But between the raw data and the set of data is a correction. Without being able to show what that correction is, all the models based off the second set of val

But between the raw data and the set of data is a correction. Without being able to show what that correction is, all the models based off the second set of values is not valid science. So you have to go back and recollect the info from all these sources (not an insignificant undertaking, though mostly do-able), actually give a reason for the "corrections", and then create models that fit that data, and then issue new predictions. Without starting over from raw data and following all the way to the conclusions reached about man made global warming there is no scientific proof that man causes global warming. None of it is valid until you can show how that "correction" was made. And the loss of this data means they will never 100% be able to show that.