Some people believe the change in the moisture levels in the atmosphere may have contributed to radiation damage to the chromosomes. Errors in the DNA code over time... except that the dramatic change occurs in the aftermath of the flood.
The implication is that 900 years is our natural lifespan were it not for whatever change was introduced into the genetic code at the time of the flood. Post flood, about eighty to a hundred.
I’m in your camp. Keep your printed photos in the dark, and they keep their color. Put them in sunlight, and the UV fades them fast.
Many have theorized that these verses describe a hollow globe of water around the planet, (and not just clouds):
Gen 1:6 And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters.
7 And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so.
8 And God called the firmament Heaven. And the evening and the morning were the second day.
If that’s true, it could be that a great amount of UV light did not make it to the surface - less sunburn, less corruption.
Or, God could have just decided to change things! I can live with that. I believe it was Charles Stanley who said, “When you know who God is, you don’t have to worry about what He does.”