How dumb is this. Just off the top of my head:-
1.DNA is not stored as intact chromosomes but as fragmented libraries. So to reconstruct an organism you would have to stitch all the fragments back together. Theoretically it could be done but horrendously difficult for a full organism.
2.No one has reconstructed a cell from DNA alone, it is always injected back into a pre-existing cell and (as far as I know) always from the same or very similar organism. DNA doesn’t actively do anything, it needs the rest of the cell to work.
3. It would be easier to store frozen embryos; except that for anything like a mammal you need a womb, and no one has yet made an artificial womb that can take the embryo to term.
4. Even if you could, the newborn requires intensive care. Where is it going to come from if the rest of the world is a burning relic?
6. To preserve all the species (that’s what it says) would be a trick given that we don’t know all the species on Earth. We do know there are a lot (e. g. 34,000 known species of spiders alone). Are we going to preserve them all or just the ones we like? Who decides?
7. As things stand we are struggling to preserve the species we have; does he really think that any one surviving a global catastrophe is going to worry about the green spotted bobble bird? (Except possibly for lunch).