You're talking about a New Orleans type mass exodus and relocation occurring on every coastline on the planet. Hundreds of millions of people fleeing. You're talking islands as Japan, Taiwan, the Philippines, England, Iceland, Hawaii etc. quite possibly getting submerged or made much smaller. Whose going to take in the refugees when every country already has to find room for their own displaced coastline dwellers?

Hate to say it but even cutting all greenhouse gas emissions at this moment will not stop the warming trend. I don't think there is anything anyone can do. We can only hope that we are not the sole cause of it and pray it might just turn around on its own but that could take centuries and we don't have centuries. What will have to happen is that there must be a mass die-off of life, including human (especially human), so that what land areas are still above the water won't be unbearably overcrowded and there's still room for any wildlife that survives.

I just hope I'm dead by the time things get to that point because it's not all that far into the future. All the sudden immortality doesn't look like such a desirable thing.