put it bluntly: how difficult can it be to grab a thermometer and actually measure the temperatures?
I would like to know if this has been done already. And if not, why not? It seems so obvious.
Another poster suggested that this could be a new campaign that complements the surface stations campaign. I think that’s an excellent idea.
Chris
REPLY: The idea to make a campaign out of this has been on my mind for some time, I just need (ahem) the right vehicle. Mainly, something that is affordable. I think I may have a solution that would allow this to be done for under $100 per city. – Anthony
Mike C.
We understand they “admit it”…we also understand that IPCC “admitted it”.
The problem is that based on close examination of the “science” involved, or lack thereof, many (me included) believe that the impact of UHI on the overall picture has been underestimated. Some believe this is simply based on poor science, others believe it’s a deliberate manipulation of the data to make it fit a projection/prediction.
This could easily be put to rest IMHO if the two sides would engage in an open debate about the experiments and the results, but frankly, it seems to me that the AGW camp is completely unwilling to do so.
Jim (who would REALLY like to SEE that debate…)
Has it occurred to anyone in the BBC that this 4’C differential urban to rural is the same ‘catastrophic’ warming that they claim will occur longterm? You’d think commuters would have noticed by now – its clearly nothing we can live with!
I believe this graphic was posted on this site a while back. It seems relevant [note Reno on the map], so here it is again: click
This is a great little illustration of how out to lunch people are when considering scientific information. People still buy the “hockey stick” after numerous debunkings. Yet despite believing that the world is getting warmer from people driving cars and emitting CO2, they refuse to believe that one local area could be warmer from people driving cars and emitting heat. Therein lies the reason this debate is so screwed.
One note on DOE for Anthony. Many of the areas in and around the Sierras, are well known for extensive microclimates. Someone inclined to take pot shots at your conclusions may raise this point. You may want to consider setting a control for your experiment to combat such claims. Something like taking temperature measurements as you drive concentric circles around Reno (that is outside the UHI affected perimeter) might work. This will help to establish whether or not there are any macroscale or microscale temperature gradients present that may be influencing the appearance of UHI. Given your skill with statistics, once you made such a determination, I think you have the tools to determine the scope of any observed microclimate impact on your results based on their size and location in relation to your UHI-indicating measurements. Obviously if you see a gradient from outside the city flowing seamlessly into the observed UHI gradient, this may just be the effect of microclimates. But if you universally see the heat gradient pointing into the city at all points along the circumference, then UHI becomes the only logical explanation.
Just some food for thought. God know’s there’s enough BAD science being done, and where it’s put us. Now that you’ve started, why not make this as thorough and rock solid as possible, given it’s potential to shake the foundations of the AGW argument. Great stuff as always!
This entire thread illustrates the difficulty inherent in discussing global temperature, anthropomorphic effects, and data collection.
Truism: all things do not remain the same.
Truism: it takes money to staff a weather recording site. It takes more money to connect a weather station to a structure with a cable.
Truism: airports were extensively used to collect weather data, because of the need for weather information for the use of aircraft landing and taking off. Example: the weather station in Washington, DC was downtown for a number of years. It was moved to Reagan National Airport because the data was needed there anyway, and the station could be permanently staffed. And airports are paved with black asphalt these days, which absorbs heat.
Truism: whatever the effects of UHI, those effects are related to population density.
Truism: too few of the existing weather stations meet all of the CURRENT criteria for measurement of temperature, wind speed and direction, relative humidity, and precipitation. It is possible to imagine measurements which would demonstrate the difference between a weather station in use and a nearby (5 miles, let us say) station which fully meets CRN1 requirements. I do not know a method for projecting any such difference into the past, before urbanization.
Truism: an equally spaced grid of weather stations would be hideously expensive, and is not under consideration.
The entire collection of arguments, over tenths of a degree celsius, is more heat than light. Remember that Galileo made one of the FIRST temperature measuring devices, and that the technology to draw a glass tube with a uniform internal diameter came more than a century later!
I wish everyone would take a deep breath and stop imputing motives, and see some more devotion to collecting good data!
