Well, it seems folk weren't impressed with the technical aspects of your question, but I'll give it a shot and ignore the moral aspect entirely.
What would happen at "100 times that rate"? That's about 10cm a month, or four inches a month for Americans.
Firstly, the coast does not slope back at a constant angle from the sea, so you can't just move uphill a few yards and think that everything will be fine. Even if you could, try it now: try moving to an area that's, say, 20 yards uphill from where you are. Today. Do you see the immediate problem?
But let's say you're already a fair height above sea level, so you've got a few years, and you live in a coastal town. What is going to happen? Well, after a few months, you're going to start having issues with high tides. Sewers will flood, so you'll literally have a river of shite flowing in the streets below. The piers down at the harbour will become dangerous at high tide. Breakwaters will become ineffective. Warehouses will flood.
You've probably got a coastal road out of the town. With the higher tides, you've got increased erosion, so after a particularly bad storm, there's a major landslip, and you lose not only the road but the rail link out as well. Goods can't get in or out of your town now.
The higher parts of the town are now islands, and you don't have a functional slipway so it's difficult to even use boats. The shape of the coastline is now in constant flux; it changes with every tide as mud and sand gets sloshed around, which means that tides are completely unpredictable. Sometimes you get a massive tide as more water is funnelled in, and other times it's barely noticeable as mudbanks cut off whole areas of water.
Now, all this might even be manageable, if you have access to plenty of money to rebuild, but who is going to rebuild when they'll have to do it all again next year? And you're not going to get help from anywhere else, because this is happening to every coastal town all at once.
Of course, this is based on your extreme case of 10cm per month, so the real question is "at what stage does this become unmanageable?". Is it 10cm per year? 1cm per year over the course of a decade? Somewhere inbetween?
At the current rate of melt, how long is it until Greenland is out of ice and we don't have to worry about it contributing 1.1mm of sea level rise a month?
I dunno, a 1000 years or so? It doesn't seem worthwhile even roughly calculating since it's rather obviously going to accelerate as it gets warmer. It would be bizarre if it didn't!
What would happen at "100 times that rate"? That's about 10cm a month, or four inches a month for Americans.
Firstly, the coast does not slope back at a constant angle from the sea, so you can't just move uphill a few yards and think that everything will be fine. Even if you could, try it now: try moving to an area that's, say, 20 yards uphill from where you are. Today. Do you see the immediate problem?
But let's say you're already a fair height above sea level, so you've got a few years, and you live in a coastal town. What is going to happen? Well, after a few months, you're going to start having issues with high tides. Sewers will flood, so you'll literally have a river of shite flowing in the streets below. The piers down at the harbour will become dangerous at high tide. Breakwaters will become ineffective. Warehouses will flood.
You've probably got a coastal road out of the town. With the higher tides, you've got increased erosion, so after a particularly bad storm, there's a major landslip, and you lose not only the road but the rail link out as well. Goods can't get in or out of your town now.
The higher parts of the town are now islands, and you don't have a functional slipway so it's difficult to even use boats. The shape of the coastline is now in constant flux; it changes with every tide as mud and sand gets sloshed around, which means that tides are completely unpredictable. Sometimes you get a massive tide as more water is funnelled in, and other times it's barely noticeable as mudbanks cut off whole areas of water.
Now, all this might even be manageable, if you have access to plenty of money to rebuild, but who is going to rebuild when they'll have to do it all again next year? And you're not going to get help from anywhere else, because this is happening to every coastal town all at once.
Of course, this is based on your extreme case of 10cm per month, so the real question is "at what stage does this become unmanageable?". Is it 10cm per year? 1cm per year over the course of a decade? Somewhere inbetween?