I hope this is sarcasm, we have many indirect sources we can cross-reference to obtain a fairly accurate estimate of temperatures over tens of millions of years

I hope this is sarcasm, we have many indirect sources we can cross-reference to obtain a fairly accurate estimate of temperatures over tens of millions of years, if not more. Including data on atmospheric and oceanic composition, the lifeforms it harbored, and weather patterns in various parts of the world, to an extent, thanks to the fossil (and glacial, albeit on a smaller scale) record -- some of which we burn in our cars. Here's a random link in my first page of results [1]. In case you are serious, you are probably going to dismiss my claim. In that case, feel free to dismiss anything else that bothers you. Rules are for NPCs after all; and climate scientists, geologists, meteorologists, archaeologists, paleontologists and chemists are notoriously unreliable and more biased, partial and bought out than in every other field. (yes, I'm being sarcastic, sorry about that). Re-reading your question, it has merit, if it didn't come across as dismissive of the hard work that has been done by all these people over the years. Correlation does not equate causation, but the correlation is undeniable, and hypothesis that have been formulated to test for anthropogenic climate change tend to be successfully validated. Furthermore, multiple physical phenomenon at play are well understood, even if their interactions are complex (full of feedback loops, and unknowns: what will happen when the Siberian permafrost will thaw? Methane emissions? How much?). All in all, the picture looks pretty bleak, and we should not play too much with stuff we don't fully understand. [1]: https://scitechdaily.com/66-million-years-of-earths-climate-history-uncovered-puts-current-changes-in-context/ https://scitechdaily.com/66-million-years-of-earths-climate-...