The IPCC claims that UHI is almost negligible
Are you sure? I think everyone acknowledges that urban areas are significantly warmer than rural ones. The IPCC certainly do …
“Clearly, the urban heat island effect is a real climate change in urban areas” (Box 2.1)
but the question in a climate change context is how significant is this real effect on the observed global warming trend? And this breaks down into two related questions: are urban areas warming at a faster rate than rural areas and is the effect of increased urbanisation significant? The IPCC conclude that the answer to both is that the impact on the global trend is insignificant.
They base this on an array of evidence (see the above link), including a comparison of the trend for all stations and rural-only stations which show a difference of about just 0.05C over the period 1900-1990, and similar comparisons of the surface record with glacial, borehole and sea temperatures, all of which agree well with the global trend but obviously cannot be influenced by urbanisation.
The small contribution of UHI to the trend may appear counter-intuitive, but go back to first principles – 70% of the globe is ocean and cannot be influenced by urbanisation, of the remaining 30%, one entire continent (Antarctica) has no urban areas, Central Greenland and Central Australia have no significant urbanisation, Siberia has virtually no significant urbanisation (but shows above-average warming) and so on. Indeed if all of the continental US was concreted over it would only cover 2% of the surface area of the globe. So an insignificant contribution by the UHI effect to the observed global trend seems to me entirely plausible.
So climate scientists are well aware of the UHI and the fact that it can have significant local and even regional effects but an insignificant effect on larger areas. For example, this paper concludes a significant regional climate effect from the rapid urbanisation of China.
It was edited by James Hansen.
JP.
REPLY: Obviously you haven’t read this flawed but oft cited paper from Dr. David Parker over there at Hadley. He’d deluded himself into thinking UHI doesn’t exist, and people that are either too stupid, too entrenched, or too lazy to look for the answers themselves are following his lead.
See: http://www.climateaudit.org/?p=1718
From Parker 2006 this whopper of a wishful conjecture: …many “urban” observations are likely to be made in cool parks, to conform to standards for siting of stations.
To which McIntyre writes:
And we know from the surfacestations.org project that the majority of USHCN stations are compromised by microsite effects, which could be characterized as a form of UHI since the issues are related to urbanization around the station.
You write:
Bollocks. Care to rephrase that? You completely contradicted yourself. “…rapid urbanisation of China.” aka UHI over a wide area. Also explain why in the face of such widespread microsite bias, the lack of imagined “cool parks”, and “rapid ubanizations” such as China, that UHI only gets a 0.05 degree adjustment.
– Anthony
JimB,
The IPCC kind of admits it… they use Peterson and Parker (and Jones) to show that UHI is .02Deg C per decade. What too many skeptics do not acknowledge is that the UHI they show is after adjustment for UHI.
Peterson does not work because he used dense temperature networks in his study and the stations he used were as messed up as any that Anthony has shown. Dense networks are much better in adjusting for UHI, where sparse networks (like those monitoring most of the worlds land mass) are lousy for adjusting for UHI.
Parker used the wind proxy, windy vs calm days and how it affected the boundary layers. Parker failed to mention that he did not actually study windy vs calm days, it was actually the third windiest vs the third least windy… the third least windy were just as caable of mixing the boundary layers. Also, he failed to recognize that the boundary layers varied in thickness from station to station, skewing his experiment.
I’m not so sure if a debate on UHI would be productive… both sides would just offer a spun view which would probably lead to more confusion. I think a few good papers on temperatures and how they are affected by everything involved… UHI, Micro-climate, equipment, solar, ocean circulation, lack of data (including spatial variation over time) and etc.
Ric Werme (05:07:28) :
A little more seriously, I don’t have hard data, but I’ve noticed that between my usual parking place at work (shaded in the afternoon, at the bottom of a short hill going up to self-storage place) and the Turnpike heading north, I’ll see a 2-3 F rise. Some of it may be from sun, the temperature sensor is in the exterior rearview mirror, but I think most is from the hillside and car being in the shade at work.
How is traffic? I have done some quick calculations on how much heat a car dumps, and it is not negligable. May be you are just measuring the waste heat of the car in front of you.
The calc:
A car needs around 10 kW at the crankshaft to do 100 kph. Since an average engine is around 20% efficient, the total amount of heat produced is 50 kW. If cars are spaced 100 m apart, on traffic lanes 4m wide, the forcing is 50.000/400 = 125 W/m2. This is a considerable figure. All this heat is dumped near the surface, where your temperature sensor is.
