I was imagining a sort of post-apocalyptic/collapse setting, where a few centuries of climate catastrophes brought on by climate change cause essentially your general end of the world as we know it due to droughts and storms and floods and sea level rise and warfare, etcetera, but not so dramatically that no society can rebuild.
But then, the fears of the early 2000s comes true, and the melting ice disrupts ocean currents and causes a massive cold snap on the scale of the Younger Dryas, which completely messes up the trying-to-recover societies' efforts.
My question is basically how long would it take for sea levels to begin to drop? Assuming this period lasts about as long as the irl Younger Dryas (1200-1500 years), would sea level rise caused by modern warming be reduced? Would it even last long enough to have a meaningful effect? I was hoping that a major generational issue could be sea level drop making harbors harder to access, etc., but I'd like to know if that'd even happen to begin with.