A lot of people don't the difference between a scientific hypothesis and a scientific theory. These climate change models are just hypothesis in software form. We won't able to run experiments for these hypothesis in our lifetimes, and in turn they will never reach the level of a scientific theory in our lifetime.
There's an oversimplified version of the Scientific Method that says we start with a scientific hypothesis, which is a conjecture or a guess, then we run an experiment, the experiment either contradicts the hypothesis or confirms it, and after X number of confirming experiments the hypothesis becomes a Theory. In practice, its more complicated than that and the transition from a conjecture to a theory is not binary. The theory of anthropomorphic global climate change is a large set of interlocking and overlapping smaller theories combined. For example, the theory of the greenhouse effect is strongly confirmed: different gasses in the atmosphere affect the absorption and radiation of infrared radiation in different ways, affecting the amount of net heat energy trapped on the surface of the Earth and lost to space. That's pretty settled. We can't, of course, experiment with thousands of different planet's atmospheres to test that theory in the simplified way, but we can do experiments on smaller scales and correlate them with Earth's atmosphere and the atmospheric conditions of other planets we can observe.
We know the first order effect of increased CO2: it tends to trap more heat energy. But that doesn't automatically mean global temperatures have to rise. That's the natural presumption, but Earth's surface is a complex environment. More heat energy could cause more clouds to form, causing a negative feedback effect which tends to slow or halt increased temperatures by blocking radiation from reaching the surface. The oceans have a huge impact on energy distribution on the surface of the Earth, and can sequester heat energy for a very long time in principle.
However, the net result of all of these various conjectures and theories in the aggregate is that the most logical explanation for the observed increase in global surface temperatures over time is the increase in CO2 caused primarily by human activity. That statement is less a theory, and more of an explanation for all the other smaller theories that individually explain small parts of the whole.
The transition from scientific hypothesis or conjecture rests not just with how many experimental wins the conjecture accumulates, but also the degree to which the conjecture accurately makes useful predictions and the degree to which it synergizes and accommodates other more well confirmed theories. We're never going to be able to experiment with other universes in all likelihood, but that doesn't mean the Big Bang will always be a scientific conjecture. Philosophers might make that claim, but the Big Bang is considered a genuine scientific theory because it makes testable predictions that are not just confirmable, but very powerful and wide-reaching. There's no obvious reason why we should observe the nucleosynthetic proportions we see in the observable universe, and yet the Big Bang makes very specific predictions about how much helium we should see relative to hydrogen. If the Big Bang was wrong, the odds of it making such a prediction accurately are extremely low. At some point, its not luck but skill, and in the same way at some point scientists decide a conjecture can't be that lucky, and therefore must, to a high degree of probability, incorporate some fundamental truth about the universe. It might not be precisely right, but it can't be completely wrong.
Over three hundred years after Newton published Principia, the theory of Newtonian gravity has held up remarkably well. Einstein didn't completely overthrow Newton, and after centuries its highly unlikely anything will: it simply makes too many predictions that are always confirmed. What Einstein did was modify Newton's theory, and only in extreme cases Newton could not possibly have tested. But its important to note that we don't trust Newtonian gravity just because of an abstract Scientific Method scorecard. We trust it as a scientific theory for a more practical reason: it works, and in all but the most extreme cases it always does. We still plot spacecraft trajectories with Newtonian gravity, to extremely high degrees of precision. Even if we couldn't test the fundamentals of Newton's theory (we can), it would still be a Scientific Theory for that reason.