REPLY: Anne, nice try, but no. I’m not measuring the waste heat of the car in front of me. I purposely chose that time of night because there was so little traffic, and I was careful to avoid any cars ahead.
Prior to this I did some tests in my own driveway, and the sensor didn’t pick up proximity of vehicles. Including idling my own for short periods, such as would be simulated by a stoplight. – Anthony
Hi Ric Werme I wasn’t you either… not the last time I looked in the mirror…
Coby, your two pics point to different realities. The temp anomalies pic is a composite of land, sea and satellite data that to my eye shows some pretty interesting factors: NH warming, Antarctica cooling, and landmasses warming generally more than oceans which are cooling in places. I believe we can explain it all in terms of Sun and oceans, remembering the Sun gives off 24,000 times our human output – but we might still cause a tiny NH anthropogenic warming effect. No GHG though, because CO2’s GHG effect is already saturated, it’s like adding ink to inky water. The lights picture could relate to surface stations data, so I’d like you to show a warming anomalies map drawn ONLY from surface stations data.
Nobody here is saying UHI accounts for all the recent warming. Please correct your representation of skeptics as saying “The apparent rise of global average temperatures is actually an illusion due to the urbanization of land around weather stations, the Urban Heat Island effect”. People here just note that surface records have been shown to be suspect regarding UHI, and that this evidence suggests the IPCC corrections are way too small.
Yes, McIntyre makes the same category error and attacks the same Straw Man.
One of the main IPCC creeds is that the urban heat island effect has a negligible impact on large-scale averages such as CRU or GISS. The obvious way of proving this would seem to be taking measurements on an urban transect and showing that there is no urban heat island.
Except the IPCC completely acknowledge the existence of UHIs, as does Parker. It is entirely possible to have island hotspots, if you will, that have a negligible effect on the global trend, given the relative size of the globe and the urban areas. You say China is a ‘large’ region yet it is a similar land area to the US, about 2% of the globe’s total. The effectively unpopulated Antarctica has >50% more area. To repeat myself, the UHI effect is real, but its influence on the long term global trend is massively diluted by the oceans and the vast areas of the planet that are not urbanised. Or, to quote IPCC AR4 WG1 Chap 4:
“Urban heat island effects are real but local, and have
not biased the large-scale trends. A number of recent studies
indicate that effects of urbanisation and land use change on
the land-based temperature record are negligible (0.006ºC per
decade) as far as hemispheric- and continental-scale averages
are concerned because the very real but local effects are
avoided or accounted for in the data sets used.
Bye for now.
JP.
REPLY: “massively diluted”…still bollocks. Why? check the station distribution. Your argument assumes there are more stations in the oceans and the poles, i.e. a more evn distribution…but the reality is far different. In fact, there has been a sustained loss of stations at high latitudes in the past 20 years.
– Anthony
John Phillip, It is not the land area of the UHI effect that is important, it is that the temperature probe sits in the middle of it. Even moving from a 100′ clear area to within 10′ of a rural house because the data cable is restricted in length causes UHI. Look at the surfacestation.org data showing a bias from the almost 50% of US sites investigated of +1.95 C. This does have an effect not accounted for by the IPCC.
[…] UHI is real, in Reno at least A couple of days ago there was a guest post from Russ Steele citing a California study “Feeling the Heat” […] […]
Today’s (31Oct08) “The Advertiser” newspaper (South Australian daily paper) there is an article titled “Temperatures changing face of Adelaide” stating:
“Adelaide is 1.5C hotter today than it was almost 100 years ago. This is altering the coastline and climate, new research shows.”
“The metropolitan urban jungle is trapping the day’s warmth after sunset more than before.
The heat radiates at night and keeps temperatures higher than if the heat could dissipate into the atmosphere.”
“University of Adelaide researchers have found this heat is drawing the afternoon sea breeze into land more quickly than in previous decades making sea breezes stronger”
“The breezes affect the size of waves in Gulf St Vincent. That affects the movement of sand and sediment along the gulf, causing beach erosion.”
The research was undertaken by Civil, Environmental and Mining Engineering honours students.
If, according to the IPCC, UHI effects are negligible and local:
* this research appears to show that UHI has added at least 1C to Adelaide’s average temperature which is around the same increase attributed to CO2
* how ‘local’ is ‘local’ – the effects of the Adelaide UHI cover St Vincent Gulf which is 90 miles long and 45 miles wide?
