How were the estimates shown to be reliable? Were actual measurements made of those areas where estimates had earlier been made? How else can interpolation be shown to be reliable, to be accurate?
The gaps in coverage aren't an issue? You don't know that they aren't. 7,000 long term stations locations (what's the source for that number?) on a planet of half a billion square kms a third of which is land appears to leave a lot of gaps. That then leaves a lot of interpolating. Isn't temperature so variable, so interrupted if I can use that word, that the accuracy of filling in blanks with estimates has to be questioned. At the very least, stations are randomly located which must make estimating a pattern of temperature questionable, particularly over such an enormous surface area.
Please don't accuse me of bias simply because I question statements which you make as though they are fact. I have no vested interests in the AGW debate, no skin in the game.
