Per Roy Spencer:
Significantly, extrapolating to zero population density would give essentially no warming in the United States during 1973-2011. As we shall see (below) official temperature datasets say this period had a substantial warming trend, consistent with the warming in the highest population density locations.
How can one explain this result other than, at least for the period 1973-2011, (1) spurious warming occurred at the higher population density stations, and (2) the evidence supports essentially no warming if there were no people (zero population density) to modify the microclimate around thermometer sites?
I am not claiming there has been no global warming (whatever the cause). I am claiming that there is evidence of spurious warming in thermometer data which must be removed.