* Adelaide is a coastal city in South Australia with a population of approx 1 million. What effect do much larger cities have on weather patterns and climate that is blamed on CO2?
Anthony thanks for doing this great work. Don’t let the nonsense from some of these people discourage you. Some on here are trying to be to analytical/negative in regard to your study, while inferring things from it that you have not implied. The large UHI effect is so obvious that you must simply be a fool for not believing it. Here in Central California on calm clear nights in both summer and winter temperatures in rural areas are routinely 5-11 degress cooler than urban areas like Fresno and Bakersfield.
I know this from first hand temp readings with 2 Nimbus NTL thermometers with an accuracy of .02 degrees that I had up several years ago while living in the country 15 miles from Fresno. I had several thermometers up at the same time just to verify each other as I didn’t believe them at first. Also one can easily look at the NWS Hanford Regional Temperature Roundup to see the UHI effect for themselves.
It’s so upsetting that some try to be so smart and in doing so miss the obvious. Some just don’t know how to objectively take a step back and look at the big picture. Some are just to prideful, which clouds their judgement. Sorry for the rant, just wanted to present my thoughts. Thank You again for your work Anthony.
Your argument assumes there are more stations in the oceans and the poles, i.e. a more even distribution-but the reality is far different. In fact, there has been a sustained loss of stations at high latitudes in the past 20 years.
No I do not make that that assumption. In GISTEMP, for example, the contribution of each grid cell to the global mean is identical (after weighting for latitude band) regardless of the number of stations within it. So the contribution of a cell with relatively dense station coverage (eg Reno, presumably) and that of a grid cell with fewer cells (e.g.in rapidly-warming Siberia) to the global mean is identical.
I always thought ‘Bollocks’ was a British coinage. Interesting to see it is used over the pond.
REPLY: Still bollocks. Even with such cell weighting, the majority of stations are still being impacted by ubanization though city scale UHI as well as microsite urbanization issues, thus UHI is contributing to the signal on a broad scale, and .05 doesn’t begin to cover it.
I can say with certainty, that the overwhelming majority of stations we’ve studied so far are affected with urbanization issues, either on a city scale and/or microsite scale. only 4% of stations surveyed are truly pristine.
As surfacestations.org has shown, even remote stations can suffer from localized urban effects. So while IPCC, Hansen, Parker and other armchair data jockeys claim they have it under control, the simple fact is they have absolutely no idea of the magnitude of the local effects nor have they even lifted a finger to study the issue. They just dismiss it with a wave of the hand.
Parker’s ridiculous “cool parks” statement demonstrates his complete lack of understanding of the measurement system and it’s problems, thus rendering his conclusions moot. – Anthony
typo
‘fewer cells’ should read ‘fewer stations.’
Apologies.
My take is that truly rural stations tend to show either no trend, or a cooling trend over the las 100 years, while those closer to urban areas show mostly a warming trend. Then adjustments occur, for no logical reason, on those rural stations, making the trend change based on other stations up to 1500km distant. Completely ludicrous. It tells me that even if UHI isn’t a major factor in the surface record, GW aint global.
Anne (15:42:32) :
Ric Werme (05:07:28) :
That ranks a high 2nd on my list of culprits. The road is asphalt, widened from 4 lanes several years ago. Traffic does move at or above the speed limit now. That, combined with solar warming during the afternoon is likely significant.
I haven’t noticed a similar effect on cloudy days – then again, I haven’t looked, I should, though there is something to be said for watching traffic, not thermometers.
Anne and I are talking about Nashua NH at 1730 and a sensor in a external rearview mirror (black housing), not Reno at night with good equipment.
One could discover UHI contamination in 100% of the US surface stations [ Though this seems improbable ] and all this would demonstrate would be that 2% of the globe is affected by urbanisation. . Everyone acknowledges the reality and the scale of UHI, and that there are localised temperature gradients of several degrees in urban areas compared to surrounding countryside, and indeed all datasets attempt to correct for this , but one cannot just wave away the fact that there can be no such effect in the oceans, in Antarctica, in Greenland, in Central Australia and hence the overall impact on the global long term trend from urbanisation is insignificant.
