That's long been a point of confusion for me. My understanding is that the Sahara was a grassland until a relatively modern era - modern enough that hominid rock drawings indicate as much - and that the Mediterranean basin was closed on the western end as well. If recollection serves, it was the flooding of the Mediterranean that is held to have changed the climate of the Sahara and turned it into desert. Yet, I've never seen any hominid migration routes that just cross over the Sahara and Mediterranean into Europe.
Of course, plenty of critters don't walk someplace just because they can. They keep to their range for one reason or other, and hominids definitely had a range during the epochs in question, but it's just a little point of confusion on my part. I'm not sure I have the timelines right in my head.
The Mediterranean Ocean has dried out more than 40 times however, the last time was 5 million years ago. There is salt two miles thick on the bottom that was formed by drying in sunlight
Now, it is my opinion that the Med was blocked at Gilbralter during the Ice Age and the water level in the Med was greatly reduced, that would have allowed Neanderthal to walk across.
This theory would have allowed for large areas of the Mediterranean to have been dry and also contain a larger number of islands during the long period of the Ice Age.
If Atlantis was in this area, the flood waters, earthquakes, volcanos and tsunamis at the end of the Ice Age would have wrecked it and sent it below the inflowing water. The timing would be about right and the flooding into the Med would have columinated with the (Now documented) Black Sea flood.
When the Nile flowed east to west and dumped into the Atlantic, the Sahara was far more hospitable.
I call it ‘presentism’ but no clue what, if anything, its official name is, but it’s often a problem with wackademics.
Everything then was just as we see it today, geography, climate/habitation capability, wise.
You’ll, occasionally, get one of the wacks to acknowledge that the terrain in an area of study was very much different in the distant past, and apply it to that very limited location, but then in big picture, he’ll be right back to what is now is like it was then.