As things are going, the Earth seems like it will have signed up for 6 meters of sea level rise. That'll make Shanghai look like Amsterdam! Wait, Amsterdam is fine... what's going on here?
Considering how negative sea levels have been handled by humanity for hundreds of years, it does strain credulity that sea level rises themselves are a meaningful issue to the almost immeasurably wealthier and better at construction present-day human, forgetting that by 2100 we will be even better than we are now, and richer, so we could pay for what we need.
There are serious issues, mostly (as far as I can detect) involving agriculture, extreme temperature habitability (although I've lived near Phoenix, Arizona long enough to know, humans already thrive in places that, by all rights, should kill us), and ocean acidification. All of those are (at first blush) much bigger deals than sea level rise. I think.
That's my fundamental confusion. To be concerned about Shanghai reaching the elevation of Amsterdam is ahistorical. Why on Earth would that be a global disaster, even if it were replicated a hundred times (100 seems like an approximate upper bound for how many cities of that scale you'd need to retrofit)? Ocean acidification is clearly a much bigger problem, and yet is discussed much less, even in this fantastic and measured video on the subject by someone who knows much, much more than me.
Perhaps people aren't in a panic because we only discuss harms that simply aren't that dangerous? We certainly need to articulate the vision clearer, because there is a big empathy gap between experts and laypeople on this, and I don't know why they would freak out over sea levels alone. Maybe they do know why it matters, they just haven't said so publicly enough to reach me?