Something I’ve wondered, whenever looking at this map, is what areas if any would be considered “uninhabitable” on the current earth. For instance, would places like the Sahara desert qualify, according to the scale they use, or do they imagine something worse, for the places marked as such? Mainly because, people do still live in places like the Sahara, even if not at great density, which implies them to not be completely uninhabitable so much as places where human habitation is more difficult than other places.