And then move again when the variables change (because they could change, for example, by people moving all to the
same area, creating a
heat island effect, thereby being a self - defeating prediction).
... he also knows that urban
heat island effects are corrected for in the surface records, and he also knows that this doesn't
effect ocean temperatures, and that the station dropping out doesn't affect the trends at all (you can do the
same analysis with only stations that remained and it makes no difference).