We can ascertain some things about the pre-Flood world.
Redwood trees grew in (what is now) the Arctic Circle. (Toss out their conjecture of “millions of years ago” per their dating methods that do not work, but keep the REAL evidence - redwood trees grew in the Arctic prior to the Flood.) When? - they are in error due to putting their religion ahead of good science. So they do not know. We do however, since we have a book that tells us of a radically different pre-Flood history.
Palms also grew in (what is now) Antarctica. The pre-Flood (not “pre-historic” as the evolutionists claim) world was very different. The Piri Reis Map shows that men once could go to Antarctica; from long ago; it was mapped in the former time. Like post-Flood peoples, there were explorers among them.
There were tree rings, indicating that even back then there were fruit bearing cycles, the periods when the trees would “reset” internally. In the post-Flood world (since about 2400 B.C.) tree rings usually follow the annual seasons, but it is possible for a tree to have two rings in one year.
The Earth was probably tilted on its axis, as we see it today. The tilt may have been about 1 degree different prior to about 700 B.C. But it was essentially the same. And the original year may have been 360 days, as evidenced by many ancient calendars, that is until about 700 B.C.
Genesis tells us that a mist rose from the ground each morning and that the waters were separated above and below. This would indicate a completely different hydrologic cycle, according to theory. Dragons reigned in some areas, mammals in others. Generally the pre-Flood climates (all at the same time - but in different places) would have been warmer