And the other 2.6 percent?
Just a lucky guess on their part.
I'm an engineer. I have the sense to preface any assumptions with "Hey, this is a total SWAG (Seriously Wild-Assed Guess), but here's what I think is going on......."
I also have the sense when to say: "This is what is happening. And, here are the data points to back it up...."
I'm still employed, so I guess that I'm right more than 2.6% of the time.
The global warming people don't have any (or much, at least) hard data. They did (and still do) exactly the same thing that I do with assumptions, but neglect to mention the SWAG part.
Their willing accomplices in the media report the assumptions as The Gospel Truth. AND....they ignore the hard data when it disproves some of the earlier assumptions....
Fools, all.