How is the "earth" temperature calculated?

Question

For global warming studies, how do we know that we have thermometers positioned in every correct location?

How high off the ground are they? How evenly spaced out are they? How frequently are the measurements taken? To what degree of accuracy is there? Are the lengths of the lows and highs taken into consideration?

I guess I just find it hard to find the temperature of something that is so large, experiences seasons, experiences day and night, and all the other constantly changing aspects of this planet.

Answer 1

The bottom line is that we do not know what the planet's current temperature is, although satellite-mounted instruments and Argo autonomous floats are giving us a better picture than we had before...

http://junkscience.com/Greenhouse/Earth_...

Much 'science' these days is purposefully skewed towards a predisposed outcome.  Always be skeptical when someone tells you ANYTHING and remember, it almost always comes down to money or power.

Answer 2

You have a very good point which is, incidentally, the base of the so-called Butterfly effect, the theory of chaos and the fact that we will never be able 100 percent accurately the weather in the future.

The Standard Atmosphere (SA) which is what all instruments are calibrated for says that the average temperature on earth is 15 degrees Celsius and the pressure 1,013.25 HectoPascal.

But how to measure the way it changes due to the global warming? Good question! However I have a hut in the mountains, here in Norway. Some 30 years ago, it was only short bushes around it. Today, those are small trees higher than me. The Hardanger Jøkulen is a nearby glacier. During the past 30 years, it has shrunk nearly a kilometer.

So yes, the average temperature is increasing. At least, at my latitude.