What will most likely happen is changes in weather caused by climate change will alter rainfall patterns, which will cause cause changes in agriculture and land use, which will cause economic and industrial dislocations. After that comes war, famine, plagues, mass migrations, civil unrest, social disturbances and so on.

You know, like....right now!

And it will happen gradually, so society will (in some places) be able to adjust to it. But to people living through it, it will seem like things are slowly coming unraveled. Of course, if you've got money, or access to political power and economic clout, you'll probably do all right, or at least, convince yourself you can.

It will be a lot like Europe in the Dark Ages. If you've got a farm and a couple of hundred people working for you, and a gang of tough guys with truncheons on your side, you'll probably do just fine -- as long as you can make the payroll.

This isn't the first time in history this has happened, you know. Environmental degradation has always led to collapse of civilizations. Sometimes its drought, sometimes its climate change, sometimes its sea level rise (or fall), sometimes its a disease that kills the crops, or a bug that eats them. The difference with us is that it will happen all over at once, and it will happen in one lifetime.

But don't fantasize you'll be able to go out into the woods and ride it out. As soon as the word gets out you've got canned goods. a rifle and pretty daughters they'll come and take them from you.