Christians who believe a global flood occurred: How do you explain these problems?

1. The ark couldn't possibly have been big enough to fit two each of all the land animals in the world. Some say Noah only had to bring a few kinds of animals and they evolved from there, but the flood was supposedly only about 4000 years ago. That much evolution cannot happen that fast.

2. If even one animal died (disregarding the clean animals that they brought extras of), its species would go extinct, so none of the animals on the ark could have died. Zoos employ far more people to do this kind of work and they still can't ensure no animals will die in an entire year. There's no way Noah's family could have cared for them all on their own.

3. There is not enough water on the planet to cover all landmasses. Feel free to provide any explanation for this, and I will add an additional comment telling you why your theory is impossible (unless you just say God did it by magic). Also, where did it go? Water doesn't just disappear.

4. Noah didn't bring fish on the ark, but many species of fish need specific salt levels in the water to survive. A flood would have caused mass extinctions of fish. Likewise, most plants could not have survived being underwater for the better part of a year. Even their seeds would have died from prolonged exposure to saltwater, rendering the vast majority of plants permanently extinct. Also, some kinds of bacteria can only survive in human or animal hosts. This means that the animals and humans aboard the ark would have to collectively been infected with smallpox, polio, gonorrhea, etc. for those diseases to still exist today.

5. Most of the animal species would have quickly gone extinct in a post-flood world. Again, the plant life would have been devastated, so herbivorous animals would have died quickly. Carnivorous animals would find all of their prey long dead, and if they ate anything that had been on the ark, we wouldn't still have those species. The inhabitants of the ark could not possibly have repopulated the earth.

6. If there was really a worldwide flood, the geological evidence should be everywhere, but there is none. We have ice cores and tree rings that show us thousands of years of geological history, with no disturbances to suggest a year when the earth was covered by water. Studies of the ocean floor also provide no evidence of a flood. Most damning of all, there are civilizations that have been recording history since before the flood. Not only should these have been destroyed in the flood, their historical accounts don't even mention a flood.

There are more problems than this, but these are enough to make my point. Be careful if you're tempted to reply "God could do all of this because he's omnipotent". Why would God have used such an inefficient method of cleansing the earth that would have required him to use so much "magic" just for any life to recover? Surely a perfect god could have done better than this. And why would he have painstakingly covered up the evidence of the flood afterwards? Undeniable evidence of a clearly supernatural flood could have caused thousands, myself included, to convert. That's not consistent with the idea of a god who wants us to know and worship him.

I don't ask this to troll or to try to "convert" you to atheism, but I'm genuinely perplexed as to how anyone could believe this after applying even the slightest bit of critical thought.