The theories of AGW are supported by literally hundreds of evidence chains across the spectrum of the physical sciences. I am not aware that any of these chains have been substantively and compellingly overturned. The only way to effectively supercede theories that have advanced to this level of support and integration across the range of physical sciences is to find a theory that explains these disparate evidence chains better than the existing AGW theory explanations. That is how science works.
I must admit I find it odd how the climate science field backed away from their responsibility for keeping the discussion reasonable and even allowed the 'null hypothesis' to become flipped from 'natural causes with anthropogenic effect' to 'anthropogenic effect with little natural cause'.
the whole thing reminds me of the old joke about the drunk who dropped his keys getting into his car but searches for them under the street lamp because the light is better there. climate science is drunk on funding directed at CO2 and cannot easily leave the 'light' because of the loss of respect that would cause.
natural causes control the climate, just because we do not understand the mechanisms that does not mean they are not there.
CO2 affects the climate to some unspecified degree. pretending that CO2 is the main factor in controlling the climate is ridiculous in the extreme. removing the effect and weighting of natural causes and then only considering CO2 and other man made contributions skews the 'probabilities' because if you only look at man made factors it is impossible to get any other answer but man made causes!