I mean, predicting the climate must be one of the hardest numerical simulations you can run. Climate models are famously incomplete. But the results turned out to be way more accurate than I would have thought. That's some impressive modeling, and I would assume that models have only improved since then.
The most chilling thing (and not in a good way) about it is that popular science type repotrs for the general public usually indicate an interval between a good case and a bad case, with a nice line in between. In retrospect we have been pretty much perfectly tracking the bad case line ever since.