In 100 years our technology would be so advanced that people would be much much more prosperous. Ok sure a few cities drown but people move and adapt.
I still hold ground on the fact that people will be more prosperous in 100 years with sea level rising - in the sense that a person would prefer to live then rather than now
The point of view changes according to the sets of people one belongs to while still being alive, eg living in a warming Denver or attempting not drown in NYC?
Look at America/Trump right now with economic immigrants alone. This caused half the country to go "Yea, locking up people in cages and letting losers with guns shoot whoever they want while supporting an authoritarian regime is perfectly ok". Just what do you think it's going to look like when the numbers are 10x that from inside the country alone (a huge amount of the population lives close to the ocean).
Advanced technology has nothing to do with wealth equality and with the costs of making said technology it may be even further reverse correlated in the future.
Overall maybe, even if 2 or 3 C more in the average temperature can be hard to bear in summer in some places or require much more energy to cool us, which means that we won't be as adapted to those places as we used to be.
In some spots of the world, tough luck. I would like to see (actually I don't) what happens if the sea rises a few meters. Will the people in the north east of Italy and China build coastal dams and raise river beds or let those regions go underwater and migrate somewhere else? There are certainly some areas of the USA that will go underwater too (Florida? NYC?)
And what if the Gulf Stream really stops and Western Europe gets the same climate of the regions of the USA and Canada at the same latitudes?