Ok, say that this is true, what should we do to prevent it?
Because I can't see humanity surviving an ice age of 1300 years.
Even if we find shelter, what would we eat?
I can't see any way out of a scenario like this, and since if this is true it is a true inevitabillity we have zero reason to panic since it won't help.
If this is accurate, it is way, way, way too late for that.
Also how long to you believe the fuel would last?
The only somewhat reliable energy I could see powering an underground bunker for 1300 years of ice age is geothermal, but that would only save a tiny fraction of people untill the food runs out.
If this scenario is comming, we are gone, there are no ifs or buts about it.
Preparation is irrelevant: We. Are. Gone.
We have no resources to save enough people to keep going.
1300 years, let me put that into perspective:
1300 years ago was the year 724 AD, a time eighty years before the Viking age, it was during the 700s that the Mayan civilization started to decline, that is how much time we are talking about.
Generators or Frostpunk Prime Generals won't matter.