So this is basically a climate model of a limited nuclear exchange between India and Pakistan. Results: global cooling, a shortened frost-free growing season and wicked sunburn for every living creature for like 25 years. Good times.
Twilight at Noon (1982) was no joke (you are forgiven for being unfamiliar) but it also presupposed a full-fledged 6GT nuclear exchange at which point you've long since stopped giving a shit about the ozone layer.