If you want an interesting dark view, try Blindsight by P. Watts. It's SF, but it's 10+ hard on Mohs scale of SF hardness, with 100 references to papers in the end. Contains a number of, mmm, interesting social vistas.
Since another replier gave a book for 100 years, here's one of those... http://ageofem.com/ Though I imagine 50 years has a small but non-zero probability in Prof Hanson's distribution, and he's pretty careful of not seeming overly certain: "Conditional on my key assumptions, I expect at least 30% of future situations to be usefully informed by my analysis. Unconditionally, I expect at least 10%."
I know it's a bit further out than 50 years, but I remember enjoying this book/series of essays that discusses what humanity could look like in 1,000,000 C.E.
Not quite the timescale you asked for, but The World in 2050 by Laurence C. Smith was an interesting read. At the time of writing he was predicting things about 40 years ahead.
