It's possible to extrapolate from a horoscope too, it's just not that useful. Let's talk about the massive difference in the extrapolation being done here, climate change vs AI.
In climate change, we are analyzing historical climate data using weather models representing known physical processes. We try to predict the data using these models, and we are only able to do so if we include the forcing from greenhouse gases. From this we can constrain the range of impacts these gases could be having on temperature and forecast likely futures. The forecasts are heavily informed by a thoroughly validated base of prior knowledge, not just drawing lines through a log log plot.
None of this has any counterparts in AI. We don't understand AI systems to anywhere near the level that physics affords understanding of physical systems. We don't even understand them at a Moore's Law level, where you can at least know what engineering innovations are in the pipeline and how far they could plausibly go. Predicting the sophistication of future AI is just Nostradamic prognostication.
Yann LeCun recently gave a presentation arguing that LLMs are a dead end and proposing a completely different approach. His arguments were extremely heuristic and unconvincing, but this at least shows that both sides have bigwigs with unconvincing heuristic arguments.