Regular readers will know that if the Plausible Midfuture unfolds even remotely as I have speculated here, the vast majority of the human race will still be living on Earth after the next few centuries. Any other outcome requires either a truly staggering increase in the space population or a truly horrific reduction in Earth's population, or both.
Also bear in mind that most humans today 'still' live in the Old World.
So what happens on Earth over the next few hundred years will be overwhelmingly important to most people. Even if the space population turns out to be surprisingly large, what happens there will still be massively shaped by developments on Earth.
This is a topic that I have only sporadically addressed here, which means that it has not yet been beaten half to death. And, happily - just as I was futzing around and getting increasingly antsy about needing to post something here - Winch of Atomic Rockets sent me a link to this MetaFilter page, which in turn led me to a two-part piece on the near to midfuture by Charlie Stross.
(No more links in the body of this post, I promise!)
I come neither to praise Stross nor to bury him. Follow the links or ignore them. Like him I am generally conservative. On the whole I think we are in something of a decelerando, at least compared to the era around 1870-1930, when the Western world went pretty much from post-medieval to proto-contemporary.
I do make, as Stross does, the general presumption that post-industrial civilization is viable enough to last at least through the medium term. Obviously this is not guaranteed to be the case. Post-apocalyptic futures are a whole different matter. On the flip side, post-Singularity futures are also a whole different matter. I am fairly skeptical of either class of outcome, and will ignore them both. (But commenters are not under obligation to do so.)
So we are dealing here with intermediate cases. The future, then, is broadly recognizable to us - even, in many details, rather familiar. Our neighborhood was built some 80 years ago, and mostly still dates to that era. Newer buildings are identifiable by period, coming full circle to the post-modernist retro style.
Within the next century or so most of the old buildings will probably be worn out and replaced, by buildings that probably won't look like the zeerust future. They may get solar roofs sooner than that, barely noticeable from street level.
What things look like at street level may not be the most critical or awesome element of the future, but it is what would give us that all-important first impression. (Compare to the visual appearance of spacecraft.)
In the past month or so an interesting discussion has shown up in some corners of the blogosphere about whether the traditional fashion cycle has broken down, eliminating one of our standard markers of the passage of time. (No links - practice your Google fu!)
The argument is that while the worlds of 1932, 1952, and 1972 had obvious looks that distinguish them from each other as well as from the present, the world of 1992 looked pretty much like it does today, other than the absence of smartphones. Even pop-culture excess has hardly changed - swap in Madonna for Lady Gaga and you're good to go.
My subjective impression is this is broadly true. Hemlines no longer rise and fall consistently; post-post-modernist architecture steals freely from all past epochs as well as from itself; generic no-era cars park freely alongside evocative ones like the Cooper Mini.
Project this into the future, and 2062 and 2112 - even 2212 - might be hard to tell apart, and not that easy even to tell from the present. No monorails, no aircars.
The world of classical antiquity was rather like that (or at least my impression of classical antiquity is like that). Costume, temple design, and the like changed at only a glacial pace. Classical civilization had style, which is timeless, but not fashion.
Having said that, even if we are into a decelerando there will be a great deal of technological progress, if only working out the implications of established technologies. We see a lot of that in the cybertech industry today. We do not have HAL 9000 or anything remotely close, and so far as I can tell, contemporary programming languages are no profound advance over plain vanilla Kernighan & Richie C.
What we do have is enormous raw computing horsepower, and the large-scale computerized mediation of communication between people, of which this blog is a minor example.
The technology that might most exemplify the sort of tech progress that people at midcentury did not expect is the shipping container. It is hard to imagine anything less futuristic - just a big steel box. But it revolutionized cargo transportation, and played a substantial role in the current era of economic globalization.
Because I do not want to keep you my loyal readers waiting even longer than I already have, I will resist the impulse to speculate at length about all the usual things - from medical miracles (or lack of) to the consequences of global climate change.
On the latter, suffice to say that some places will become more or less uninhabitable; some places now subarctic may become gardens; lots of places will become more hot and humid, at times miserably so. Some places will see surprising climate changes, even becoming colder as patterns shift. If world agriculture is severely disrupted, things could get out of hand, but I said I wasn't dealing with post-apocalyptic scenarios, and I won't.
But I will toss in a speculation inspired by recent political issues. An emergent global economic elite could change power politics from horizontal to vertical alignments. Put simply, an elite that socializes and does business together, and not infrequently intermarries, could develop global solidarity. (Or not, per Queen Victoria's grandchildren.) But if they do, the lines of conflict could be within territories and societies rather than between them.
These two container ships entered San Francisco Bay side by side - first time I'd seen that.