I’ve already posted a bit about how humanity might fare in the future. Aside from problems resulting from contact with alien microorganisms though, how might this future Earth look?
Much of the heavy industry would benefit from being situated in places with access to raw materials. In other words, the rest of the solar system and beyond. This means that Earth can be greener, more tranquil, and free from most of the 21st-century pollutants.
Having also established some colonies, the resident population on Earth may well be much lower than it is today, putting far less strain on its natural resources.
There will finally be contact with alien civilisations, but it may not be as fantastic as we imagined it. After all, the universe does not revolve around one upstart species from the third rock of a yellow star. Hopefully though, we humans bring a youthful enthusiasm and optimism to the intergalactic community.
Earth will also learn a lot about alien civilisations, both existing and long-gone. So there would be some cultural exchange centres, as well as expeditions going off-world to discover and explore worlds that have long been devoid of civilisation. The competition of the day would be to discover new knowledge or wisdom, not acquire material wealth. We may well discover that our theories about the universe need to be updated.
To someone time-travelling from 1985 or even 2014, this Earth will be startlingly different. After all, four hundred and odd years is a long time for the fashion industry to create all manner of exciting new ranges. 😉