WHAT IS SURFACE AVERAGE TEMPERATURE?

Here is an interesting look at what is actually meant by the term Surface Average Temperature. It is a tricky thing to define as the link shows. As this is the fundamental measurement that the whole global warming debate is about it is important to understand it - or at least to understand just how difficult it is to define or measure accurately. At present it would be fair to say that the inaccuracy in measuring it is almost as great as the total amount of warming over the twentieth century. That is a sobering point in such a heated subject.