so then your conclusion would be that specific temperatures play no part in global warming? if its cold somewhere then it stands to reason that its cold somewhere nearby? this is the answer to decreasing data station useage?
if its cold in St Louis then it must be cold in Kirksville since its only a couple hundred miles away.......... so we will just use the temperature in St Louis (even though its 6 degrees warmer) to represent both places.... after all cold is cold right?
Don't you get it? They take a set area. They take a set amount of measurements within that area. They reason that if there is a trend, that the trend will show within that area, which is not hinged upon the individual temperatures of all the represented stations.
Over time, if a trend develops and matches, the other stations don't matter.
It's like taking a frying pan and dividing it up into 100 1 inch squares. (HEAT IT, COOL it, WHATEVER !!!!)
In each 1 inch square you take three measurements at different points inside the square ( Points A, B, C). Even though the different 1 inch squares will have a different overall temp, and will heat differently, you can get the overall amount of heating within each 1 inch square, through each of the measurements taken within the square.
You can imply, that since A, B, C are all all within X amount of distance, that they are undergoing very similar radiative heating. Therefore D through infinity stations within that 1 inch square can be inferred to have similar properties.
Once you do this for all the squares on the frying pan, you can get the overall picture,
and don't need to study the heating of each atom of iron within the frying pan, as you are implying needs to be done for
climate.
A, B, C stations within all 100 of those squares comprise very little of the actual area of the pan. But, they do illustrate the heating trend within that pan nicely.
The actual temperature within each means nothing. THE CHANGE in temperature over time, DOES.
WEATHER AND CLIMATE,
AGAIN