We have quite some understanding that a mayor nuclear war will cause nuclear winter, by generating huge amounts of smoke at high altitudes which will block the sunlight.
We also know that it causes an extinction event, since it was one of the effects of the K-t extinction event 60 million years ago. It is the one that killed the dinosaurs, and many more: A huge number of species, including almost any large land animals, dies. It is unlikely that homo sapiens would survive this time.
We also know that it causes an extinction event, since it was one of the effects of the K-t extinction event 60 million years ago. It is the one that killed the dinosaurs, and many more: A huge number of species, including almost any large land animals, dies. It is unlikely that homo sapiens would survive this time.