It’s not news but I didn’t really find a place for it.
I don’t think that 2cm/decade is an urgent problem.
it definitely is when accounting for sea level rise, which is accelerating and a huge problem for NYC in the future. across the next hundred years (and assuming that isn’t understating the scope of the sinking), that’ll cause the city to sink by at least 8 inches on top of however much rise occurs. that might be the entire difference between some parts of the city flooding or not
yes but what was NY like 100 years ago. It’s a long time.
100 years ago the sea level was a full 9 inches lower and a lot of NYC’s waterfront had just been reclaimed from the water to begin with, because most of it is unnatural. huge portions of the modern end of Manhattan and adjacent territory used to be water and were made into port infrastructure that isn’t exactly ideal for keeping out water (and that has subsequently been redeveloped into other stuff). if we didn’t artificially impose land there, a lot of NYC’s coast wouldn’t exist at all–and since we have and sea level rise is accelerating, those areas are extremely and increasingly prone to flooding.
it’s pretty likely most of NYC will need to actively be placed behind levees or other structures mid-century because just the “expected” sea level rise by 2050 is another 8 inches–not accounting for sinking–and anywhere from 15 to 75 inches (2 entire meters) by the end of the century. (and the most doomer estimates place potential rise at up to 5 meters!)
It’s my understanding that a lot of cities are built on the bones of previous iterations - even my current major metro, Seattle, is built on top of a lot of old ruins. That doesn’t mean it’s not a problem, it just means we’ve previously been able to conquer it by just… building up from the lower levels. It’s kinda crazy that that’s our best effort for the littoral cities - but I think even Denver is built on some “old” ruins and they were exposed (to my absolute fascination) when they were replacing the streets way down town (like 16th street mall / wynkoop, iirc). I was absolutely fixated on the … legacy city that was going down like 8’ below current denver!
Anyway, I don’t want to act like this fact makes it not a problem; I simply can’t imagine all of lower manhatten wanting to raze every skyscraper and start over either. I’m pretty sure most of these city-on-a-city situations are after major fires kinda force everyone’s hand, so it really is a huge catastrophe!
Anyway, I don’t want to act like this fact makes it not a problem; I simply can’t imagine all of lower manhatten wanting to raze every skyscraper and start over either. I’m pretty sure most of these city-on-a-city situations are after major fires kinda force everyone’s hand, so it really is a huge catastrophe!
hence, the levee solution. in the future future even that’s probably not going to work (at least not for NYC) and it’s pretty likely then people will just have to abandon levels of buildings to rising sea level if they want to continue using them, but for right now most cities just want to buy their populations time to adapt further. (and for residential structures it’s probable people will move or be forced to move)