By Steven Goddard and Anthony Watts
Fort Collins, Colorado is most famous for Balloon Boy, and Boulder, Colorado is most famous for Jon Benet and Ward Churchill.
Both are hotbeds of Climate Science, with familiar names like Roger Pielke (Jr. and Sr.) Walt Meier, William Gray, Kevin Trenberth and Mark Sereeze. Both are of similar size (Boulder 91,000 and Fort Collins 130,000) and located in very similar geographical environments along the Front Range – about 50 miles apart. The big difference is that Fort Collins has tripled in size over the last 40 years, and Boulder has grown much more slowly. Fort Collins population is shown in blue and Boulder in red below.
Sources:
http://en.wikipedia.org/wiki/Fort_Collins,_Colorado
http://en.wikipedia.org/wiki/Boulder,_Colorado
Until the mid-1960s, NCDC temperatures in the two cities tracked each other quite closely, as you can see below. Again, Fort Collins in blue, and Boulder in red – with Fort Collins temperatures shifted upwards by two degrees to normalize the left side of the graph. Since 1965, temperatures in Fort Collins have risen much more quickly than Boulder, paralleling the relative increase in population.
Source: NCDC Boulder Temperatures NCDC Fort Collins Temperatures
The graph below shows the absolute difference between Fort Collins temperatures and Boulder temperatures since 1930. There is some sort of discontinuity around 1940, but the UHI imprint is clearly visible in the Fort Collins record. The Colorado State Climatologist, Nolan Doesken manages the Fort Collins Weather station. He has told me that it has never moved or changed instrumentation. and that he believes the increase in temperature is due to UHI effects.
Roger Pielke Sr. further commented:
“the Fort Collins site did have the introduction of the CSU Transit Center a few years ago, although this is well after the upturn in temperature differences between Boulder and Fort Collins started to increase.”
From the promotional photo on the CSU website, the Fort Collins USHCN weather station (below) seems reasonably sited.
However when you look at the Google Earth street view, you realize that it is surrounded by concrete, asphalt, nearby parking, and a building just 7.5 meters away (By the GE ruler tool). It would rate a CRN4 by the surfacestations rating. It also appears to have been modified since the promo photo was taken as there is a new fence with shrubbery and wood chips surrounding it.
Besides the pressure of CSU expansion, Fort Collins has seen an increase of about two degrees since 1970, corresponding to a population increase of 90,000. This is probably a little higher than Dr. Spencer’s estimates for UHI.
The Boulder weather station is similarly sited since the concrete path is just under 10 meters away.
It is at the campus of NOAA’s and NIST’s headquarters in Boulder. Anthony Watts visited the station in 2007 and took photos for the surfacestations project. Like Fort Collins, it gets similar expansion pressure due to nearby construction as seen in this aerial photo.
Here are the temperature records fro these two USHCN stations:
NCDC Fort Collins Temperatures
There is some UHI effect visible in the Boulder record below, but much less than Fort Collins.
Conclusion:
We have two weather stations in similarly sited urban environments. Until 1965 they tracked each other very closely. Since then, Fort Collins has seen a relative increase in temperature which tracks the relative increase in population. UHI is clearly not dead.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
good: But too vague: “tracked each other nicely?”
you can probably get the city populations (decade resolution). That would
be interesting as well
Does Ft. Colling vs Boulder follow the same pattern of the UHI showing the nightime temps (lows) rising where the daytime temps (highs) remain on a fairly level trend?
The area just to the north of the Boulder station is Greenlawn Cemetery, which buffers it from Boulder proper. The only development nearby is that to the south, the former National Bureau of Standards.
— HM (BHS ’63).
Dudes: you forget that the people in Boulder are, like, cooler. And so they would respond to this Urban Heat Island thing by saying, “Are UHI? Of course I’m high, man!”
Lame but irresistible try for humor.
What is the trend from 1930 – 2000, i.e. before the uhi came in to effect?
But… BUT… all data this is homogenized and anomalized and fortified with calcium to make our bones strong so when it comes out the other side it’s all good right?
/sarcoff
Top graph shows 1970 forward, but is labeled 1930 to 2006
This shows how valuable the Surface Stations project is.
When I started writing this story, I was under the impression (based on the CSU web site) that the Fort Collins station was very well sited – until Anthony straightened me out.
Hey Steve, what is the orientation of that Boulder picture and what is the prevailing wind in winter and summer, northerly in winter, southerly in the summer? I guess I’m asking, would a light prevailing wind for any season bring the heat from that vast pavement spread over that weather station? You might be able to coax a bias out of the numbers since Boulder seems directionally biased and Fort Collins definitely isn’t. I don’y think any station analysis has concretely answered that question.
It appears those are yearly points but if they were season points centered on first day of Nov-Feb-May-Aug the bias at Boulder should appear when split by seasons.
Fort Collins fixed that symmetry problem by putting concrete all around it, and presto, no wind bias!
BTW, good post.
Will the boulder station be in the shade for part of the day. It is difficult to see from the images how close the trees are?
