Climategate

I don't think there was a conspiracy to "make up"  AGW, but if you have "true believers" you get this: [Link]

Scientific fraudsters are not, in general, people pushing theories they know to be false. Outright charlatanism is not actually common, because it’s relatively easy to detect. Humans are evolved for a social competitive environernt
and are rather good at spotting lies, except when they’re fooling themselves because they want to believe.
In general, scientific fraudsters are people who are overinvested in a theory that they believe. Because they know it must be true, they interpret predictive failures as “The data is surely wrong”. It is only a short step from “The data is surely wrong” to fixing the pesky data until it looks right — see my previous post for an immediate example.
It’s only slightly longer step after that to destroying the inconvenient data that fails to fit your theory — something one of the hockey-teamers actually called for and there is strong reason to suspect they actually did.