More great work from Steve McIntyre

Here.

An excerpt:

In this data set that supposedly shows the following:

Contrary to generally accepted wisdom, no statistically significant impact of urbanization could be found in annual temperatures.

actual cities have a very substantial trend of over 2 deg C per century relative to the rural network - and this assumes that there are no problems with rural network - something that is obviously not true since there are undoubtedly microsite and other problems. At the very end of the graphic, the change levels off - I wonder if that might indicate increased settlement effects at rural sites.


(click to enlarge)

Now this doesn’t prove anything one way or the other about other networks - other than there is a need to be wary. However, the notion that Peterson 2003 is a sustainable authority for the IPCC proposition that “rural station trends were almost indistinguishable from series including urban sites” seems increasingly difficult to accept.