Proponents of Anthropogenic Global Warming often defend their case by stating that models can match observations only “when anthropogenic forcing is included“.
That is a very fallacious argument.
A model, any model is a representation of the world, and as such its internal behaviour demonstrate nothing about its validity as a faithful representation of the world.
Astronomy was able to function for 1400 years between Ptolemy and Copernicus depicting planetary movements with epicycles and deferents. That model works pretty well (have a go at this website), still would anybody use that to argue that the Earth is at the center of the Universe?