So let's say that average world per-capita GDP exceeds $100,000 by 2050, and is well over $20,000,000 by 2100. What does that imply?
1) More Evidence that Global WarmingWorries are Nonsense: It's already obvious to those of us who have studied the matter that the Intergovernmental Panel on Climate Change's (IPCC's) projections for methane concentrations, CO2 emissions and concentrations, and temperatures in the 21st century constitute the greatest fraud in the history of environmental science. But even if the projections were anywhere close to accurate (which they are not), it probably would still not be moral to do anything today for the benefit of people living in 2100. As Wilfred Beckerman points out, people in 2100 are going to be "incomparably richer" than we are today. And his basis for saying that was 1.5% per year per capita GDP growth in the 21st century!
2) The Kids are Gonna Be Alright: It bothers me that the U.S. Social Security system is currently a Ponzi scheme , and that people who retire in generations X, Y, and Z (i.e., the generations after the Baby Boomers) are going to put a whole lot more into Social Security than they will ever get out. That is, their return on "investment" will almost certainly be negative. But I gotta admit, knowing how rich anyone who retires after about 2050 (or a bit earlier) is going to be, the fact that they're going to get hosed on Social Security now bothers me much less.
3) Should be Very Interesting Times: It's hard to imagine living in a time where essentially no one has to work a day in their entire life. One might think that people will be slackers. But based on billionaires with whom I'm acquainted (no need to drop names) I think that most people will work just as hard. They'll merely work only on stuff that interests them. And with all that dough, they should be able to accomplish some really amazing things. For example, based on what I've read, constructing a "space elevator" is estimated to cost $10 billion. Well, let's say that estimate is too low by a factor of 10. That's 100 billion. Well, that's a hundred thousand people willing to give $1,000,000. Right now, it's hard to find a hundred thousand people each with a spare $1,000,000. But half the population of the planet has 10 times that $1,000,000, it should be easy to find a hundred thousand people willing to try it. Just because it's so interesting. Or fusion energy. Maybe that will take $100 billion to commercialize. Well, circa 2050+, that should be no problem. (That cuts CO2 emissions to zero, by the way!)
4) Machines Do Everything: Paul Ehrlich (don't get me started), in his incredibly ironically titled, "Betrayal of Science and Reason," had a passage that made fun of economists for even thinking that economic growth could continue for several hundred years at rates observed during the 19th and 20th centuries. Being the MacArthur "Genius" that he is (don't get me started) he calculated that continuing such growth into the 23rd century would produce an average per capita annual income for the world of more than $1 million. He snidely asked who would do all the chores like garbage collection, if everyone was making that kind of money? Well, Paul, they're called robots. It's really unfortunate that you probably won't live long enough to see just how ignorant your question was. But your children and grandchildren will.
5) People Become Machines: There's a lot of speculation about humans using genetic manipulation to get smarter children. I think Ray Kurzweil is correct here, too. People won't bother with genetic manipulation, which can only carry a human brain so far. Electronic brain implants that have way more capability will be way people will go. (Maybe that "people will go" is literal. Homo Sapiens are defined mainly by their brains. When people have brains that are 1000+ times more capable than their current brains, can they still be considered the same species?)
Those are just a few implications that I can think of right now. Hopefully, I'll live long enough to see whether they come true.