butcherboy, I thought it would have been obvious. If the greenhouse effect is primarily a warming mechanism, then surely the benchmark that is used to measure any changes logically has to be the average minimum temperature. Do you agree? Why then is this not used as the benchmark?
Re your second point, "Logic says that the trend will be the same or very similar for both does it not?"
Without thinking about it you would think so. If you found that they were different, what conclusions would you draw from that? I shouldn't have to spit it out, perhaps do your own research for locations in your vicinity as I outlined earlier and let us know what you find, and if it differs from what your logic says, any reasons why that you can think of. If enough people do it for their own locations we may find out whether there are any patterns that emerge, or whether it is completely random.
