Which cities and what timeline are you talking about? Sea level has risen like a half a foot in the last 70 years. That's not all that fast.
Meanwhile, places like Netherlands are increasing their land area over that time.
That’s in a rich country with a lot of resources, and at least a history of helping other states out. Bangladesh is facing another climate change-boosted storm but has thousands of people who are still homeless from last year’s storm which also hammered food production. That’s the kind of scenario where things get ugly because millions of people live in areas which will see the worst impacts but lack anything like the resources to harden infrastructure or relocate large numbers of people.
Before they moved, some family members saw hefty increases for insurance premiums and restricted coverage – and that trend is just getting started. Each of the things which needs to be hardened or redesigned costs billions, and there’s no guarantee that those projects will be enough, or that there won’t be other impacts on the economy if, say, popular tourist beaches aren’t as attractive due to erosion or some hotels are severely damaged.
"Miami is going to be fine, mostly" isn't a slam dunk argument that climate change won't have real impacts, because Miami has already been fighting against it. (A lot of the rest of Florida has more to worry about in part because they haven't been nearly as proactive.)
If you consider the current risk of flooding as a stochastic process, moving the mean may result in an exponential risk increase.
There is no evidence that hurricanes are getting bigger or more frequent. If anything, the record shows the opposite.
https://www.nhc.noaa.gov/pastdec.shtml
Edit: this data set goes through 2022 (the previous chart only went up to 2004)
https://www.aoml.noaa.gov/hrd/hurdat/All_U.S._Hurricanes.htm...
We have continued to build in disaster-prone areas. That's a real problem. But that is somewhat orthogonal to climate change.
Imagine a world without climate change. Are there still hurricanes? Is Miami still a low-lying city in a high-hurricane area? Do we continue to build more condos there?
Imagine a world without climate change and ask again: How much more are you willing to pay to rebuild Miami after "a big" hurricane does damage?
Miami will likely end up mostly underwater and dykes and seawalls will not be able to protect it. The city is built on porous limestone that will allow seawater to just bypass them unless you dig down past that limestone bedrock layer.
The pace of ice melting is still an unpredictable process due to its non-linearity, but the current imbalance between ice melting and new snow in the Greenland ice sheet commits a 27cm rise, according to [1]. This with current temperatures (not temperature rises).
From my layman understanding, antarctic runoff is less understood, but also its effect is potentially much larger. Article : [2]
Finally people with more knowledge than me, IPCC AR6, have estimates based on paleoclimates that depend on climate trajectory. [3], box TS4 pp. 77-78. Their optimistic story is 28-55cm by 2100. Their pessimistic assessment is "Under the higher CO2 emissions scenarios, there is deep uncertainty in sea level projections for 2100 and beyond". Also note that even in the best scenario, sea doesn't stop rising after 2100. Sea level rise is likely locked in for centuries.
A last word on "mean sea level": it's just a mean, impact may be worse for some areas.
> Meanwhile, places like Netherlands are increasing their land area over that time.
That's, like, a tiny confetti of wealthy people. Not sure this kind of anecdotal information is relevant to rising sea levels.
[1] https://www.nature.com/articles/s41558-022-01441-2 [2] https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201... [3] https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6...
