AGW is falsifiable. For example, if the world started cooling, it would be falsified. Since the world keeps warming, AGW is instead confirmed. There are many examples of things that could falsify AGW theory. None of them happen. Instead, the predictions keep coming true. Those past decades of seeing predictions proven correct over and over is the reason why AGW science has such credibility.
In contrast, Kosh's cult of denialism doesn't even have the guts to state a theory or make a prediction. It is entirely unfalsifiable, and hence instantly identifiable as pseudoscience.