Of course UHI is not dead! It seems apparent from this article that despite some similar local conditions (buildings, concrete, asphalt) such that would create an upward bias for the readings of temperature stations in both the Boulder and Ft. Collins, the big difference in population rise would mean that Ft. Collins got lots more houses with their hot roofs, lots more asphalt or concrete driveways and roads to access the houses, lots more schools for the kids from the houses, lots more stores for the kids and their parents to shop in, lots more big asphalt parking lots for the stores, etc., etc., etc. Don’t all these things warm the layer of air air near their surfaces via convection?
However, some will counter this argument with the notion that there are also lots more people exhaling carbon dioxide, and that their exhaled contribution to global warming is what caused the difference!
As an aside, I think the “discontinuity” you mention occured around 1945, not 1940 as mentioned in your essay above and pasted below:
<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>
“Boulder and Ft. Collins – overlaid for trend comparison only
Source: NCDC Boulder Temperatures NCDC Fort Collins Temperatures
The graph below shows the absolute difference between Fort Collins temperatures and Boulder temperatures since 1930. There is some sort of discontinuity around 1940,….”
Or maybe it all corresponds to the number of people driving Priuses in the “bubble” vs the number of Priuses in Ft. Collins. All kidding aside, I have a friend who works at NCAR and she tells me Kevin Trenberth is an arrogant jerk. No big surprise there.
rbateman (09:23:22) :
Excellent question. Fort Collins low temperatures do show a much stronger warming trend than high temperatures.
http://cdiac.ornl.gov/cgi-bin/broker?id=053005&_PROGRAM=prog.gplot_meanclim_mon_yr2008.sas&_SERVICE=default¶m=TMIN&minyear=1930&maxyear=2008
http://cdiac.ornl.gov/cgi-bin/broker?id=053005&_PROGRAM=prog.gplot_meanclim_mon_yr2008.sas&_SERVICE=default¶m=TMAX&minyear=1930&maxyear=2008
wayne (09:46:45) :
Anthony will have to answer your question. He researched the Boulder site and took the pictures.
If Fort Collins has been experiencing an increasingly greater amount of UHI than Boulder over time, I would expect the temperatures at those two sites to be diverging.
Instead, judging from your third figure their temperatures appear to be converging, with the difference approaching zero.
What am I missing here?
Dear Mr Watts
Thank you for running an excellent site. I thought I’d mention some history which might be worth following up.
In England the Exchequer Pipe Rolls (Medieval tax returns) are very detailed for the whole of England and Wales. I understand, but have not verified myself, that they show clearly te tax returns from the great estates and monasteries in the North of England. These include proof of grape harvests and making of altar wine at places in teh Vale of York where even today growing of grape vines is not possible.
I further recommend you revisit HH Lamb’s books on Climatology. In one of his earlier works (I have it but cannot locate it just now, being in the middle of a house move to Singapore) he demonstrates, by reference to Exchequer returns and aerial photography, how the use of arable land in England today is different from that in the Middle Ages in the sense that the frost line has moved down slope since circa 1250 AD.
In short, physical evidence 800 years old demonstrates it was much warmer in Medieval England than it is now.
Until this and similar evidence is distinguished and explained (it cannot be refuted) by the Warmist Brigade, there can be no suggestion that the climate change we are experiencing at present is “unprecendented”.
On a separate note, if you ever want to get a Class Action off the ground against the Warmists, please do contact me. I will gladly assist on a costs plus basis – all to be negotiated. I’d love th eopportunity to cross-examine the fraudulent swine who perpetrate the AGW myth.
Best regards
Kevin Oram
Okay, what am I missing:
– In 1970 Ft. Collins had less population than Boulder.
– In 1970 Ft. Collins had higher temperature than Boulder; and the the trends had already diverged.
Shouldn’t we conclude that something other than UHI was causing warming?
Boulder is morally superior. They have removed autos from downtown and other endeavors. The geography is also different. Boulder is adjacent to the slopes and mountains and Fort Collins is 15 miles east of the mountains.
A C Osborn (09:37:12) :
Both cities tracked closely from 1895-1960.
Here is the population graph going back to 1930
https://spreadsheets.google.com/oimg?key=0AnKz9p_7fMvBdElxNDA4Vlh2OGhvOUdEX1N0bm1CeWc&oid=3&v=1268331325501
Typo: Sereeze should be Serreze. Thanks.
steven mosher (09:22:43) :
The city populations at decade resolution is the first graph.
Rather then using the city population you should use with them Metropolitan Statistical Area population.
http://recenter.tamu.edu/data/popmd/pm2080.htm
http://recenter.tamu.edu/data/popmd/pm2670.htm
City boundaries are arbitrary and may affect the growth rates.
There is a most interesting graph on Chiefios’ site http://chiefio.wordpress.com/2010/03/11/germany-not-warming that shows what a well operated national weather service can do.
Steve, or Anthony are you sure that the jump in readings at Fort Collins in 2000 is due to UHI, if you plot the 2 lines on one graph, it looks more like Fort Collins has been adjusted to Match Boulder?
They haven’t done a correction have they?