Here’s the setup: Finland has nuclear waste which can be dangerous to humans for 100,000 years. So they’ve decided to bury in a way that it will be safe for 100,000 years.
As the film details in thoughtful depth, this involves a couple of problems, the least of which is how to keep nuclear waste harmless for 100,000 years. The simple answer is to bury it very deep in bedrock, then seal the whole miles long and deep structure with concrete.
Where it gets complicated is: what if somebody finds the stuff. Seems unlikely, but as the film emphasizes, anything can happen in 100,000 years. How can you warn them off when you don’t know what kinds of creatures they will be in 100,000 years, much less what language they’ll speak? This is what one of the talking heads in the film calls the ultimate decision under uncertainty: what do you do when you don’t know what you don’t know?
The Finnish government decided in its infinite wisdom to solve the problem of how to guide future civilizations for 100,000 years by requiring that instructions be given now, in Finnish — a language that the vast majority of even modern humans don’t understand. I suppose the intuition is that the super-Millennium will bring us the Age of Finland.
The film’s subtext is that, if this is the best we can do, maybe we shouldn’t mess with nuclear power at all. And don’t forget the film was made and released before the earthquake. The film doesn’t tell us what we should do instead.
Here’s another take on the problem: the effects of anything we do now are unknowable over much shorter periods than 100,000 years. Trying to micromanage the future is folly.
What you need is an institution that can utilize the knowledge that is dispersed through many people over time and space. This institution is the market, which aggregates and communicates knowledge through prices. See Hayek.
Trusting markets may not be perfect. But the film’s real lesson is that this is likely to work out better than trusting the Finnish (or any other) government to come up with the ultimate solution now.