ST88 wrote: Or is the argument similar to the modern idea of a greenhouse effect, with its layer of vapor acting as a uniform insulator around the entire world?
As to the actual composition of the water canopy, I don’t know. And nobody can really say for sure. But, my guess is what you described above. Perhaps it’s a water vapor layer that produced that the greenhouse effect on the earth.
So, one question is, why is a water canopy necessary in the FM? It would help explain why animals and plants grew to be so large in the past. It would also explain the extinction of the dinosaurs.
Obviously the environment and climate was different during the time of the dinosaurs. But, why did things grow to be so large? What can explain it?
The greenhouse effect would produce a more tropical environment on the earth. This in turn would cause plants to grow faster. There wasn’t the seasons back then as we know now. It certainly didn’t have seasons of dryness. This is evidenced in trees found in the Carboniferous period. Trees in this period are characterized by having no growth rings. This implies that there was no changing periods of wetness, dryness. And based on the size of the plants, it can only mean it was wet all the time. Now, how can a climate be wet all the time? A greenhouse scenario is the best guess.
A water vapor layer would also act as a shield to harmful radiation from the sun. And thus lowering the effect of harmful mutations from ultraviolet light.
The water canopy layer also could have increased the atmospheric pressure. And thus allowed for things to grow bigger.
So, one major cause of the extinction of the dinosaurs was a dramatic climate change during the flood.
https://debatingchristianity.com/forum/viewtopic.php?p=3142#p3142