Rich countries are in a better position to mitigate the effects of global warming and climate change than poor countries. Rich people will be better able to insulate themselves from the effects that do occur in their country than poor people do.
Imagine New York is about to flood. Rich New Yorkers will probably already have a house somewhere else. The poor ones won't. And they can't afford to buy a new house if their current one becomes worthless. Their jobs are also more tied to the city than those of rich people. Moving Wallstreet will cost a lot of money, but that money is there.
If wealthy nations today can adapt to rising sea levels, and today's poor countries will eventually become just as wealthy, why will they be unable to adapt as well?
Please explain your reasoning.
There is no reason to believe that countries that are becoming uninhabitable will become wealthy at the same time. The people who are best positioned to create wealth are exactly those who flee first.