REPLY: “Seems improbable”, but the fact is that even stations in the absolute middle of nowhere are affected by microsite biases that are not accounted for. The fact is that rural vs urban categorizations have been shown to be wholly unrepresentative of the measurement environment around the thermometer. For example, here’s a “rural” station, which is badly polluted.
Miami, AZ USHCN station shown here
And there are plenty more where that came from.
The rural -vs- urban assignment is essentially useless for determining potential bias impact on the thermometer. Where large scale UHI might not be can easily be replaced or even be greater in bias by local site issues. Just moving the thermometer to an improper setting can dwarf UHI effects.
And, none of theses studies by Hansen, Jones, Parker, et al even touch on it. The are absolutely clueless about the measurement environment because they never look at the experiment in progress themselves. Any scientist that doesn’t look at where the data is gathered and assure themselves of it’s integrity, relying on the face value of the data aloine is not truly a scientist in my book.
As for that 2% well, we see the problem elsewhere too, as the US system is supposedly the best. Do you really think that the same sorts of problems I’ve documented only exist in the USA? Seems improbable that would be true. Human folly is universal. – Anthony
AnneI have done some quick calculations on how much heat a car dumps, and it is not negligable.
Crossing Westminster Bridge yesterday after the famous snow… the pavement was divided by a clear line down the middle, bone dry roadside, dripping wet riverside. Mind you, there could be a “fan” effect as well as warming from cars.
John Philip:
“Everyone acknowledges the reality and the scale of UHI…”
Half right, John.
The problem is the scale. The UN/IPCC incorrectly minimizes the effect of the UHI influence. The UHI effect is present, and that effect is much greater than the UN/IPCC assumes in its computer modeling.
If the UN/IPCC were honest about the effect of the UHI adjustment, the scientific community would see that the only credible measurements are those that rigorously adjust for external influences, preferably by siting surface stations well away from urban heat sources.
Anne (15:42:32) :
REPLY: Anne, nice try, but no. I’m not measuring the waste heat of the car in front of me. I purposely chose that time of night because there was so little traffic, and I was careful to avoid any cars ahead.
Anthony, perhaps you didn’t notice, I was answering Ric Werme, not commenting on your article. I was well aware that you drove at night.
Sorry if this has been listed before-found a NASA news release about urban heat-in 2000 they said that urbanisation created “vast heat islands” and “This could be demonstrating a profound urban heat island effect”
”
Lynn Chandler
Goddard Space Flight Center, Greenbelt, Md.
(Feb. 21, 2000
RELEASE NO: 00-23
URBAN SPRAWL REDUCES ANNUAL PHOTOSYNTHETIC PRODUCTION
A study of the impact of urbanization and industrialization over the past seven years using satellites shows that annual photosynthetic productivity can be reduced by as much as 20 days in some areas where urbanization is intense, not unlike turning the lights off in a greenhouse during the growing season.
The study also reveals that urbanization may be creating vast heat islands that can actually lengthen the growing season, but do not improve the productivity of the land..
NASA Goddard Space Flight Center (Greenbelt, Md.) researcher Dr. Marc L. Imhoff presents his findings during a news media briefing at the 2000 American Association for the Advancement of Science (AAAS) Annual Meeting
According to Imhoff’s research, urbanization and industrialization have resulted in the development of mega-cities and urban and suburban sprawl. The environment is altered as a result of replacing land cover with roads, housing, and commercial and industrial structures…
..A most interesting finding according to Imhoff was that urbanization seems to elongate the growing season, yet still reduces the overall productivity of the land. “…. “This could be demonstrating a profound urban heat island effect and have implications in climate change, especially in the northern Hemisphere where urban development is most intense.”
For supporting images: http://svs.gsfc.nasa.gov/search/Keywords/URBAN.html
This text derived from http://www.gsfc.nasa.gov/news-release/releases/2000/00-23.htm
Nasa put out a news release in 2000 about “vast” and “profound” urban warming/heat islands from Marc Imhoff.
It describes longer growing season but less productivity.
Havent found a retraction! Is it still current thinking in certain corners of NASA?
http://earthobservatory.nasa.gov/Newsroom/NasaNews/2000/200002211661.html
[…] Read more here Consider then UHI, and my recent measurement of a temperature transect from Reno, NV […]
[…] Here is what a surface temperature transect of Reno looks like, I did this one myself: […]