Eventually Firaxis released a DLC that includes global warming as a mechanic, along with various kinds of natural disasters (volcanic eruptions, typhoons, etc). As of now it might be worth wondering if they considered including (you might know if you bought it):
- Wildfires, prefereably non-random, but taking into account changing circumstances.
- Seismic and volcanic risks that take into account location, following a division of the surface of the planet into plates, for planest where there is an active plate tectonics.
- Biotic risks such as plagues that affect food supply or human health, appearing due to changing circumstances, with a transmission boosted by the volume of commerce (and, just for fun, by contact with units or cities that have already been contaminated).
About the reasons for this, it might have been planned from the beginning (but then Sid's talk made a disservice to the game), or it might be an afterthought... Or probably it falls in a middle space in between... Since surely
some people in Firaxis might have wanted to keep an aspect of the game that had been present since the beginning of the series... With the prevailing decision
against doing so, and then they had Sid cover for the fact as well as he could. Never mind: at least they have tried to fix it.
What is more interesting is the way in which the two DLC try to tackle a criticism that Civilization has received over the years: that it transmitted the idea that infinite growth and developement were both possible and desirable
[1]. Also that well-played Civs tended to have rather flat histories, from the Neolithic to the near future.
A palliative to that was the fact that Civs played imperfectly had troubles that arose from internal problems, and that the contact with barbarians and other civilizations might lead to dark periods or even to the extinction of the Civilization, sometimes with a newer, younger one replacing it.
But it was true that it was an imperfect palliative, as were the limitations on growth that have been essayed in the series. Now, two DLC explicitly address this problem:
Civilization VI: Rise and Fall tries to deliver dark periods that a Civ can survive (or not) along with periods of splendor that feel less new, since Golden Ages were already known to players of former titles in the series.
Civilization VI: Gathering Storm includes what is mentioned above, and a few other feature.
Not without excusing themselves: "No, I don't think that's about making a political statement.
We just like to have our gameplay reflect current science."
Which was the point from the beginning.
[1] Actually, the expectation of future growth is deeply ingrained into our economies, so much that without it, new ways to encourage investment ought to be devised. But that is just a digression, although not entirely off-topic as it is something that a Civ dealing with global worming-climate change or some other kind of crisis (as depicted in Rise and Fall) should have to face. Possibly with the help of new advancements via research within the game. See, plenty of room for improvement.