Climategate

[Thorne]

Manchester is the preeminent source. And its repports are the primary source for the topic.
But you seem convinced that people are saying all the data has been corrupted. When what has been said is that the preeminent source appears compromised. With having disposed of their data, even they can not repeat their experiment. Then there is the matter of their refusal to reveal the factor that they use to "adjust" their data.

If Manchester has behaved in this manner then they won't maintain their preeminence for long. This is the very antithesis of good science. However, that does not negate the good science being done elsewhere.

Just saying that data can be selected or refused based on "proper" calibration is already inducing a bias. Besides if all of the data comes from "properly" calibrated primary sources, why does it then require "tweeking" to produce a result?

Any properly designed experiment relies on properly calibrated instruments for the detection of data. These instruments should be calibrated on a specific schedule. If, for some reason, a stations instruments are not properly calibrated then their data is suspect and should be discarded. This does not say that the data is necessarily wrong, just that you cannot be sure it is right.
Tweaking of results is done to correlate data from differing environments. For example, if you are measuring the air temperature near your home and you use one thermometer which is in shade all of the time, another thermometer which is in sunlight most of the time, a third thermometer which is near the black top of the street and a fourth which is closer to a pond, you will get greatly differing results, solely due to local variations in the environment. You need to eliminate those variations to gain any meaningful results, which is done through tweaking. Contrary to what it may sound like, this is not done to force results, but to clarify them.