We've all seen those small white boxes with slates on the side and
vaguely know they are related to measuring the weather. Turns out
they are called "Stevenson Stations" and they contain the themometers
used as the basis if the claims of global warming. Apparently, the
original stations were spec'd as being coated with whitewash but in
1979, this was changed to white latex. Now, just by coincidence, the
global warming supposedly took off about that time.
This guy had the bright idea to look at the diffs between whitewashed
and latexed stations. WOW. The diff he finds easily easily covers
almost all the supposed warming. Check it out at:
http://wattsupwiththat.com/test/
Even more interesting is the heat island effect on stations he
discusses.