If in 50 years, we find out that the predictions made by our models had been wrong (either the measures we take to reduce CO2 don't lead to the results we expec

If in 50 years, we find out that the predictions made by our models had been wrong (either the measures we take to reduce CO2 don't lead to the results we expected, or the warming we see is outside of the expected ranges) - in the post-mortem of the models, what would we likely say had gone wrong? This has already happened. Models developed in the 1990s didn't match what happened in the 21st century. The resulting controversy is called the pause. Why did temperatures stop rising when models said they should continue? We didn't stop putting CO2 in the atmosphere after all. For better or worse, the controversy was resolved by scientists "correcting" the historical temperature datasets to erase the pause from the record. The data was brought into line with the theory. You can go read old news stories or articles about the pause and look at the temperature graphs in them, then compare to the current, up to date temperature graphs and see that they don't match. If you like there's a talk here by a guy who started out as a skeptic because he kept spotting errors in studies, and became a peer-reviewed, published climate scientist. He's still a skeptic about the models used to predict the future (he says he thinks the basics of climatology are sound though): https://www.nicholaslewis.org/wp-content/uploads/2019/09/Lewis_Climate-Sensitivity_talk_Dublin2019-slides.pdf https://www.nicholaslewis.org/wp-content/uploads/2019/09/Lew... That talk is quite technical but might provide some answers to how the models could be wrong. Ultimately nothing surprising: they're based on major approximations and the underlying datasets may have issues. Go read his papers for more details.