For those of you that want to see a detailed analysis of the data the weather stations mentioned here have produced, please take a look at Climate Audit at www.climateaudit.org
There a number of highly intelligent people are thinking through a number of the issues raised here. For example, it appears that adjustments made to the measured data by researchers may actually enhance the urban heat island effect.
But its hard to tell for sure, because key software programs and formulae used to create such types of analyses for the IPCC haven’t been made fully public. There is a Freedom of Information act effort going on in that regards because some requests for data sharing and formulae used to analyse the data have been rebuked.
Whats certain is that between the inconsistencies found with some of the surface weather stations and the lack of full disclosure on the methods used it warrants further study and investigation. One of the tenets of good science is data and methods sharing and repeatability by others. It is baffling that NOAA is not allowing their methods to be tested in this way.