WUWT - (EXCERPT):
[Karlen] I have noticed that major cities often demonstrate a major urban effect (Buenos Aires, Osaka, New York Central Park, etc). Have data from major cities been used by the laboratories sending data to IPCC? Lennart Bengtsson and other claims that the urban effect is accounted for but from what I read, it seems like the technique used has been a simplistic
[Trenberth] Major inner cities are excluded: their climate change is real but very
[My comment] It is true that the IPCC Chapter 3 FAQ says this:
Additional warming occurs in cities and urban areas (often referred to as the urban heat island effect), but is confined in spatial extent, and its effects are allowed for both by excluding as many of the affected sites as possible from the global temperature data and by increasing the error range (the blue band in the figure).
To check this claim, I took the list of temperature stations used by CRU (which I had to use an FOI to get), and checked them against the GISS list. The GISS list categorizes stations as “Urban” or “Rural”. It also uses satellite photos to categorize the amount of light that shows at night, with big cities being brightest. It puts them into three categories, A, B, and C. C is the brightest.
It turns out that there are over 500 cities in the CRU database that the GISS database categorizes as “Urban C”, the brightest of cities. These include, among many others:
AUCKLAND, NEW ZEALAND
BANGKOK METROPOLIS, THAILAND
BUENOS AIRES, ARGENTINA
CHRISTCHURCH, NEW ZEALAND
GUATEMALA CITY, GUATEMALA
MOSKVA, RUSSIAN FEDERA
PRETORIA, SOUTH AFRICA
RIYADH, SAUDI ARABIA
SAO PAULO, BRAZIL
So the CRU is using Tokyo? Beijing? Seoul? Shanghai? Moscow? Their claim is entirely false. In other words, once again the good folk of the CRU are blowing smoke. I can understand why it took me a Freedom of Information request to get the station list.
THE EXTENSIVE USE OF URBAN DATA SKEWED THE RESULTS - AND THEY STILL NEEDED TO "HIDE THE DECLINE" BY TWEAKING THE CODE!
THE WHOLE DAMN AGW THING IS A MASSIVE FUC*ING FRAUD AND A COLOSSAL FUC*ING LIE.