Oh good grief. Your own explanation included multiple confidence bounds, and if we fall badly outside of these then that model is falsified.

There are other observations--tons of them--that would invalidate the whole shebang. The only problem is that we made a ton of those observations and they didn't invalidate the whole shebang. They were broadly consistent with the theory. (IPCC AR5: The Physical Science Basis is chock full of the stuff.)

There's a also a difference between "climate doomsayers" (which, depending on how you define the term, do have a tendency to overstate things) and "climate science" (which is most of what you've presented).